USEP JOURNAL

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USEP: Journal of Research Information in Civil Engineering

 

                                                Vol. 13, No. 3, 2016

Hospital Infection Rate following Sewage Malfunction in a Nigerian Hospital: An Observational Study O. A. Mokuolu, A. Sojobi  and M. Adejumo

Observed and projected trends in livestocks methane emission: Analysis of five decades of data from Nigeria, R.O. Yusuf, J. A. Adeniran and O.A.A. Eletta

Reliability Analyses of a Typical Mega-Water Pumping Station, S. A. Y. Amuda L. O. Afolabi and A. Abdulkarim

 Time Headway and Vehicle Speed Studies of a Road Section in Ilorin, Nigeria,  T. Ako and I. T. Yusuf

Effects of Geometric Features on Roundabout Performance: Case Study of Two Roundabouts in Ilorin, Nigeria., I. K. Kolo, Y. A. Abdulkareem and I. T. Yusuf

Stochastic Sensitivity Assessment of Reinforced Concrete Folded Plates M.T. Abdulwahab and O.A.U. Uche

Effect of Cement Slurry on the Tensile Strength of Treated and Untreated Fanpalm Specimens A. A. Raheem and M. T. Audu

;MAP CHART: an Android Based App for Smart Cities, J. O. Olusina

.General Polynomial Model Formulation for Predicting Traffic Flow in Lagos Island J. O. Olusina

Vol. 13, No. 2, 2016

First Order Reliability Design of Glulam Timber Beams with Bottom Reinforced FRP Plate O. S Abejide, A. V. Ihiabe  and A. Shittu

Variability In the Chemical Properties of Rice Husk Ash (RHA), G. A.Akeke and N. N. Osadebe

Deterioration Assessment of Selected dams in Kwara State, Nigeria, Y.P. Bolaji and A.A. Adedeji

Stress/Strain, Strain-rate Analyses and Materials’ Properties Determination of Heat Treated Medium Carbon Steel, T. K. Ajiboye.

Evaluation of the Swelling Potential of Black Cotton Soil with Added Bituminous Emulsion, A.Y. Abdulfatah, M. B. Ibrahim, A. Usman and S. A. Salisu

Effect of Synthetic Hair fibre additions on the strength characteristice on the Concrete, S. I. Adedokun, S. O. Ajamu and H. T. Aderinto

Atmospheric Loading of Non- Methane Gaseous Pollutants from a Liquiefied Natural Gas Operation, J.A. Adeniran, R.O. Yusuf, L.A. Jimoda, A.J. Adesanmi and J.A. Sonibare

Design of Low-Cost Vehicle for Nigerian Rural Farmers for Transportation of Farm Produce, K. O. Abdulrahman and S. A. Yahaya

Analising Sandy Soils from Hadejia Area of Nigeria with Bitumen Emulsion, A. Y. Abdulfatah, U. M. Gulloma and M. B. Ibrahim

 Vol. 13. No. 1, 2016

Free-flowing Traffic on Two-lane Single Carriageways
F. O. Akintayo1 and O. A. Agbede2
1,2Department Civil Engineering, University of Ibadan,
Ibadan, Nigeria
1fo.akintayo@ui.edu.ng 2 oluwoleagbede@yahoo.com
Abstract
Studies on vehicle headways are employed to understand traffic flow on highways. We model the vehicle headway distributions on a two-lane single carriageway in Ibadan, Nigeria. The Headway Generation Algorithm (THEGA) was developed to generate theoretical values for headway distribution modelling. Headway data for model calibration and validation were collected along Ibadan-Abeokuta road for five days in April 2008 using a video camera. The generated headways fitted hyperbolic distribution models and a spreadsheet of cumulative headway distribution was developed for a user-specified volume for flows ranging from 700 to 1000 vehicles per hour (vph). The results associated long headways with low flows, which reduced to short headways as flows increased and random arrival of vehicles changed to a car-following system. The validation of results with the Kolmogorov–Smirnov goodness-of-fit test at 0.01 significance level indicated good fits for the range of observed traffic volumes. The algorithm developed can be used to simulate traffic flows on two-lane single carriageways with the overall goal of efficient and effective traffic management of highway systems
Keywords
Headway, headway generation algorithm, hyperbolic distribution models, free-flowing traffic, two-lane single carriagewaysImpact of Travel Time Variability on Planning for Daily Work Trip along Keffi – Abuja Road  

Impact of Travel Time Variability on Planning for Daily Work Trip along Keffi – Abuja Road Biliyamin A. Ibitoye, Yunus A. Jimoh and Abosede A Bello

Computation of Flow in Ruptured Horizontal Oil Pipe, Dada J. Obadote and John A. Olorunmaiye

Design, Construction and Testing of a 3.04m/60 kg /50W, 24V D.C. Capacity Electrically Powered Sliding Residential Gate , J.A. Ige, S.M. Adedayo and K.O. Abdulrahman

Optimal Road Pricing using Binomial Logistic Regression, J.O. Olusina and K.S. Hassan

Effects of Nano-Chemical on Geotechnical Properties of Ogoja Subgrade, D.E. Ewa, E.A. Egbe and G.A. Akeke

Stochastic Evaluation of Offshore Carbon Fibre Reinforced Concrete Decks , O, S Abejide , O. S Abejide  and I Abubakar

Vol. 12. No. 2, 2015

Engineering Education: Effect of Disproportional Expansion of Nigerian Universities, Yahya Ismail Akolawole

Characterization and Grading of South Eastern Nigeria grown Irvingia gabonensis Timber in Accordance with BS 5268, J. I. Aguwa1, P. C. Chukwu2 and S. M. Auta3

Determination of Reliability Indices of Reinforced Concrete Column-beam Frame by Deterministic and Optimum Design based on Eurocode 2, Ketkukah Titus Saul and Abubakar Idris

Assessing the Generation and Composition of Medical Waste in a  University Teaching  Hospital, Olubunmi A. Mokuolu, Hannah O. Olawumi, Bolaji F. Sule

Vol. 12. No. 1, 2015

 Vehicle Headway Distribution Modelling of Free-flowing Traffic on Two-lane Single Carriageways, F. O. Akintayo and O. A. Agbede

 Past and Present Teaching Methods in Faculties of Engineering in Nigerian Universities J A Olorunmaiye

 Optimum Design of Loadbearing Wall from Sandcrete Blocks in Ibadan (SBI), Nigeria , I.    A. Yahaya  and A. A. Adedeji

 An Empirical Travel Cost Modelling in Lagos, Nigeria , J. O. Olusina and O. Omotunde

 System Dynamo Modeling Approach to Forecast Planning Hospital Care Facility , K. A. Akande

 Optimal Coverage Analysis of Existing Public Facility using the Capacitated P-Center Model, J.O. Olusina and E.A. Adesina

Vol. 11. No. 2, 2014

Determination of  the temporal variation of suspended sediment concentrations along selected rivers within a watershed situated at the upstream of Jebba dam at North central, Nigeria, A.  G. Adeogun*, B. F. Sule, U.T Bakare and  A.W. Salami

 

Vol. 10. No.1, 2013

 Engineering Properties of Unused and Cement Stabilized Used Laterite Soils (272-283), A. O. Adeboje, O. S. Olaniyan, O. S. Oladeji and O. M. Osuolale

Optimization of Performance Parameters of a Cowpea Wet Dehulling Machine (284-318), Funke B. Olotu  and Joshua O. Olaoye

Structural Reliability of the Nigerian Grown Gmelina Timber as Bridge Beam Subjected to Compression and Shear Forces (319-338), Aguwa J. I.e

Investigation on the Use of Clay Soil Mixed with Cow Dung to Produce Bricks for Low Cost Buildings (340-371), D. Katale, 2 V. S. Kamara and 3 A. A. Adedeji

 Effect of Fly Ash Treatment on Compressive Strength of Soft Lateritic Soil Road Pavement Subgrade (372-385), Agapitus Ahamefule Amadi   

Vol. 9, No. 2, 2013

The  Effects of Environmental and Social Factors on the Collapse of Isale Igbehin Bridge, Abeokuta, Nigeria (157 - 166) O. A. Apampa1 and Y. A. Jimoh

 Comparing Genetic Algorithms and Pattern Search for Design of Thrust Restraint Systems (167 – 181) A. R. Anwar, A. Y. Abdul Fatah, A. A. Adedeji  

Meeting the Millennium Development Goals Through Biomass Waste Recycling in Civil Engineering Construction – Case Study of Corn Cob Ash (182 – 196)  O. A. Apampa1 and Y. A. Jimoh2

The Internal Response of Lined and Unlined Water Pipes to Increased Level of Metals in Drinking Water (197 - 216) A. Y. Abdulfatah, A. R. Anwar and S. Danazumi

Effects of Palm Kernel Shells Sizes and Mix Ratios on Lightweight Concrete (217 – 226D. O. Oyejobi1, T. S. Abdulkadir, I. T. Yusuf and M. J. Badiru

 Modelling the Prism of Termitarium-Strawbale Composite Masonry for its Bearing Capacity (227 – 256)

V. S. Kamara, D. P. Katal2 and A. A. Adedeji

 Reliability Assessment of Bridge Decks: A Case Study of Three Bridges Along Lagos – Ibadan Expressway (257 – 271)

 W. O. Ajagbe,  A. A. Ganiyu  and O. O. Alade .

 

 


Engineering Properties of Unused and Cement Stabilized Used Laterite Soils (272-283)













1
A. O. Adeboje, 2O. S. Olaniyan, 3O. S. Oladeji and 4O. M. Osuolale

1Department of Civil and Environmental Engineering,

University of Lagos, Lagos, Nigeria.

2, 3, 4 Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria

Abstract

The practice of building local housing units with laterite is common in Ogbomoso, Oyo State, Nigeria. This practice helps to reduce the rising cost of building construction. This paper investigates the engineering properties of both used and unused laterite soils with intent to reuse the laterite soil in construction of housing units. Disturbed samples of both used and unused laterite soils were investigated for engineering index, compaction and strength properties. Sieve analysis, atterberg limits, specific gravity, compaction, air-dry moisture content, triaxial compression and compressive strength tests were performed on the samples of two types of soils in accordance with BS 1377-2; 1990. The results from the study revealed that the geotechnical properties of the unused laterite soil samples are better than that of the used laterite soil samples, which supports their suitability and preference for construction of local houses than the used laterite soil samples. However the used laterite soil can be re-used or reutilized to build local houses in subtropics by addition of 0.5% Portland cement. Furthermore, addition of 0.75% Portland cement to the used laterite soil makes it stronger and more suitable for construction of housing units than the unused laterite soil.

 Keywords: Laterite, compaction, geotechnical, construction, strength

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 Optimization of Performance Parameters of a Cowpea Wet Dehulling Machine (284-318)

 Funke B. Olotuand Joshua O. Olaoye2*

1 National Centre for Agricultural Mechanization, P.M.B. 1525, Ilorin, Nigeria

2 Agricultural and Biosystems Engineering Department, University of Ilorin, P.M.B, 1515, Ilorin 240003, Nigeria;

*jolanoye@unilorin.edu.ng

Abstract

Dehulling refers to the removal of the seed coat (hull) which results in the separation of the cotyledons. There are two major methods of dehulling; wet and a combination of the dry method with the wet. In the rural sector, the dehulling process is still a part of the households activities in food preparation. Dehulling machines for soaked cowpea have been developed to produce clean dehulled cowpea for use in food preparation. This study was to determine the optimum operating speed of the dehuller and the soaking time of cowpea seeds for dehulling. Four-variety of cowpea seeds were used to evaluate and optimize the performance of the dehuller. Optimization of performance parameters of the dehuller was carried out on the results of performance using regression analysis technique, Excel Solver and SPSS 16.0 software packages. However, the process models developed could be used to select any combination of the operating speed and soaking time that will give the best performance of the dehuller. The optimization of the performance of the dehuller showed that Yari Hausa, IAR60/62, IAR48 and Oloyin varieties of the cowpea seeds gave the optimal values of dehulling efficiency at operating speed of 150rpm with their  soaking times  at 8.8mins, 5.65mins, 6.09mins and 10mins respectively. IAR48 had the highest dehulling efficiency of 99% while Yari Hausa gave the lowest value of dehulling efficiency of 77.72%.The optimization of performance of the dehuller also showed that the optimal values of cleaning efficiency, feed rate and output capacity were at operating speed of 350rpm and at about 10mins soaking time for all the varieties of cowpea seeds used, except for IAR60/62 whose optimal values were at operating speed of 150rpm.

Keywords: Optimum, performance, dehulling, cowpea, dehuller

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Structural Reliability of the Nigerian Grown Gmelina Timber as Bridge Beam Subjected to Compression and Shear Forces (319-338)

 Aguwa J. I.

Department of Civil Engineering, Federal University of Technology, Minna, Zip Code 23401, Nigeria

jiaguwa@yahoo.com

Abstract

An experimental and structural reliability studies were performed on the Nigerian grown Gmelina timber as a structural bridge beam material. The procedure involved natural seasoning of the Gmelina, determination of their strength properties at a moisture content of 18%, statistical analysis, structural analysis and deterministic design of the Gmelina bridge beam under the ultimate limit state of loading. Using a computer programme developed in FORTRAN language, structural reliability analysis of the timber bridge beam as designed was performed to ascertain its level of safety using First-Order Reliability Method (FORM). Sensitivity analysis was conducted by varying the depth of beam, imposed live load, breadth of the beam, unit weight of the Gmelina timber, span of the beam as well as the end bearing length. The result revealed that the Nigerian grown Gmelina timber is a satisfactory structural timber bridge beam material in compression perpendicular to the grain under the ultimate limit state of loading. However, it is not a good structural bridge beam material in shear parallel to the grain under the designed conditions. The probabilities of failure of the Nigerian grown Gmelina timber bridge beam in compression perpendicular to the grain and shear parallel to the grain are 0.00146% and 4.65%, respectively under the specified design conditions.

Key words: Compression, Nigerian grown Gmelina, Shear, Strength properties, Structural reliability, Timber bridge beam.

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    Investigation on the Use of Clay Soil Mixed with Cow Dung to Produce Bricks for Low Cost Buildings (340-371)

1 D. Katale, 2 V. S. Kamara and 3 A. A. Adedeji

1, 2 Department of Civil Engineering, School of Engineering and Information Technology, Namibia University of Science and Technology (Fmr Polytechnic of Namibia), Windhoek, Namibia

dkatale@polytechnic.edu.na1, vkamara@polytechnic.edu.na2

3 Department of Civil Engineering, Faculty of Engineering and Technology, University of Ilorin,  Ilorin, Nigeria aaadeji@unilorin.edu.ng3

 Abstract

This study was conducted to investigate the significance of clay bricks mixed with cow dungs to construct sustainable and environmentally friendly buildings. The clay soil was collected at about 5km South of Okahandja, and the cow dung was obtained from Rietfontein in the Omaheke region of Namibia. Analysis of all the test samples suggest that the California Bearing Ration (CBR) decreases as the amount of cow dung is increased across the entire sample. The cow dung has been added as reinforcing agent in different proportions. The results suggest that an increase in cow dung reduces the maximum dry unit weight, and increases the optimum moisture content. The compression test outcome suggests that at the addition of 20% cow dung the sample had the highest compressive strength.  It was observed that the tested samples take a longer period to fail as the cow dung percentages increased. 

Keywords: Clay soil, cow dung, sustainable bricks, CBR, compressive strength

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 Effect of Fly Ash Treatment on Compressive Strength of Soft Lateritic Soil Road Pavement Subgrade (372-385)

Agapitus Ahamefule Amadi

Department of Civil Engineering,

Federal University of Technology, Minna, 920001, Niger State, Nigeria. agapitusahamefule4@yahoo.com

Abstract

A laboratory study was undertaken to assess the effectiveness of different percentages of fly ash in improving the compressive strength of pavement subgrade dominated by wet and soft fine-grained lateritic soil. Index properties and unconfined compression strength (UCS) tests were conducted on lateritic soil stabilized by the addition of 0, 5, 10, 15 and 20% fly ash and compacted with West African Standard (WAS) compaction effort at pre-selected moisture contents (10 – 20%) simulating the range of in-situ conditions that prevail in the study area. Results indicate that the plasticity of study soil was progressively lowered as the fly ash content increased resulting in significant loss of plasticity and improved workability. When fly ash percentage in the mixture was 5% and 10%, slight increases in maximum dry unit weights were produced with corresponding increases in optimum moisture contents (OMC). Maximum dry unit weights decreased for 15 and 20% fly ash mixtures. Addition of 5%, 10%, 15% and 20% fly ash to the native soil increased the UCS by factors of 1.4, 2, 2.5 and 1.9 respectively compared to 188.25 kN/m2 without fly ash. The maximum strength realized in soil mixtures for the 0%, 5%, 10%, 15%, and 20% fly ash contents were 376.48, 528.44, 750.88, 754.29 and 598.88 kN/m2 respectively, occurring at moisture contents 1 – 5% below OMC. The results of this study demonstrate that the soft fine-grained lateritic soil can be stabilized to acceptable level of strength for use in subgrade construction.

Keywords:  Fly ash, lateritic soil, pavement subgrade, unconfined compressive strength

Vol. 9. No.2, 2012

The Effects of Environmental and Social Factors on the Collapse of Isale Igbehin Bridge, Abeokuta, Nigeria (157 - 166)

 O. A. Apampa1 and Y. A. Jimoh

Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria.

1pampasng@yahoo.com

Abstract

Not all engineering structure collapse results from poor quality materials or workmanship.The environment in which the structure is situated and the attitudinal and cultural habits of the people living in that environment can often be major factors. This paper presents the sequence of progressive failure that led to the collapse of a bridge at Isale Igbehin, Abeokuta, Nigeria, and highlights how the equilibrium of the forces acting on the bridge became progressively and unfavourably altered under the influence of environmental and social factors. The 10m wide bridge deck with a span of 10m, carried by 20No 600mm deep precast prestressed concrete I-beams, failed by a rotation of one of the abutments about the toe.  The paper examines the roles played by the government and the attitude of people of Nigeria which can unwittingly lead to the collapse of engineering structures, using the Isale Igbein bridge as case study. The paper concludes by highlighting the need for government agencies, the professional bodies and the academia to rise up to their responsibilities and to defend and protect public interest and infrastructure at all times.

Keywords: Engineering regulation, environment, progressive collapse, prestressed concrete, bridge, beam.

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Comparing Genetic Algorithms and Pattern Search for Design of Thrust Restraint

Systems (167 – 181)

A. R. Anwar1, A. Y. Abdul Fatah2, A. A. Adedeji3

1, 3Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria, saiyadianwar@yahoo.com, aaadeji@unilorin.edu.ng

2Department of Civil Engineering, Bayero University, Kano, Nigeria, ayfatah@yahoo.com

Abstract

The main aim of the article is to compare the performance of the genetic algorithm and pattern

search in designing thrust block for thrust restraint of buried pipelines. The optimum design model was simulated using genetic algorithm and pattern search algorithm. Soft clay, silt, sandy silt, sand, sandy clay and hard clay soils were used for the simulation. The statistical analysis carried out proved that both methods were capable of producing reliable design accurately. The root mean square error and mean square error for genetic algorithm were 0.004517 and 0.0039 respectively while root mean square error and mean square error for pattern search algorithm were 0.001783 and 0.0017 respectively. The volume of material provided by pattern search algorithm was slightly lower than that of genetic algorithm with maximum difference of 0.0173m3. Pattern search was also slightly more economical in terms of time needed for the analysis to converge to a global solution. The maximum time was about two seconds less when compared to that of genetic algorithm.

Keywords: Genetic algorithm, pattern search algorithm, DIPRA, thrust block

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Meeting the Millennium Development Goals Through Biomass Waste Recycling in Civil Engineering Construction – Case Study of Corn Cob Ash (182 – 196)

O. A. Apampa1 and Y. A. Jimoh2

1,2Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria

1pampasng@yahoo.com 2dryajimoh@yahoo.com

Abstract

The aim of this paper is to establish a link between biomass waste reuse in civil engineering construction and socio-economic well being of the society by contrasting the menace posed by biomass waste with its potential as tool for poverty alleviation in developing countries. The paper reviews existing literature on the effective use of biomass ash as pozzolan, paying particular attention to corn cob. Corn is a widely produced crop in Nigeria, ranking third among all crops. The paper presents the mechanism of its pozzolanic action and highlights the data gap in the available literature. The paper concludes by identifying the Millennium Development Goals (MDG) that would be achieved if efforts are made towards the effective utilization of corn cob as a pozzolan and calls on researchers to take steps in filling the critical data gap required to move the research to development, deployment and marketing stages.

Keywords: Biomass, Corn Cob, Pozzolan, MDG.

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The Internal Response of Lined and Unlined Water Pipes to Increased Level of Metals in Drinking Water (197 – 216)

A. Y. Abdulfatah1, A. R. Anwar2 and S. Danazumi3

2Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria.

Abstract

This study was aimed at establishing the risk of pipeline internal corrosion from high levels of inorganic chemicals in drinking water. Copper (Cu), Chromium (Cr), Nickel (Ni) and Lead (Pb) were investigated for their effects on internal corrosion of both lined and unlined ductile iron water distribution pipeline. Internal corrosion experiments were conducted by raising levels of Cu, Cr, Ni and Pb in drinking water circulated through two ductile iron pipe sections. There was an increase in both soluble and total iron concentrations from an average background value of 1.5 mg/l to concentrations of 4.5 mg/l soluble and 6.2 mg/l total iron respectively. Although iron release does not directly relate to corrosion rate, an increase in iron content is an indication of iron release from corrosion scales or pipe material itself.  

Keywords: Lined and unlined water pipes, metals, drinking water

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Effects of Palm Kernel Shells Sizes and Mix Ratios on Lightweight Concrete (217 – 226)

D. O. Oyejobi1, T. S. Abdulkadir, I. T. Yusuf and M. J. Badiru

Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria

Correspondent author: 1oyewumioyejobi@gmail.com

Abstract

This paper gives an account of the study conducted on the effects of Palm Kernel Shells (PKS) sizes and percentages in lightweight concrete. It is aimed at determining the properties of PKS that make it suitable for light weight concrete works and the effects of proportion of sizes and percentages on the strength characteristics of palm kernel shell concrete. A number of tests were conducted on the PKS and concrete produced with it. Tests conducted on PKS were sieve analysis, specific gravity, water absorption capacity and moisture content, while tests conducted on palm kernel shell concrete (PKSC) included slump test, compressive strength test, modulus of rupture and splitting tensile strength test. Concrete mixes of 1:1½:3, 1:2:4, 1:3:6 and 1:4:8 were used to produce cubes, beams and cylinders which were cured for 7, 14 and 28 days before testing. PKSC had density that was less than 2000 kg/m3 for a light weight concrete. The results showed that concrete mix of 1:1½:3 with compressive strength of 20.1N/mm2 at 28 days hydration period met the British Standard recommended minimum strength of 15N/mm2 for structural lightweight concrete while other concrete mixes did not but they can also be employed as plain concrete. Results of tests on modulus of rupture and splitting tensile strength exhibited similar trend to that of compressive strength test. The nominal mix 1:1½:3 gave the highest values of modulus of rupture and splitting tensile strength.

Keywords: Lightweight concrete, PKS, nominal mixes, compressive strength

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Modelling the Prism of Termitarium-Strawbale Composite Masonry for its Bearing

Capacity (227 – 256)

V. S. Kamara1, D. P. Katale2 and A. A. Adedeji3

1,2Department of Civil Engineering, University of Science & Technology (former Polytechnic of Namibia),

Windhoek, Namibia

3Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria

Abstract

The paper reports the response of termitarium-strawbale composite prism (T-SBP) under compression (vertical) and thermal (lateral) loads, using SAP2000 for the finite element method of analysis. The analysis was carried out considering the same thickness of T-SBP formed rectangular section with different heights. The parameters of stresses under certain pressures and their comparative results were obtained from stresses and applied loads. The comparison of the results between the termitarium plastered strawbale masonry and the cement plastered strawbale masonry shows that the former has much more stresses affected by the loadings than the later, given that maximum allowable stress, due to compression and thermal loads, for termitarium plastered strawbale wall is 62.2kN/m2 and of the cement is 9.6kN/m2.

Keywords: SAP2000, termitarium, strawbale, prism, stress rectangular masonry, composite, finite element method.

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Reliability Assessment of Bridge Decks: A Case Study of Three Bridges Along Lagos – Ibadan Expressway (257 – 271)

W. O. Ajagbe 1,  A. A. Ganiyu2  and O. O. Alade 1

1Department of Civil Engineering, University of Ibadan, Ibadan, Nigeria. wo.ajagbe@mail.ui.edu.ng

2Department of Civil & Environmental Engineering, Kwara State University, Malete, Nigeria. abideen.ganiyu@kwasu.edu.ng

Abstract

The ageing and gradual deterioration of bridges in Nigeria needs balancing of cost-effective plans for bridge maintenance, rehabilitation and replacement. This research aims at assessing the reliability of bridges using three existing highway bridges along Lagos-Ibadan expressway as a case study. Visual inspection, sounding, half-cell potential and chloride concentration tests were utilized to evaluate the conditions of the bridges. Deteriorations were observed on the decks’ surfaces. The level of corrosion on one deck was active and uncertain in the remaining two. The chloride concentrations on all the decks were within AASHTO standards and only one of the decks had delaminated.  The results revealed that none of the decks needs total replacement but all require some form of rehabilitation.

Keywords: Bridge decks, corrosion, delamination, deterioration, rehabilitation, reliability.

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Vol. 9. No.1, 2012 

Comparative Assessment of Some Commercial Steel Bars

with Standards (73-83)

1 A. G. F. Alabi, and 2R.A Yahya,.

1Metallurgical & Materials Engineering Department, University of Ilorin, Ilorin, Nigeria

2Mechanical Engineering Department, University of Ilorin, Ilorin, Kwara State, Nigeria

Abstract

There has been inadequate information on the actual properties of the reinforcing steel bars sold in our markets which are used for construction work in structures such as bridges, platforms or high-rise building. This work is to cater for that lapse. The samples used were purchased from the local steel vendors and were subjected to a tensile test and chemical composition analysis with a view to investigating the degree of compliance with the existing standards such as the Nigeria Industrial Standard (NIS), American Society for Testing and Material (ASTM) and British Standard (BS). It was observed that only five of the samples considered (1, 4, 6, 7 & 8) conformed to specified standards for deformed high yield reinforcing steel bars. The other three samples (2, 3 and 5) were below these standards. However, the ductility of all samples were found to be good enough for construction, particularly, where strength is not a criterion. It would be necessary for proper examination, supervision and testing of the steel products in our market to be done before being used for design purposes in any construction work.

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 Use of the Beam Analogy Approach to Predict the Ultimate Shear Strength of Prestressed Flat Slab (84-95)

W.O. Ajagbe1, S. I. Adedokun2, and E. Tinubi1

1Department of Civil Engineering, University of Ibadan, Nigeria,

alpha_est1@yahoo.com

2Department of Civil Engineering, Ladoke Akintola University of Technology, Nigeria,

idowudokun304@gmail.com

Abstract

The aim of the study was to predict the ultimate shear strength of a prestressed flat slab at the slab-column junction using the beam analogy approach. The beam analogy method, with other shear strength prediction methods such as the methods proposed by Hawkins, ACI 318-02, CSA A23.3-2004 were studied. The results were compared with the BS Code results to determine the variation in shear strength values. The approach employed a hypothetical flat slab layout, which was analyzed and designed for shear using all the various approaches while considering centre, edge and corner conditions. Values of the shear capacity were obtained using spreadsheet by varying the depth of the slab, and the area of the column. The values of the shear capacity of all the four methods were compared with the BS 8110. The results showed that there was a close relationship between the beam analogy approach and the BS 8110 method of shear strength prediction. As the depth of the slab increased, the beam analogy method was found to be more conservative, and as expected, the concrete shear stress at the slab-column junction reduced with increase in slab depth, which is the same depth for the idealized beam. Also, as the column area increased, while other parameters held constant, the shear strength at the junction was fortified. Also increasing the column area gave a closer relationship between the beam analogy approach and the BS Code than increasing the slab depth.

Keywords: Beam analogy, prestressed flat slab, ultimate shear strength, slab-column connection

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Effect of Types of Sandcrete Blocks on the Internal

Microclimate of a Building (96-107)

S. O. Odeyemi,

Department of Civil Engineering, Federal Polytechnic, Offa. odeyemiso@yahoo.com

Abstract

The type of block used in a building may affect the internal microclimate of the building. This paper investigated the effects of hollow and solid sandcrete blocks on the internal microclimate of a model building. Two similar buildings were modeled, one with hollow sandcrete block and the other with solid sandcrete block. The results of one week internal and external microclimate temperature measurement shows that the model building with hollow sandcrete block has a lower internal microclimate temperature compared to that of the solid sandcrete block. It was concluded that hollow sandcrete blocks for building partition/walls will give more comfort than the use of solid sandcrete blocks.                                                                                        

Keywords: Microclimate, sandcrete, temperature, ambient, hollow block, solid block, T-test.

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Artificial Neural Network Modeling of Rainfall in Ilorin,

Kwara State, Nigeria (108-120)

1T. S. Abdulkadir, 2A. W. Salami and 3A. G. Kareem             

1, 2 Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria                       

3 National Agency for Science and Engineering Infrastructure, Garki, Abuja, Nigeria.

abdulkadirts4u@gmail.com

Abstract                                                                        

Accurate information about rainfall is essential for the management of water resources, disaster prevention, and agricultural production. On a worldwide scale, numerous attempts have been made to predict behavioural pattern using various techniques.  This paper is aimed at developing a real time Artificial Neural Network based rainfall forecasting model for Ilorin, Nigeria using observed rainfall records. This ANN model is designed to run a real time task in which the input to the model is a consecutive data of the rainfall. The neural network was trained with sixty years (1952–2011) total monthly historical rainfall data. The trained network yielded 76% and 87% of good forecast for the training and testing data set respectively. The correlation coefficient of 0.88 was obtained which showed that the network is fit to be used for the subsequent quantitative prediction of rainfall in Ilorin.

Keywords: Rainfall model, ANN, training algorithms, connection weights, coefficient of correlation.        

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The Importance of Reverse Osmosis Water Treatment

System in Renal Disease Treatment (121-132)

K. A. Akande

 Department of Biomedical Engineering, University of Ilorin, Ilorin,Nigeria,

(E-mail: akande.ka@unilorin.edu.ng Tel: +2348033440849 or +2348055275597

Abstract:                                                                                                    

Over 15,000 new cases of end stage renal disease requiring dialysis emerge each year in Nigeria and much more worldwide. Renal diseases often develop slowly and the symptoms only appear at later stages when the patient already has advanced kidney failure and may even need dialysis or renal replacement therapy to live. Statistics showed that many Nigerians with kidney problems were not aware of their health challenges. Water treatment for preparation of dialysate is probably the most neglected area of renal replacement with dialysis. Quality of water contributes very significantly in morbidity and life threatening reactions in dialysis patients in both; an acute as well as in chronic diagnosis. Heamodialysis is one method of treating renal disease patients. Haemodialysis patients are exposed to between 25 to 30 times of water during their daily therapy compared to normal individuals drinking water needs. Contaminants enter the blood compartment of dialyzers (artificial kidneys) and accumulate in the body due to inability of these patients to excrete them via their kidneys. Hence, it is very important to provide good and well designed water treatment system for heamodialysis of patients with renal failure. This paper addresses how to design appropriate and efficient pure water treatment system using reverse osmosis and other filtration equipment for medical application such as haemodialysis.

Keywords: Reverse osmosis, haemodialysis, water treatment system, renal disease, dialysis machines and membrane.

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Patronizing Indigenous Expertise for Effective Bridge

Construction in Nigeria (133-143)

1O.A. Apampa and 2Y.A. Jimoh

1, 2 Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria

1pampasng@yahoo.com Tel: 08061664780

Abstract

The paper aims at promoting the patronage of indigenous expertise in the construction of bridges in Nigeria by highlighting the processes and challenges that led to the successful completion of a recently commissioned 4x20m span bridge in Ago Iwoye, Ogun State, Nigeria. It emphasizes the fact that, though the bridge was built to international standards, the know-how was wholly Nigerian, and all materials including specialist items like bearings and expansions joints were fabricated and sourced for locally. The paper concludes that the development and encouragement of indigenous expertise in bridge construction is vital to effective transportation system in Nigeria, and calls on government at all levels to, as a matter of deliberate policy, save foreign exchange and create job opportunities locally, by patronizing Nigerian engineering expertise in bridge design and construction.

Keywords: Construction, indigenous, transportation, bridge, expertise

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 Biotechnology Applications in Environmental Management

and Process Industries (144-156)

Technical notes by

S. A. Muyibi

Department of Biotechnology Engineering

International Islamic University, Malaysia (IIUM)

Full Text......

 Vol. 8. No.1, 2011

Performance Evaluation of Beam Deflection Apparatus Using Indigenous

Materials (1-12)

1A. A. Adegbola, 2,1E. O. Sangotayo, 2,2I. A. Orowole and 2,3E. Ughojor

1Department of Civil Engineering, LAUTECH. Ogbomoso-Nigeria, dayomos2002@yahoo.com

2Department of Mechanical Engineering, LAUTECH. Nigeria, 2,1olemsangatayo@yahoo.com 2,2agboola.orowole@yahoo.com, 2.3elosko4sure2001@yahoo.com

Abstract

This paper presents performance evaluation of a designed and constructed beam deflection apparatus, using locally available materials, with aim of exploring the possibility of producing cheaper alternative testing apparatus for quality control laboratories and institutions in Nigeria.  The locally produced beam deflection apparatus has: the main body frame; beam stand; beam; clamp; hangar and mass; dial-gauge; washers; large and small bolts and nuts, as components. The apparatus was tested on steel and aluminum beams with varying load masses and varying positions of loads. The deflection on each beam was recorded and thereafter compared with results using similar procedures on theoretical approach and standard imported foreign beam deflection apparatus. The comparisons were done using graphical presentation to study the trend and analysis of variances (ANOVA) to investigate the significant difference in the results. It was established that the results of deflection of beams obtained for all the experiments carried out using theoretical approach, standard imported apparatus and locally produced apparatus have no significant difference at 95% confidence limit using ANOVA. The P-value for the experiments is greater than 0.5, which confirmed that no significant difference among the three results exist (P-value > 0.5). The production cost of the locally produced apparatus is N31,080.00k, as against the sum of $1500.00 for the purchase of standard imported apparatus.

Keywords: Beam, deflection, performance evaluation, apparatus, Analysis of Variances (ANOVA)

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 Impact of Project Environmennt on Project Time and Cost Overruns in Lagos and

Abuja, Nigeria (13 - 28).

 T. F. Obalola

Department of Quantity Surveying, Federal Polytechnic Offa, Offa, Nigeria

wolefunmioba@yahoo.com

 Abstract

This paper examines the role of project environment and its contributions to causes of time-delay and cost overruns in the construction of building project delivery.  The field study involved ranking of individual project environment variables observed by respondents that had contributed to the performance of building project constructed in Lagos and Abuja from 2005 to 2010. On the basis of the survey responses received, it is possible to identify project environment influences that are significantly contiributed to cost and time overruns.  Relative importance weight (RIW) was used to determine the relative importance of the various influences that affect performance of building project delivery. The Kendall coefficient of concordance was used to test the degree of agreement in ranking among the respondent. The results indicate the importance of economic related group of project environment influence as it is contributed to cost and time overruns. However, it was ranked highest in most building project execution.

Keywords: Project success, project environment, project performance, time delay, cost overruns.

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Road Safety Management in Nigeria: Best Practices (29 - 40)

1 A. B. Ibitoye.  and  2 A. Ajayi

1Road Sector Development Team, Federal Ministry of Works, Abuja, Nigeria.

biliyamin@yahoo.com

 2 Department of Road Safety Engineering, FRSC, Abuja, Nigeria

bayo479@yahoo.com

Abstract

Road crashes kill more than 1.2 million people and injure or disable as many as 50 million a year,placing road traffic crashes as the leading cause of death for children and young people aged 5–29 years. Also, it was of concern that more than 90% of road traffic deaths occur in low-income and middle-incomecountries and that in these countries the most vulnerable are pedestrians, cyclists, users of motorized two- and three-wheelers and passengers on unsafe public transport. Although, Federal Road Safety Corps (FRSC) in her little efforts has implemented some “good practices” – interventions to address some of the major risk factors for road traffic injuries, there are still more to be done especially in a country where more than 90% commuters depend on road transport for their daily movement. This paper focuses on the review of available literature documents on the existing road safety strategies, analyse accident data for 2001 - 2009 to identify accident effects and propose the best practices that can be adopted by all road safety stakeholders in Nigeria. The overall objective is to guide FRSC in their efforts to become more efficient, ensuring an improved safer road transport.

 Keywords: Road safety, management, best practices, public transport

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Finite Design of Solar-Chimney System by Artificial Neural Network (40-55)

S. Q. Shiru and C McCann

School of Engineering Technology and Applied Sciences, Centennial College, Toronto

Abstract

This project entails the use of Artificial Neural Networks (ANN) to optimize a solar chimney system in a residential building. Based on the analysis done in this work and use of data obtained from model of an ideal solar chimney system of a residential building, the error difference between actual and expected results is minimal. The results obtained are due to the flexibility of ANN to learn by example and its efficient in analysing problems with incomplete data, and its accurate prediction is sought more than expectation. ANN is a good method of optimization, since error observed in comparison of the actual and expected results is minimal. The ability of ANN to learn by example makes them very flexible and powerful.

 Keywords: Artificial, neural network, solar energy, chimney

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Vol. 7. No.2, 2010

Vol. 7. No.1, 2010

Effect of Project Leaders’ Planning and Monitoring Efforts on Project

Outcome (1 -19)

Tajudeen Olufemi Salami

Department Of Quantity Surveying, Kwara State Polytechnic, Ilorin, Nigeria. 

Abstract

Many recent reports from construction industry list leadership as one of the areas that must be properly shapedto meet the needs of modern construction. Project planning has been considered a major cornerstone of every successful project. Empirical studies of project management success factors suggested planning as one of the major contributors to project success. A field survey was conducted among construction leaders in Nigeria, using structured questionnaire with the aim of examining effect of project leaders’ planning and monitoring efforts on projects outcomes in the Nigerian construction industry. The responses were analysed using percentage, mean score, Friedman, Chi-square test and ANOVA.  The results revealed that there is a significant contribution of leadership to project outcome.  Majority (75%) of project leaders in Nigerian construction industry are. “task-oriented” leaders while 25% are “relationship oriented’’ leaders. The study concludes that the efforts of construction project leaders on planning and monitoring have significant  contributions to project outcomes.  It is therefore recommended  that construction professionals should design and implement management training and development programs that focus on effective and facilitative leadership.

Keywords: Effect, Monitoring Efforts, Planning, Project Leaders, Project outcome.

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Sustainable Reuse of Human Urine as a Source of Nitrogen and Phosphorus in Mali,West

Africa (20 -28)

1Ryan P. Shaw, 2Justin Meeks, 2Colleen Naughton and  2James R. Mihelcic

1Civil & Environmental Engineering, Michigan Technological University, Houghton, Michigan, USA

2Civil & Environmental Engineering, University of South Florida, Tampa, Florida, USA

Abstract

People have used animal and human excreta to fertilize crops for centuries because manure contains many plant nutrients. What most people do not know is that the majority of beneficial nutrients leave the body through urine rather than through faeces, and the majority of urine is pathogen-free. People in the developed and developing world are beginning to use this untapped nutrient potential to fertilize crops with great success. While many development organizations are focusing on expensive composting toilets to replace existing latrines, these organizations are missing the intermediate step of urine fertilizer use to ease communities into the idea of nutrient recycling. Small adjustments in behavior can be made and inexpensive systems can be designed to collect urine, which can then effectively fertilize most crops. This can lead to increased food production and simultaneously increase the overall effectiveness of on-site sanitation systems. This presentation explores current research on urine fertilizer and several aspects of urine fertilizer projects done by Peace Corps volunteers in Mali, West Africa. Volunteers there are using a pilot project approach to propagate the use of small urine collection systems in a sustainable way. The urine fertilizer trials teach people about the value of urine as a fertilizer and the value of closed-loop sanitation. These urine fertilizer projects can easily be adapted to communities in other parts of the world. As communities accept the urine fraction of their waste as a valuable resource, they can begin to embrace the more complex and expensive aspects of closed-loop sanitation.

Keywords: Human urine, Nitrogen, Phosphorus, fertilizer, pathogen content

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Management of Hospitals Wastes in Ilorin, Kwara State, Nigeria (29 - 46)

O. S. Oladejo

Department of Civil Engineering, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso, Nigeria

Abstract

A total of one hundred and one (101) hospitals, consisting of 82 private and 19 government hospitals were randomly selected in Ilorin, Nigeria. The research was conducted through questionnaire and direct observation by researchers. Analysis of data showed that hospitals in Ilorin, Nigeria generated an average of 6000m3 of medical waste annually while between 0.021m3 and 0.084m3 was generated daily per patient. The largest composition of medical wastes generated in these hospitals were sharp objects (36.22%, 9.18%) for private and Government respectively, followed by blood product (32.37%, 7.73%), Culture (3.86%, 0.97%), Isolation (1.45%, 1.45%), Radioactive (0.97% 0.48% and Cytotoxic (0%, 0.48%). Most of the hospitals (41.46%, private) and (19.51% government) use plastic containers as temporary storage units and 68.37% (private) and 14.85% (government), temporarily disposed off their wastes daily. Final disposal of medical wastes in most of hospitals in Ilorin were handled by Wastes Management Agents (59.61% for Private and 12.50% for government hospitals); Medical wastes treatment sites were found to be located outside the hospital premises. Since most of the hospitals in Ilorin are not involved in the disposal and final treatment of their wastes, most hospitals (65.35%, 1.98%) do not train personnel in handling wastes; though results showed that most people are aware of guidelines in medical waste management (75.25%, 17.82%) .  All hospitals visited make use of safety wears when dealing with wastes (81.19%, 18.81%; private and government respectively).The study revealed that waste management and environmental agents are fully involved in the handling and the disposal and treatment of medical wastes in Ilorin metropolis. The paper suggests the use of incineration for effective treatment of medical wastes, adequate training of personnel in the final handling, treatment and disposal of medical wastes and the need to educate the public on the detrimental effects of careless handling and disposal of medical wastes. 

Keywords: Blood products, Sharps objects, Ilorin Metropolis, Medical Wastes, Hospitals, Handling and Disposal

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Development of Porcelain Insulators from Locally Sourced Materials (47 - 58)

1A.O. Oladiji, 2J.O. Borode, 3B.O. Adewuyi, and 4I.O. Ohijeagbon

1-3 Department of Metallurgical and Materials Engineering,

Federal University of Technology, Akure, Nigeria.

4Department of Mechanical Engineering, University of Ilorin, Ilorin, Nigeria

Abstract

Varying composition of kaolin, ball clay, feldspar and quartz was used to produce different samples of porcelain insulators to investigate their resulting properties and suitability for mass production and commercial viability. The basic raw materials were separately prepared using a 200  sieve. The mixtures were formulated to produce porcelain samples by using sodium silicate as deflocculant, while the slip casting process was used in the production of the electrical porcelain insulator. Produced insulator samples were fired by means of bisque and glaze firing techniques respectively. The sample  with composition of 33% Kaolin, 15% ball clay, 32% feldspar and 20% quartz was found to possess the highest failing load of 8.0 kN, corresponding to water absorption (1.55%), porosity (4.64%), bulk density (1.73 g/cm3), with appreciable insulation resistance of 6,630 Mega ohms at injection of 5,000 volts. The investigation had shown that high quality electrical porcelain insulators could be achieved from locally sourced materials.

Keyword: Porcelain, Insulators, deflocculant, Mullite

Modelling of Residential Water Demand at Household Level in Ilorin, Nigeria (59 -68)

A.M. Ayanshola, B.F. Sule, and A.W. Salami,

Department of Civil Engineering, University of Ilorin, Ilorin,  Nigeria

Abstract

Accurate estimation of water use is one of the challenges facing water supply sector in our society.  This is due to lack of adequate and reliable supply and demand data. This paper examined and determined water demand at household level in some randomly selected houses within the city of Ilorin. The study evaluated household water consumption with the aid of structured questionnaire to sample people’s opinion in the study area. Regression analysis was used to determine the variables that affect household water consumption. Based on the analysis the average daily consumption was found to be 86.22 l/c/d.  The study also showed that income, education level, and sex have significant effect on water demand in the sampled households.

Keywords: Modelling, water demand, residential, household

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A Computer Program for Design of a Swimming Pool to Enhance Water Use Efficiency (69 -84)

K.A. Azeez and S.A. Raji

Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria,

Abstract

This paper highlights the basic information on the general type, planning, design consideration, and structural design of swimming pool for optimum water usage. In designing this swimming pool structure, an interactive program was developed using Visual Basic programming language 6.0, which provides a graphics interface. The wall and base of this swimming pool were treated as slab, following the limit state philosophy and codes of practice for reinforced concrete design. The result from the computer program was compared with result generated by a commercial structural analysis package, SAP2000. The slight difference observed between the two methods was as a result of approximations associated with the computation. The computer program has also reduced the design time considerably with high precision. For optimum water usage, the edges of the swimming pool should be shaped in parabolic form, in order to achieve a complete water re-circulation, which will eventually prevent bacteria growth and some other insect larva in the pool. This in turn will reduce cost of water treatment and ensure sustainable use of water.

Keywords: Swimming pool, optimum design, efficiency concrete

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Cost Effective Strategy for Sustainable Urban Water Supply – The Place of Geotechnical Investigation (85 -92) 

Y. A. Jimoh,  A. W. Salami, and O. G. Okeola

Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria. 

Abstract

This paper discusses the relative advantage of subsoil and geotechnical investigations in an urban water supply. For example, an urban water scheme for a population of more than 30, 000 heads requires of 0.03 % of the initial cost for the geotechnical investigation studies.   A commitment of that paltry percentage of the initial cost of the development of the scheme would eliminate possible additional cost which may reach up to 120 %. It is recommended that geotechnical investigation is accorded the desired attention in order to ensure sustainable urban water supply in a developing economy like Nigeria.

Keywords: Cost, scale of fees for consultancy services in construction industry, risks elements in non execution of geotechnical investigation.    

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Engineering Education and Sustainable Development in Nigeria (93 -98)

1H. A. Ajimotokan, 1K. R. Ajao, 2K. A. Adebiyi, 3A. Dainkeh and 4A. A. Oloyede

1Department of Mechanical Engineering, University of Ilorin, Ilorin, Nigeria;

2Department of Mechanical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria;

3Department of Electrical Engineering, University of Ilorin, Ilorin, Nigeria

4Department of Electronics, University of York, York, UK;

Abstract

This paper examines Engineering Education (EE) in Nigeria as a suitable vehicle towards sustainable development of the socio-economic infrastructures necessary for the growth of enterprise, and for the maximization of social welfare. The state of EE in Nigerian Universities was examined using data derived from the database of the regulatory bodies. A data register was employed to capture the needed data and these were analyzed using statistical analysis.  Results of the 1999/2000 accreditation exercise of the 17 Engineering disciplines available in 129 Engineering departments of Nigerian Universities, show that twenty-one (16.28%) got full accreditation, 69 (53.49%) got interim, while 39 (30.23%) got denied accreditation. Sadly, these figures are alarming and may be detrimental to the Nigerian thirst for national development and socioeconomic growth. Undoubtedly, the quest for sustainable development depends on the extent to which EE is revamped and transformed to compete globally. Research and technology development for sustainable national development must be encouraged and well funded.   This  will  enable Nigeria to surmount present dependence on imported technologies, goods and services.

Keywords: Engineering education, engineering skill acquisition, research and technology development, Nigeria 

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Vol. 6, No. 2, 2009

 

Assessment of Properties of Natural Moulding Sands in Ilorin and Ilesha, Nigeria

 

J. O. Aweda and Y. A. Jimoh

 

Abstract The mechanical and permeability properties of natural sand deposits at Ilesha (south west) and Ilorin (middle belt) in Nigeria used in the foundry as moulding sand for casting of non-ferrous metals were investigated. The aim was to determine the optimum moisture content (OMC) for appropriate foundry works. The variation of the green strength of the moulding sand with the mixing water content was conducted to establish the OMC of 8% and 9% respectively for Ilesha and Ilorin sands. The corresponding values of the green compression strength of 52kN/m2 and 50kN/m2, dry compression strength of 285kN/m2 and 300kN/m2, shatter index values of 38 and 37 and the permeability index of 50 and 47.5 for Ilorin and Ilesha deposits respectively obtained at OMC of 8-9% were found adequate to produce sound casting of non-ferrous metals. The results indicate that with water addition in the range of 8-9%, the natural sands exhibit appropriate casting properties for non-ferrous metals in accordance with the standards and specifications of the America Foundry Society (AFS).
Keywords: casting, sand moulding, natural sand
 

Modelling the Projectile Motion of a Soccer Ball under Linear Drag Influence
O.A. Lasode, O.T. Popoola and O. Olaleye

Abstract: The paper presents an investigation into the projectile motion of a soccer ball. The equation of motion that determines the trajectory motion of the soccer ball was developed. In order to check on the accuracy of the equation for the linear drag force, a perturbation expansion technique was employed to solve for the range of soccer ball in motion under specific conditions of initial velocity and launch angle. The perturbation expansion was solved up to the third order and the result obtained from previous research work was verified. Result shows that for a soccer game scenario where a player tries to score a goal from free kick at 20m; if the ball is kicked at 18.86m/s then the most suitable angles for scoring a goal are 52° and 55° . This is because the barrier formed by the players will surely be overcome and the ball will reach the goal post regardless of any obstacles. A follow up comparison between linear drag theory and experimental observation on the field of play is also suggested.
Keywords: Projectile, drag force, perturbation, soccer

Vol. 6, No. 1, 2009

Assessment of Compressive Strength of Concrete Bridge using Destructive/Non-Destructive Tests at Elevated Temperature, 418-422
S. S. Kolo  Adeleke O. O., Yusuf I.T., Olise E. N., Aminulai H. O. and Abdullahi A
Abstract:Concrete bridge structure when subjected to high temperature, exhibit good behaviour as a result of their low thermal conductivity associated with their great capacity of thermal insulation. However, there is a fundamental problem of ?spalling? caused by high temperatures on concrete. To investigate the problem caused by high temperatures, concrete cubes of grade 25 were prepared and cured in water for 28 days and subjected to elevated temperature at varying degrees ranging from 100 to 600 oC for various timing of ½, 1, 1½, 2, 2½ and 3hrs, after which non-destructive and destructive testing methods were carried out on the samples to compare the compressive strengths obtained. Direct and deductive results obtained shows that there was a drop in the compressive strength of the specimen after it had been subjected to elevated temperature for all methods. The result also showed that the non-destructive testing method is more reliable as it also allows a physical examination of the interior properties of the samples. In addition, the combined pulse velocity and rebound index method has no effect on the accuracy of the interpretation. However, it is clear that any of the three methods can be adopted depending on the situation at hand.
Keywords: Concrete, temperature, strength, non-destructive, destructive.

Utilization of Palm Kernel Shell Ash as a Stabilizer of Lateritic Soil for Road Construction
T. Ako and I. T. Yusuf
Abstract:Concrete bridge structure when subjected to high temperature, exhibit good behaviour as a result of their low thermal conductivity associated with their great capacity of thermal insulation. However, there is a fundamental problem of ?spalling? caused by high temperatures on concrete. To investigate the problem caused by high temperatures, concrete cubes of grade 25 were prepared and cured in water for 28 days and subjected to elevated temperature at varying degrees ranging from 100 to 600 oC for various timing of ½, 1, 1½, 2, 2½ and 3hrs, after which non-destructive and destructive testing methods were carried out on the samples to compare the compressive strengths obtained. Direct and deductive results obtained shows that there was a drop in the compressive strength of the specimen after it had been subjected to elevated temperature for all methods. The result also showed that the non-destructive testing method is more reliable as it also allows a physical examination of the interior properties of the samples. In addition, the combined pulse velocity and rebound index method has no effect on the accuracy of the interpretation. However, it is clear that any of the three methods can be adopted depending on the situation at hand.
Keywords: Concrete, temperature, strength, non-destructive, destructive.

Prestressed Composite Concrete incorporating Complast SP430 and Rice Husk ash, 434-441
O. J. Suleiman
Abstract:Self-Compacting Concrete (SCC) was developed in Japan about twenty-seven years ago and has been used successfully in numerous applications where normal concrete is difficult to place and consolidate due to reinforcement congestion and difficult access. This study describes how Self-Compacting Concrete can be applied for prestressed concrete. Eighteen 150x150mm cubes were cast in the Civil Engineering laboratory, Department of Civil Engineering, University of Ilorin. Six cubes were cast with conventional concrete as control using supaset cement and a mix ratio of 1:1½ :3. Six cubes were cast with SCC using supaset cement, conplast SP430 as plasticizer and a mix ratio of 1:2½ :2 and six cubes cast with SCC using supaset cement, conplast SP430 and Rice Husk Ash as plasticizers and a mix ratio of 1:2½:2. The hardened property i.e. compressive strength, of the two self-compacting concrete mixtures and the conventional concrete was measured. The fresh properties of self-compacting concrete included slump flow and passing ability as measured by L-Box. In general, twelve 150x150mm cubes were cast without external vibration or compaction using self-compacting concrete and showed higher compressive strength than the conventional concrete. the self-compacting concrete mixture with conplast SP430 and Rice Husk Ash as plasticizers had a higher compressive strength than the self-compacting concrete mixture with just conplast SP430 as plasticizer.
Keywords: Compressive strength, self-compacting concrete, prestressed concrete, plasticizer, Complast SP430, rice husk ash.

 

Prediction of global warming movement to the South  

Achimpong Kufor

 

Abstract:The risk of sea level rise due to melting land ice is one of the most recognized?if controversial and hard to predict?threats posed by global warming. Other potential impacts from global warming include increasingly powerful storms and floods of the sort that have ravaged Australia this past month and a half (while recognizing scientists can't yet fingerprint individual weather events as caused by warming). 

 

Keywords: global, warming, sea level, storm, flood

 

Vol. 5, No. 1, 2008

 

Investigation on the Level of Compliance of Sandcrete Blocks in Ibadan, 362-369

  1. A. Yahya

Abstract: Good design of sandcrete block as a load bearing element requires the provision of adequate effective area for intended load. One of the causes of poor quality sandcrete blocks is non-compliance to standard provisions in relation to adequate size, strength, and quality of structural elements. In this study the level of compliance on standard specification of sizes of sandcrete blocks, by makers of the product was investigated. It was assumed in this study that other quality assurance parameters, except size properties of sandcrete blocks are satisfactory. This study determines factor of safety for area of sandcrete block and recommend such, to validate the design factor of safety of load bearing wall, as specified in BS 8110 and other design codes in Nigeria. Samples of sandcrete blocks were taken from ten different block making industries located in different areas of Ibadan for this study. The sizes of Block samples were measured and their areas determined and compared with specifications by Standard organization of Nigerian in NIS 2007. Statistical analysis was carried out on the measured data and the results indicate that an area factor of safety of 0.94 and 1.19 are suitable for 150mm and 225mm sandcrete block respectively.

Keywords; Sandcrete blocks, compliance, factor of safety, size, effective area, specification

 

Optimization of Project Construction Management for Client Involvement in Nigeria, 370-379

A. Adedeji, O. A. Lawal and  O. I. Ojetade

    Abstract: In order to optimize client involvement in the design stage of a project, the client has to increase their involvement with all the stake holders involve in the execution of a construction project. This is necessary since the more detailed clients definition of the scope of his project to the designers, the better the degree of pre planning and investigation, which will reduce the incidence of cost and time overrun of the project. The study has been conducted in two states on Nigeria, where designed questionnaires were administered to the party involved in construction. The study has shown that the client level of involvement stands at 45%, in the construction stage of a project. The construction phase of a project is where 2/3 of the bulk of expenses on a project is incurred, it is also at this stage of a project that cost and time overrun and poor quality of project is more pronounced owing largely to the improper implementation of project management practices by the contractors. Clients level of participation from the existing 45% to 74% would improve the output of a project. Project owners must be aware that the decisions that are made in the initial stages of planning and design are difficult and costly to change once construction begins, there is therefore the need for the owners to play active part in the various phases of a project particularly the design phase in order to ensure quality of project at a reduced cost and time. It is recommended that the client gives all relevant information required by the designers and make his brief concise in the design phase of a project to avoid significant problems which may arise in the successive stages of the project such as redesign and rebuild. 

    Keywords: client, construction, project, optimisation, genetic algorithms, excel solver


    Structural Behaviour of Plastered Strawbale Reinforced with Chicken Wire and Diamond Lath under Compression Tests, 380-389

    1. M. Matanmi 

    Abstract: The aim of this work is to determine the structural behavior of plastered straw bale reinforced with chicken wire and diamond lath under compression test. Results in this work shows independent of plaster type, the use of reinforcement has a significant effect on compression strength and to an extent the stiffness. Pre-compression improve initial stiffness of the straw bale test. In general, plastered straw bale reinforced with diamond lath has an average compressive strength of 1.606N/mm²; similarly plastered straw bale reinforced with chicken wire has an average compressive strength of 1.162N/mm². Plastered straw bale without reinforcement has an average compressive strength of 0.950N/mm².

    Keywords, Diamond lath, chicken wire, compressive tests

     

    Comparism of Physical Properties of Palm Kernel Shells and Conventional Light-weight Aggregates, 390-395

    S.A.Ogbaje. 

    Abstract:The physical properties of palm kernel shells were compared with that of conventional light-weight aggregates used in lightweight concrete works to examine the light-weightiness of palm kernel shells relative to conventional light-weight aggregates. Results obtained from the physical properties tests were compared with specified range of standard values of the various characteristics of conventional normal and light-weight aggregates gotten from ASTM 127 and www.constructionZ.com. The results of the specific gravity, fineness modulus, average moisture content and aggregate crushing value of the palm kernel shells obtained were less than that of normal weight aggregate but within the specified range of values for light weight aggregates classifying palm kernel shells concrete as lightweight aggregate. The palm kernel shell has bulk density of 580kg/m3 and aggregate impact value of 16.19% which is an indication that palm kernel shells can conveniently be used for structural light weight constructions as light weight aggregate. The particle size distribution shows that palm kernel shell has a maximum grain size within the range 16.0mm and 17.0mm, although this is less than that of normal weight aggregates; Palm kernel shell can be used conveniently in light weight concrete works.

    Keywords   Physical properties, palm kernel shells, light-weight aggregates.

     

    A Review on the Properties of Concrete incorporated with Waste Glass as a Substitute for Cement, 396-407

    K L Okeke and A. A.  Adedeji

    Abstract: Researches have shown that it is possible to use recycled materials to replace some of the traditional mixture components in concrete products and produce a more sustainable building material. One common material that can be recycled and have the possibility of use in concrete applications is waste plain glass. Waste glass is not really a waste but a resource. Its use in the construction industry is gradually gaining some ground. Waste glass has diverse application in the industry such as a building materials, concrete ingredient and paving applications, in place of sand and other natural resources. When used in construction applications, waste glass must be pulverized to very fine particle size. Today many researches are ongoing into the use of Portland cement replacements, using many waste materials like pulverized fly ash (PFA) and ground granulated blast furnace slag (GGBS). Like PFA and GGBS, waste glass powder (GLP) is also used as a binder with partial replacement of cement which take some part of reaction at the time of hydration, also it is act as a filler material. The presence of silica in cement is the binding property for the concrete, the strength of the concrete mainly depends upon the binding property of cement. In glass silica is rich. Waste glass can be used as pozzolanic material in concrete production, and has demonstrated significant influence in improving the mechanical and durability properties of concrete as shown by the results of several researchers. Waste glass undergoes beneficial pozzolanic reactions in the concrete and could replace up to 30% of cement in some concrete mixes with satisfactory strength development. This paper presents an overview of the works carried out on the use of waste glass powder as partial replacement of cement concrete.

     

    Keywords:  Recycled material, waste glass, cement, concrete, concrete strength

    Vol. 4, No. 1,  2007

    Reliability Design Format for Steel Plate Girder to BS 5950 (2000), pp 330-338

    O. A. Ahmed and O. A. Uche

    Abstract: The paper presents reliability assessment of deterministic design of steel plate girder considering both ultimate and serviceability limit state in accordance with BS 5950 (2000). The reliability analysis was carried out using First Order Reliability Method (FORM). Design variables such as strength of the material (Py), width of the flange, flange thickness, web thickness as well as the span of the girder were considered random and stochastic. It was shown among the findings that, when the span (L) of the plate girder was kept constant with increase in the magnitude of live-dead load ratio, the safety indices decreases, as deflection criterion was considered. Also, the design of the plate girder in accordance with BS 5950 considering shear and deflection is safe for almost all the range of variables considered. On varying the depth of the plate girder, safety indices increase with increase in depth and decrease with increase in live-dead load ratio, when shear criterion was considered. The deflection is the most critical mode of failure on varying the span and load ratio, with safety index less than the recommended value by JCSS 2000 for structural members with moderate to large consequences of failure of 3.3 to 4.4. Therefore, BS 5950 design result seems unsafe with respect to bending (under high live-dead load ratio) and satisfactory with respect to shear and deflection. It is then, recommended that the design of steel plate girder base on BS 5950 be reviewed to incorporate reliability analysis.

    Keywords Reliability design, steel plate girder, safety index, deterministic design

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    An Empirical Assessment of Causes of Building Collapse in Lagos State, Nigeria, pp 344-352

    O. G. Okeola A. A. Okeola and M. G. Ameen

    Abstract: The unremitting cases of building collapses in Nigeria have become a source of national and international concern. Many efforts have been directed towards identifying the critical factors responsible for these collapses with the aim of finding appropriate strategies that is proactive and pragmatic in preventing further occurrences. One of the bottlenecks that have clog efforts to determine the causes of collapses is the absence of a comprehensive analysis of records of building collapses. This study gives an empirical assessment of causes of building collapse in an economic hub state of Nigeria by statistically analysing records of building collapses in Lagos state. The findings indicate poor quality materials and workmanship, faulty design/construction methodology and excessive loading as the major factors responsible for building collapses in Lagos state. Based on the findings recommendations to stem the tide in the short and long term were given.

    Keywords:  Building Collapse, Structural, workmanship, materials, Lagos

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    Vol.6. No.1, 2009

    Treatment and Disposal Management of Medical Wastes from Hospitals in Ogbomoso, Nigeria

    (1 - 15) 

    O. S. Oladejo

    Abstract

    One hundred and four randomly selected hospitals in Ogbomoso responded to a questionnaire intended to identify their waste disposal practices. Survey responses 53 private and 51 Government hospitals showed that hospitals in Ogbomoso generated average medical waste of 1500m3 annually and between 0.007m3 and 0.021m3 per patient per day. The findings revealed that medical wastes generated consist of isolations wastes (1.5%), cultures (2.2%), sharp objects (50.6%), human blood and blood products (32%), radioactive wastes (1.1%), cytotoxic wastes (1.1%) and others (7.9%). 71% of respondents temporarily dispose their wastes daily. About 38% of the hospitals dispose  medical wastes, by open air burning and 22.6% by open dumping. Only three hospitals (2.4%) incinerate, while 8.9% use landfill. 45.6% of the hospitals employed services of waste management agents in handling and disposing of their wastes, about forty-eight percent (47.6%) use private individual to dispose the waste. Eighty-four percent (84%) of the hospitals treat  medical wastes outside hospital premises while about 96.2% of the hospitals in Ogbomoso are aware of the guidelines and regulations governing the treatment and disposal of medical wastes. The study revealed a high level of risk of infections especially from blood products and sharp objects. The final disposal method employed is inimical to human health as noxious gases and substances are released during the burning process.

    Keywords: Blood products, Hospitals, Infectious wastes, Medical wastes, Sharps objects,

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    Improvement of Water Supply to the National Centre for Agricultural Mechanization, Ilorin, Kwara state, Nigeria  (16 - 20)

    B.F. Sule, O. O. Olla and K. A. Adeniran

    Abstract

    A structured questionnaire was administered for the determination of the water requirements of residents, staff and visitors at the National Centre for Agricultural Mechanization (NCAM), Ilorin, Kwara State, Nigeria. The analysis of the questionnaires showed that NCAM will require about 288 m3 of  water daily. The water will be obtained from an existing dam and treatment plant about 2 km from the center. A network consisting of 40 pipes with 29 nodes is needed to distribute the water within the centre. A computer software which utilizes the Hardy Cross method was used to analyze the network.  The result of the analysis showed that water will flow throughout the entire network with adequate velocity and pressure. The head losses in the pipes varied between 0.9 x 10-6m and 0.015m while the nodal pressures were found to lie within a minimum of 5.0 m to a maximum of 19.77m.

    Keywords: Water supply, water requirement, pipe network, adequate velocity and pressure. 

    Traffic Performance Characteristics of a Two-Lane Road under Heterogeneous Traffic Conditions (26 - 33)

    A. B. Ibitoye and B. S. Jimoh

    Abstract:

    Road characteristics including road geometry, number of lanes, lane-width, and grade are important factors affecting traffic speed, flow and traffic capacity. The purpose of this study is to investigate the performance characteristics of a two lane road, serving  the University of Ilorin main campus. The study is aimed at providing basic understanding of the behaviour and the operation of mix traffic on this road and the level of the effectiveness in facilitating the desired vehicular traffic flow. A maximum traffic flow of 893 veh/hr was observed on Monday and lowest value of 114 veh/hr on Saturday. Taxi/Cabs have the highest percentage composition of 41%. The highest speed of 114 km/hr was also observed for the Taxi/Cabs. The traffic stream speed of 72 km/hr was obtained using weighted mean speed method and this is above the recommended speed limit of 60 km/hr for the road. This implies that the speed limit is not consistent with the traffic operation on this road and may result in severe road safety hazards. The finding from this study may be used to plan adequate traffic performance characteristics of this type of road.

     Key words: Road characteristics, Mixed traffic, Traffic Performance, Traffic flow, Traffic Speed.

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    Effects of Reprocessed Polyethylene Water Sachets on Strength and Permeability of Laterized Concrete (34 - 46) 

    S.A Raji* , S.A. AbdulKareem** and A.O Ibrahim

    Abstract

    This research work was carried out to investigate the effect of a chemically reprocessed Polyethylene Water Sachets (PWS) on the strength and permeability of laterized concrete. The concrete specimens used for the tests were cubes measuring 150x150x150mm prepared in accordance with BS1881 Part B. The concrete consists of cement used in conjunction with the reprocessed PWS, laterite as fine aggregate, crushed stones (granite) as coarse aggregate and water. The proportion of the reprocessed PWS in the concrete was varied by replacing 2%, 4%, 6%, 8%, and 10% cement content with the reprocessed PWS. The mix ratio of 1:2:4 was employed in the preparation of the specimens. Compressive strength test was carried out on the specimens in conformity with BS 1881 Part116.The permeability of the specimens was determined by carrying out water absorption test on the specimens in accordance with BS1881 Part 5. Results showed that the strength at 28 days curing age increased from 11.29 N/mm2 at 2%PWS content up to 15.51 N/mm2 at 8%PWS content and then dropped to 8.27 N/mm2at 10%PWS content. Increase in values of compressive Strength was indicated for corresponding increase in curing age. The addition of the reprocessed PWS to the concrete also resulted in density reduction of the concrete for all the percentages considered.  The water absorption test showed that the permeability of the concrete reduced from 3.4% at 0%PWS to 2.67% at 2%PWS and again increased to 3.69% at 8%PWS content before it again dropped to 2.96% at 10%PWS content. The results also showed that at 28 days curing age, the PWS laterized concrete has maximum compressive strength of 15.51N/mm2.

    Keywords: Polyethylene Water sschet (PWS), laterized concrete, compressive, strength permeability.

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    Use of  Poultary Dung and sawdust to Improve Physical properties of Crude Oil Polluted Soils (47 - 55)

    A.Y.Sangodoyin and J.A. Okoro

    Abstract

    The effects of crude oil pollution on the physical properties of soil and the effectiveness of poultry manure and sawdust as restorative measures were studied. The study was carried out on two experimental plots containing sandy loam soil, each of dimensions 90cm x 90 cm . The plots of land were divided equally into three  sub-plots each of dimension 90cm by 30cm. Two of the sub-plots in each plot were polluted with crude oil and treated after three days with poultry manure and sawdust each at a rate of 6 tonnes/ha and compared with a control sample. Poultry manure and sawdust were spread evenly over the soil. The physical properties of the soils were determined before pollution and gradually monitored from three days after pollution to 8th week period of remediation. Results of the study showed that treatment with poultry manure increased infiltration rate to 27.1mm in plots 1 and 2 whereas sawdust increased it to 18.7mm and 18.9mm in plots 1 and 2 as compared to 13.9 and 13.5mm in plots 1 and 2 after pollution. Organic matter content in plots 1 and 2 increased from 4.21% and 4.31% to 10.08% and 9.80% respectively but later declined to 6.90% and 6.50% in poultry manure sub-plots and to 5.80% and 5.30% in sawdust sub-plots. Variations were also noticed in soil parameters like bulk density and saturated hydraulic conductivity with time. Data from the study indicate that poultry manure and sawdust could be used in a farm settlement contaminated by crude oil.

    Keywords: Poultry dung, sawdust, organic, saturated hydraulic conductivity

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    Vol. 5. No.1, 2008

    Vol. 4. No.2, 2007

    Vol. 4. No.1, 2007

    A Comparative Evaluation of manual and automatic methods of Traffic Control at some Road Intersections in lagos, nigeria (1 - 16) 

    O. M. Osuolale, R. E. Okewusi, and A. P. Adewuyi

    Abstract 

    The research is aimed at assessing the operational efficiency of manual (traffic warden) and automatic (traffic signal) means of controlling traffic at road intersections in terms of: level of service (delay), right of way on demand and safety. The study was carried out around Ikeja in Lagos State with a total of ten road intersections; five traffic warden controlled and five traffic signalised intersections. Observatory volume study was carried out at each intersection approach in order to determine the morning, afternoon and non peak hours. Delay study was also carried out during the various peak hours using stopped vehicle count survey while the conflict study was carried out in form of accident and near accident occurring manoeuvres at the intersections. The research shows that during morning, afternoon and non peak hours, majority of the traffic signals operated in the Level of Service (LOS) B and C while those of traffic warden are in the LOS of A and B. The right of way on demand during morning, afternoon and non peak hours values in term of the percentage of vehicles stopped for traffic signal controlled intersections range between 50 and 80%, 41 and 80% and 36 and 86% respectively; while for the corresponding traffic warden controlled intersections, the ranges are between 3 and 70%, 10 and 71% and 7 and 60% respectively. The level of conflicts for the traffic signalisation scheme is high, ranging between 254 and 524 vehicles while that of traffic warden is lower, ranging between180 and 213 vehicles.

    Keywords: Evaluation, Efficiency, Traffic Signal, Traffic Warden, Delay, Level of service and Safety.   

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    Local materials : Thermal transmission characteristics and models for single and double panels timber walls (17 - 29)

    A.A. Jimoh  

    Abstract

    Thermal transmission characteristics analysis of single panel timber wall and double panel timber walls with cavity air of 20 mm or more thick, is presented.  The study considered four timber wall materials for investigation, namely: Ayin (Anogeissus leiocarpus), Iroko (Milicia excelsa), Mahogany (Khaya senegalensis) and Fanpalm (Borassus aethiopum). In order to accomplish the study, thermal transmission equations for the walls were analysed , in terms of  the wall panel thickness and panel material thermal conductivities. The thermal conductivities were determined experimentally and substituted in the heat flow equations while panel thickness ranging from 10 to 50 mm were used, to obtain the values of heat flow per m2/K . Results show that, the higher the thickness of wall panel, the lower the heat flow. It was found that heat transmitted by a double panel wall with cavity air is 40% of the heat that is allowed by single panel wall of similar panel thickness.  A general heat flow equation was derived  to relate the heat transmitted to the thickness of the wall panel for the single and double panel walls , respectively.

    Keywords: Thermal conductivity , heat transmission, timber, wall, panel    

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    Evaluation of some squeeze cast parameters of aluminium (30 - 43)

    J. O. Aweda 

    Abstract

    Effects of applied pressures and die pre-heat temperatures on the heat transfer coefficients of aluminium were determined using the solidification temperature histories of the cast metal. The heat transfer coefficients at the cast metal/steel mould interface during solidification of squeeze cast aluminium were investigated using the inverse heat conduction method. The heat transfer coefficients were determined by both experimental and numerical methods. The results show an increase in the value of heat transfer coefficients with applied pressure and a decrease with high die pre-heat temperatures. The numerical heat transfer coefficients were in good agreement with the experimental values.

    Keywords: Squeeze casting, temperatures, applied pressure, die pre-heat

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    EVALUATION OF VIBRATION-BASED STRUCTURAL DAMAGE IDENTIFICATION TECHNIQUES ( 44 - 67)

    A. P. Adewuyi 

    Abstract

    This paper compares and evaluates the global methods currently proposed for structural damage identification that use changes in the modal properties of the structure (i.e. modal frequencies and mode shapes) and to provide an assessment of the effectiveness of the methodologies studied by applying them to the same structures having different degrees of damage. The success of individual vibration-based damage detection (VBDD) approach is measured through computer simulation studies. It may, however, be noted that additional practical difficulties that cannot entirely be reproduced through computer simulation exist, which makes vibration-based damage identification a challenging field with many unanswered questions.

    Keywords: health monitoring, vibration-based damage detection, modal properties, natural frequencies

     ANALYTICAL STUDY OF FLUID FLOW AND HEAT TRANSFER IN THE ENTRANCE REGION OF HEATED CONCENTRIC ELLIPTIC ANNULI

     I. K.  Adegun 

    Abstract

    This research work presents analytical study of laminar forced convection in the entrance region of concentric elliptic annuli using scale analysis. Scale analysis or scaling is an    analytical method, based on heuristic reasoning, used extensively in heat transfer and fluid mechanics. The object of scale analysis is to invoke the basic principles of fluid mechanics and heat transfer (convective, conductive, etc.) to produce the order – of - magnitude estimates for the quantities of interest. The technique adopted evaluates the flow and heat transfer parameters.  These parameters are the generalized and non-dimensional thermal entrance length, Ltg, hydrodynamic entrance length Lhg , friction coefficient, Cfg  and the mean Nusselt number, NuD*. Results for developing hydrodynamic and thermal boundary layers indicate that, for air, the generalized parameters depend only on the eccentricity, e and aspect ratio AR of the annuli. For concentric annuli of e=0 and AR >50, results approximate to those for the corresponding circular tubes. The results also show that the heat transfer coefficient, NuD* is independent of fluid properties but solely depends on eccentricity of the ellipse and aspect ratio of the geometry.             

    Keywords: Analytical study, scale analysis, entrance region, concentric elliptic annuli 

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    Vol. 3. No.1, 2006

    Vol. 2. No.1, 2005

    Vol. 1. No.1, 2004
      

     

     Vol. 13, No. 3, 2016

    Hospital Infection Rate following Sewage Malfunction in a Nigerian Hospital: An Observational Study

    O. A. Mokuolu, A. Sojobi  and M. Adejumo

    Abstract: Patients in healthcare institutions contract nosocomial or Hospital Acquired Infections (HAI) that require extended hospital stays, costs and increased use of antibiotics. Such infections can cause patients great discomfort and adversely impact the overall quality and cost of healthcare. Contaminations into the environment by malfunction engineering infrastructure are a rare consideration in Healthcare facilities, while striving to lower the incidence of HAI by implementing surveillance programs, policies and procedures that aid in breaking the chain of infections. Nosocomial infection can be acquired directly or indirectly. This report is based on the observation on repercussion of sewage malfunction in a Nigerian Hospital where infection rate increased up to 200.2% during sewage malfunction and 246.2% at Neonatal Intensive Care Unit during similar occurrence. There is need for a multi prong approach to Hospital infection control in addition to the popular advocacy on hand hygiene and physical protective equipment.

    Keywords: Engineering, facility, infections, Nigeria, sewage, protective, malfunction

    Observed and projected trends in livestocks methane emission: Analysis of five decades of data from Nigeria

    R.O. Yusuf, J. A. Adeniran and O.A.A. Eletta

    Abstract: The devastating effects of climate change as a result of the emission of greenhouse gases into the environment have assumed global proportions. The purpose of the study is to estimate and project the tend emission of methane from livestocks production in Nigeria. Livestock data from 1961 to 2012 was used to estimated methane emission using the Tier I and Tier II emission factor approaches. Auto-Regressive Integrated Moving Average (ARIMA model) was used to project methane emissions from livestock in Nigeria from 2013 to 2025. The estimates showed that methane emissions from cattle, sheep and goats accounted for over 95% of total emissions while emissions from camels, horses, asses, pigs and poultry contributed less than 5%. Emissions from cattle are expected to increase from 620 Gg in 2013 to 710 Gg by 2025 while emissions from sheep and goats for the same period will increase from 201 Gg to 251 Gg and 303 Gg to 330 Gg, respectively. Emissions from camels, horses and asses were predicted to remain constant while pigs and chicken emissions were predicted to rise from 25 Gg to 33 Gg and 9 Gg to14 Gg, respectively within the same period. The fitted values of methane emissions for all the animals were in close agreement with the calculated values indicating that the ARIMA models were correctly specified within the upper and lower confidence levels.

    Keywords:ARIMA, livestocks, methane, projection

    Reliability Analyses of a Typical Mega-Water Pumping Station

    S. A. Y. Amuda, L. O. Afolabi and A. Abdulkarim

    Abstract: Maintainability and reliability are among key criteria considered in engineering for performance monitoring and evaluation when installing any system that is expected to have a life span of more than two decades. This informed our comparative studies on the 2011 commissioned mega-water treatment and pumping stations in Kwara State, with the use of the two reliability analyses techniques. The Weibull function was used to predict projected reliability for two decades from the year of installation. In the same way, the estimated reliability of the system for each year was obtained using exponential distribution. Based on the four pumping stations, the results shows that on average, the intake pumping station has estimated reliability of 91.885% compare to projected reliability of 99.115%. Similarly, the lowlift pumping station has an estimated reliability of 67.1275% compare to projected reliability of 81.0375% and same pattern for the highlift and treatment stations. It was also discovered that, the current poor rating of the maintenance of some basic components of the plant can course a complete breakdown of the plant in less than 10 years after its commissioning. Component importance analysis is carried out in order to define rank of each unit to the system reliability. The analysis has shown that some treatment plant components are at critical stage when considering reliability improvements. On the other hand, when planning a maintenance action lowlift unit is the most critical.

    Keywords: Maintainability, Reliability, MTBF, Weibull, Exponential, Pumping station

    Time Headway and Vehicle Speed Studies of a Road Section in Ilorin, Nigeria

    T. Ako and I. T. Yusuf

    Abstract: The properties of vehicle speed and time headways are fundamental in traffic engineering applications, such as capacity and level of service studies on highways, un-signalized intersections, and roundabouts. This paper analysed the time headway and vehicle speed on urban road and investigate their statistical relationship to demonstrate the potential for improving traffic flow by controlling the speed and headway of individual vehicle in accordance with an assessment of the urban traffic demands. 50 vehicles were sampled on a 100 m section of Tanke-University of Ilorin (Tanke-Unilorin) road for speed studies for four days, analysed and plotted. Data were also collected simultaneously at that section of the road and analysed for headway distribution. Results obtained were 85th percentile speeds of 17.2, 11.4, 11.2, and 22.2 m/s, 50th (median speed) percentile speed of 9.0, 8.3, 8.3, and 14.0 m/s, and the mean speed of 11.7, 8.66, 9.46, and 14.33 m/s for day 1 - 4 correspondingly. Frequency tables generated and plotted for theoretical and observed values show that, at higher speed, there was shorter time headways, implying that, headway times were influenced by vehicle speeds. Also, time headways plotted against vehicle speeds yielded a headway – speed polynomial relationship in the form, α₁x² - α₂x + c, at R² values in the range 0.966 – 0.996. This indicates a very high correlation between vehicle headway and speed and thus, can be used to determine the desired time headways at various vehicle speeds on Ilorin roads and other urban roads.

    Keywords: Time headway, traffic characteristics, urban roads, vehicle speed

    Effects of Geometric Features on Roundabout Performance: Case Study of Two Roundabouts in Ilorin, Nigeria.

    I. K. Kolo, Y. A. Abdulkareem and I. T. Yusuf

    Abstract: The study investigated the effects of roundabout geometry on its performance. The effects of the geometries on the performance of Gari - Alimi Roundabout and Police A – Division Roundabout in Ilorin, Nigeria were studied. ‘The inscribed circle diameter, entry width, circulatory roadway width, central island, entry angle, and entry half width of the two roundabouts were measured and their respective capacities determined using the British Manual of Geometric Design of Roundabout. The 12 hour traffic volume counts were conducted for three working days at each of the roundabouts in order to determine the trend of traffic flow and the operational performance. Characteristic delay studies were also carried out to determine the Level of Service (LOS) of each approach during the morning and late afternoon peak periods. Results show that the geometric shape of a roundabout has an impact on its operational performance. For instance, an oval and irregular shaped roundabout may be difficult to negociate, while a symmetical roundabout promotes an orderly and regimented traffic flow.

    Keywords: Geometry, capacity, performance, roundabout, LOS 

    Stochastic Sensitivity Assessment of Reinforced Concrete Folded Plates

    M.T. Abdulwahab and O.A.U. Uche

    Abstract: The paper presents stochastic sensitivity assessment of reinforced concrete folded plates in accordance with Euro code 2. This was based on the first order reliability method (FORM) using FORM5. Limit state equations for reinforced concrete folded plate subjected to bending, longitudinal stress and deflection were derived and their implied reliability levels evaluated. All basic design variables involved are treated as random variables with their statistical characters adopted from literature. Sensitivity assessments show that the reliability index ( ) values for design of reinforced concrete folded plates are mostly influenced by the, characteristic compressive cylinder strength of concrete, plate thickness, plate depth and span of the plate. It was noted that safety index increases with increase in variables such as characteristics compressive cylinder strength, plate thickness and plate depth, while it decreases with increase in span of the plate.

    Keywords: Reinforced concrete plates, Reliability index, Stochastic assessment, Sensitivity study

     

    Stability Analysis for HVDC/AC Power Systems Based on a Modal Series Method

    I. S. Madugu, B.J. Olufeagba, N. Magaji, A. Abdulkarim, M.S. Gaya, M. Ahmad, A. Y. Iliyasu, A. Bala

    Abstract: Modal series methods can be used to represent the dynamic characteristics of a nonlinear system. In this paper the modal series method is applied to investigate the stability and the nonlinear modal interaction in HVDC/AC power systems. A comprehensive analytical technique based on the modal series method and symbolic computer algebra is proposed for the analysis of power systems that include HVDCs. In order to test the viability of the proposed methodology, a test system is used. Using this method, we can study the oscillation modes and non-linear dynamic behavior of power systems subjected to large disturbances. The results are suitable for complex power system stability analysis and control system design. The proposed method is general and may be extended to include other FACTS devices. In addition, analytical results are compared with detailed non-linear time-domain simulations.

    Keywords: Flexible AC Transmission System (FACTS), transient stability, HVDC Transmission

    Effect of Cement Slurry on the Tensile Strength of Treated and Untreated Fanpalm Specimens

    A. A. Raheem and M. T. Audu

    Abstract: This paper presents the effects of cement slurry, an alkaline medium on the tensile strength of fanpalm, a prospective local reinforcing material alternative to steel reinforcements. Fanpalm specimens were soaked in cement slurry for specific periods up to 1 year to expose item to alkaline attack. Protective agents (sodium sulphate, sodium hydroxide and Sulphur) were applied as treatment agents to some other set and then embedded in cement slurry for the same specific durations under the same laboratory conditions. Tensile strength tests were carried out on these specimens and results presented. The result revealed that as the duration of soaking in cement slurry of uncoated fanpalm increases, the nominal ultimate strength of the fanpalm decreases exponentially from 140 to 33.00 N/mm2 at 366 days in cement slurry. While the coated specimens decreased from 140 to 40.00 N/mm2 at 270 days in cement slurry. At 270 to 366 days, there is constancy in the strength 40.00 N/mm2 for the coated specimens. It shows that the nominal ultimate strength of coated specimens improves with the application of sulphur, sodium sulphate and hydroxylamine on the surface of fanpalm before embedded in alkaline media.

    Keywords:: Fanpalm; Cement slurry; Tensile strength; Sulphur; Sodium Sulphate; Hydroxylamine;

    MAP CHART: an Android Based App for Smart Cities

    J. O. Olusina

    Abstract: Map Chart is an android based app that allow lands to be charted prior to purchase or processing Certificate of Occupancy (C of O). It demonstrates the powerful capability of geospatial mapping on mobile devices fusing accuracy into simple yet fascinating Graphic User Interface (GUI). The applications allows coordinates to be specified in both Geographic and Universal Traverse Mercator (UTM) coordinates.

    Keywords: App, coordinates, map, chart, landed property.

    General Polynomial Model Formulation for Predicting Traffic Flow in Lagos Island

    J. O. Olusina.

    Abstract: Over the years, basic-road and traffic conditions have always determine traffic efficiency. Optimum efficiency can be attained when proper and adequate traffic management measures are put in place with minimum delay and cost at different entry points. The traffic network in Lagos Island is not structured to accommodate heavy flow. In addition, the ever increasing population of Lagos Island has caused a lot of changes in land-use pattern especially in the area of transportation. Therefore, the need to study the rate of flow of traffic in Lagos Island is very crucial for future planning and management. Eight (8) major link bridges and roads were considered in this study. Traffic data at peak and non-peak periods were collected and analysed. General polynomial models were developed for both inflow and outflow traffic. Ranking of the routes was carried out. Out of all the eight link bridges and roads, Third (3rd) Mainland Bridge was found to be ranked first in terms of vehicular flow at both periods of the day, while Marina St. has the shortest travel time of 3.083mins and least volume of vehicles.   

    Keywords: Road, Traffic flow, Traffic congestion, Transportation System Management (TSM), Geospatial Information Systems (GIS).