Archive

Vol. 16, No. 2, 2019 

Assessment of Mechanical Properties of a Modified Tyre-Fibre Concrete.

A. O. Ibrahim and A. A. Adedeji

Abstract: Increase in the deposition of waste tyre in the landfill has posed a serious problem to the ecosystem all over the world (IbroSkenderovic, 2015). Research from literature reviewed had shown that inclusion or partial replacement of waste tyre fibre for aggregates in concrete will reducing the percentage of waste tyre deposited at landfill. However, this research focused on the use of waste tyre fibre as partial replacement for coarse aggregate at different percentages (0%, 2.5%, 5%, 7.5% and 10%) to assess the mechanical properties of the concrete (M25). The compressive and Split tensile strengths’ results obtained are as follows(0%-22.2N/mm2;3.51N/mm2,2.5%20.1N/mm2:2.29N/mm2;5%17.6N/mm2;2.00N/mm27.5%-13.2N/mm2; 1.84N/mm2, and 10%-9.3N/mm2;1.42N/mm2). The concrete strengths reduced respectively with increase in the tyre fibre content.

Keywords::Tyre Fibre, Concrete, Mechanical, Coarse aggregate, Compressive, Tensile, Strength, conductivity, Density

Assessing the Effect of Some Physical Properties on the Bending Strength of Nigerian-Grown African Birch (Anogeissus leiocarpus) Timber

U. N. Wilson, J. O. Afolayan,, J. E. Sani and J. A. Alomaja

Abstract: The study investigates the effect or contribution of some identified physical properties such as moisture content, specific gravity, and density alongside other parameters like the Young’s modulus and force at failure to the static bending strength parallel to grain of the Nigerian-grown African birch. Nigerian-grown African birch (Anogeissus leiocarpus) timber were seasoned and sawn into small clear test specimens in accordance with BS 373 of 1957. These were tested in the laboratory to determine the static bending strength. It was observed from the R2 (correlation coefficient) values gotten from the plots of the static bending strength against each parameter considered that, the force at failure has the highest effect on the bending strength. This is followed by its Young’s modulus, moisture content, specific gravity and density in that order. A mathematical model which represents the predicted static bending strength was formulated from the statistical analysis which will enable the theoretical computation of the static bending strength of the Nigerian-grown African birch (Anogeissus leiocarpus). Considering the error margin and the R2 value between the theoretical and experimental results obtained from the laboratory, these provide an evidential basis for the veracity of the mathematical model.

Keywords: African birch, physical properties, static bending strength, mathematical model, regression analysis.

Characterization of Solid Waste Generated on the University of Ilorin Campus and Recycling of the Paper Content.

S. O. Bilewu and O.V. Oluwaseun

Abstract: This work presents the characterization of solid waste generated on the university of Ilorin main campus and recycling of the paper content with faculty of Engineering and Technology buildings as a case study. A total of 91.7kg of waste was sampled and characterized and it was concluded that various types of waste generated are: Cardboard/carton, Nylon, PET bottles, Paper, Wood, Food waste, Aluminum can, Yard waste, Glass bottle, Packaging wraps, Computer hardware, Metal scraps, Laboratory waste such as hardened soil samples, bamboo stalks, Lead acid accumulator, and ink cartridge. The most prominent ones among these waste components was found to be the Miscellaneous with a percentage component of 29.85. Miscellaneous comprises of photocopier parts, broken crates, ink cartridge and laboratory wastes. Cardboard/carton seconded with a total percentage of 20.55% while Wood was the third largest with a percentage of 12.88%. Others include: Food waste, 6.58%; PET bottles,5.68%; glass bottles, 5.92%; yard waste, 4.26% aluminum cans,3.11%; nylon,2.0%; paper, 2.88%; yard waste, 2.28%. packaging wraps with a percentage composition of 1.11% was the least. Finally, some of the waste paper were recovered and recycled.

Keywords: Solid waste, characterization, recycling. paper, cardboard, metal scraps.

Characterization of Belle Natural Moulding Sand for Foundry Applications

Y. L. Shuaib-Babata, M. B. Nafiu, K. S. Ajao, I. O. Ambali, Z. U. Elakhame, Y. O. Busari, H. K. Ibrahim and N. I. Aremu

Abstract: There exists vast availability of natural sands which may be suitable for foundry applications in different locations Kwara State in particular and generally in Nigeria. The sands need to be identified and characterised for productive and profitable foundry practices. In this study, assessment of chemical and physico-mechanical properties of the natural moulding sand in Belle community of Kwara State, Nigeria was carried out to ascertain its suitability for foundry applications. The analysis of the sand samples’ Chemical compositions were done using an XRF Analyser, while American foundry-men Society, ASTM and British standards laboratory tests procedures were adopted appropriately to determine the sand’s physico-mechanical properties. The results of chemical composition analysis showed that SiO2 have dominance proportion in the sand sample with an average value of 92.90 %, followed by Al2O3 (5.13%). CaO, Fe2O3, MgO, K2O, Na2O, ZnO and MnO were present within acceptable limits as trace elements. The results showed average physico-mechanical properties of the natural moulding sand sample to include grain fineness number (126), bulk density (1765 Kg/m3), moisture contents (7.66%), specific gravity (2.64), permeability (0.1cm/s), green compressive strength (51KN/m2), dry compressive strength (209KN/m2), flowability (65.22%), clay content (10%) shatter index (76%) and refractoriness (>900oC), which were within the required standards for casting of non-ferrous metal. Thus, Belle sand was found suitable for casting of non-ferrous metals. Though, there may be a need for the use of additives like bentonite, to enhance the sand’s clay content in order to increase the sand potential for foundry applications.

Keywords: Characterisation, natural moulding sand, non-ferrous metals, sand casting.

 Evaluation of Predictive Capability of Artificial Neural Network and Multiple Linear Regression: A Case Study of Lipid Extraction from Microalgae using Quaternary Solvents

S. I. Mustapha, F. A. Aderibigbe and I. A. Mohammed

Abstract: Thiresent study was carried out to evaluate the performance of artificial neural network (ANN) and multiple linear regression (MLR) as modelling tools for predicting the lipid yield obtained from microalgae using quaternary solvent mixtures. The MLR models were developed using two different mathematical softwares viz. Microsoft excel (model 1) and Polymath (model 2). The augmented simplex lattice design under the mixture methodology of the Design Expert software was used to generate the design of experiments used in this study. A comparison of the models developed using ANN and MLR for the extraction process was carried out based on pertinent statistical parameters. Although the results from both MLR models were very close, the calculated values of coefficient of determination (R2) of 0.9934 and the average absolute deviation (AAD) of 2.4789 for the ANN model when compared with values obtained from the MLR (R2 = 0.9898 and AAD = 2.9821 for model 1) and (R2 = 0.9898 and AAD = 2.9825 for model 2) showed that the ANN model was more accurate and precise than the MLR models. The actual maximum lipid yield of 19.4 wt% lipid g-1 DCW was obtained at solvent mixture in the volume ratio of 1:5:1:1 for chloroform, methanol, ethanol, and dichloromethane respectively.

Keywords:: Artificial neural network, multiple linear regression, lipid extraction, modelling

 Influence of Residential Environment on Cooking Behaviour of Students on the University of Ilorin, Nigeria.

Joy Kikelomo Adelabu and Amole Dolapo

Abstract: This study assessed the effect of student residence hall design on cooking behaviour of undergraduate students residing on campus residence halls in the University of Ilorin, Nigeria. It compared the cooking behaviour of students in different residence hall types with respect to kitchen design (i.e. the suite type, the shared kitchen, the kitchen per floor and the no kitchen residence halls). It also identified differences in the cooking behaviour of males and females in the residence halls. A survey was conducted and 430 questionnaires were administered to elicit information from students in the residence halls on their socio-economic characteristics and cooking behaviour. Cooking brhaviour was conceptualized as cooking preference, cooking frequency, cooking location and perception of cooking convenience in the residence halls. 416 questionnaires were retrieved (representing 97% response rate) and used for the analysis. Information on the residence hall design and availability of kitchen, washing sinks, and worktops in the residence halls was collected through the use of the observation schedule which was prepared and filled objectively by the researcher. Data was analyzed using descriptive and inferential statistics. The results revealed that gender and residence hall type significantly influenced the cooking behaviour of students. The paper concludes that architects and managers of students’ residences need to pay attention to the provision of cooking spaces in female residence halls than in male residence halls. Also, cooking spaces should be located within or close to students’ rooms to encourage use.g behaviour, Residence halls, Kitchen design, Student housing, Dietary habits, On campus housing. 

 Vol. 16, No. 1, 2019

 Low Carbon Infrastructure Concrete Binders for Sustainable Development in Nigeria: A Review.

Joseph O. Ukpata, Okiemute R. Ogirigbo, Desmond E.In In Ewa and Odo J. Ukpata

Abstract: Concrete constitutes the most applied infrastructure material in Nigeria for both urban and rural development. However, the production of conventional Portland cement binders in concrete contributes about 7% of the world’s anthropogenic carbon dioxide emissions. Therefore, this study presents a state-of-the-art review on the use of low-carbon supplementary cementitious materials (SCMs), as an approach to ensure durability and sustainability of concrete infrastructures. SCMs are known to reduce cost, energy and carbon footprints associated with Portland cement production as well as, ensure durability of concretes in aggressive environments by refining the concrete microstructure, when applied appropriately. Hence, the use of binary and ternary blends of SCMs with Portland cement has continued to receive global attention and Nigeria cannot be left out, particularly, given favourable climatic temperatures for SCMs’ accelerated hydration and microstructural development. The common SCMs are critically reviewed with suggestions for potential application of available SCMs, in order to enhance sustainable infrastructural development in Nigeria.

Keywords:Supplementary cementitious materials, sustainability, durability, infrastructure

Strength and Workability Characterization of Quarry Dust as a Replacement for Sand in Concrete Production

T. C. Okeke, T. O. Onuorah and D. Olojo- Kosoko

Abstract:Uncontrolled extraction of natural sand especially in regions with limited number of streams has lead to researches on suitable alternatives considering the environmental challenges posed. This study features an experimental study on the replacement of sand with quarry dust and its influence on the properties of fresh and hardened concrete. In this study two different experiments were conducted using: unwashed in-situ aggregates for Experiment 1, and washed aggregate for Experiment 2. Samples used for Experiment 2 were sieved and washed to reduce the finess characteristic of the quarry sample. Sand was replaced with quarry dust at varying percentage (0%, 25%, 50%, 75% and 100%) for both samples. Compressive strength and workability test for a concrete grade 20 with a mix ratio of 1:2:4 was conducted. Value form the workability test shows a decrease in slump value as higher percentage of sand is replaced with quarry dust. For the compressive test, the control experiment shows better appreciation in strength for the washed sample. At 25 and 50% replacement, concrete cubes produced from Experiment 2 indicate better strength gained compared to concrete cube produced from sample (1), and even show better appreciation in strength even after 28 days.

Keywords: Quarry Dust, Aggregates, Sharp Sand, Workability, Crushing Strength

The Effect of Improper Curing on the Strength and Transport Properties of High and Low Strength Concrete in Tropical Environments

O. R. Ogirigbo and J. Ogbeide

Abstract: Curing plays a vital role on strength development and durability of concrete. It begins after concrete placing and finishing, and involves maintaining required moisture and temperature conditions, for sufficient periods of time. Failure to cure concrete properly may result in development of cracks and ultimately in the failure of the structure, especially in high temperature environments. The aim of this study was to look at the impact of improper curing on the strength development and transport properties of a high and low strength concrete in a tropical environment. Three different curing methods were used in the study. The first involved curing of the concrete samples continuously under water, while the second method involved curing of the concrete samples under ambient air. The third method, which was a combination of the first two methods, involved curing the concrete samples under water for an initial period of 3 days followed by curing under air. The first curing method was taken as the ideal or proper curing method and was used as a means of comparison for the other two curing methods. Various tests such as compressive strength, water absorption and depth of chloride penetration, were carried out on concrete samples cured using the three different curing methods. The results obtained showed that improper curing had adverse effects on the strength development and transport properties of the concrete. However, the effect was seen to be more pronounced on the low strength concrete than the high strength concrete. This was attributed to the higher water content of the low strength concrete. Of the three curing methods studied, concrete samples cured under ambient air had the least performance, while those cured continuously under water had the best performance in terms of strength and resistance to the penetration of water and chloride ions.

Keywords: Improper curing, high strength concrete, low strength concrete, tropical environment

A Review of Fish Scales as a Source of Biosorbent for the Removal of Pollutants from Industrial Effluents

A. A. Omodele Eletta and Joshua O. Ighalo

Abstract: Biosorbents prepared from fish scales has been used to treat wastewaters containing heavy metals, dyes and pharmaceuticals. These pollutants have been reported in effluents from pharmaceutical, textile, automotive battery and tannery industries amongst others. Biosorption is a cheaper and more environmentally friendly alternative to other treatment technologies including the use very popular activated carbon adsorption. The aim of this review is to catalogue the progress made over the past 15 years in the utilisation of fish scales as biosorbents for the treatment of industrial effluents. Key domains are in source fish species, biosorbent preparation technique, target impurities, optimal levels of biosorption factors, equilibrium and kinetic best-fits and thermodynamic findings. The biosorbents are generally prepared by a two-stage chemical pre-treatment process. It is then dried, pulverised and sieved and in some cases calcined. Fish scale biosorbents have been found to have very good adsorption capacity for heavy metals, dyes and pharmaceutical compounds and with excellent removal efficiencies (50-100% for heavy metals and 78-90% for dyes). Optimal biosorption parameters vary significantly for the different target impurities and is only consistent for pH (acidic) and temperature (30-500C). Fish scale biosorption equilibrium is always best fit to Langmuir or Freundlich isotherms with newer models having poorer coefficients of determination. Fish scale biosorption kinetics is best fit to the pseudo-second order model. The review also revealed that fish scale biosorption is generally spontaneous and endothermic (for heavy metals alone).

Keywords: Waste management, biosorption, fish scale, heavy metals, dyes, pharmaceuticals

Reliability Assessment of Ejigbo Campus Library Building of Osun State University, Osogbo

S. O. A. Olawale, M. A. Tijani, O. I. Folayan and E. O. Bolaji

Abstract: The spate of recent collapse of structures in the country has increased enormously and it could be linked to factors such as low quality of workmanship, design defects and a few other issues. One of such looming disaster is the university library in Ejigbo campus at Osun State University. The library building is in a despicable condition and is no longer safe for human occupation. A physical structural assessment was carried out and the stress distribution in the structural members was found to be below the design strength in excess of 10%. A reliability structural analysis shows clearly that a safe reliability index of the building is dangerously low. The results of the java program developed clearly indicated that about 2.2% of steel ratio is required but about 1.5% was provided in the design of building structural elements.

Keywords: Reliability index, directional cosine, vector space, AFOSM: Advanced First Order second Moment, CPD: Cumulative Probability Density, ULS: Ultimate Limit State

Relationship between Workspace Utilization (WSU) and Indoor Environmental Quality (IEQ) in Offices of University Lecturers

I. A. Jimoh and B. Suleiman.

Abstract: Academic productivity and functional comfort of university lecturers have been subjects of concern to stakeholders in the Nigerian education sector. This study investigates the relationship between Workspace Utilisation (WSU) and Indoor Environmental Quality (IEQ) in offices of lecturers in three Federal universities. Objectives include determination of the extent to which lecturers use workspaces, the quality of indoor environment for assigned academic duties and the level of satisfaction felt by the lecturers. 360 questionnaires were administered, through purposive sampling, to obtain perception of lecturers on WSU, IEQ and satisfaction with workspace. 169(47%) valid returned questionnaires were analyzed using Means, ANOVA and Spearman correlation. Overall intensity of WSU by the university lecturers was 37.81% .There was no significant difference between intensities of WSU amongst the three universities. Out of the 13 uses, WSU on formal Reading (42.13%), formal Writing, (40.94%) and Internet surfing (40.19%) ranked 1st, 2nd and 3rd respectively. Building integrity (5.83%), Control facilities (5.47%) and Size of workspace were the 3 top ranking IEQ parameters. Weak positive correlations (0.1567, 0.1729, 0.1816, 0.1909 & 0.2534) were deduced on 6 out of the 91 relationships, between WSU and IEQ, investigated. Overall WSU of 37.81% compares favourably with fairly good use category of the Space Management Group. Higher intensity could however be achieved through improved IEQ in workspaces. Retrofitting by Works and Maintenance unit of each university is recommended on contextual IEQ variables in order to raise level of comfort, intensity of WSU and academic productivity.

Keywords: Indoor Environmental Quality; Lecturers; Office; University; Workspace utilisation.

 Performance Indices of Heated Tyre-Fibre Concrete Due to Spalling Mitigation

A. O. Ibrahim and A. A. Adedeji

Abstract: Due to waste tyre beneficial properties like high shear strength, low thermal conductivity and low density (Safriat, 2014). Research from literature reviewed had shown that inclusion or partial replacement of waste tyre fibre for aggregates in concrete will enhance fire resistance and mitigate spalling action. However, this research focused on the use of waste tyre fibre as partial replacement for coarse aggregate to mitigate spalling action in concrete under elevated temperature. The thermal analysis was carried out on Concrete cubes (0%, 2.5%, 5%, 7.5% and 10% replacement) for spalling test in accordance with (EN 1363-1, 2002 and ISO 834) using Furnace (Carbolite, 1300oC). It was found that the temperature increases, cracking depth (about 71.4% higher than the tyre fibre concrete) and loss in weight (about 50.1% less to plain concrete) decreases, with increase in percentage of tyre fibre added.

Keywords: Tyre fibre, plain concrete, fire, coarse aggregate, temperature, spalling, shear strength, thermal analysis, cracking depth

Assessment of the Suitability of Wudil Soil for Rammed Earth Structures

A.Y. Abdulfatah, M.U. Zango, H.H. Ahmad and K.R. Usman

Abstract: Earthen construction such as adobe, rammed earth and compressed earth block has been a historical construction technique and still remains a world-widely construction technique. One of the main problems in earth construction technique is the selection of suitable raw materials for the construction. This study is aimed to determine the engineering properties of a collection of soil samples from Wudil in Nigeria with the aim of examining their suitability for rammed earth construction. Samples were collected from five different locations within the locality of Wudil. Sampling and the conduct of all experiments were carried out using the same compactive effort, in order to ascertain their performance and conformity to the specifications for rammed earth structures. The geotechnical properties studied were particle size distribution, natural moisture content, Atterberg limits, maximum dry density, optimum moisture content, abrasion resistance and unconfined compressive strength. The compressive strength values for the samples obtained over a wide range of dry densities and moisture contents revealed that the soil samples with little modification will be suitable materials for rammed earth construction. The soil sample collected from Indabo Area was found to be the best for being closer to the specifications with an unconfined compressive strength value of 103 kPa, abrasion resistance of 3.13 cm2/g and drying shrinkage of 0.8%.

Keywords: Soil properties, rammed earth, compressive strength, sustainable housing, green house

Evaluation of Groundwater Exploration Methods Used in Benin City

A. Rawlings and J. E. Matthew

Abstract: In this study, data concerning groundwater exploration methods in Benin City were collected via Questionnaire Survey Method and analysed using SPSS (Statistical Package for the Social Sciences) statistical software. About thirty Questionnaires were administered to professionals dealing on groundwater drilling in four Local Government Areas (Ikpoba Okha, Oredo, Ovia North East and Egor Local government areas) in Benin City. These questionnaires were designed to extract data on the demographic features of professionals dealing on groundwater drilling in Benin City. Twenty- two (22) copies were completed and returned, while seven (8) copies were not returned. Hence, Twenty- two (22) Questionnaires were analysed. Results showed that the groundwater exploration methods used by professionals in the field include Test drilling, Aerial, Esoteric, Surface and Sub-surface methods with usage of about 14%, 9%, 14%, 41% and 23% respectively. Results further revealed that Surface method is simple, cost effective, reliable in estimating aquifer thickness and locating the best place to drill in Benin City. Hence, is the most predominantly used method of groundwater exploration in Benin City. It was recommended that places with similar geology as that of Benin City should adopt this method of groundwater exploration as it might help augment the groundwater supply in such places.

Keywords: Groundwater, exploration, methods, soil, bstraction, borehole, Benin City

Geotechnical Evaluation of Lateritic Sil in Baba-Ode Area, Ilorin, North – Central Nigeria

R. I. Obaro, O. A. Odediran, K. O. Iheme, O. C. Akakuru, O. C. and A. F. Gbadebo

Abstract: This study was carried out on lateritic soil at Baba-ode,North-central Nigeria with aim of denoting the geotechnical properties of lateritic soil and its suitability as construction materials. Two disturbed lateritic soil samples (sample A and B) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt – clayey sand while sample B is silt – clayey gravel composition. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit while sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. The samples contain inactive clay indicating little or no swelling tendency and therefore good for construction materials and this would prevent foundation failures. The California Bearing Ratio (CBR) values are 2 – 3% (mean = 2.75%) and 2 - 4% (mean = 2.75%) in sample A and sample B respectively. This implies they are good as subgrade construction materials. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor for sample B is 15.2% and 14.0% respectively. The compaction tests for Sample A indicate a higher fine fraction and thus a higher optimum moisture content while sample B has higher coarse fraction with lower optimum moisture content. The cohesion falls within 70-90Kpa (mean = 80Kpa) and the internal friction ranges from 250 - 310 with mean of 290. The results obtained from geotechnical analysis suggest that the soil have high bearing capacity, hence, it can be used as construction materials in engineering works. The soil could also support shallow foundation, dam construction, embankments, slope stability and subgrade materials in road constructions.

Keywords:Lateritic soil, compaction, California bearing ratio, Nigeria

Investigation in to the Suitability of Aggregates for Use in Superpave Design Method

A. Idris, A.S. Labo, A.Y. Abdulfatah and M. Umar

Abstract: Superpave is the short form of Superior Performing Asphalt Pavement and represents a basis for specifying component materials, asphalt mixture design and analysis, and pavement performance prediction. This new technology is the result of long research projects conducted by the Strategic Highway Research Program (SHRP) of the Federal Highway Administration of the United States. The current research is aimed at examining the suitability of Aggregates located in Kano, Nigeria for used in superpave design method. Aggregates samples were collected from different sources in Kano and their engineering properties, as they relate to the superpave design requirements were determined. The average results of Coarse Aggregate Angularity in Kano were found to be 87% and 86% of one fractured face and two or more fractured faces respectively with a standard of 80% and 85% respectively. Fine Aggregate Angularity average result was found to be 47% with a requirement of 45% minimum. A flat and elongated particle which was found to be 10% has a maximum criterion of 10%. Sand equivalent was found to be 51% with the criteria of 45% minimum. Strength tests were also carried out, and the results reflect the requirements of the standards. The tests include impact value, aggregate crushing value and aggregate abrasion and the results are 27.5%, 26.7% and 13% respectively with maximum criteria of 30%. Specific gravity test was also carried out and the result was found to have an average value of 2.52 with criteria of 2.6 to 2.9. Water absorption result was 1.41% with maximum criteria of 0.6%. From this study, the results of the tests indicated that the aggregates properties have met the requirements of Superpave design method based on the specifications of ASTMD 5821, ASTM D 4791, AASHTO T176, and AASHTO T33.

Keywords::Superpave, Asphalt Mix, Aggregates, Pavement design

Performance Comparison of Monthly Stream flow Forecast with Auto-Regressive Integrated Moving Average (ARIMA)

O.G. Okeola and S.E. Ayenigba

Abstract: This paper attempts comparing the performance of two statistical models for monthly streamflow forecasting in a small catchment with data from 1972 to 1981. The time series data was modelled with statistical package for Social Sciences (SPSS) and R software packages. The forecasting method adopted in both software was the Auto-Regressive Integrated Moving Average (ARIMA) while the performance criteria are the Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE) and Mean Absolute Error (MAE).  Based on minimum Bayesian Information Criteria (BIC) values and the residual plots, ARIMA(1,0,0)(0,1,1) was identified the best model in both packages. For the model fitting, R performed better than SPSS with RMSE values of 0.385 and 0. 0.455, and MAPE values of 41.46 and 52.06 for R and SPSS respectively. In the forecasting stage, R also performed better than SPSS with RMSE values of 1.044 and 1.051, and MAPE values of 0.816 and 0.848 for R and SPSS respectively. The result will enable researchers have a better insights the selection of tools for streamflow modeling and forecasting.

Keywords:: ARIMA, forecasting, performance,SPSS, streamflow

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Vol. 15, No. 4, 2018

  Wind Induced Loads Effects on the Optimum Location of Shear Wall on High-Rise R.C Building

A. O. Ibrahim and S. A. Raji

Abstract: Some tall buildings that extend into the region of high wind velocity have swayed excessively in strong wind. This and many other problems have emphasised the importance of a clearer understanding of shear wall performance. The number of severe wind induced damage incidents causing loss of life, serious societal impact and threat to national as well as regional security is also increasing. During the last two centuries, major structural failures due to wind action have occurred periodically, and provoked much interest in wind forces by engineers.  As a result of the challenges posed by the wind, earthquake etc. there is needed to investigate the performance of shear wall on multi-storey buildings. Shear wall is a structural element used to resist horizontal forces parallel to the plane of the wall. In this project, study of 8 storeys building (University of Ilorin Senate building) is presented with some investigations to determine the performance of the shear wall. This project employed two phases in achieving the aim and objectives. The first phase considered a bare frame with a frame with shear wall. The second phase considered introduction of shear wall and changing various location of shear wall (i.e internal, centre, edges and combined) for determining parameters like storey overturning moments, storey shear forces and displacements. The static analysis of the frame was done by using standard package MIDAS/Gen. From the study, it was concluded from the analysis result that maximum deflection, forces and overturning moment values for frame with shear wall differs from that of bare frame with 69.7%, 38.23% and 15.18%.  It was also found that the frame with shear wall edges shows better location of shear wall since lateral displacement (0.0022mm), overturning moment (162 kNm) and shear forces (52.4323 kN) are less as compared to other models (centre, internal and combined).

Keywords: Shear wall, multi-storey building, Midas/gen, structural failure, overturning moment, deflection

The Effects of Fire on Bearing Capacity of Reinforced Concrete Slab

A.O. Ibrahim and A. A. Adedeji

Abstract: Fire has become one of the greatest threats to buildings. Concrete is a primary construction material. However, there is a fundamental problem caused by high temperatures that is the separation of concrete masses from the body of the concrete element "Spalling phenomenon". This work presents the behaviour of reinforced concrete slab exposed to fire. Two stages of  analysis  was carried out using Finite  Element  package software SAFE  to  find  thermal  response  of structural  members namely thermal analysis and structural analysis. The distribution of the temperature (due to fire) over the slab at different time interval was determined (using SAFE) in accordance with ISO-834 temperature curve. And this was observed to vary directly with time. In addition, reinforced concrete slabs were modelled using SAFE to show the role of reinforcement, width of slab and temperature condition when expose to fire loading. It was found that temperature decreases along the depth of the slab. Deflection increases with increase in width of slab and decreases when percentage of steel in RCC slab increases.              

Keywords: Reinforced concrete, fire, slabs, modelling, spalling, SAFE, thermal analysis, structural analysis

Assessment of Water Quality Supply and Distribution Networks in Sokoto Metropolis

M. T. Bello

Abstract: Water supply at consumers tap from Sokoto water distribution network is observed to be turbid and in some instances disease was been traced to the water consumed (Tayyib, 2013). Assessment of quality of water supply and water distribution network in Sokoto metropolis was assessed with a view to ascertain the quality of piped water supply system of Sokoto metropolis. Twenty one (21) sample points were carefully selected, including the treatment plant and Two (2) distribution reservoirs from Sokoto township pipe distribution map. Water samples were collected from the selected sources on weekly basis for the period of 3 months. The collected samples were subjected to quality assessments.  Parameters tested include: turbidity, temperature, pH odour, alkalinity, sulphate, chlorine, copper, zinc, manganese, iron & total coli-form.  The results obtained for the tests showed that colour, odour, total alkalinity, sulphate, chlorides, zinc, manganese and copper, generally conformed to the Nigerian Standard for Drinking Water Quality (NSDWQ) and WHO guideline values. Turbidity was in the range of 0.8 to 11NTU and should not exceed 5NTU based on WHO standard, temperature was in the range of 22 to 32oC, temperature of about 10oc is highly desirable, while temperature above 25oc are considered objectionable, pH value was in the range of 5.2 to 8.1, and NSDWQ maximum permissible limits for pH is  6.5-8.5, while total coli-form was in the range of 0 to 60 per 100ml,NSDWQ recommends MPL of 10 cfu/ml. The assessment of Sokoto metropolis water supply quality was effectively accomplished through the parameter analysed.

Keywords: Treatment plant, Distribution Network, Pumping Station, Distribution Reservoir, Water Distribution Network.

Sensitivity Analysis on Multi-Storey Structure Subjected to Tsunami Loading in Lagos

Ojo Theophilus Kayode and A. A. Adedeji

Abstract: This study evaluates the sensitivity of relationship between tsunami disaster and building structure situated along coastal lines. Non-linear analysis was performed on the building structure which is designed to BS 8110. Tsunami forces on structures depend up on the strength, rigidity particularly at lower levels, tsunami wave height and bathymetry. The structure has a fair resistance to a moderate tsunami run up height as the performance point is 0.077m from the pushover curve.

Assessment of Air Quality in Bompai, Challawa and Sharada Industrial Areas in Kano Metropolis, Nigeria

E. V. Nwadiani, K. Mohammed

Abstract: Clean air is an essential requirement to sustain life. The present study assesses the air quality in the three major industrial areas of Kano metropolis,: Bompai, Challawa and Sharada industrial areas, with a view of evaluating some criteria pollutants in the area. Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Carbon Monoxide ( CO), and particulate matter (PM10) were the criteria air pollutants measured. Other relevant parameters monitored includes ambient temperature, wind direction, wind velocity and relative humidity. There are many industries in these surrounding that continuously add smoke and harmful gases into the air that create problems in human health and damage to the natural environment. Direct field air quality measurement was carried out in these areas over a period of three months, using mobile gas censors for the gases and a Haz-Dust 10μm Measuring instrument for the particulate matter. Some of the results obtained especially in the industrial areas of Challawa and Sharada were found to be above the stipulated air quality standard limits by the Nigeria Federal Environmental Protection Agency (FEPA). All the four monitored air pollutants while compared with Air quality index levels (AQI) were in the range of: Poor to moderate and moderate to poor in different locations for CO, very poor to poor for SO2, very poor to poor for NO2, poor to very poor and hazardous in certain locations for PM10 . The overall comparison of data for different exposure periods showed that Challawa at point source had the highest concentration (15 ppm) of CO between the period of 12 to 1pm and SO2 with a concentration of (0.15ppm) from 10 to11am. Sharada had NO2 concentration of 0.16ppm from the hours of 10 to 11am, and 3 to 4pm, PM10 with concentration of 354.2μg/m3 from11am to 12noon. This implies that the quality of air in these areas is poor and can be hazardous to health and may affect the natural beauty of the surrounding. There is considerable air-related pollution in the study areas which may led to possible severe health consequences. It is therefore recommended that tighter industrial emission regulations should be enforced on the polluters.

Keyeords: Air quality, industrial, metropolis, particulate matters, environment

Application of Bone Char in Bioremediation of Crude Oil Polluted Soil: Optimization and Kinetic Analysis

J. Omotosho, O. L.Y. Momoh and C.F Ikebude

Abstract: In this study, the possibility of bone-char derived from cow bones to stimulate and optimize total hydrocarbon biodegradation in soil was investigated. A 32 factorial design was used to design the experimental set up that yielded nine trial runs labelled A-I, each containing crude oil (Bonny light) polluted soils with initial total hydrocarbon content (THC) of 5542mg/kg. The sample labelled A, D and G, served as the controlled un-amended soil samples, while the remaining 6 runs were amended with different range bone-char with particle sizes, (ps) that ranged as follows; (ps) ≤ 0.2 mm; 0.2 < ps ≤ 0.69mm; and 0.69 < ps ≤ 1.18mm at different dosage of bone char. The bio-remediation process lasted for a period of 56 days under laboratory conditions after which, the removal efficiencies of the amended and un-amended soils were observed to range from 74-85% and 44% respectively while, the biodegradation first order rate constants ranged from 0.1797-0.2505wk-1 and 0.0799wk-1 for the amended and un-amended soils respectively. Optimum removal of total hydrocarbon was observed for soil sample comprising 1532.6 g (97%) of polluted soil and 47.4g (3%) of bone-char possessing particle sizes (ps) ≤ 0.2 mm. In general, soil amendment with bone-char is strongly recommended due to its efficient, environmentally friendly and relatively cheap approach in mitigating hydrocarbon contamination of soil.

Keywords: Bone-char, total hydrocarbon content, biodegradation, kinetics.

Estimation of Hydraulic Properties of Aquifer Systems Using Geophysical Methods

K. O. Ibrahim, M. A.Yusuf, O. K. Iheme and O. K. Ali

Abstract: Determining aquifer characteristics is important in the sustainability and management of groundwater resources. Estimating aquifer properties by means of pumping test is financially cost and requires much time, therefore, applying geoelectric method in characterizing aquifer properties is an alternative method and cost effective. Geoelectric method was employed to determine hydraulic characteristics of groundwater aquifer systems in the rural localities of Ilorin, Northcentral Nigeria. Twenty (20) VES data were collected using Schlumberger array with a maximum half current electrode (AB/2) spacing of 100m. Sounding curves were initially interpreted by partial curve matching which gave resistivities of the layers with thicknesses and later inverted by IPI2 WIN software. The characteristics nature of the curves obtained from the VES data shows that the study area consists of three to five geoelectric layers. The results of the interpretation indicates that top soil possess resistivity and thickness ranges between 44.1- 862Ωm and 0 – 2.5m, second layer which is lateritic layer possess resistivity and thickness between 106 - 2001 Ωm and 0.6 – 10.3m, third layer is weathered basement having resistivity and thickness ranges from 22.3 – 166 Ωm and 3.1 – 52.0m while the fourth layer is fractured basement with resistivity and thickness between 78.4 - 138 Ωm and 14.8 – 71.1m and final layer is fresh basement which possess resistivity ranges between 40.1 – 136 Ωm. The hydraulic characteristics of the aquifers in the area determined from geoelectric parameters shows that hydraulic conductivity ranges between 0.16 – 24.8 m/day, transmissivity between 0.5 – 408 m2 / day and porosity was determined in the laboratory from collected field core samples with values ranges between 26 – 41% and these implies that aquifer systems in the area have tendency of transmitting water that good for sustaining water need of he area. This study has proved the usefulness and effectiveness of geoelectric method in characterizing groundwater aquifer systems.

Keywords: Aquifer systems, Geoelectric, Hydraulic conductivity, Transmissivity, Porosity, Rural area.

Hydro-Geophysical Assessment of Groundwater Resources within Parts of Omu Aran, South Western Nigeria

K. O. Iheme, A. O. Usman, R. I. Obaro, C. I. Aganigbo and A. F. Gbadebo

Abstract: Hydro-geophysical assessmeassessmentnt of groundwater resources in part of Omu Aran South Western Nigeria has been evaluated and analyzed with a view of delineating the groundwater potentials and aquifer characteristics within the study area. Eleven-(11) vertical electrical soundings (VES) were acquired with a maximum half current electrode spacing of 75 metres using ABEM 3000 SAS Tetrameter and the sounding data were processed and interpreted using partial curve matching method by the computer iteration techniques. Results from the geo-electric sections revealed the presence of three to five geo-electric layers. The depth to water table ranges between 2.59m and 71.9m and a resistivity of 89.9 to 3072 Ωm. The depth to Watertable is deepest around Omu area with depth of 71.9m. The result of the geophysical analysis correlates positively with themselves showing similarity in geology. The result shows that the weathered basement is a primary target for ground water exploration in the studied area, as the area is void of prominent fracture which is a target for ground water exploration. It is recommended that an average depth of 7.0m should be drilled for borehole within the northern part of the studied area and a depth of about 10.0m in the southern part of the study area. All these deductions were reached after qualitative and quantitative interpretation of the geophysical data, and considering geology of the area

Keywords: Groundwater potential, Geoelectric section, Aquifer characterization, resistivity pseudo-section and Correlation

Correlation Between CBR, Compaction Properties and Compaction Delay on the Cement Kiln Dust Stabilized Lateritic Soil

M. H. Idris and A. A. Khalid

Abstract: This research is to investigate the Correlation between CBR, Compaction properties and Compaction delay on the Cement Kiln Dust (CKD) stabilized Lateritic Soil. The tests carried out on the CKD Stabilized lateritic soils were the Compaction test and California Bearing Ratio (CBR) test. Statistical analysis on the effects of compaction delays on properties of CKD stabilized lateritic soil was conducted using analysis of variance and multiple regression analysis using statistical package for social sciences (SPSS). The data was taken from Compaction tests and soaked CBR tests results on Soil-CKD mixtures at different time interval. The good R-square value of 96.5% indicated that these correlations were reasonable. The results also indicate that there is a good correlation between the CBR, Compaction properties and the Compaction delay. By using this correlation, the soaked CBR of a particular lateritic soil- CKD mixture of different compaction delay with various CKD content can be predicted.

Keywords: nCalifornia Bearing Ratio (CBR), Compaction Delay, Regression and Correlation Analysis, Cement Kiln Dust (CKD)

Volume. 13(3), 2016

Vol. 16, No. 2, 2019 

Volume. 13. A. Adedeji

Abstract: Increase in the deposition oofoofff waste tyre in the landfill has posed a serious problem to the ecosystem all over the world (IbroSkenderovic, 2015). Research from literature reviewed had shown that inclusion or partial replacement of waste tyre fibre for aggregates in concrete will reducing the percentage of waste tyre deposited at landfill. However, this research focused on the use of waste tyre fibre as partial replacement for coarse aggregate at different percentages (0%, 2.5%, 5%, 7.5% and 10%) to assess the mechanical properties of the concrete (M25). The compressive and Split tensile strengths’ results obtained are as follows(0%-22.2N/mm2;3.51N/mm2,2.5%20.1N/mm2:2.29N/mm2;5%17.6N/mm2;2.00N/mm27.5%-13.2N/mm2; 1.84N/mm2, and 10%-9.3N/mm2;1.42N/mm2). The concrete strengths reduced respectively with increase in the tyre fibre content.

Keywords::Tyre Fibre, Concrete, Mechanical, Coarse aggregate, Compressive, Tensile, Strength, conductivity, Density

Assessing the Effect of Some Physical Properties on the Bending Strength of Nigerian-Grown African Birch (Anogeissus leiocarpus) Timber

U. N. Wilson, J. O. Afolayan,, J. E. Sani and J. A. Alomaja

Abstract: The study investigates the effect or contribution of some identified physical properties such as moisture content, specific gravity, and density alongside other parameters like the Young’s modulus and force at failure to the static bending strength parallel to grain of the Nigerian-grown African birch. Nigerian-grown African birch (Anogeissus leiocarpus) timber were seasoned and sawn into small clear test specimens in accordance with BS 373 of 1957. These were tested in the laboratory to determine the static bending strength. It was observed from the R2 (correlation coefficient) values gotten from the plots of the static bending strength against each parameter considered that, the force at failure has the highest effect on the bending strength. This is followed by its Young’s modulus, moisture content, specific gravity and density in that order. A mathematical model which represents the predicted static bending strength was formulated from the statistical analysis which will enable the theoretical computation of the static bending strength of the Nigerian-grown African birch (Anogeissus leiocarpus). Considering the error margin and the R2 value between the theoretical and experimental results obtained from the laboratory, these provide an evidential basis for the veracity of the mathematical model.

Keywords: African birch, physical properties, static bending strength, mathematical model, regression analysis.

Characterization of Solid Waste Generated on the University of Ilorin Campus and Recycling of the Paper Content.

S. O. Bilewu and O.V. Oluwaseun

Abstract: This work presents the characterization of solid waste generated on the university of Ilorin main campus and recycling of the paper content with faculty of Engineering and Technology buildings as a case study. A total of 91.7kg of waste was sampled and characterized and it was concluded that various types of waste generated are: Cardboard/carton, Nylon, PET bottles, Paper, Wood, Food waste, Aluminum can, Yard waste, Glass bottle, Packaging wraps, Computer hardware, Metal scraps, Laboratory waste such as hardened soil samples, bamboo stalks, Lead acid accumulator, and ink cartridge. The most prominent ones among these waste components was found to be the Miscellaneous with a percentage component of 29.85. Miscellaneous comprises of photocopier parts, broken crates, ink cartridge and laboratory wastes. Cardboard/carton seconded with a total percentage of 20.55% while Wood was the third largest with a percentage of 12.88%. Others include: Food waste, 6.58%; PET bottles,5.68%; glass bottles, 5.92%; yard waste, 4.26% aluminum cans,3.11%; nylon,2.0%; paper, 2.88%; yard waste, 2.28%. packaging wraps with a percentage composition of 1.11% was the least. Finally, some of the waste paper were recovered and recycled.

Keywords: Solid waste, characterization, recycling. paper, cardboard, metal scraps.

Characterization of Belle Natural Moulding Sand for Foundry Applications

Y. L. Shuaib-Babata, M. B. Nafiu, K. S. Ajao, I. O. Ambali, Z. U. Elakhame, Y. O. Busari, H. K. Ibrahim and N. I. Aremu

Abstract: There exists vast availability of natural sands which may be suitable for foundry applications in different locations Kwara State in particular and generally in Nigeria. The sands need to be identified and characterised for productive and profitable foundry practices. In this study, assessment of chemical and physico-mechanical properties of the natural moulding sand in Belle community of Kwara State, Nigeria was carried out to ascertain its suitability for foundry applications. The analysis of the sand samples’ Chemical compositions were done using an XRF Analyser, while American foundry-men Society, ASTM and British standards laboratory tests procedures were adopted appropriately to determine the sand’s physico-mechanical properties. The results of chemical composition analysis showed that SiO2 have dominance proportion in the sand sample with an average value of 92.90 %, followed by Al2O3 (5.13%). CaO, Fe2O3, MgO, K2O, Na2O, ZnO and MnO were present within acceptable limits as trace elements. The results showed average physico-mechanical properties of the natural moulding sand sample to include grain fineness number (126), bulk density (1765 Kg/m3), moisture contents (7.66%), specific gravity (2.64), permeability (0.1cm/s), green compressive strength (51KN/m2), dry compressive strength (209KN/m2), flowability (65.22%), clay content (10%) shatter index (76%) and refractoriness (>900oC), which were within the required standards for casting of non-ferrous metal. Thus, Belle sand was found suitable for casting of non-ferrous metals. Though, there may be a need for the use of additives like bentonite, to enhance the sand’s clay content in order to increase the sand potential for foundry applications.

Keywords: Characterisation, natural moulding sand, non-ferrous metals, sand casting.

 Evaluation of Predictive Capability of Artificial Neural Network and Multiple Linear Regression: A Case Study of Lipid Extraction from Microalgae using Quaternary Solvents

S. I. Mustapha, F. A. Aderibigbe and I. A. Mohammed

Abstract: Thiresent study was carried out to evaluate the performance of artificial neural network (ANN) and multiple linear regression (MLR) as modelling tools for predicting the lipid yield obtained from microalgae using quaternary solvent mixtures. The MLR models were developed using two different mathematical softwares viz. Microsoft excel (model 1) and Polymath (model 2). The augmented simplex lattice design under the mixture methodology of the Design Expert software was used to generate the design of experiments used in this study. A comparison of the models developed using ANN and MLR for the extraction process was carried out based on pertinent statistical parameters. Although the results from both MLR models were very close, the calculated values of coefficient of determination (R2) of 0.9934 and the average absolute deviation (AAD) of 2.4789 for the ANN model when compared with values obtained from the MLR (R2 = 0.9898 and AAD = 2.9821 for model 1) and (R2 = 0.9898 and AAD = 2.9825 for model 2) showed that the ANN model was more accurate and precise than the MLR models. The actual maximum lipid yield of 19.4 wt% lipid g-1 DCW was obtained at solvent mixture in the volume ratio of 1:5:1:1 for chloroform, methanol, ethanol, and dichloromethane respectively.

Keywords:: Artificial neural network, multiple linear regression, lipid extraction, modelling

 Influence of Residential Environment on Cooking Behaviour of Students on the University of Ilorin, Nigeria.

Joy Kikelomo Adelabu and Amole Dolapo

Abstract: This study assessed the effect of student residence hall design on cooking behaviour of undergraduate students residing on campus residence halls in the University of Ilorin, Nigeria. It compared the cooking behaviour of students in different residence hall types with respect to kitchen design (i.e. the suite type, the shared kitchen, the kitchen per floor and the no kitchen residence halls). It also identified differences in the cooking behaviour of males and females in the residence halls. A survey was conducted and 430 questionnaires were administered to elicit information from students in the residence halls on their socio-economic characteristics and cooking behaviour. Cooking brhaviour was conceptualized as cooking preference, cooking frequency, cooking location and perception of cooking convenience in the residence halls. 416 questionnaires were retrieved (representing 97% response rate) and used for the analysis. Information on the residence hall design and availability of kitchen, washing sinks, and worktops in the residence halls was collected through the use of the observation schedule which was prepared and filled objectively by the researcher. Data was analyzed using descriptive and inferential statistics. The results revealed that gender and residence hall type significantly influenced the cooking behaviour of students. The paper concludes that architects and managers of students’ residences need to pay attention to the provision of cooking spaces in female residence halls than in male residence halls. Also, cooking spaces should be located within or close to students’ rooms to encourage use.g behaviour, Residence halls, Kitchen design, Student housing, Dietary habits, On campus housing. 

 Vol. 16, No. 1, 2019

 Low Carbon Infrastructure Concrete Binders for Sustainable Development in Nigeria: A Review.

Joseph O. Ukpata, Okiemute R. Ogirigbo, Desmond E.In In Ewa and Odo J. Ukpata

Abstract: Concrete constitutes the most applied infrastructure material in Nigeria for both urban and rural development. However, the production of conventional Portland cement binders in concrete contributes about 7% of the world’s anthropogenic carbon dioxide emissions. Therefore, this study presents a state-of-the-art review on the use of low-carbon supplementary cementitious materials (SCMs), as an approach to ensure durability and sustainability of concrete infrastructures. SCMs are known to reduce cost, energy and carbon footprints associated with Portland cement production as well as, ensure durability of concretes in aggressive environments by refining the concrete microstructure, when applied appropriately. Hence, the use of binary and ternary blends of SCMs with Portland cement has continued to receive global attention and Nigeria cannot be left out, particularly, given favourable climatic temperatures for SCMs’ accelerated hydration and microstructural development. The common SCMs are critically reviewed with suggestions for potential application of available SCMs, in order to enhance sustainable infrastructural development in Nigeria.

Keywords:Supplementary cementitious materials, sustainability, durability, infrastructure

Strength and Workability Characterization of Quarry Dust as a Replacement for Sand in Concrete Production

T. C. Okeke, T. O. Onuorah and D. Olojo- Kosoko

Abstract:Uncontrolled extraction of natural sand especially in regions with limited number of streams has lead to researches on suitable alternatives considering the environmental challenges posed. This study features an experimental study on the replacement of sand with quarry dust and its influence on the properties of fresh and hardened concrete. In this study two different experiments were conducted using: unwashed in-situ aggregates for Experiment 1, and washed aggregate for Experiment 2. Samples used for Experiment 2 were sieved and washed to reduce the finess characteristic of the quarry sample. Sand was replaced with quarry dust at varying percentage (0%, 25%, 50%, 75% and 100%) for both samples. Compressive strength and workability test for a concrete grade 20 with a mix ratio of 1:2:4 was conducted. Value form the workability test shows a decrease in slump value as higher percentage of sand is replaced with quarry dust. For the compressive test, the control experiment shows better appreciation in strength for the washed sample. At 25 and 50% replacement, concrete cubes produced from Experiment 2 indicate better strength gained compared to concrete cube produced from sample (1), and even show better appreciation in strength even after 28 days.

Keywords: Quarry Dust, Aggregates, Sharp Sand, Workability, Crushing Strength

The Effect of Improper Curing on the Strength and Transport Properties of High and Low Strength Concrete in Tropical Environments

O. R. Ogirigbo and J. Ogbeide

Abstract: Curing plays a vital role on strength development and durability of concrete. It begins after concrete placing and finishing, and involves maintaining required moisture and temperature conditions, for sufficient periods of time. Failure to cure concrete properly may result in development of cracks and ultimately in the failure of the structure, especially in high temperature environments. The aim of this study was to look at the impact of improper curing on the strength development and transport properties of a high and low strength concrete in a tropical environment. Three different curing methods were used in the study. The first involved curing of the concrete samples continuously under water, while the second method involved curing of the concrete samples under ambient air. The third method, which was a combination of the first two methods, involved curing the concrete samples under water for an initial period of 3 days followed by curing under air. The first curing method was taken as the ideal or proper curing method and was used as a means of comparison for the other two curing methods. Various tests such as compressive strength, water absorption and depth of chloride penetration, were carried out on concrete samples cured using the three different curing methods. The results obtained showed that improper curing had adverse effects on the strength development and transport properties of the concrete. However, the effect was seen to be more pronounced on the low strength concrete than the high strength concrete. This was attributed to the higher water content of the low strength concrete. Of the three curing methods studied, concrete samples cured under ambient air had the least performance, while those cured continuously under water had the best performance in terms of strength and resistance to the penetration of water and chloride ions.

Keywords: Improper curing, high strength concrete, low strength concrete, tropical environment

A Review of Fish Scales as a Source of Biosorbent for the Removal of Pollutants from Industrial Effluents

A. A. Omodele Eletta and Joshua O. Ighalo

Abstract: Biosorbents prepared from fish scales has been used to treat wastewaters containing heavy metals, dyes and pharmaceuticals. These pollutants have been reported in effluents from pharmaceutical, textile, automotive battery and tannery industries amongst others. Biosorption is a cheaper and more environmentally friendly alternative to other treatment technologies including the use very popular activated carbon adsorption. The aim of this review is to catalogue the progress made over the past 15 years in the utilisation of fish scales as biosorbents for the treatment of industrial effluents. Key domains are in source fish species, biosorbent preparation technique, target impurities, optimal levels of biosorption factors, equilibrium and kinetic best-fits and thermodynamic findings. The biosorbents are generally prepared by a two-stage chemical pre-treatment process. It is then dried, pulverised and sieved and in some cases calcined. Fish scale biosorbents have been found to have very good adsorption capacity for heavy metals, dyes and pharmaceutical compounds and with excellent removal efficiencies (50-100% for heavy metals and 78-90% for dyes). Optimal biosorption parameters vary significantly for the different target impurities and is only consistent for pH (acidic) and temperature (30-500C). Fish scale biosorption equilibrium is always best fit to Langmuir or Freundlich isotherms with newer models having poorer coefficients of determination. Fish scale biosorption kinetics is best fit to the pseudo-second order model. The review also revealed that fish scale biosorption is generally spontaneous and endothermic (for heavy metals alone).

Keywords: Waste management, biosorption, fish scale, heavy metals, dyes, pharmaceuticals

Reliability Assessment of Ejigbo Campus Library Building of Osun State University, Osogbo

S. O. A. Olawale, M. A. Tijani, O. I. Folayan and E. O. Bolaji

Abstract: The spate of recent collapse of structures in the country has increased enormously and it could be linked to factors such as low quality of workmanship, design defects and a few other issues. One of such looming disaster is the university library in Ejigbo campus at Osun State University. The library building is in a despicable condition and is no longer safe for human occupation. A physical structural assessment was carried out and the stress distribution in the structural members was found to be below the design strength in excess of 10%. A reliability structural analysis shows clearly that a safe reliability index of the building is dangerously low. The results of the java program developed clearly indicated that about 2.2% of steel ratio is required but about 1.5% was provided in the design of building structural elements.

Keywords: Reliability index, directional cosine, vector space, AFOSM: Advanced First Order second Moment, CPD: Cumulative Probability Density, ULS: Ultimate Limit State

Relationship between Workspace Utilization (WSU) and Indoor Environmental Quality (IEQ) in Offices of University Lecturers

I. A. Jimoh and B. Suleiman.

Abstract: Academic productivity and functional comfort of university lecturers have been subjects of concern to stakeholders in the Nigerian education sector. This study investigates the relationship between Workspace Utilisation (WSU) and Indoor Environmental Quality (IEQ) in offices of lecturers in three Federal universities. Objectives include determination of the extent to which lecturers use workspaces, the quality of indoor environment for assigned academic duties and the level of satisfaction felt by the lecturers. 360 questionnaires were administered, through purposive sampling, to obtain perception of lecturers on WSU, IEQ and satisfaction with workspace. 169(47%) valid returned questionnaires were analyzed using Means, ANOVA and Spearman correlation. Overall intensity of WSU by the university lecturers was 37.81% .There was no significant difference between intensities of WSU amongst the three universities. Out of the 13 uses, WSU on formal Reading (42.13%), formal Writing, (40.94%) and Internet surfing (40.19%) ranked 1st, 2nd and 3rd respectively. Building integrity (5.83%), Control facilities (5.47%) and Size of workspace were the 3 top ranking IEQ parameters. Weak positive correlations (0.1567, 0.1729, 0.1816, 0.1909 & 0.2534) were deduced on 6 out of the 91 relationships, between WSU and IEQ, investigated. Overall WSU of 37.81% compares favourably with fairly good use category of the Space Management Group. Higher intensity could however be achieved through improved IEQ in workspaces. Retrofitting by Works and Maintenance unit of each university is recommended on contextual IEQ variables in order to raise level of comfort, intensity of WSU and academic productivity.

Keywords: Indoor Environmental Quality; Lecturers; Office; University; Workspace utilisation.

 Performance Indices of Heated Tyre-Fibre Concrete Due to Spalling Mitigation

A. O. Ibrahim and A. A. Adedeji

Abstract: Due to waste tyre beneficial properties like high shear strength, low thermal conductivity and low density (Safriat, 2014). Research from literature reviewed had shown that inclusion or partial replacement of waste tyre fibre for aggregates in concrete will enhance fire resistance and mitigate spalling action. However, this research focused on the use of waste tyre fibre as partial replacement for coarse aggregate to mitigate spalling action in concrete under elevated temperature. The thermal analysis was carried out on Concrete cubes (0%, 2.5%, 5%, 7.5% and 10% replacement) for spalling test in accordance with (EN 1363-1, 2002 and ISO 834) using Furnace (Carbolite, 1300oC). It was found that the temperature increases, cracking depth (about 71.4% higher than the tyre fibre concrete) and loss in weight (about 50.1% less to plain concrete) decreases, with increase in percentage of tyre fibre added.

Keywords: Tyre fibre, plain concrete, fire, coarse aggregate, temperature, spalling, shear strength, thermal analysis, cracking depth

Assessment of the Suitability of Wudil Soil for Rammed Earth Structures

A.Y. Abdulfatah, M.U. Zango, H.H. Ahmad and K.R. Usman

Abstract: Earthen construction such as adobe, rammed earth and compressed earth block has been a historical construction technique and still remains a world-widely construction technique. One of the main problems in earth construction technique is the selection of suitable raw materials for the construction. This study is aimed to determine the engineering properties of a collection of soil samples from Wudil in Nigeria with the aim of examining their suitability for rammed earth construction. Samples were collected from five different locations within the locality of Wudil. Sampling and the conduct of all experiments were carried out using the same compactive effort, in order to ascertain their performance and conformity to the specifications for rammed earth structures. The geotechnical properties studied were particle size distribution, natural moisture content, Atterberg limits, maximum dry density, optimum moisture content, abrasion resistance and unconfined compressive strength. The compressive strength values for the samples obtained over a wide range of dry densities and moisture contents revealed that the soil samples with little modification will be suitable materials for rammed earth construction. The soil sample collected from Indabo Area was found to be the best for being closer to the specifications with an unconfined compressive strength value of 103 kPa, abrasion resistance of 3.13 cm2/g and drying shrinkage of 0.8%.

Keywords: Soil properties, rammed earth, compressive strength, sustainable housing, green house

Evaluation of Groundwater Exploration Methods Used in Benin City

A. Rawlings and J. E. Matthew

Abstract: In this study, data concerning groundwater exploration methods in Benin City were collected via Questionnaire Survey Method and analysed using SPSS (Statistical Package for the Social Sciences) statistical software. About thirty Questionnaires were administered to professionals dealing on groundwater drilling in four Local Government Areas (Ikpoba Okha, Oredo, Ovia North East and Egor Local government areas) in Benin City. These questionnaires were designed to extract data on the demographic features of professionals dealing on groundwater drilling in Benin City. Twenty- two (22) copies were completed and returned, while seven (8) copies were not returned. Hence, Twenty- two (22) Questionnaires were analysed. Results showed that the groundwater exploration methods used by professionals in the field include Test drilling, Aerial, Esoteric, Surface and Sub-surface methods with usage of about 14%, 9%, 14%, 41% and 23% respectively. Results further revealed that Surface method is simple, cost effective, reliable in estimating aquifer thickness and locating the best place to drill in Benin City. Hence, is the most predominantly used method of groundwater exploration in Benin City. It was recommended that places with similar geology as that of Benin City should adopt this method of groundwater exploration as it might help augment the groundwater supply in such places.

Keywords: Groundwater, exploration, methods, soil, bstraction, borehole, Benin City

Geotechnical Evaluation of Lateritic Sil in Baba-Ode Area, Ilorin, North – Central Nigeria

R. I. Obaro, O. A. Odediran, K. O. Iheme, O. C. Akakuru, O. C. and A. F. Gbadebo

Abstract: This study was carried out on lateritic soil at Baba-ode,North-central Nigeria with aim of denoting the geotechnical properties of lateritic soil and its suitability as construction materials. Two disturbed lateritic soil samples (sample A and B) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt – clayey sand while sample B is silt – clayey gravel composition. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit while sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. The samples contain inactive clay indicating little or no swelling tendency and therefore good for construction materials and this would prevent foundation failures. The California Bearing Ratio (CBR) values are 2 – 3% (mean = 2.75%) and 2 - 4% (mean = 2.75%) in sample A and sample B respectively. This implies they are good as subgrade construction materials. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor for sample B is 15.2% and 14.0% respectively. The compaction tests for Sample A indicate a higher fine fraction and thus a higher optimum moisture content while sample B has higher coarse fraction with lower optimum moisture content. The cohesion falls within 70-90Kpa (mean = 80Kpa) and the internal friction ranges from 250 - 310 with mean of 290. The results obtained from geotechnical analysis suggest that the soil have high bearing capacity, hence, it can be used as construction materials in engineering works. The soil could also support shallow foundation, dam construction, embankments, slope stability and subgrade materials in road constructions.

Keywords:Lateritic soil, compaction, California bearing ratio, Nigeria

Investigation in to the Suitability of Aggregates for Use in Superpave Design Method

A. Idris, A.S. Labo, A.Y. Abdulfatah and M. Umar

Abstract: Superpave is the short form of Superior Performing Asphalt Pavement and represents a basis for specifying component materials, asphalt mixture design and analysis, and pavement performance prediction. This new technology is the result of long research projects conducted by the Strategic Highway Research Program (SHRP) of the Federal Highway Administration of the United States. The current research is aimed at examining the suitability of Aggregates located in Kano, Nigeria for used in superpave design method. Aggregates samples were collected from different sources in Kano and their engineering properties, as they relate to the superpave design requirements were determined. The average results of Coarse Aggregate Angularity in Kano were found to be 87% and 86% of one fractured face and two or more fractured faces respectively with a standard of 80% and 85% respectively. Fine Aggregate Angularity average result was found to be 47% with a requirement of 45% minimum. A flat and elongated particle which was found to be 10% has a maximum criterion of 10%. Sand equivalent was found to be 51% with the criteria of 45% minimum. Strength tests were also carried out, and the results reflect the requirements of the standards. The tests include impact value, aggregate crushing value and aggregate abrasion and the results are 27.5%, 26.7% and 13% respectively with maximum criteria of 30%. Specific gravity test was also carried out and the result was found to have an average value of 2.52 with criteria of 2.6 to 2.9. Water absorption result was 1.41% with maximum criteria of 0.6%. From this study, the results of the tests indicated that the aggregates properties have met the requirements of Superpave design method based on the specifications of ASTMD 5821, ASTM D 4791, AASHTO T176, and AASHTO T33.

Keywords::Superpave, Asphalt Mix, Aggregates, Pavement design

Performance Comparison of Monthly Stream flow Forecast with Auto-Regressive Integrated Moving Average (ARIMA)

O.G. Okeola and S.E. Ayenigba

Abstract: This paper attempts comparing the performance of two statistical models for monthly streamflow forecasting in a small catchment with data from 1972 to 1981. The time series data was modelled with statistical package for Social Sciences (SPSS) and R software packages. The forecasting method adopted in both software was the Auto-Regressive Integrated Moving Average (ARIMA) while the performance criteria are the Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE) and Mean Absolute Error (MAE).  Based on minimum Bayesian Information Criteria (BIC) values and the residual plots, ARIMA(1,0,0)(0,1,1) was identified the best model in both packages. For the model fitting, R performed better than SPSS with RMSE values of 0.385 and 0. 0.455, and MAPE values of 41.46 and 52.06 for R and SPSS respectively. In the forecasting stage, R also performed better than SPSS with RMSE values of 1.044 and 1.051, and MAPE values of 0.816 and 0.848 for R and SPSS respectively. The result will enable researchers have a better insights the selection of tools for streamflow modeling and forecasting.

Keywords:: ARIMA, forecasting, performance,SPSS, streamflow

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Vol. 15, No. 4, 2018

  Wind Induced Loads Effects on the Optimum Location of Shear Wall on High-Rise R.C Building

A. O. Ibrahim and S. A. Raji

Abstract: Some tall buildings that extend into the region of high wind velocity have swayed excessively in strong wind. This and many other problems have emphasised the importance of a clearer understanding of shear wall performance. The number of severe wind induced damage incidents causing loss of life, serious societal impact and threat to national as well as regional security is also increasing. During the last two centuries, major structural failures due to wind action have occurred periodically, and provoked much interest in wind forces by engineers.  As a result of the challenges posed by the wind, earthquake etc. there is needed to investigate the performance of shear wall on multi-storey buildings. Shear wall is a structural element used to resist horizontal forces parallel to the plane of the wall. In this project, study of 8 storeys building (University of Ilorin Senate building) is presented with some investigations to determine the performance of the shear wall. This project employed two phases in achieving the aim and objectives. The first phase considered a bare frame with a frame with shear wall. The second phase considered introduction of shear wall and changing various location of shear wall (i.e internal, centre, edges and combined) for determining parameters like storey overturning moments, storey shear forces and displacements. The static analysis of the frame was done by using standard package MIDAS/Gen. From the study, it was concluded from the analysis result that maximum deflection, forces and overturning moment values for frame with shear wall differs from that of bare frame with 69.7%, 38.23% and 15.18%.  It was also found that the frame with shear wall edges shows better location of shear wall since lateral displacement (0.0022mm), overturning moment (162 kNm) and shear forces (52.4323 kN) are less as compared to other models (centre, internal and combined).

Keywords: Shear wall, multi-storey building, Midas/gen, structural failure, overturning moment, deflection

The Effects of Fire on Bearing Capacity of Reinforced Concrete Slab

A.O. Ibrahim and A. A. Adedeji

Abstract: Fire has become one of the greatest threats to buildings. Concrete is a primary construction material. However, there is a fundamental problem caused by high temperatures that is the separation of concrete masses from the body of the concrete element "Spalling phenomenon". This work presents the behaviour of reinforced concrete slab exposed to fire. Two stages of  analysis  was carried out using Finite  Element  package software SAFE  to  find  thermal  response  of structural  members namely thermal analysis and structural analysis. The distribution of the temperature (due to fire) over the slab at different time interval was determined (using SAFE) in accordance with ISO-834 temperature curve. And this was observed to vary directly with time. In addition, reinforced concrete slabs were modelled using SAFE to show the role of reinforcement, width of slab and temperature condition when expose to fire loading. It was found that temperature decreases along the depth of the slab. Deflection increases with increase in width of slab and decreases when percentage of steel in RCC slab increases.              

Keywords: Reinforced concrete, fire, slabs, modelling, spalling, SAFE, thermal analysis, structural analysis

Assessment of Water Quality Supply and Distribution Networks in Sokoto Metropolis

M. T. Bello

Abstract: Water supply at consumers tap from Sokoto water distribution network is observed to be turbid and in some instances disease was been traced to the water consumed (Tayyib, 2013). Assessment of quality of water supply and water distribution network in Sokoto metropolis was assessed with a view to ascertain the quality of piped water supply system of Sokoto metropolis. Twenty one (21) sample points were carefully selected, including the treatment plant and Two (2) distribution reservoirs from Sokoto township pipe distribution map. Water samples were collected from the selected sources on weekly basis for the period of 3 months. The collected samples were subjected to quality assessments.  Parameters tested include: turbidity, temperature, pH odour, alkalinity, sulphate, chlorine, copper, zinc, manganese, iron & total coli-form.  The results obtained for the tests showed that colour, odour, total alkalinity, sulphate, chlorides, zinc, manganese and copper, generally conformed to the Nigerian Standard for Drinking Water Quality (NSDWQ) and WHO guideline values. Turbidity was in the range of 0.8 to 11NTU and should not exceed 5NTU based on WHO standard, temperature was in the range of 22 to 32oC, temperature of about 10oc is highly desirable, while temperature above 25oc are considered objectionable, pH value was in the range of 5.2 to 8.1, and NSDWQ maximum permissible limits for pH is  6.5-8.5, while total coli-form was in the range of 0 to 60 per 100ml,NSDWQ recommends MPL of 10 cfu/ml. The assessment of Sokoto metropolis water supply quality was effectively accomplished through the parameter analysed.

Keywords: Treatment plant, Distribution Network, Pumping Station, Distribution Reservoir, Water Distribution Network.

Sensitivity Analysis on Multi-Storey Structure Subjected to Tsunami Loading in Lagos

Ojo Theophilus Kayode and A. A. Adedeji

Abstract: This study evaluates the sensitivity of relationship between tsunami disaster and building structure situated along coastal lines. Non-linear analysis was performed on the building structure which is designed to BS 8110. Tsunami forces on structures depend up on the strength, rigidity particularly at lower levels, tsunami wave height and bathymetry. The structure has a fair resistance to a moderate tsunami run up height as the performance point is 0.077m from the pushover curve.

Assessment of Air Quality in Bompai, Challawa and Sharada Industrial Areas in Kano Metropolis, Nigeria

E. V. Nwadiani, K. Mohammed

Abstract: Clean air is an essential requirement to sustain life. The present study assesses the air quality in the three major industrial areas of Kano metropolis,: Bompai, Challawa and Sharada industrial areas, with a view of evaluating some criteria pollutants in the area. Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Carbon Monoxide ( CO), and particulate matter (PM10) were the criteria air pollutants measured. Other relevant parameters monitored includes ambient temperature, wind direction, wind velocity and relative humidity. There are many industries in these surrounding that continuously add smoke and harmful gases into the air that create problems in human health and damage to the natural environment. Direct field air quality measurement was carried out in these areas over a period of three months, using mobile gas censors for the gases and a Haz-Dust 10μm Measuring instrument for the particulate matter. Some of the results obtained especially in the industrial areas of Challawa and Sharada were found to be above the stipulated air quality standard limits by the Nigeria Federal Environmental Protection Agency (FEPA). All the four monitored air pollutants while compared with Air quality index levels (AQI) were in the range of: Poor to moderate and moderate to poor in different locations for CO, very poor to poor for SO2, very poor to poor for NO2, poor to very poor and hazardous in certain locations for PM10 . The overall comparison of data for different exposure periods showed that Challawa at point source had the highest concentration (15 ppm) of CO between the period of 12 to 1pm and SO2 with a concentration of (0.15ppm) from 10 to11am. Sharada had NO2 concentration of 0.16ppm from the hours of 10 to 11am, and 3 to 4pm, PM10 with concentration of 354.2μg/m3 from11am to 12noon. This implies that the quality of air in these areas is poor and can be hazardous to health and may affect the natural beauty of the surrounding. There is considerable air-related pollution in the study areas which may led to possible severe health consequences. It is therefore recommended that tighter industrial emission regulations should be enforced on the polluters.

Keyeords: Air quality, industrial, metropolis, particulate matters, environment

Application of Bone Char in Bioremediation of Crude Oil Polluted Soil: Optimization and Kinetic Analysis

J. Omotosho, O. L.Y. Momoh and C.F Ikebude

Abstract: In this study, the possibility of bone-char derived from cow bones to stimulate and optimize total hydrocarbon biodegradation in soil was investigated. A 32 factorial design was used to design the experimental set up that yielded nine trial runs labelled A-I, each containing crude oil (Bonny light) polluted soils with initial total hydrocarbon content (THC) of 5542mg/kg. The sample labelled A, D and G, served as the controlled un-amended soil samples, while the remaining 6 runs were amended with different range bone-char with particle sizes, (ps) that ranged as follows; (ps) ≤ 0.2 mm; 0.2 < ps ≤ 0.69mm; and 0.69 < ps ≤ 1.18mm at different dosage of bone char. The bio-remediation process lasted for a period of 56 days under laboratory conditions after which, the removal efficiencies of the amended and un-amended soils were observed to range from 74-85% and 44% respectively while, the biodegradation first order rate constants ranged from 0.1797-0.2505wk-1 and 0.0799wk-1 for the amended and un-amended soils respectively. Optimum removal of total hydrocarbon was observed for soil sample comprising 1532.6 g (97%) of polluted soil and 47.4g (3%) of bone-char possessing particle sizes (ps) ≤ 0.2 mm. In general, soil amendment with bone-char is strongly recommended due to its efficient, environmentally friendly and relatively cheap approach in mitigating hydrocarbon contamination of soil.

Keywords: Bone-char, total hydrocarbon content, biodegradation, kinetics.

Estimation of Hydraulic Properties of Aquifer Systems Using Geophysical Methods

K. O. Ibrahim, M. A.Yusuf, O. K. Iheme and O. K. Ali

Abstract: Determining aquifer characteristics is important in the sustainability and management of groundwater resources. Estimating aquifer properties by means of pumping test is financially cost and requires much time, therefore, applying geoelectric method in characterizing aquifer properties is an alternative method and cost effective. Geoelectric method was employed to determine hydraulic characteristics of groundwater aquifer systems in the rural localities of Ilorin, Northcentral Nigeria. Twenty (20) VES data were collected using Schlumberger array with a maximum half current electrode (AB/2) spacing of 100m. Sounding curves were initially interpreted by partial curve matching which gave resistivities of the layers with thicknesses and later inverted by IPI2 WIN software. The characteristics nature of the curves obtained from the VES data shows that the study area consists of three to five geoelectric layers. The results of the interpretation indicates that top soil possess resistivity and thickness ranges between 44.1- 862Ωm and 0 – 2.5m, second layer which is lateritic layer possess resistivity and thickness between 106 - 2001 Ωm and 0.6 – 10.3m, third layer is weathered basement having resistivity and thickness ranges from 22.3 – 166 Ωm and 3.1 – 52.0m while the fourth layer is fractured basement with resistivity and thickness between 78.4 - 138 Ωm and 14.8 – 71.1m and final layer is fresh basement which possess resistivity ranges between 40.1 – 136 Ωm. The hydraulic characteristics of the aquifers in the area determined from geoelectric parameters shows that hydraulic conductivity ranges between 0.16 – 24.8 m/day, transmissivity between 0.5 – 408 m2 / day and porosity was determined in the laboratory from collected field core samples with values ranges between 26 – 41% and these implies that aquifer systems in the area have tendency of transmitting water that good for sustaining water need of he area. This study has proved the usefulness and effectiveness of geoelectric method in characterizing groundwater aquifer systems.

Keywords: Aquifer systems, Geoelectric, Hydraulic conductivity, Transmissivity, Porosity, Rural area.

Hydro-Geophysical Assessment of Groundwater Resources within Parts of Omu Aran, South Western Nigeria

K. O. Iheme, A. O. Usman, R. I. Obaro, C. I. Aganigbo and A. F. Gbadebo

Abstract: Hydro-geophysical assessment of groundwater resources in part of Omu Aran South Western Nigeria has been evaluated and analyzed with a view of delineating the groundwater potentials and aquifer characteristics within the study area. Eleven-(11) vertical electrical soundings (VES) were acquired with a maximum half current electrode spacing of 75 metres using ABEM 3000 SAS Tetrameter and the sounding data were processed and interpreted using partial curve matching method by the computer iteration techniques. Results from the geo-electric sections revealed the presence of three to five geo-electric layers. The depth to water table ranges between 2.59m and 71.9m and a resistivity of 89.9 to 3072 Ωm. The depth to Watertable is deepest around Omu area with depth of 71.9m. The result of the geophysical analysis correlates positively with themselves showing similarity in geology. The result shows that the weathered basement is a primary target for ground water exploration in the studied area, as the area is void of prominent fracture which is a target for ground water exploration. It is recommended that an average depth of 7.0m should be drilled for borehole within the northern part of the studied area and a depth of about 10.0m in the southern part of the study area. All these deductions were reached after qualitative and quantitative interpretation of the geophysical data, and considering geology of the area

Keywords: Groundwater potential, Geoelectric section, Aquifer characterization, resistivity pseudo-section and Correlation

Correlation Between CBR, Compaction Properties and Compaction Delay on the Cement Kiln Dust Stabilized Lateritic Soil

M. H. Idris and A. A. Khalid

Abstract: This research is to investigate the Correlation between CBR, Compaction properties and Compaction delay on the Cement Kiln Dust (CKD) stabilized Lateritic Soil. The tests carried out on the CKD Stabilized lateritic soils were the Compaction test and California Bearing Ratio (CBR) test. Statistical analysis on the effects of compaction delays on properties of CKD stabilized lateritic soil was conducted using analysis of variance and multiple regression analysis using statistical package for social sciences (SPSS). The data was taken from Compaction tests and soaked CBR tests results on Soil-CKD mixtures at different time interval. The good R-square value of 96.5% indicated that these correlations were reasonable. The results also indicate that there is a good correlation between the CBR, Compaction properties and the Compaction delay. By using this correlation, the soaked CBR of a particular lateritic soil- CKD mixture of different compaction delay with various CKD content can be predicted.

Keywords: nCalifornia Bearing Ratio (CBR), Compaction Delay, Regression and Correlation Analysis, Cement Kiln Dust (CKD)

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