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ABSTRACT There are often some modifications to be made on construction project designs either at the design stage or construction stage, which usually bring about change order in construction projects. This however, presents problems to all parties involved in the construction process and execution. This study investigates the main causes of change order  and its effects on  construction  projects  using questionnaire  surveys  which  were distributed  to Engineers, Architects  and Technologists ...

Abstract Construction industries are prone to competitiveness and loss of profits. This is due to multiplicity of groups of companies handling projects nowadays. Empirical evidence from previous studies shows that lack of risk management processes affects profit output. Identification of risk management processes and critical risk factors is important to minimising the likelihood of non-profits occurring in the industries. Thus this study is aimed at investigating risk management processes, identifying ...

ABSTRACT Contamination of existing and potential agricultural lands is a major problem associated with the processing and distribution of crude and refined petroleum products in many oil producing countries like Nigeria. Hydrocarbon contaminants in soil are potentially phytotoxic to plants and can  interfere  with  plant  establishment  and  growth  as  well  as  other  potential  land  uses. Pollution control strategies involving physico-chemical methods are usually expensive and have often aggravated the problem ...

ABSTRACT The  primary  objective  of  this  work  is  to  form  the  foundation  of  a  Road Management   Maintenance   System  (RMMS)  that  Road  Maintenance   Agencies  like FERMA   can   immediately   implement   to   make   better   decisions   pertaining   to rehabilitation options. Further, this is to allow for appropriate decisions about the best type  of maintenance  and rehabilitation  interventions  to apply  to the  poor  state  ofarterial roads taking into consideration various factors, least of which are ...

ABSTRACT This work analysed the performance of an automatic control system for the online blending of petrol with corrosion inhibitor in the direct, continuous electronic fuel injection automobile engine. The automatic control system was designed by superimposing  a  feedforward  control system on  a  feedback  control system.  The design of the automatic control system was analysed by the method of direct substitution. The governing equations used in analysing the blending process, ...

ABSTRACT The assumed deflection shapes used in the approximate methods such asin the Rayleigh–Ritz method were normally formulated by inspection andsometimes by trial and error, until recently, when a systematic method ofconstructing such a function in the form of characteristic orthogonal polynomials(COPs) was developed in 1985. However, vibrational analyses of plates with all edges free or clamped are much more complicated. This project aims at establishing particular expressions for the ...

Abstract The primary objective of this study was to investigate the rank importance or most significant motivating factors on construction employees in South-South Nigeria. The research method for the study included a literature review and field survey. A sample population was selected from the target location. The findings indicated that the  construction workers’ top five (5) motivation factors were: leadership,  supervisor’s  loyalty to employees,  good  salary, goal- setting, and good ...

ABSTRACT Analysis of all identified hazards and assessment of risks influencing project performance from the highway and railway construction industries in the  Eastern part of Nigeria was conducted for reducing the dangers of a specific task and the risk of injury to workers. Likert scaling using mean index formula was used to calculate the data gotten through a questionnaire survey administered by self to the construction industries after a mini ...

ABSTRACT Environmental pollution with petroleum and petrochemical products has been recognized as one of the most important and serious challenges facing environment engineers. Disposal from mechanic sites, accidental leakages from petroleum carrying ships, vandalization of pipelines, have all contributed to the current common oil pollution in Nigeria today. The currently used physical and chemical remediation are effective for the degradation of petroleum products but the affected medium lose the desired ...

ABSTRACT Energy  and  exergy  analysis  of  solar  air  heater  with  phase  change  material  energy  storage  is considered in this research work. Energy and exergy models for component systems like flat plate solar collector and phase change material in one-dimensional heat conduction in a cylindrical pipe, for storing periods were obtained. Exergy analysis, which is based on the second law of thermodynamics, and energy analysis, which is based on first law, ...

ABSTRACT This study adopted experimental design to investigate the suitability of abandoned solid waste site soil (ASWSS) as a foundation material for building construction. Measurements of geotechnical properties of stratified random soil samples of ASWSS and adjoining natural soil (NS) at depths 1.5, 2.0, 2.5, 3.0 and 3.5 m were obtained from six test points in Kaduna, Nigeria. The soil samples were subjected to sieve analysis, Atterberg limits (liquid limit, ...

ABSTRACT The effect of notches on the strength of Coir – reinforced cashew nut shell resin composite was investigated. Composite laminates with six different fibre contents (0,0,1, 0.2, 0.3, 0.4 and 0.5 volume fractions)  were  fabricated  using  the  hand  lay  –  up  moulding method.  A  static  fracture  testing  equipment  was  designed  and fabricated in the absence of a functional fracture testing machine. Static  fracture  tests  were performed  on  the notched ...

ABSTRACT Thin-walled  box girder  bridges  are very efficient  structural  solution  for long-span  bridges because  of  their  high  torsional  resistance,  stability,  economy,  and  aesthetic  appearance. Though, this type of bridge is not common in Nigeria,  it is envisaged  that  they may offer economic advantages in future high way projects in Nigeria.  Analytically, however, the box girder bridge is a very complex indeterminate problem. Therefore, the primary objective of this research was ...

ABSTRACT The  study  was  undertaken  to  measure  the  variational  change  in residual chlorine decay in water distribution network. A total of  330 water sample were collected at different periods of the day for ten days. Ten water sample locations at water stand taps, were  taken for the study area in Calabar South Local Government  Area  of Cross River State, Nigeria. The effect of various Pipe diameter, water sample point distance, ...

ABSTRACT Energy benchmarking and carbon footprint reduction opportunities in Portland cement manufacturing processes in Nigeria are presented. Life Cycle  Assessment (LCA) is used to estimate the environmental impact of three cement manufacturing processes in Nigeria. The energy consumption of the cement manufacturing processes are evaluated using energy Benchmarking  and Energy  Savings Tool for cement (BEST-Cement). BEST-Cement  evaluates  and  compares  the  energy  consumption  of  the  cement manufacturing processes in Nigeria to ...

ABSTRACT The rate at which roads fail in Nigeria should worry any responsible citizen. Considering the enormous resource expended to construct a kilometer of road, it is heart breaking  when the same road fail barely six (6) months after construction. For in the life of our dear country, the all important economic theory of opportunity cost is applicable just as it is elsewhere in the world. Stabilization is a viable ...

ABSTRACT The need to clean-up heavy metals that contaminate water cannot be over emphasized. This paper examined the kinetics of lead adsorption using activated rice husk ash. The influences of contact time, adsorbent dose, pH and temperature on adsorption were investigated. From the results obtained, by  analyzing the  effect  of  contact time,  it  was discovered that  maximum adsorption of about 90 % removal efficiency took  240 minutes using 0.2g of ...

ABSTRCT This study “Modeling Nitrate Transport with Dispersion in Soil”. presented finite element and empirical models to predict transport of   nitrates in a soil.  Three different soil samples were  selected  which  includes  sand,  clay  and  silty  soil.  Each  sample  was  gradually introduced into a fabricated iron column, having a length of horizontal column 30cm and vertical part 60.96cm. A solution of silver nitrate was allowed to pass through the vertical ...

ABSTRACT It is generally known that  the  major  causes  of failure  in asphalt pavement is fatigue cracking  and  rutting deformation,  caused  by  excessive  horizontal tensile  strain  at the bottom of the asphalt layer and vertical  compressive strain  on top of the subgrade due to repeated traffic loading.  In the design  of asphalt pavement, it is necessary to investigate these  critical  strains  and  design  against  them.  This study  was  conducted to ...

ABSTRACT The Design of an Efficient Solid Waste Management and Disposal Scheduling System in a metropolis is hereby presented. The design employed ten landfill sites in contrast to the existing one landfill site in the metropolis. The metropolis was divided into ten zones and a Hungarian mathematical model was used to get the optimal assignment of the proposed landfill sites to the zones. This model was applied to the field ...