Open Access Original Research Article

Geophysical and Geotechnical Studies of a Proposed Structure at Akure, Southwestern Nigeria

Ilugbo Stephen Olubusola, Adebo A. Babatunde, Ajayi Oluwasayo Adegbola, Adewumi Olufemi Olaoluwa, Edunjobi Hazeez Owolabi

Journal of Engineering Research and Reports, Page 1-12
DOI: 10.9734/jerr/2018/v2i29910

Geophysical and geotechnical studies were carried out at a proposed location for the construction of a multi-storey structure in Akure, Southwestern, Nigeria. The aim was to ascertain the suitability of this location for both Founding and Engineering structures. The geophysical investigation involved the Vertical Electrical Sounding (VES) technique using the Schlumberger configuration, Dipole-Dipole Horizontal Profiling and a geotechnical investigation. A total of twenty-one (21) VES and five (5) Cone Penetration Test (CPT) locations were occupied within the study site. Dipole-Dipole Horizontal Profiling was occupied along traverses 1 and 2 within the investigated area. The electrode separation varies from 1 to 75 m. The investigation delineated three major layers which are topsoil, which is excavated before any foundation is laid. The second layer delineated was lateritic and the last was weathered layer. From the result obtained, depth to lateritic layer ranges from 1.1 to 9.0 m while resistivity defining the lateritic layer ranges from 150 Ωm to 792 Ωm. Some of the sounding curves generated over the VES stations and Dipole-Dipole Horizontal Profiling fairly correlated with those of the CPT profile. The high cone penetration resistance recorded at CPT point 4 and 5 is manifested as high geoelectric resistivity values recorded at VES 13. This shows that the soil has fairly low clay content. It also seen from the study that the geophysical studies has a greater depth penetration, and it also provide better layer characterization compared to geotechnical studies. The choice of foundation material, clay content and topography elevation should be taken into cognizance, since the load bearing capacity of the lateritic layer was appreciably high.

Open Access Original Research Article

Effective Implementation of Maintenance Models in Building Maintenance Process

E. Ogunoh, Peter, E. C. Mbanusi, Okoye Uchenna Peter

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2018/v2i29937

Buildings are essential facilities which represent a substantial percentage of most tertiary institutions assets, user needs and operating costs. The maintenance levels of these buildings are very crucial to educational effectiveness. However, in spite of the crucial role of these buildings in the education and construction sector of the economy, most educational buildings in Nigeria are in deplorable conditions as a result of lack of maintenance. The efficient and effective maintenance management of both new and old buildings constitutes a challenge to the management. Presently, studies on maintenance of buildings have not been conducted in sufficient details for educational buildings in Nigeria. This research was therefore, aimed at effective implementation of maintenance models in building maintenance process. Maintenance is reactive rather than proactive and no evidence of maintenance plan and manual were in use.

Open Access Original Research Article

Deturbidization of Vegetable Oil Refinery Wastewater with Extracted Fish Scale Biomass via Coagulation Process; Non-linear Kinetics Studies

C. F. Okey-Onyesolu, O. D. Onukwuli, C. C. Okoye

Journal of Engineering Research and Reports, Page 1-14
DOI: 10.9734/jerr/2018/v2i29943

Chito-protein was successfully synthesized from fish scale. The ability of a coagulant (chito-protein) prepared from fish scale (FSC) to carry out an effective removal of pollutants from food processing industry (vegetable oil industry wastewater, VOW) was evaluated at bench scale using a simulated jar test analysis. The coagulant was characterized via proximate analysis and instrumental analysis: Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The maximum kinetic parameters determined were recorded at K of 2x10-5L/mg.min, 1g, t1∕2= 50 min, R2= 0.9245 and pH of 2.Regression coefficient analysis (R2) was used to ascertain the accuracy of the fit to the postulated kinetic model. However, it was concluded that the second order kinetic model described the reaction most adequately. Removal efficiency of turbidity (87.21%) was obtained at optimum contact time of 30 min, pH 2, coagulant dosage of 1.5g and temperature of 323K. Kinetic study showed that Pseudo first order and pseudo second order models were the best two models in describing the coag-adsorptive kinetics of the coagulant. Similarly, the predicted kinetic data were adjured statistically significant using F- test and T-test.

Open Access Original Research Article

Effect of Waste Tyre-Rubber Aggregate on the Strength Properties of Concrete

Adetoye T. Oyebisi, Cordelia O. Osasona

Journal of Engineering Research and Reports, Page 1-9
DOI: 10.9734/jerr/2018/v2i29948

This research studied strength-characteristics of concrete using waste tyre-rubber as partial replacement for coarse aggregate in concrete construction and compares the results to those of conventional concrete. The specimens were produced with percentage replacements of the coarse aggregate by 5%, 10% and 15 % of rubber aggregate. A control mix with no replacement of the coarse aggregate was produced, to make a comparative analysis. The samples consisted of concrete cubes, cylinders and beams. Various tests (such as slump, compressive strength, splitting tensile strength and flexural strength tests), were conducted. Data-collection was mainly based on the results of the tests conducted on the specimens in the laboratory. The results show that there is a reduction in the compressive strength of the concrete, due to the inclusion of rubber aggregates. Compressive strength losses of 12.69%, 17.75% and 25.33% were noticed for 5%, 10%, 15% replacement of coarse aggregate, respectively; tensile strength losses of 13.01%, 20.12%, and 24.76% were observed, respectively, when 5%, 10%, 15% of the coarse aggregate was replaced, after 28 days of curing; -0.1%, -0.15% and 0.2% decrease in flexural strength was observed for 5%, 10% and 15% replacement, respectively, after curing for 28 days. Rubberised concrete was found to have some desirable characteristics (such as lower density, enhanced ductility, and a slight increase in flexural strength in the lower compressive strength concrete categories). The overall results show that it is possible to use recycled rubber tyres in concrete construction, as a partial replacement for coarse aggregates. Nevertheless, the percentage of replacement should be limited to 10% (which ensures the strength of the concrete is kept within the required range), and the application should be restricted to particular cases where the properties related to the replacement with the rubber aggregates clearly indicate an improvement on conventional concrete, and so are desirable.

Open Access Case study

Modeling and Optimization of Operational Costs of Nissan Urvan Vehicles of a Fleet Operator

Harold C. Godwin, Patrick S. Aguh, Anthony O. Umeozokwere

Journal of Engineering Research and Reports, Page 1-14
DOI: 10.9734/jerr/2018/v2i29916

This study focused on Modeling and Optimization of the operational costs of Nissan Urvan Vehicles of a fleet operator in Anambra State Nigeria. The special design used to fit a second order model needed to optimize the operational costs of Nissan Urvan Vehicles was Box - Behnken design while response surface method (RSM) was used to model and optimize performance characteristics of the vehicles. The response function of the second order model is best characterized by multivariate power equation. Ten (10) years operation data were collected from two sources, namely primary and secondary sources. The primary source of data was from the workshop manager and the statistical office of the company, and from Metrological Institute of Nigeria. The secondary source of data was from Books consulted at different Libraries. The outcome of the analysis of variance (ANOVA) for RSM optimization of operational costs of Nissan Urvan vehicles showed that all the control factors are significant except factors (B, C, D) of replacement costs. From the result of the income generated at optimum condition and the sum of the maintenance & replacement costs compared, by the year 2013 the income generated is less than the sum of maintenance & replacement costs. It was observed that the operation of the transportation system is economical for a period of 8 years (from 2005 – 2012), where the income generated is more than the maintenance & replacement costs.It is hereby recommended that response surface model should be deployed for the operation analysis of the case study company vehicles to enhance efficient utilization and profitability.