P. N. OGBEIFUN

This study evaluates the compliance of borehole drilling practices with established standards at Utekon and Oluku in Benin City. A total of three boreholes were assessed, and data on drilling methods, casing, cementation, well completion were collected and soil logs used for sieve analysis to obtain D10 value used to obtain constant of permeability. The research aims to evaluate the level of adherence to industry guidelines and best practices in drilling of boreholes, with a focus on ensuring the sustainability and safety of groundwater resources.A comprehensive field investigation was conducted, involving the collection and analysis of data from a representative sample of boreholes in the study area. The study assessed various aspects of borehole drilling, including drilling methods, casing, cementation practices and well
completion. The results of the study reveal significant deviations from standard practices in some aspects of borehole drilling, which could compromise the quality and sustainability of groundwater resources in the area. During investigation some drilling standards were ignored e.g. noncompliance to distance of borehole from structures such as septic tanks and inadequate site investigation and proper hydrological test conduction to know the depth of water table, the use of gravel packing was also ignored. Although the position of screen and the number of casings used were adequate.

This study evaluates lightweight concrete produced by partially replacing conventional coarse aggregate with crushed coconut shells, aiming to develop an eco-friendly and cost-effective solution for rigid pavement construction. The research investigates the feasibility of using coconut shells (a readily available agricultural waste) as a substitute to reduce concrete's overall weight while maintaining adequate structural performance. A comprehensive experimental test was carried out in which concrete mixes were designed with varying levels of crushed coconut shell replacement (e.g., 0%, 10%, 20%, and 30%) for the coarse aggregate replacement. The fresh concrete properties were evaluated using standard slump tests, while the hardened concrete was tested for compressive, flexural, and splitting tensile strengths at 7, 14, and 28 days of curing. The tests were conducted following standard procedures, and the resulting data were tabulated and compared across different replacement percentages. The 7-day compressive strength for the control mix (0% replacement) was 21.09 N/mm², while the 10% replacement mix recorded 20.48 N/mm²; at 28 days, the control mix achieved 30.51 N/mm² compared to 28.27 N/mm² for the 10% replacement. Similarly, flexural strength values at 28 days decreased from 5.75 N/mm² for the control to 5.25 N/mm² at 10% replacement.