L. O. Bobor

All over Nigeria as well as to the overseas the fuel oils as well as crude oils are transported through distribution pipes, tankers cargo ships. Although the processes are well laid out to avoid leakages of pipes, accidents of service tankers these events still happens on a regular bases especially in the niger delta region of the country where pipe vandalism due to oil bunkery is on the rise. All these processes leads to the leakages of fuel oils e.g kerosene which eventually settles on coastal waters. The leaked oil products would result in contaminating the water which are used in the concrete mortar and the sandcrete industry which are the cement dependent industry. In this study, the effect of water contaminated with kerosene on the compressive strength of conventional normal ordinary Portland cement has been evaluated in various exposure conditions. Kerosene (0, 2, 4 and 6%) by weight of water) was used to contaminate water to prepare cement mortar cubes specimens. A number of nine uncontaminated samples were prepared with fresh water. A number of nine samples each were prepared with contaminated water at 2%, 4%, 6% Kerosene replacement. Three samples each of percentage replacement and three uncontaminated samples were crushed at the age of three days, seven days and 28 days of curing. From the results gotten the maximum reduction in the compressive strength of 9.21% occurred at the six percentage contamination at the age of seven days. From results obtained it was seen that as the percentage of contamination increase the compressive strength decreased.

Electronic waste is an emerging issue posing serious pollution problems to human and the environment. The specific objectives of this work are to determine the physical properties of crushed e-waste materials, granite and aggregates, to design a concrete mix incorporating e-waste and granite as the coarse aggregate, to investigate the strength development of e-waste concrete at 7, 14 and 28 days, under standard curing method, to determine the effect of e-waste replacement on the compressive and flexural strength of concrete, and to analyse the result and ascertain the benefits of e- waste in the production of concrete. The research methodology will involve performing a comprehensive literature reviewand laboratory investigation of compressive strength and flexural test. Before that, several series of test would be carried out which includes specific gravity test, sieve analysis test, mix design, slump test, and casting of concrete test cubes. The results showed that adding e-waste as a partial replacement for coarse aggregate increased workability but reduced strength. Slump values rose from 27mm in the control mix to 61 mm at 20% replacement, indicating greater fluidity due to the smooth, non-absorbent surface of e-waste particles. In contrast, compressive strength dropped from 20.09 N/mm² to 10.43 N/mm², and flexural strength from5.25 N/mm² to 0.38 N/mm² as e-waste content increased. The mix with 5% e-waste achieved 18.12N/mm², close to the control, showing that small replacements maintain acceptable performance. Overall, e-waste improved workability but reduced strength, with 5% replacement identified as the optimum level for structural use. Using e-waste as a partial replacement for coarse aggregate is feasible up to 5%, giving the best compressive and flexural strength. Higher replacements (above 10%) reduce strength significantly. Further studies are recommended under real site conditions, for longer
curing periods, and in combination with other waste materials to improve performance.