The use of agricultural waste as pozzolan is widely accepted, because of several improvements possible in sandcrete composites and the overall economy. However, eggshell ash is a pozzolan that appears to have significant potential for the production of high strength and high performance sandcrete block. Although available information on eggshell ash sandcrete is limited, this research attempt to investigate and presents an experimental study on the effect of replacing cement with eggshell ash (ESA) in sandcrete block production. Results of the compressive strength test of sandcrete block containing ESA at varying replacement levels were discussed and compared with those obtained with the control (100% Portland cement sandcrete block). The total partial replacement was considered in the range of 0% (control specimen) to 40% by weight in steps of 5%. The combination for each replacement level apart from 0% are as follows: 95% cement and 5% ESA, 90% cement and 10% ESA, 85% cement and 15% ESA, 80% cement and 20% ESA, 75% cement and 25% ESA, 70% cement and 30% ESA, 65% cement and 35% ESA, 60% cement and 40% ESA. Sandcrete blocks specimen were produced and tested at 7, 14, 21 and 28 days of curing respectively to appreciate the strength development of each replacement value. It was observed that the strength decrease with increase in percentage replacement. But the best results were obtained at 30% replacement with a value of compressive strength of 4.7N/mm2 of the 28day strength of that of the control at 28days, which met the standard requirement in Nigerian building code.
Keywords: Cement, Eggshell ash, Sandcrete block and Compressive strength
