An assessment on the effects of adding rice husk ash on locally manufactured burnt clay bricks.

Abstract

The search for alternative building materials has continued in the research world. Some of these researches are for low cost housing; others are for environmental friendly materials, while others are for strength and durability. This has prompted research into even agricultural wastes. The difficulty in the provision of housing is as a result of high cost of building materials which has contributed to make ownership of houses more and more difficult for the poor, especially in developing countries and also high costs of cement has made concrete blocks out of reach for many. The study set out and produced locally burnt brick by mixing rice husk ash with anti-hill clay. Three specific objectives and three research questions guided the study. The study employed an experimental design. Sixty (60) specimen bricks were produced and tested in the laboratory for the compressive strength and water absorption rate. The bricks were of different mix ratios 1:4, 1:5, 1:6, 1:7, 1:8 and 1:9 that is rice husks ash to anti-hill clay (RH:AC) and for each mix ratio five (5) bricks were produced and three (3) were tested. The rice husk ash bricks attained their highest mean compressive strength of 4.8 MPa at the mix ratio of 1:9 whereas bricks of mix ratio 1:4 attained the lowest mean compressive strength of 3.9 MPa. The highest water absorption rate was 14.4% attained by bricks of mix ratio 1:4 while the lowest mean water absorption rate for rice husk ash bricks was 12.6% attained by bricks of mix ratio 1:9. The cost implication for adding rice husks ash was determined and this varied with the mix ratio