EFFECT OF PROCESSED RICE HUSH ASH ON THE MECHANICAL PROPERTIES OF NON-LOAD-BEARING BLOCKS

ABSTRACT In Nigeria, sandcrete blocks are among the most commonly used materials for constructing walls, particularly for non-load-bearing structures in residential and commercial buildings. These blocks are typically made from a mixture of cement, sand, and water, molded into hollow rectangular shapes for ease of handling and cost efficiency. This research investigates the effect of rice husk ash (RHA) as a partial replacement for cement on the mechanical properties of non-load bearing sandcrete blocks of size 450 × 225 × 150 mm. The rice husk ash used for the study was obtained from the Hillcrest Farm rice mill dumpsite at Amberi, Ajase-Ipo, Kwara State. The ash was collected from a steam engine after combustion at about 600°C and passed through a 150-micron British Standard (BS) sieve. Cement was partially replaced with RHA at 0%, 10%, 20%, 30% and 40% by weight. The blocks were cured for 7, 28, and 56 days, and tested for compressive strength, and density test in accordance with standard. The results revealed that up to 10% RHA replacement slightly reduced the compressive strength but still met the standard requirement for non-load bearing blocks. Beyond 10%, the strength declined significantly. The density of the blocks decreased with increasing RHA content, indicating lighter blocks with improved sustainability and reduced cost. The study concludes that 10% replacement of cement with rice husk ash is the most effective proportion for producing 6-inch non-load bearing sandcrete blocks suitable for partition walls and other light structural applications