Strength of Blended Cement Sandcrete & Soilcrete Blocks Containing Cassava Waste Ash and Plantain Leaf Ash

摘要

This work investigated the compressive strength of binary and ternary blended cement sandcrete and soilcrete blocks containing cassava waste ash (CWA) and plantain leaf ash (PLA). 135 solid sandcrete blocks and 135 solid soilcrete blocks of 450mm x 225mm x 125mm were produced with OPC-CWA binary blended cement, 135 with OPC-PLA binary blended cement, and 135 with OPC-CWA-PLA ternary blended cement, each at percentage OPC replacement with pozzolan of 5%, 10%, 15%, 20%, and 25%.Three sandcrete blocks and three soilcrete blocks for each OPC-pozzolan mix and the control were crushed to obtain their compressive strengths at 3, 7, 14, 21, 28, 50, 90, 120, and 150 days of curing. Sandcrete and soilcrete block strengths from binary and ternary blended cements were found to be higher than the control values beyond 90 days of hydration. The 150-day strength values for OPC-CWA-PLA ternary blended cement sandcrete and soilcrete blocks were respectively 5.90N/mm 2 and 5.10N/mm 2 for 5% replacement, 5.80N/mm 2 and 4.95N/mm 2 for 10% replacement, 5.65N/mm 2 and 4.85N/mm 2 for 15% replacement, 5.60N/mm 2 and 4.75N/mm 2 for 20% replacement, and 5.25N/mm 2 and 4.65N/mm 2 for 25% replacement; while the control values were 5.20N/mm 2 and 4.65N/mm 2 . Thus, OPC-CWA and OPC-PLA binary blended cements as well as OPC-CWA-PLA ternary blended cement could be used in producing sandcrete and soilcrete blocks with sufficient strength for use in building and minor civil engineering works where the need for high early strength is not a critical factor.