Performance of Sand Cement Block Produced With Partial Replacement of Cement by Rice Husk Ash

The sand cement blocks are cement composites and have been widely used in many countries including Sri Lanka. Rice husk ash (RHA) is a waste material with pozzolanic properties. The use of RHA as a substitute of cement is a sustainable application which solves the problem of its disposal by minimizing the environmental pollution. This paper discusses on the performance of a cellular sand cement block containing rice husk ash through an experimental investigation. The burning temperature of the RHA obtained from power plant is 650°C. Ordinary Portland Cement (OPC) was partially replaced with RHA having different fineness at 5%, 10% and 15% replacement levels to produce sand cement blocks. Particle size of the finer RHA was less than 75 jim. Compressive strength increased up to the 10% cement replacement level only with finer RHA. Replacement percentage beyond the 10% lead to decrease the compressive strength of sand cement block. However, cement replacement with coarser RHA decreased the compressive strength at all the replacement percentages. The density of sand cement block decreased as RHA content increased. Moreover, higher water absorption capacity was observed at higher RHA content