Pozzolanic contribution of rice husk ash in cementitious system

Rice husk ash (RHA) is an established supplementary cementitious material (SCM). Extensive research has been carried out to incorporate RHA as a SCM in casting concrete and mortar. RHA contributes in two fold of effects in concrete or mortar; i.e. filler effect and pozzolanic effect. Replacement percentages of RHA used in various previous studies were chosen arbitrarily like 5%, 10%, 20% and so on to determine the total effect of RHA. But the unique filler effect or pozzolanic effect of RHA in cementitious system is yet to be investigated comprehensively by the scientific community. This study was carried out to find the maximum pozzolanic (chemical) contribution of RHA in cementitious system in terms of replacement percentage. The determination is analytical and based on the hydration reaction of cement and the pozzolanic reaction of RHA with the hydration product. The obtained result was also verified with the experimental results available from published literatures.