A discussion of the paper “Study on the pozzolanic properties of rice husk ash by hydrochloric acid pretreatment” by Q. Feng, H. Yamamichi, M. Shoya, S. Sugita

Abstract

This brief commentary discusses a recent study (Feng et al, 2004) on the pozzolanic properties of rice husk ash by hydrochloric acid pretreatment. In the study, the heat evolution and the hydration heat of cement, the Ca(OH)2 content in the mortar and the pore size distribution of mortar were determined. The results showed that pozzolanic activity of rice husk ash (RHA) is not only stabilized but also enhanced by pretreatment. In this commentary, Demirbas notes that the very high surface area of RHA increases its pozzolanic activity to compete with those of much finer admixtures. Demirbas calls for additional attention on the chemical effects of pozzolanic materials on crystal formation during the hydration. Demirbas also refers readers to another study in which the pozzolanic properties of hydrochloric acid-treated RHA were systematically investigated (Yalcin and Sevinc, 2001).