Strength property of rice husk based geopolymer mortar
  Salmabanu Luhar, Pushkal Agrawal, Shubham Goswami and Sandeep Chaudhary
  This paper presents a comparative study on compressive strength of fly ash based geopolymer mortar with partial replacement of fly ash with rice husk ash. Amount of fly ash replaced was varied from 0% to 30% with a progressive increase of 10%. Further variations were done by using different combinations of sea sand and sea water in place of conventionally used river sand and ordinary distilled water respectively. This was done to access the use of locally available cheap ingredients (sand and water) near coastal areas to diminish costs. Results show that samples with 0%, 10% and 20% replacements of fly ash with rice husk ash achieved 7-day compressive strength higher than that of the 28th day compressive strength of equivalent H1 category of conventional OPC based mortar (i.e. higher than 10MPa). These results conclude high and early strength gain property of geopolymer mortars. It is also found that 10% replacement of fly ash with rice husk ash gives the maximum (more than that of 0% replacement) compressive strength for all the four combinations. All these results support the idea of using these two waste products in a definite proportion to achieve sustainable construction.