Dipak Paudel, Arvind Pathak and Vinay Kumar Jha

Central Department of Chemistry, Tribhuvan University, Kirtipur, Kathmandu, Nepal

The demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak in recent days which in turn generates a huge amount of demolished-cement-sand-mixture (DCSM) waste. This DCSM waste is rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from DCSM waste using NaOH and Na2SiO3 as activators. Some parameters like alkali concentration, particle size variation, ratio of Na2SiO3 to DCSM waste and curing time have been varied in order to improve the quality of geopolymeric product. The results obtained revealed the maximum compressive strength of 46.95 MPa at the ratio of sodium silicate to DCSM waste of 1.5 (w/w) on 28 days curing time at 40ºC temperature.