Physico-chemical characteristics of Geopolymer cement prepared from some Industrial solid wastes

Abstract

Due to increasing concerns about environmental pollutions especially caused by production of Ordinary Portland cement, many authors studied the synthesis of new binding materials instead of cement especially by using solid waste. This was carried out by using the alkaline activation process for some solid wastes, in other words geopolymerization process.. Therefore, the aim of this investigation to study the physico-chemical characteristics of geopolymer cement prepared from some solid wastes .

The wastes used in this study were ground granulated blast-furnace slag (GGBFS), homra (H), marble dust (MD) and granite powder (GP). The alkaline activators used in geopolymerization process were (NaOH, 10M) and (Na2SiO3, 6M). The activators used in five different ratios. GGBFS was used as blank material which replaced by homra, MD and GP with different ratios.

Each mix was first mechanically mixed in the dry state in ball mill to attain complete homogeneity. The geopolymer cement pastes were prepared by mixing each dry mixture with the liquid alkaline activators, without addition of water or superplasticizer. After complete mixing the resulted pastes were molded into one inch cubic moulds. The moulds containing the pastes were then cured at about 100% relative humidity for the first 24 hours at room temperature (25 ˚C ± 1) in order to attain the final setting of the specimens. The hardened geopolymer cement pastes were then removed from the moulds and cured at ~ 100% RH up to 90 days. The applied time intervals were 3, 7, 14, 28 and 90 days. Samples