Studies On Preparation And Properties Of Geopolymer

Geopolymer was prepared by using kaolin, sodium silicate and sodium hydroxide as main raw material. Influence of processing parameters on geopolymer was studied, such as sodium silicate amount, quantity of sodium hydroxide and water, curing time and temperature of geopolymerization, and so on. The results showed that the optimum processing parameters for preparing geopolymer is as follows: the sodium silicate amount and water amount were 40vol% and 21wt% respectively, the quantity of sodium hydroxide was 20wt%, the maintain time of polymerization was 5h and the maintain temperature of polymerization was 80℃, while the compressive strength of geopolymer achieves 54.1MPa after 14 days. geopolymer sample was dipped into water for 1 day at the normal temperature and 50℃, then fought the pH of water were 7.3 and 7.38. The prepared geopolymer performance prefect water resistance satisfied actual production demand.Study on enhancing mechanical properties of geopolymer was made; the results showed that alkali metals hydroxide is more effective than alkali metals carbonate. The optimum temperature of calcined kaolin is 800℃. While the optimum temperature of calcined kaolin mixture can be reduced to 600℃added sodium hydroxide. The additive must be able to dissolve in water or dispersed in activator homogeneous by vigorous agitation. Inorganic additive calcium chloride could obviously enhance properties of geopolymer. Organic additive furfuralcohol could obviously enhance properties of geopolymer, and the compressive intensity of geopolymer achieves 74.3MPa after 14 days. The pH of water was 7.11 and 7.13 respectively, after geopolymer samples dipped into water for 1 day at the normal temperature and 50℃.This dissertation described relation between geopolymer microstructure and property by means of XRD, SEM and IR.