Physical and Mechanical Properties of Silica Fume and Calcium Hydroxide Based Geopolymers

Conventional portland cement has found worldwide usage in the production of cementitious materials in recent years. Nevertheless, environmental problems such as high demand of raw materials, energy consumption and high amount of carbon dioxide emission take place before and during manufacturing process. The attempts have been made to seek alternative binders and develop supplementary materials for construction sector. Therefore, this study reports the results of an experimental program on the comparison of geopolymers with different compositions in terms of evaluating their physical and mechanical behavior. For that purpose, the effect of binder types and amount of binders and alkali activator (sodium hydroxide) was investigated. In addition, acidic pumice and waste aluminium particles were also used as fine aggregate and air entraining agent, respectively, in geopolymer production. The test results revealed that as the content of alkali activator increased, compressive and flexural strength decreased. Addition of waste aluminium particles decreased bulk density and strength owing to the some extent of entrained air.