Abstract
The environmental impacts of ordinary Portland cement raise a need for alternative cements to be used as binders in concretes. A number of studies have shown that geopolymers could be employed as sustainable binders to replace the use of Portland cement in concrete. However, these new binder systems need to be investigated on different aspects before being employed at industrial scale. Fly ash is one of the common geopolymers, which has attracted research interest due to its wide availability for use as a starting material of acceptable performance. The present thesis addresses two different research challenges conducted in two phases. The first phase of this study deals with the strength of a fly ash - based geopolymer system, focusing on the development of a mix design method for fly ash - based geopolymers activated using different combinations of sodium hydroxide and sodium silicate solutions as alkali - activators. For this purpose, the effects of different mixture parameters on the strength of fly ash - based geopolymer pastes and mortars were investigated...
D.Phil. (Civil Engineering Science)