Study on performance of aIkali-activated flyash-based geopolymer reinforced by silica fume and styrene-acrylic emulsion

摘要

In order to improve the inherent fragility of alkaliactivated fly ash-based geopolymer, the silica fume and styrene-acrylic emulsion were used to reinforce and toughen the geopolymer. The phase structure, morphology and chemical composition were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF). The results showed that the mechanical properties of alkali-activated fly ash-based geopolymer were dramaticlly improved and the specimen with doping content of 10 wt% silica fume, lwt% styrene-acrylic emulsion and 15wt% the alkaline excitation agent Na2SiO3·9H2O showed the highest compressive and flexural strengths of 42.11MPa and 5.30MPa in the ambient temperature curing 28d, respectively. SEM results indicated that doped silica fume and styrene-acrylic emulsion were embedded within the matrix of fly ash-based geopolymer. XRD results demonstrated that the mineral structures did not change obviously when silica fume and styrene-acrylic emulsion were added to the geopolymer.