Fiber reinforced geopolymer from synergetic utilization of fly ash and waste tire

Fiber reinforced geopolymer and its technology using fly ash and waste tire was developed and investigated. The fiber reinforcement originated from shredded car tire was processed by a preparation technology consisting comminution and separation steps resulted in various fractions in size and quality. Furthermore, the binder of the composite was made of mechanically activated fly ash and activator solution (NaOH and Na-K water glass). The goal of the present work was to examine the effect of addition of various quality steel fibers, in the ratio of 1, 3, 5 w/w%, on the compressive- and flexural strength as well as on the structure of geopolymer. Meanwhile, most processes of the suggested technology of fly ash and waste tire preparation were tested in pilot scale. As a result of the experiments, it was found that specimens containing pure steel fibers have higher strength than geopolymer containing rubber contamination beside steel fiber. Increasing the amount of fiber has a positive effect on the development of strength. Steel fiber reinforcement in 5w/w% reached significant growth in compressive strength and three times growth in flexural strength as compared to the neat geopolymer. The fracture surface was analyzed by scanning electron microscopy. Furthermore, FTIR results shown difference in the material structure between the inner part of geopolymer matrix and the interface of geopolymer - rubber. SEM results confirmed the satisfactory strength results concerning the bonding between steel fiber and geopolymer matrix.