High temperature and freeze-thaw performance of geopolymers with glass fiber and natural zeolite

Cement used in concrete production contributes to environmental problems and global warming due to

high energy consumption, carbon footprint, and excessive use of natural resources. In this direction, research into

sustainable binders is increasing. Geopolymer concrete, which has superior mechanical and durability properties,

stands out as an environmentally friendly alternative due to its potential to use industrial waste as a raw material.

In this study, the effect of 15% substitution of ground blast furnace slag (GBFS) with natural zeolite (NZ) and

0.3% and 0.6% by volume of glass fiber (GF) on the physical and mechanical properties of concrete in geopolymer

composite based on GBFS, an industrial by-product, was investigated. The conclusion display that adding GF and

NZ reduces the geopolymer composite's porosity and water absorption percentage. As a result of the reduction in

porosity, an increase in flexural and compressive strength was noted in the specimens containing GF and NZ.

When compressive strength and mass loss were evaluated by exposing the samples to temperatures of 200°C,

400°C and 600°C, the strength increased with increasing gel formation at 200°C. In comparison, a decrease was

observed at 400°C and 600°C. However, increasing fiber content and zeolite addition positively affected hightemperature strength. It was also found that adding NZ and GF reduced the loss of compressive strength in

specimens subjected to 18 freeze-thaw cycles. In general, 15% zeolite substitution and 0.3-0.6% GF were found

to improve the performance of geopolymer composite.