Pre- and post-fire mechanical performances of high calcium fly ash geopolymer concrete containing granite waste

Abstract

The purpose of this study was to investigate the properties of fresh and hardened geopolymer concrete made with granite fines waste. In order to reduce the consumption of natural aggregates, the granite waste sourced from the stone industry was used as fine aggregates for making geopolymer concrete cured at room temperature. Natural river sand was replaced with the granite waste at 25% and 50% by weight. The effect of moisture conditions of fine aggregates on the properties of the geopolymer concrete were also investigated. The fine aggregates were prepared in three different moisture states: saturated surface dry (SSD), air-dry (AD) and oven-dry (OD). It was found that the slump flow of the geopolymer concrete increased with the increasing proportion of the granite waste in the mixture. Meanwhile, the initial and the final setting times were not influenced by the inclusion of the granite waste except when the fine aggregates were saturated. The presence of angular shaped particles enhanced the early compressive strength of geopolymer concrete with 50% replacement of natural sand by the granite waste. Furthermore, the fire test results showed that the geopolymer concrete with the granite waste had a similar spalling behavior to the one made entirely with the natural sand, but tended to show inferior post-fire residual strengths, particularly when the oven-dried aggregates were used.