Fire endurance of steel reinforced fly ash geopolymer concrete elements

•Effects of fire on reinforced fly ash geopolymer concrete elements were studied.•Geopolymer concrete panels had no spalling and less cracks than OPC panels in fire.•Geopolymer panels retained higher strength than OPC panels after 2 h in fire.•Over all, reinforced fly ash geopolymer concrete showed superior fire endurance.

As a new alternative to OPC, investigation into the fire endurance of geopolymer concrete is of utmost importance in order to ensure safety. Geopolymer and OPC concrete panels of 125–175 mm thickness containing a layer of steel mesh were exposed to fire for 2 h. Test results show higher heat transfer rate and less cracking and spalling in the geopolymer concrete specimens. The residual load capacity was between 61% and 71% for the geopolymer and between 50% and 53% for the OPC concrete panels. Thus, the reinforced geopolymer concrete elements demonstrated superior fire endurance than the OPC counterparts.