Rheology and elevated temperature performance of geopolymer foam concrete with varying PVA fibre dosage.

• PVA fibre affects strength, rheology and fire resistance of geopolymer foam (GFC) • Compressive strength continuously increased with the PVA fibre dosage. • It highly improved the fire resistance until 200°C, above which the impact was mild. • A very high PVA dosage worsened the fire resistance above 200°C. • It increased the yield stress of interstitial paste more than the geopolymer slurry. This study presents the effects of Poly Vinyl Alcohol (PVA) fibre on the rheology and fire resistance of geopolymer foam concrete (GFC), which are important for the foam stability and elevated temperature performance of GFC respectively. The yield stress of fresh geopolymer slurry and the interstitial paste, the strength of the hardened GFC and their fire resistance were assessed and correlated to the fibre content. The results showed that the yield stress of geopolymer slurry and interstitial paste increased with the fibre dosage by up to 16 times. Adding fibre also continuously improved the compressive strength by up to 54%. Furthermore, the residual strength after exposure to elevated temperatures was improved with the fibre until 2% dosage; this was noticeable until 200°C. However, further increasing the fibre dosage deteriorated the residual strength. [ABSTRACT FROM AUTHOR]