Experimental investigation of transient strains of GGBS-FA-SF blended geopolymer concrete at elevated temperatures

Fire is one of the most severe conditions encountered during the lifetime of a structure. Consequently, the provision of proper fire safety measures for structural members is a major safety requirement in building design. In this paper an experimental study is reported on the axial deformation of GGBS-FA-SF blended geopolymer mortar and geopolymer concrete with and without steel fibre when they are subjected to both mechanical and thermal loadings. The transient tests were conducted in Instron machine with additional heating facility. During the test the specimen was first subjected to a pre-defined mechanical load and followed by thermal heating. The transient axial deformations of the tested specimens were recorded using digital image correlation camera. By using the experimentally obtained temperature-dependent thermal strains of the specimen with different preloads the transient strains of the geopolymer mortar and geopolymer concrete with and without steel fibre are analysed and evaluated. Finally, empirical formulas are also proposed to reproduce the influence of the preload, heating temperature and constituents of the mix on the transient strain of geopolymer mortar and geopolymer concrete.