Study on High-Temperature Behavior of Coal Gangue-Based Geopolymer Concrete Beams

Abstract

A newly coal gangue-based geopolymer concrete made from alkaline dry powder activator, coal gangue, and fly ash has been proposed by the authors. High-temperature behavior of the proposed geopolymer concrete beams with different cross sections reinforced with steel bars is investigated in the work here. High-temperature behavior by numerical simulation is validated by the existing experiment. High-temperature behavior is investigated by analysing the geopolymer concrete beams with different cross section dimensions. Temperature distribution and deformation of the beams from room temperature to fairly high temperature are studied. The isotherm contours of beams at different temperatures and the thermal stress contours of the beam at different time steps are obtained and analyzed. First, cracking load and ultimate load of the geopolymer beams with different concrete cover thicknesses are analyzed under different high temperature conditions. It is found that the temperature at the cross section centerline of coal gangue-based geopolymer concrete beam gradually decreases along the vertical direction. The cracking load and ultimate load of the geopolymer concrete beams at high temperature are affected by the thickness of concrete cover. With the increase of temperature, the mid-span deflection of the beam increases gradually. High temperature is a key factor for analysing the behaviors of coal gangue-based geopolymer concrete beams.