Mesoscale modelling for investigating the thermo-mechanical behaviour of geopolymer concrete

Advancing the understanding of the behaviour of geopolymer concrete subjected to both thermal and mechanical loadings provides valuable assistance in the fire safety design of geopolymer concrete structures. Here in this research, a mesoscale modelling technique was proposed to simulate the free thermal expansion and behaviours of geopolymer concrete subjected to two different loading schemes. Results showed that transient thermal strain was clearly observable in the mesoscale modelling, and due to the existence of transient thermal strain, behaviours of geopolymer concrete under heat-then-load and load-then-heat schemes were quite different. Another further close look at the effect of volume fraction of aggregate found that change in volume fraction of aggregate altered the distributions of stress and strain in the geopolymer concrete. Both averaged strain and equivalent stress increased as the volume fraction of aggregate increased. • Thermo-mechanical behaviour of geopolymer concrete was investigated. • Mesoscale modelling was proposed to study behaviour of geopolymer concrete. • Coupled damaged plasticity microplane model was employed in mesoscale modelling. • Volume fraction of aggregate affected behaviour of geopolymer concrete. • Investigation on transient thermal strain was carried out.