Drying shrinkage and thermal expansion of metakaolin-based geopolymer concrete pavement reinforced with biaxial geogrid

The most often used material in concrete pavement slabs is ordinary Portland cement concrete (OPC). Many of OPC pavement slabs crack due to drying shrinkage and thermal expansion of OPC before applying traffic loads. Geopolymer concrete is an environmentally friendly type of concrete that achieves early strength without the need of moisture curing and can be strengthened further by heating. Metakaolin – based geopolymer concrete (GPC) present a suitable behavior against volumetric changes in previous researches. Biaxial geogrid layers can be an effective and durable alternative for steel reinforcement to reduce cracks propagation and volumetric changes in concrete. In this research, biaxial geogrid reinforced GPC was investigated to evaluate its drying shrinkage and thermal expansion properties which affect cracks propagation due to thermal volumetric changes in concrete pavement slabs. Geogrid reinforcing in GPC and OPC displayed a suitable performance against drying shrinkage and thermal expansion. Biaxial geogrid reinforcement in GPC resulted in about 48% reduction in drying shrinkage strains and 45% reduction in thermal expansion strains.