Discussion on the suitability of dynamic constitutive models for prediction of geopolymer concrete structural responses under blast and impact loading

Abstract

Compared to ordinary Portland cement-based concrete (OPC), geopolymer concrete (GPC) is an environmental-friendly construction material because it is mixed by replacing Portland cement with industry wastes such as fly ash. Despite intensive researches in the last two decades, application of geopolymer concrete in construction is still rather limited. One of the reasons is the quasi-static and dynamic material properties of geopolymer concrete, which are different from those of ordinary Portland-cement concrete, are not well defined yet, and the available design guides for geopolymer concrete structures are very limited. The existing design guides and dynamic constitutive models for OPC cannot be directly employed in design analysis and numerical modelling of GPC structures subjected to blast and impact loads. This paper first summaries the available dynamic material testing data on GPC, compares them with the widely used dynamic constitutive models for OPC, and discusses the suitability of those models for modelling GPC structures. Then, based on the available GPC material testing data, new material constants for strength model, equation of state and dynamic increase factors are derived for GPC. Finally numerical modellings are carried out using these material models with modifications for GPC material to examine their accuracies in simulating the dynamic responses and damages of structural components made of GPC subjected to blast and impact loads.