Simplified chemo-mechanical model of hydration/expansion of calcium-oxide-type expansive agent in cement-based materials Available to Purchase

The restrained volume expansion of expansive agents during hydration is often used to offset strains caused by the shrinkage of cement-based materials (CBMs). The hydration and expansion process of a laboratory-prepared calcium-oxide (CaO)-type expansive agent (CEA) in CBMs and modelling of the same are discussed in this paper. Based on isothermal calorimetry and thermogravimetry/differential thermal analysis, the hydration behaviour of the CEA in cement paste was examined, based on which the hydration kinetics were analysed and the apparent hydration activation energy of the CEA was calculated. Based on the degree of hydration, a chemo-mechanical model of the expansion of the CEA in CBMs was developed and analysed by comparison with experimental data obtained by the dual-ring restraint test method. Based on this model, it is possible to predict the expansion performance and crack resistance of concrete containing CEA agent.