Modelling Damage from the Nano-Scale Up

In the light of the developing use of cementitious materials in safety critical, high temperature applications associated with energy industries (nuclear, oil and gas) this work looks to the nano-scale to consider the origins of macro-scale phenomena. It enables a first comparison of nano-scale results with macro-scale observations, toward the inclusion of physico-chemico-mechancial processes in models at larger scales and a move away from phenomenological models. Assuming the development of nano-scale porosity to be the principal effect of temperature at the nano-scale, comparisons are here developed between nano-scale measurements, simulations and macro-scale experimental results. The results suggest that the effect of temperature on the nano/micro mechanical properties of cementitious materials might be responsible for a significant part of the experimentally observed trends at the macro-scale, although more work is required to understand scaling of fracturing. It is concluded that modifying the nano-scale material response to temperature gradients could eventually impact the engineering performance of structures at elevated temperatures