Meso-scale model for concrete at both ambient and high temperature

Abstract

In this study, concrete is modelled at meso-level (10⁻⁴ - 10 cm) where aggregates, mortar and/or the Interfacial Transition Zone (ITZ) are explicitly considered. Aggregates are generated based on a given aggregate gradation and then, those are placed randomly (uniform distribution) in the concrete domain. The remaining space of concrete domain is then filled with cement mortar. In this numerical concrete model, both cube (150 mm × 150 mm × 150 mm) and cylinder (diameter 100 mm × height 200 mm) specimen are modelled, and their behaviour is simulated under uniaxial compression at ambient as well as at higher temperature. The results are validated against corresponding available experimental results reported in the literature. The results indicate that meso scale model of concrete can automatically capture the effect of specimen shape on compressive strength of concrete, consider transient creep strain and help to identify both local and global failure pattern. Such meso-scale based approach makes the modelling more robust with explicit consideration of the effect of aggregate and mortar. Simulated results also show that different random configurations of aggregates have negligible effect on the homogenised compressive strength of concrete.