Stress–strain behaviour and failure properties of ultra-high-performance concrete

In this paper, ultra-high-performance concrete (UHPC) and its constituents were evaluated by way of instrumented and non-instrumented mechanical-property tests and imaging techniques. Through image analysis, the average size, per cent area, nearest-neighbour distance and relative number density of each inclusion type were determined. Instrumented mechanical-property testing was conducted to obtain estimates for the relative behaviour of UHPC's various constituents. Different combinations of constituents were produced to measure indirect tensile strength, compressive strength, elastic modulus, Poisson's ratio and overall stress–strain behaviour to failure at early and later ages. Stress–strain behaviour and Poisson's ratio of UHPC aligned well with the literature, while constituents of UHPC also showed linear stress–strain relationships and comparable Poisson's ratios. Tensile behaviour at early and late ages was characterised and was found to be driven by inclusion of fibres. Characterisation of UHPC and its constituents is envisioned to be used to further modelling efforts by basing mathematical relationships on physical measurements.