Experimental test methods to determine the uniaxial tensile and compressive behaviour of ultra high performance fibre reinforced concrete (UHPFRC)

Ultra High Performance Fibre Reinforced Concrete (UHPFRC) is an exceptional type of concrete with superior mechanical and durability properties. The development of appropriate test methods to determine the mechanical properties of this material, especially the tensile behaviour, have been found to be challenging. This paper presents experimental studies using simple test methods to study the modulus of elasticity, stress–strain curve and post peak behaviour in both tension and compression of UHPFRC reinforced with and without steel fibres. Dog-bone shaped and cylinder specimens were tested in tension and compression, respectively. The tests were conducted using controlled closed-loop testing machines and Linear Variable Displacement Transducers (LVDTs), in a relatively straight forward manner. The effects of steel fibres on the tensile and compressive strength, modulus of elasticity and post-cracking behaviour at different ages were investigated. The efficiency and simplicity of the proposed tests method were studied. Finally, using the test methods described here, a complete stress–strain curve for UHPFRC was obtained, which can be used in advanced numerical modelling.