Effects of binder content and curing type on the mechanical and fracture properties of ultra high strength fiber reinforced concrete

An investigational study was implemented to examine the effects of the different amount of binders on the most mechanical and fracture parameters such as; compressive and tensile strengths, modulus of elasticity, bending, toughness, stiffness, brittleness and ductility of Ultra-High Performance concretes (UHPCs) reinforced with 2% of micro steel fibers for generating Ultra-High Performance Fiber Reinforced Concretes (UHPFRCs). Depending on water curing (WC) and steam curing (SC) of the same water per binder ratios (w/b) of 0.12, two sets of UHPFRCs each of containing 850, 900, 950, 1000, 1050, 1100, 1150, and 1200 kg/m3 binder (85% of cement+15% of silica fume (SF)) were produced and tested for the compressive strength, splitting tensile strength, modulus of elasticity, modulus of rupture, load versus displacement curves, fracture energy, and characteristic length. This study revealed that the mixtures with 1150 kg/m3 of total binder contents exhibited the best results for all tests measured. The results also showed that at 1200 kg/m3 of total binder content, all improvements slightly began to decrease. On the other hand, all mechanical and fractural test results showed that steam cured much preferred than corresponded curing by water.