Influence of steel fiber on compressive properties of ultra-high performance fiber-reinforced concrete

• X-ray scanning, as a non-destructive detection method, can test the pore structure of UHPFRC. In this paper, negative effect mechanism steel fiber on compressive properties UHPFRC is analyzed through flowability 36 UHPFRCs with different volume fractions and aspect ratios, scanning used to compare fresh hardened Based positive effects fiber, combined analysis data, prediction semi-empirical formulas strength modulus elasticity (MOE) were proposed, calculation accuracy was verified by collected data in work. Collected existing relationship between MOE strength. Then, experimental new empirical proposed. And collecting from literature. The (include elasticity) Ultra-high performance fiber-reinforced concrete (UHPFRC) are most important index structural design. This paper presents results tests conducted ratios investigate indicated that increase fraction or ratio increases. However, trend slowed down when exceeded 2%. It observed restrain occurrence development cracks specimens compressed, provided for reinforcing UHPFRC, but it also reduced which effect. CT revealed porosity size increased due its weakened flowability. A model established based fiber. Semi-empirical proposed regression revised database 155 addition, formula presented, 320 around world.