Flexural performance of functionally graded RC cross-section with steel and PP fibres

Many studies have been conducted on the behaviour of reinforced concrete (RC) to determine the effects of different fibre types on the mechanical properties of concrete. Tests such as flexural and shear tests are used to evaluate the behaviour of RC. Most previous studies have focused on reinforcement of the entire cross-section with one fibre type, but the use of double-type reinforcement is growing and the lower cost of polypropylene (PP) fibres can be a significant factor in the use of double-type reinforcement. Therefore, in this work, experimental tests and numerical simulations were carried out to study reinforcement of the cross-section with steel fibres, PP fibres or both, in two separate layers. Beams were reinforced using 0·5%, 1% and 2% fibre volume fractions of steel and PP fibres. The beams with a reinforced cross-section with one or two fibre types were evaluated under flexural loading. The results showed that reinforcement of the entire cross-section with steel fibres led to a higher load-carrying capacity than reinforcement of the cross-section with two fibre types in two separate layers.