Cracking in FRC R/C elements: a preliminary experimental study

Tension stiffening is still a matter of discussion in the scientific community. The ability of resisting tensile stresses by concrete within cracks is significant in diminishing the deflection of members. With the adoption of tougher material in tension, such as Fiber Reinforced Concrete (FRC), also the beneficial effect of tension softening can be considered. Therefore the deflection decreases in a more significant way and, moreover, the crack spacing changes determining, in general, a more distributed crack pattern characterized by narrower cracks which are more closely spaced. This paper aims at investigating this phenomenon by reporting and discussing preliminary tension stiffening tests on reinforced concrete prisms having different size, reinforcement ratios, concrete cover and amount of fibers. The influence of fibers in enhancing the post-peak response in terms of reduction of displacements and crack spacing will be widely investigated and discussed.