Upgrading the push-off test to study the mechanisms of shear transfer in FRC elements

In this paper an upgrading of the push-off test in pre-cracked specimens is presented. The test is performed under conditions of crack control both in the pre-cracking and in the push-off stages. To this end, transversal forces to control the crack opening are introduced. Additionally, this confinement system avoids unnecessary movements that may introduce strains in the specimen. It is also included the methodology to perform the pre-cracking of the specimens prior to the push-off test. Specimens of 40 MPa of concrete compressive strength are used with two types of steel fibers type as well as with transverse reinforcement. It can be concluded that it is possible to perform the push-off test under crack control as it is shown with the results of crack width obtained with different measurement techniques. Different types of behavior after cracking can be detected such as hardening or the evolution of post-cracking residual stresses.