Experimental Study on the Influence of the Shape of the Cross-Section on Fracture of Lightly Reinforced Concrete Beams

Abstract

This paper analyzes results from an experimental program planned to investigate the influence of the shape of the cross-section on the fracture of lightly reinforced concrete beams. Eight micro-concrete reinforced beams were tested. Tests were performed on beams with rectangular and three different T shapes, with two different arrangements of longitudinal reinforcement. Concrete mechanical properties were obtained from independent tests. Experimental errors due to material heterogeneity or imperfect test set-up were minimized to ensure a high level of control during test
execution. This experimental program demonstrates numerical results by G. Ruiz and J.R. Carmona, Mater. & Struct. 39, pp. 343-352, (2006), which indicate that the peak loads of T beams increase less than expected according to the traditional assumption that the crack zone develops as if a T-beam were a wider rectangular beam. A second peak is observed in the load-displacement curve due the progress
of the crack though the head of the beam.