Experimental analysis of longitudinal shear between the web and flanges of T-beams made of fibre-reinforced concrete

The longitudinal shear between the web and flanges of T-beams is an Ultimate Limit State contemplated by technical codes. For this reason, the longitudinal shear must be compared with the longitudinal shear resistance of the flange. Longitudinal shear strength can be increased by including steel fibres in the concrete mass. This article shows the experimental results of 13 T-beams mounted on two supports subjected to two central loads. Four of these beams were made with conventional concrete and nine with fibre-reinforced concrete. The direct instrumentation results are discussed and the failure process is described. Longitudinal shear cracking load is studied on the basis of both a theoretical approach and experimental results. An analysis is performed to evaluate each specimen's longitudinal shear, not only in the ultimate state, but also throughout the loading process evolution, based on load and strain records. This process involves determining each beam's effective width. The experimental data confirm an increase in longitudinal shear strength caused by adding steel fibres to concrete.