Experimental investigation on the use of Fabric-Reinforced Cementitious Mortars for the retrofitting of reinforced concrete dapped-end beams

The structural performance and durability of reinforced concrete (RC) dapped-end beams may be significantly threated by the effects of deterioration and environmental actions, compromising the structural robustness of important infrastructures such as bridges. The study of the critical role of dapped-ends has grown in recent years, focusing in particular on the implementation of innovative retrofit solutions capable of extending the service life of these structural elements. In this paper, an experimental investigation on the contribution of Fabric-Reinforced Cementitious Matrix (FRCM) retrofitting system to the load bearing capacity of RC dapped-end beams is presented. A set of eight full-scale dapped-ends was subjected to monotonic loading tests. The presence of cracks prior to the application of the retrofitting composite, which may represent the actual state of conservation of existing RC half-joints subjected to heavy traffic loads, is reproduced by testing the specimens up to the reaching of the ultimate design load. Different orientations of the alkali-resistant glass fabric composing the FRCM system were tested, and the results allow to discuss the effectiveness of the retrofitting solution.