Performance of reinforced mortar with meshes: study of cracking and mechanical behavior

Abstract The use of mesh for facade cladding reinforcement has become a highly effective way to help in preventing and reducing cracks, as it can absorb the stresses that occur in the coating system. This research study seeks to evaluate the incidence of cracks in mesh reinforced coatings submitted to thermal variation, aiming to contribute to the knowledge of the performance and behaviour of mesh in mortar coatings. Hence, the direct tensile strength of three different meshes (one made of polyethylene and two galvanised ones) was evaluated with regards to their use as reinforcement in mortars. The properties analysed were compression, tensile, flexion and shear strength. Thereafter, prototypes of facades coated with mortar reinforced with mesh were constructed, observing the behaviour of the system after thermal loading (38 ºC and 80 ºC) by means of thermography, crack mapping and impact resistance, further evaluating the efficiency of two crack repair methodologies (polyester mesh with acrylic plaster and epoxy resin). The results revealed that the electro-welded galvanised mesh produced a better performance, as it absorbed part of the stresses and reduced the crack openings, guaranteeing better flexural strength. Both repair methodologies showed an adequate performance with regards to thermal exposure.