Thermal shock in mortar coatings on building facades

Among the various categories of mortar coatings based on hydraulic binders, cement-based coatings are used in many countries as a layer of protection for the structure and sealing and, at the same time, as a decorative finish. In order to maintain the expected level of performance throughout its useful life, the coating must withstand both the stresses that arise at an early age and those that, in its hardened state, are promoted by degradation agents that generally act simultaneously. One of the agents of mechanical degradation of cement-based materials, widely recognized in the literature, is temperature, above all because its variation inevitably causes tensile stresses, which are the most damaging due to the low tensile strength of mortars.