Thermal stresses in repair mortar

Mortars have increasing application in the repair of damaged reinforced concrete structures. One of the solutions could be polymer modified cement based mortars. Material properties of concrete and repair mortar are very often different. Concrete usually has the greater modul of elasticity than it is the designed modul of elasticity of repair mortar and, because of that, a repaired structural element behaves like a composite element formed of several layers with diferent properties. In this paper we have observed stresses that appear in a composite element composed of the concrete substrate and repair mortar, because of rapid temperature change. Properties and dimensions of the analyzed elements were taken according to HRN EN 13687:1999. It has been analyzed how the distribution of stresses depends on the thickness of the repair mortar overlay of certain properties and on the modulus of elasticity ratio between the substrate and mortar. The analysis was performed on a 2D model in the finite element analysis program.