Thermal, Mechanical and Structural Properties of Mortars for Rehabilitation of Buildings Contaminated by Chlorides

An adequate choice of repair mortars is critical to the success of a restoration process. Renovation of old, damp, salty walls must solve the problems related the presence of salts dissolved in water. It is often connected to reconstructing the damp-course and repairing the facade together with cleaning, pointing, surface strengthening, hydrophobizing, as well as repairing or replacing the old, destroyed plasters, etc. As salt crystallization causes cracks, efflorescence, an increase in hygroscopicity, and overall decrease in functionality and durability of masonry and coating mortars, we focused at the presented paper on the assessment of the effect of chlorides presence on the thermal, mechanical and structural properties of two types of mortars designed for building renovation. The studied coating mortars are composed of lime hydrate, Portland or white cement, crushed limestone, perlite and chemical additives improving their workability and hydrophobicity. Except of standard moist curing, part of samples is immersed into the saturated NaCl solution. The obtained results show distinct effect of chloride ingress on mortars pore size and porosity what led to the significant changes in their thermal properties and mechanical resistance. Based on the experimental findings, it can be concluded the performed tests proved the applicability of studied mortars for renovation of buildings possessing excessive moisture and salt content.