Drying index for in-service physical performance assessment of renders

This paper presents two experimental programs, in laboratory and in situ, which studied various drying parameters (drying rate and drying resistance index) and the corresponding relationships with hardened physical characteristics (water vapour permeability, open porosity and bulk density) relevant to characterize the in-service performance of mortars. Based on the experimental results, it is concluded that the drying resistance index (Di) is a good indirect measure of the in-service water vapour permeability of renders applied on building façades.