Drying index for in-service physical performance assessment of renders

摘要

The water vapour permeability of renders is related with the greater or lesser drying ability of this coating mortar system. Easy drying of an applied render allows a better water resistance and consequently its greater durability versus the physical degradation mechanisms in real in-service conditions. Presently this standard characteristic is not measured on site, and neither are there consensual in situ methods that allow an indirect relationship with this property. 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 fa ades. (C) 2016 Elsevier Ltd. All rights reserved.