Drying kinetics of building materials capillary moisture

Abstract

Drying of building materials capillary absorbed water is one of the main factors that determine buildings materials durability. Thus, the investigation of drying kinetics of capillary absorbed water can be very useful in understanding the causes of decay of building materials and in saving cost and improving the energy efficiency of constructions. In general, environmental conditions, such as air temperature, air velocity and air relative humidity, affect drying kinetics of various building materials.Most of the drying kinetics mathematical models use as initial moisture content the amount of water resulting by saturation of samples through immersion. In the present work, the drying process of capillary absorbed water, which describes more accurately materials behavior in buildings, was experimentally studied. An existing mathematical model was utilized. Several natural and artificial building materials were selected and examined (stones, clay bricks and natural hydraulic lime based mortars).The proposed mathematical model was found to fit successfully experimental drying kinetics data. Moreover, this model incorporated the environmental conditions, as well as the materials characteristics on the drying process. Thus, it can be applicable for use in building simulators concerning moisture transfer phenomena in building physics.