HYGROTHERMAL CHARACTERIZATION OF POROUS BUILDING MATERIALS-EXPERIMENT RESEARCH ON LIQUID WATER ABSORPTION AND DRYING

摘要

The research on the water absorption and drying ability has an important function on the controlling and solving hygrothermal problems, such as durability, thermal insulation, mold growth and indoor air quality, when building materials are in high humidity environment, especially there is liquid water, e.g. substructure, exterior wall flushed by rain water. In this paper, the eco-stucco was tested according to traditional method to operate the water uptake and drying experiment. The surface character of eco-stucco has a huge influence on water absorption coefficient. Aw is 0.10107 kg·m-2·s-0.5 when there are lots of porous on the surface of eco-stucco contacting with water, while Aw is 0.04652 kg·m-2·s-0.5 when there are less of porous, that means more capillary tube, the larger water absorption coefficient, the stronger water uptake ability. Meanwhile logistic model could be used to describe the drying process of eco-stucco pretty well and has a meaningful physic significant. At the same time, SEM was used to test and analyze surface characteristics of eco-stucco, which has the big effect on water adsorption coefficient. For the same materials with the different surface character due to the curing process or other factors, water adsorption coefficient is different.