Cross validation of hygrothermal properties of historical Chinese blue bricks with isothermal sorption experiments

Abstract

The historical, cultural, and social value of heritage buildings mandates special protection of these structures. Blue brick is one kind of the main construction materials of heritage buildings, which is porous material and easily subject to deterioration due to environmental factors such as humidity. Therefore, determining the dynamic moisture content rule of materials under fluctuant ambient humidity is necessary for preventative conservation. This study measured the equilibrium moisture content of eight types of Chinese blue bricks under isothermal conditions with varying humidity levels. The results show that when ambient humidity increased from 10% to 90%, the moisture sorption of historical Chinese blue bricks tripled, which is 3 times greater than that of modern Chinese blue bricks and 10 (at low humidity) to 20 times (at high humidity) greater than that of clay bricks in the international handbook. The results contribute to the improvement of the international building material database and research related to hygrothermal performance of heritage buildings in East Asia.