Study on the influence of sample size and test conditions on the capillary water absorption coefficient of porous building materials

Abstract

Capillary water absorption coefficient is one of the important wet parameters that characterize the liquid water absorption capacity of porous building materials. Relevant standards uniformly stipulate the size and test conditions of the specimen in analysis of this hygrothermal parameter for porous building materials. However, different porous building materials have different water absorption capabilities due to their pore structures. Therefore, the use of the same test conditions or standards when obtaining the capillary water absorption coefficient of the material will affect the accuracy of the obtained results. In this paper, an experiment with capillary water absorption was performed to study the influence of sample size, ambient temperature and water immersion depth on the capillary water absorption coefficient of foamed cement (FC), aerated concrete (AAC) and coral sand concrete (SHS) with different pore structures. The results show that the sample size and the depth of water immersion have a significant influence on the capillary water absorption coefficient value of FC; the ambient temperature has a significant influence on the capillary water absorption coefficient value of AAC. When temperature increases from 5°C to 35°C, the growth rate of the AAC capillary water absorption coefficient is about 71.3%. The depth of water immersion significantly affects the capillary water absorption coefficient value of the SHS. When the depth of water immersion increases from 3 mm to 10 mm, the growth rate of the SHS capillary water absorption coefficient is about 38.4%. ∙ Analyze the water absorption process of different pore materials. ∙Analyze the data processing method of capillary water absorption coefficient in different water absorption processes of materials. ∙Analyze the influence of sample size, ambient temperature, and water immersion depth on the capillary water absorption coefficient of different pore materials. ∙Weight analysis of factors affecting the capillary water absorption coefficient of different porous building materials. ∙Provide sample size, ambient temperature, water immersion depth and other experimental conditions and data processing methods for the determination of the capillary water absorption coefficient of different porous building materials.