The hygroscopic properties of wood fibre, sepiolite and expanded perlite-based breathable wall for moderating the humidity environment

摘要

This paper presents an evaluation of a series of novel wood fibre, sepiolite and expanded perlite (WSE)-based mortars that have been developed by Hunan University. The evaluation investigated the influence of morphology structure and the effect of different hot-humid environments on hygroscopic properties of WSE-based mortar to form breathable wall which can provide a moderation of moisture, indoor air quality and thermal insulation of building. The microstructure, thermal conductivity, mechanical properties and hygroscopic properties of WSE-based mortar specimens were assessed to characterize the relationship between performances of the material. WSE is an inorganic porous fibre-aggregate mixture. The hygroscopic properties of the mortars can be greatly improved by adding the WSE fibres-aggregates, especially under high temperature (40℃) and high relative humidity (98%) during summer. The addition of admixture can improve the properties of WSE-based mortar to meet requirements of special performances (such as compressive strength) without affecting the hygroscopic properties. The WSE-based breathable wall is a good moisture buffering controller that could improve indoor air quality. The evaluation presented in this paper should provide the design fundamental for development of breathable wall for future built environment, to allow optimizing the boundary conditions for energy saving and control of indoor humidity environment by incorporating the mortars as finishing materials.