Coupled heat and moisture transfer in hollow concrete block wall filled with compressed straw bricks

Coupled heat and moisture transfer has a severe influence on building envelop durability. This phenomenon has more concerns as the rapid development of new moisture buffering materials. In this paper, a detailed description of hollow concrete block filled with compressed straw bricks is presented. In order to reveal heat and moisture coupling mechanism of the multilayer energy-saving wall, a series of tests were developed based on our designed controllable coupled heat and moisture test. The experiments were divided into 3 groups according to directions of heat and moisture transfer and the variations of boundary conditions. The temperature and humidity profiles within the wall thickness through two different directions are monitored during the test. The experimental results highlight the important influence of temperature and relative humidity gradient on the hygrothermal properties of the multilayer wall. It also illustrates that filling compressed straw bricks into hollow concrete block can hinder heat transfer and improve moisture buffering performance of multilayer wall. Based on our developed model, a piece of software (HMCT 1.0) to simulate the hygrothermal performance in multilayer wall was proposed for deep understanding of the experimental results. A good agreement was found between simulation results and tested values.