Light Straw Composite Wall Construction Thermophysical Properties Research

Low-density wheat straw multi-layer wall (LWSMW) is a new building material in which low-density wheat straw board is used for thermal insulation, its invention and application provide a new way to make better use of wheat straw, settle the raw material problem in wood, reduce the energy consume. Low-density wheat straw multi-layer wall building provides people with a friendly and residential environment, and improves people's living level.The basic thermal properties of low-density wheat straw boards (LWSB) are measured by using Transient Plane Source (TPS) technique. Effects of thickness on thermal properties are studied .The result shows that LWSB are the heat insulation material of air bubble and organic matter, and have the good thermal properties. The thickness of 80 mm is good and it is small between inner-surface temperature and environment temperature. In addition, the heat resistance almost increases linearity with thickness adding.JW-I apparatus measures effects of the structure on the heat-transfer resistance of LWSMW and the heat-transfer resistance of LWSMW is compared with other walls. The results indicate that the heat-transfer resistance of experiment is bigger than theory. The factor of air layer has no effects on the heat-transfer resistance. The heat-transfer resistance of the structure A (fibre floor slab+ LWSB+ air layer+OSB) is the biggest and one of the structure B (fibre floor slab+ LWSB +OSB) is the most reasonable, one of these two structure is bigger than other walls.It tests thermal properties of demonstration house of low-density wheat straw and RC building, computes heat insulation propertiy of demonstration house and analyzes thermal inertia index by theory. The conclusion is that attenuation coefficient and delay time of demonstration house are bigger than RC building. The wall structure of demonstration house can be used in summer in Nanjing. The thermal inertia index of LWSB is bigger than common building material and thickness of acutely thermal fluctuating layers is only 32mm. The factor of air layer has no effects on the thermal inertia index. With LWSMW of having air layer and the same thickness, the thermal inertia index is bigger while the thickness of LWSB increases. The thermal inertia index of the structure B is the most reasonable and one of the structure B is bigger than other walls.