自保温混凝土-秸秆复合砌块热工性能研究

稻草秸秆作为一种新兴的绿色可再生建筑材料,在农村建筑节能开发中具有广阔的应用前景.设计了一种自保温混凝土-秸秆复合砌块,组成方式为在混凝土小型空心砌块孔洞中填充秸秆芯材.根据传热学基本理论对秸秆填充率分别为30%,35%,40%,45%,50%且长宽比不同的15组混凝土-秸秆复合砌块模型进行热工性能理论计算与模拟.研究结果表明:新型复合砌块的热工性能随着秸秆填充率的增大而加强;秸秆芯材横截面长宽比对复合砌块的传热系数影响很大,长宽比越大,传热系数越小,热工性能越好;当秸秆填充率为50%,且秸秆芯材横截面长宽比在规定范围内最大时,复合砌块热工性能较好,传热系数为0.851 W/(m2·K),保温性能远远好于相同尺寸下未填充秸秆芯材的混凝土小型空心砌块,建筑节能率达到56.2%,充分体现出该新型复合砌块的优越性.

On Thermal Performance of Self-Insulation Concrete-Straw Composite Block

As a new environmentally-friendly and renewable building material, rice straw has broad application prospects in energy conservation development of rural buildings. A kind of self insulation concrete-straw composite block is designed in this paper, which is made by filling straw core materials into the holes of small concrete hollow blocks. According to the basic theory of heat transfer, theoretical calculation and simulation of thermal performance of 15 sets of concrete-straw composite block model, whose straw filling rates are 30%, 35%, 40%, 45% and 50% respectively and have different length-width ratios, are carried out in this paper. The results show that the thermal performance of new composite block is strengthened with the increase of straw filling rate. The length-width ratio of cross section of straw core material has a great influence on the heat transfer coefficient of composite block, which indicates that the larger the length-width ratio, the smaller the heat transfer coefficient, the better the thermal performance. And when the straw filling rate is 50%, meanwhile the length-width ratio of cross section of the straw core material reaches the maximum within the specified range, the composite block of which the heat transfer coefficient is 0.851 W/(m²·K) shows good thermal performance, whose thermal insulation property is much better than the small hollow concrete block without straw core material under the same size and the building energy conservation rate reaches 56.2%. All of these characteristics fully demonstrate the comparative advantages of this new compound block.