新型软木颗粒混凝土的热湿性能及其应用研究

Hygrothermal Characteristics and Application of Novel Cork Granular Concrete

软木具有良好的保温和隔湿等优点,利用软木作为轻骨料填充混凝土可以有效改善混凝土的热湿性能,而建筑材料通常暴露在不同的湿环境中,忽略湿度对热物性参数的影响必然造成建筑能耗计算的不准确,且湿物性参数是建筑热湿耦合传递过程计算的基础参数。因此,本文利用软木的优良性能制备了不同软木体积掺量的混凝土,通过实验得到软木颗粒混凝土在不同相对湿度下的导热系数和比热,同时得到了材料的湿物性参数(等温吸湿曲线、液态水扩散系数和水蒸气渗透系数),并通过数值模拟计算软木颗粒混凝土应用到建筑上的热湿传递特性。结果表明:相对湿度从0%增加到100%时,材料的导热系数和比热随质量含湿量的最大增长率分别约为60.7%和26.7%。软木颗粒体积掺量从0%增加到50%时,导热系数最大下降率约为52%,建筑墙体内表面热流量和湿流量下降率分别约为38.2%和90.4%。

Cork has the advantages of good thermal insulation and moisture insulation,the use of cork as lightweight aggregate to fill concrete can effectively improve the thermal and moisture properties of concrete.Building materials are usually exposed to different wet environments.Ignoring the influence of humidity on thermal physical parameters will inevitably lead to inaccurate calculation of building energy consumption,and the wet physical parameters are the basic parameters for the calculation of building heat and moisture coupling transfer process Number.Therefore,this paper uses the excellent performance of cork to prepare concrete with different volumes of cork.Through the experiment,the thermal conductivity and specific heat of cork granular concrete under different relative humidity is obtained.At the same time,the hygric properties(isothermal adsorption curve,liquid water diffusion coefficient and water vapor permeability)are obtained.The results show that when the relative humidity increases from 0% to 100%,the maximum growth rates of thermal conductivity and specific heat with mass moisture content are 60.7% and 26.7%,respectively.When the volume fraction of cork particles increases from 0% to 50%,the maximum decrease rate of thermal conductivity is 52%.And the decrease rates of heat flow and moisture flow on the inner surface of building walls are 38.2% and 90.4%respectively.