相变混凝土力学热学与相变循环稳定性的试验研究
发布时间：2019-06-12 03:30
【摘要】：在混凝土中掺入相变材料制备出相变混凝土,以其能够改善混凝土蓄热性能,提高能源利用率,减少建筑能量消耗等特点,受到越来越多的关注。但相变混凝土也存在强度较低,相变循环稳定性等问题。本文将硬脂酸丁酯,用活性炭吸附后,制成活性炭储能骨料,再将该骨料掺入混凝土中,以制备出相变混凝土。对不同相变循环次数下(0次、30次、60次),不同活性炭储能骨料掺量(0%、10%、15%、20%、25%)的相变混凝土进行了基本力学性能、导热系数、储放热和相变循环稳定性试验,并对试验结果进行了分析,以其制备出一种相变循环稳定,具有良好保温储热能力,同时力学性能满足要求的新型混凝土材料。基本力学性能试验表明:增加活性炭储能骨料的掺量,将导致相变混凝土的力学性能大幅降低,但当掺量不大于15%时,相变混凝土的压拉强度下降不超过10%,抗折强度下降不超过13%。相变混凝土基本力学性能受温度影响很小,室温30℃C和10℃C下,相变混凝土压拉强度相差小于2%,抗折强度相差小于4%。试块断裂面显示,活性炭储能骨料在混凝土中分布均匀,且封装良好,但其与混凝土的粘结性较差,影响了混凝土的力学性能。导热系数试验表明:相变混凝土的导热系数,随着活性炭储能骨料掺量的增加而大幅上升。当掺量超过15%时,导热系数增加超过25%,要保证保温能力,活性炭储能骨料的掺量应小于15%。室温越高,相变混凝土导热系数越高,活性炭储能骨料掺量为15%的相变混凝土,在室温30℃C时的导热系数和10℃C时相差小于4%。储放热试验表明:通过内部相变材料的融化和凝固,相变混凝土能够储存和释放热量,其储放热能力随着活性炭储能骨料掺量的增加而增强。活性炭储能骨料掺量为15%时,可使边长100min的立方体试块,中心温度波动幅度减小1℃C左右。在温度高于相变材料熔点时,相变混凝土表面会因相变材料融化形成斑点状油渍,油渍不会因相变材料凝固而消失,且油渍数量和活性炭储能骨料掺量成正相关。相变循环试验表明:活性炭储能骨料性质稳定,在相变循环过程中理化性质未发生变化,其对相变混凝土的基本力学性能和导热性能的影响未随相变循环发生明显改变。相变混凝土的相变循环稳定性良好,相变混凝土在相变循环后由于水份蒸发会出现密度和导热系数的降低,且随着相变循环次数的增加,降低幅度变缓并趋于稳定。去除龄期的影响,相变混凝土基本力学性能在相变过程中未发生明显变化,相变循环60次后,基本力学性能变化幅度小于4%。
[Abstract]:Phase change concrete is prepared by adding phase change materials into concrete, which has attracted more and more attention because of its ability to improve the heat storage performance of concrete, improve the energy utilization rate and reduce the energy consumption of buildings. However, the phase change concrete also has some problems, such as low strength, phase transition cycle stability and so on. In this paper, Butyl stearate was adsorbed with activated carbon to make activated carbon energy storage aggregate, and then the aggregate was added into concrete to prepare phase change concrete. The basic mechanical properties, thermal conductivity, heat storage and release heat storage and phase transformation cycle stability tests of phase change concrete with different phase transition cycles (0 times, 30 times, 60 times) and different amount of activated carbon energy storage aggregates (0%, 10%, 15%, 20%, 25%) were carried out, and the test results were analyzed to prepare a kind of phase transformation cycle stability and good heat preservation and heat storage capacity. At the same time, the mechanical properties of the new concrete materials meet the requirements. The basic mechanical properties test shows that the mechanical properties of phase change concrete will be greatly reduced by increasing the content of activated carbon energy storage aggregate, but when the content is less than 15%, the compressive tensile strength and bending strength of phase change concrete will not decrease by more than 10% and 13% respectively. The basic mechanical properties of phase change concrete are little affected by temperature. At room temperature of 30 鈩，
本文编号：2497693
[Abstract]:Phase change concrete is prepared by adding phase change materials into concrete, which has attracted more and more attention because of its ability to improve the heat storage performance of concrete, improve the energy utilization rate and reduce the energy consumption of buildings. However, the phase change concrete also has some problems, such as low strength, phase transition cycle stability and so on. In this paper, Butyl stearate was adsorbed with activated carbon to make activated carbon energy storage aggregate, and then the aggregate was added into concrete to prepare phase change concrete. The basic mechanical properties, thermal conductivity, heat storage and release heat storage and phase transformation cycle stability tests of phase change concrete with different phase transition cycles (0 times, 30 times, 60 times) and different amount of activated carbon energy storage aggregates (0%, 10%, 15%, 20%, 25%) were carried out, and the test results were analyzed to prepare a kind of phase transformation cycle stability and good heat preservation and heat storage capacity. At the same time, the mechanical properties of the new concrete materials meet the requirements. The basic mechanical properties test shows that the mechanical properties of phase change concrete will be greatly reduced by increasing the content of activated carbon energy storage aggregate, but when the content is less than 15%, the compressive tensile strength and bending strength of phase change concrete will not decrease by more than 10% and 13% respectively. The basic mechanical properties of phase change concrete are little affected by temperature. At room temperature of 30 鈩，
本文编号：2497693
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