<div>Effective thermal conductivity of moist aerated concrete with different porosities</div>

doi:10.3785/j.issn.1008-973X.2015.06.014

JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE)

Effective thermal conductivity of moist aerated concrete with different porosities

YAO Xiao-li1, YI Si-yang1, FAN Li-wu1, XU Xu2, YU Zi-tao1, GE Jian3

1. Institute of Thermal Science and Power Systems, Zhejiang University, Hangzhou 310027, China；2. College of Metrological and Measurement Engineering, China Jiliang University, Hangzhou 310018, China；3. Institute of Construction Technology, Zhejiang University, Hangzhou 310058, China

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Abstract

The effective thermal conductivity of autoclaved aerated concrete with different porosities was measured using Hot Disk thermal constants analyzer, which is based on the transient plant source technique to investigate, the thermal insulation performance of autoclaved aerated concrete. Data analysis results show that this instrument has good repeatability and is suitable for the thermal conductivity testing of moist building materials. Results also indicated that the effective thermal conductivity of moist aerated concrete increases monotonously with moisture content rising, and an inflection point appears when the moisture fraction is 15%. When the moisture fraction equal 25%, the thermal conductivity of moist samples is nearly twice that of dry samples. When the moisture fraction is as high as 100%, the thermal conductivity is 4 times as that of dry samples. The thermal conductivity of aerated concrete decreased with porosity increasing under the same moisture content. The predictor formulas for the effective thermal conductivity of aerated concrete about porosity and moisture fraction was proposed.

Published: 01 June 2015

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TU 528

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Cite this article:

YAO Xiao-li, YI Si-yang, FAN Li-wu, XU Xu, YU Zi-tao, GE Jian.

Effective thermal conductivity of moist aerated concrete with different porosities

. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(6): 1101-1107.

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http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2015.06.014 OR http://www.zjujournals.com/eng/Y2015/V49/I6/1101

不同孔隙率下含湿加气混凝土的有效导热系数

为研究含湿蒸压加气混凝土的保温性能,采用基于瞬态平面热源法的Hot Disk热常数分析仪测量不同孔隙率下含湿蒸压加气混凝土的有效导热系数.分析结果表明：Hot Disk热常数分析仪的测量结果具有较好的重复性,适用于含湿建筑材料导热性能的测试. 含湿加气混凝土的有效导热系数随含水率的提高呈现单调增长的趋势,其增长曲线在质量含水率为15%时出现明显的拐点. 当质量含水率约为25%时,含湿加气有效导热系数较干燥试样增大了近一倍；而当质量含水率高达100%时,混凝土的有效导热系数约为干燥试样的4倍. 在相同含水率下,加气混凝土的有效导热系数随孔隙率的增大而逐渐降低. 根据测量数据,总结得到加气混凝土有效导热系数关于孔隙率和质量含水率的预测公式.

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