曹国举 宫经伟 蔺元 陈瑞 王亮

摘 要：为了研究水泥石在服役期的导热系数影响因素，选取0.25、0.3、0.4、0.5、0.6五种水平水胶比制作水泥石试件，采用QTM-500导热仪测定了水泥石在不同温度下的导热系数，采用甲醇法测定其孔隙率，推出密实状态下水泥石导热系数与温度之间的关系式;利用正交试验方法，选用水胶比、粉煤灰掺量、矿渣掺量作为主要因素，考察不同温度下各个因素对水泥石导热系数影响的大小顺序以及显著性， 最终得到水泥石导热系数的预测方程。研究结果表明：水泥石导热系数与水胶比、孔隙率呈负相关性，与温度呈正相关性，温度每提高1 ℃，密实状态下水泥石导热系数增大0.006 8 kJ/（m·℃·h）;在不同温度下，各因素对水泥石导热系数影响的大小顺序为水胶比>矿渣掺量>粉煤灰掺量，且各因素对水泥石导热系数的影响均特别显著;通过对试验结果进行多元回归分析，得到水泥石导热系数与各因素之间的关系式，其预测精度较高。

关键词：水泥石;导热系数;温度;影响因素;正交试验

中图分类号：TV41;TU528 文献标志码：A

doi：10.3969/j.issn.1000-1379.2020.02.020

Abstract：In order to study the influencing factors of thermal conductivity of cement stone in service life， five levels of water-binder ratio （0.25，0.3，0.4，0.5 and 0.6） were selected to make cement paste specimen. The thermal conductivity of cement stone at different temperatures （20 ℃， 0 ℃ and -30 ℃） was measured by QTM-500 thermal conductivity instrument. The variation rule of thermal conductivity was investigated at different temperatures， and the porosity of cement paste was measured by methanol method. The relation between thermal conductivity of cement stone and temperature in dense state was deduced. The study used orthogonal test method， selected the water cement ratio， fly ash and slag as major factors， investigated thermal conductivity and significant of cement stone affected by the various factors at different temperature. Finally， the prediction equation of thermal conductivity of cement stone was obtained. The results show that the thermal conductivity of cement stone with water binder ratio and the porosity has negative correlation and is positively correlated with temperature. When the temperature increases by 1 ℃， the thermal conductivity of cement stone increases by 0.006 8 kJ/（m·℃· h）. Under different temperatures， the influence of various factors to the thermal conductivity of cement stone is as follows： water binder ratio > slag content > fly ash content， and the influence of various factors to the thermal conductivity of cement stone is very significant. The prediction equation between the thermal conductivity of cement stone and various factors has been obtained by multiple regression of the results of the test， and the prediction accuracy of this equation is high.

Key words： cement stone; thermal conductivity; temperature; influencing factor; orthogonal test

導热系数是温度场计算的重要指标之一。多年来，国内外众多专家学者提出了大量混凝土导热系数预估模型[1-4]。连续相且体积分数较大的水泥石导热系数对混凝土导热系数有着较大的影响，得到密实状态下水泥石的导热系数对提高混凝土导热系数预估模型计算精度具有重要的意义。另外，随着高性能混凝土的发展，各种矿物掺和料（粉煤灰、矿渣等）得到了广泛的应用，关于掺有矿物掺和料多组分的水泥石导热系数研究被广泛关注。目前关于……