摘要
导热系数是路面材料关键的热物理参数之一,由于路面材料的多相性,现有试验方法在试件制备、测试可操作性等方面仍存在一定的不足。笔者在原ASU圆柱试样法的基础上提出了改进ASU圆柱试样法,改进方法包括采用更符合现场采样的圆柱体试样,减小试样中心导热孔以缩短试样达到温度稳定状态时间,利用外侧橡胶护圈固定表面数据采集热电偶,以及在中心孔填充试验砂等措施,以进一步提高导热系数试验结果的准确性和可操作性。分别采用改进ASU圆柱试样法和原ASU圆柱试样法对已知导热系数的超高分子量聚乙烯材料、美国4个不同州的沥青混凝土和水泥混凝土的导热系数进行了研究。结果表明,通过改进试验设备、采用湿润的有机砂填充试样中心孔洞能够有效降低试验中温度损失,提高温度数据读取的精确性,改进ASU圆柱试样法在试验可操作性、可重复性、用时以及试验结果准确度等方面均得到进一步优化,能够更好地用于沥青混凝土和水泥混凝土路面材料导热系数测量。
Thermal conductivity is one of key thermal physical parameters of pavement materials.Due to the heterogeneous nature of pavement materials,the existing test methods still have some deficiencies in the preparation of test specimen,test operability and other aspects.On the basis of the original ASU(Arizona State University)cylinder specimen method,the authors put forward the improved ASU cylinder specimen method.It includes using the cylinder specimen which is more suitable for field sampling,reducing the heat conduction hole in the center of specimen to shorten the time for the specimen to reach the temperature stable state,using the outer rubber retainer to fix the surface data to collect the thermocouple,and filling the center hole with test sand,so as to further improve the accuracy and maneuverability of thermal conductivity test results.The thermal conductivity of UHMWPE materials with known thermal conductivity,asphalt concrete and cement concrete in four different states in the United States,are studied by using the improved and original ASU.The results show that the temperature loss can be effectively reduced,and the accuracy of temperature data reading can be increased by improving the test equipment and filling the central hole of cylinder specimen with wet organic sand.Compared with the test results of ASU,test results of the two kinds of concrete using the improved ASU cylinder specimen method are lower.Compared with cement concrete,the accuracy of thermal conductivity of asphalt concrete is higher.This is mainly due to the lower water absorption of asphalt concrete materials,which makes the test less affected by water,the accuracy of the test results is improved.The improved ASU cylindrical sample method is further optimized in the aspects of test operability,repeatability,time and accuracy of test results,which can be better used for thermal conductivity measurement of asphalt concrete and cement concrete pavement materials.
作者
耿巍
郑冬
钱振东
赵尘
GENG Wei;ZHENG Dong;QIAN Zhendong;ZHAO Chen(School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China;Nanjing Vocational Institute of Transport Technology,Nanjing 211188,China;Intelligent Transportation System Research Center,Southeast University,Nanjing 211188,China)
出处
《林业工程学报》
CSCD
北大核心
2020年第5期139-144,共6页
Journal of Forestry Engineering
基金
国家自然科学基金(51678146)
南京交通职业技术学院科研基金(JZ1801)。
关键词
路面材料
导热系数
ASU圆柱试样法
改进
道路工程
pavement materials
thermal conductivity
ASU cylindrical sample method
improvement
road engineering
