沥青路面裂缝密封胶的低温应力松弛评价指标-同济大学学报.docVIP

文章编号：A Low-Temperature Stress Relaxation Evaluation Index of Asphalt Pavement Crack Sealants LI Feng, HUANG Song-chang (Research Institute of Highway, Ministry of Transport, Beijing 100088,China) Abstract: Four kinds of hot-applied sealants and two kinds of silicone sealants are tested by low-temperature extension test according to the transport industry standard to evaluate the low-temperature stress relaxation performance of the asphalt pavement crack sealants. The stress relaxation tests are started when the strain of the sealants is up to 50%. The three-parameter solid model is used to analyze the test data. The results show that the viscoelastic behavior of the sealants could be modeled very well by the three-parameter solid model, and two parameters of the solid model, maximum relaxation rate and relaxation time, which represent the viscoelastic characteristics of the sealants, has the potential of evaluating the stress relaxation performance for different sealants, though the fitting process is very complex. Furthermore, a relaxation index is defined in this work. The evaluation results with this index have no big difference with the results from the viscoelastic parameters. However, the relaxation index is more feasible and easy to use. The relaxation index can be used as a supplementary indicator for the low-temperature performance evaluation of the sealants on the basis of the transport industry standard. Key words: road engineering; sealant; stress relaxation; three-parameter solid model; viscoelastic; relaxation index 收稿日期：2011-05-23 基金项目：国家自然科学基金资助项目 第一作者：李峰（1979-），男，副研究员，主要研究方向为沥青路面养护技术.E-mail: f.li@rioh.cn 裂缝是沥青路面的主要病害之一。采用密封胶进行路面开槽灌缝，封闭路面裂缝，防止水渗入路面结构内部，是国际上公认的减缓路面病害出现、延长路面使用寿命的有效手段。目前，国内采用的密封胶来源广泛，但使用效果不尽理想，特别是低温性能普遍较差，很多密封胶一到冬季即与裂缝壁撕裂，失去了防水的效果[1]。密封胶的低温性能已经成为制约沥青路面灌缝技术发展的一个关键因素。2009年，交通运输部颁布了《路面橡胶沥青灌缝胶》（JT/T 740-2009）[2]，为规范我国沥青路面密封胶的质量提供了技术标准。该标准采用低温拉伸试验评价密封胶的低温性能，针对不同类型的密封胶，规定了不同的试验温度，并提出了相应的技术要求。经过两年多的应用，证实该标准可以有效地区分不同密封胶的低温性能，但仍然存在