沥青混凝土低温性能试验和工程应用

Study on behaviors of asphalt concrete under low temperature

本文主要介绍了研究沥青混凝土低温性能的试验装置—自动补偿式沥青混凝土冻断试验系统,以及结合实际工程,利用该系统进行的沥青混凝土低温性能试验研究成果。自动补偿式沥青混凝土冻断试验系统的特点是能模拟实际温度变化,采用测量—比较—补偿的方法进行试验控制,实现试件在长度L内的零位移,以消除试验机架、试件夹具等联结处因温度应力产生的变形对试验结果的影响。沥青混凝土低温性能试验研究表明:(1)沥青品种对沥青混凝土冻断温度有显著影响;(2)沥青含量在±0.3%范围内变化时对冻断温度影响不显著;(3)添加适量的聚酯纤维在改善沥青混凝土高温性能的同时,没有降低其低温性能。

A testing facility for studying the behaviors of asphalt concrete under low temperature is developed. In the facility the actual variation of environmental temperature can be simulated and the control of test system is according to the principle of measuring-comparing-compensating to realize the zero replacement of specimen. Thus the effects of facility deformations due to temperature variation can be avoided. The testing facility is used to study the behavior of asphalt concrete under low temperature. The results show that： 1. the variety of asphalt affects the frost-break temperature of asphalt concrete significantly ; 2. when the asphalt content changes in the rang of ± 03 %, the frost-break temperature will not change obviously; 3. the performance of asphalt concrete under low temperature will not be reduced if proper polyster fibres are added, but the high temperature stability of the asphalt concrete will be improved.