沥青混合料低温抗裂性评价方法研究

Comparison Study of Evaluation Method for Low Temperature Anti-cracking Performance of Hot Mix Asphalt

一般评价沥青混合料低温抗开裂性能可从两方面进行 ,一方面看其在低温下的变形能力 ;另一方面看其在低温断裂时所能承受的断裂拉力的大小 .但以往多以其变形能力这一单一指标来衡量沥青混合料的抗开裂能力是不全面的 .为此从如何综合反应沥青混合料断裂时的应力、应变大小的角度出发 ,提出了评价沥青混合料低温抗开裂性能的压缩应变能指标及计算方法 ,并对两种改性沥青混合料进行了冻断试验和压缩应变能试验 ,比较了它们的试验结果 .

Generally the evaluation of low temperature anti-cracking performance of hot mix asphalt(HMA) should be carried out in two aspects,that is,in low temperature deformability and at the magnitude bearing low temperature breaking tensile force.Formerly,however,most of the evaluation of low temperature anti-cracking performance with single index-deformability was not comprehensive.Concerning how to reflect synthetically the magnitude of the stress and strain at the crack point,this paper puts forward an index-compression strain energy and its calculation method that are used to evaluate low temperature anti-cracking performance.And the 'Freeze-breaking' test and compression strain energy test of two kinds of hot modified asphalt mix were completed.Moreover,the results of the two tests were compared with each other.