基于复合梁疲劳试验的沥青路面层间黏结评价

Evaluation of Interlayer Bonding of Asphalt Pavement Based on Composite Beam Fatigue Test

目的评价黏层油对沥青路面疲劳寿命的影响,确定适合北京地区沥青路面的黏层油的种类和最佳用量,研发了一种新型的复合梁疲劳试验.方法选取适用于北京市常用的橡胶沥青、橡胶SBS复合改性沥青、SBS改性沥青、SBS改性乳化沥青及普通乳化沥青5种黏层油,通过复合梁疲劳试验分析黏层种类、应变水平、结构层老化对疲劳寿命的影响并进行评价.结果使用同一种黏层油的复合梁的疲劳寿命随应变的提高而减小.使用橡胶SBS复合改性沥青作为黏层油的试件疲劳寿命均最长.复合梁疲劳寿命随黏层用量的增加呈现先增大后减小的趋势,由此可以得到复合梁疲劳寿命最大情况下的最佳黏层用量,即为疲劳寿命峰值黏层油用量.结论层间黏结效果的优劣对沥青路面结构层的疲劳寿命影响较大,两者具有良好的相关性.复合梁疲劳试验评价黏层的层间黏结效果是可行的.

A new type of composite beam fatigue test was developed to determine the type of tack coat material suitable for asphalt pavement in Beijing and the optimal dosage and to evaluate the effect of tack coat on the fatigue life of asphalt pavement.Five kinds of tack coat materials commonly used in Beijing were selected.They are rubber asphalt,rubber SBS composite modified asphalt,SBS modified asphalt,SBS modified emulsified asphalt and ordinary emulsified asphalt.The fatigue test of composite beams was used to analyze the effects of the type of tack coat,strain level and fatigue of structural layer on fatigue life.The fatigue life of composite beams using the same kind of tack coat material decreases with the increase of strain.The fatigue life of composite beams with rubber SBS composite modified asphalt as the adhesive layer is the longest.The fatigue life of the composite beam increases and then decreases with the increase of the amount of the tack coat.Therefore,the optimum dosage of the tack coat can be obtained when the fatigue life of the composite beam is maximum,which is the peak amount of the tack coat of the fatigue life.The effect of interlayer bonding has a great influence on the fatigue life of asphalt pavement layer and has good correlation.The composite beam fatigue test is feasible to evaluate the interlayer bonding effect of the tack coat.