水性环氧树脂改性乳化沥青微表处性能

Performances of micro-surfacing with waterborne epoxy resin modified emulsified asphalt

为评价水性环氧树脂改性乳化沥青微表处的性能,采用先乳化后改性的方法制备水性环氧树脂改性乳化沥青,利用三因素三水平正交试验确定最佳油水比、乳化剂掺量和水性环氧树脂掺量,并以其作为微表处胶结料。通过1h湿轮磨耗试验(WTAT)和负荷轮黏附砂试验(LWT)测定5组不同油石比微表处的磨耗值和黏附砂量,根据磨耗值或黏附砂量与油石比曲线交点确定微表处最佳油石比。采用6dWTAT、摆值试验和渗水试验分别评价微表处的抗水损坏、抗滑性能和防水性能,通过轮辙变形试验判定水性环氧树脂改性乳化沥青微表处可用于车辙填补,并利用车辙填补试验和罩面车辙试验评价微表处的抗车辙性能。研究结果表明:水性环氧树脂改性乳化沥青最佳油水比为65∶35,乳化剂掺量(质量分数,下同)为1.4%,水性环氧树脂掺量为4%,微表处最佳油石比在6.7%附近;微表处抗水损坏性能满足磨耗值不大于800g/m2的技术要求,抗滑性能满足摆值不小于70BPN的技术要求,且其高出技术要求,能为行车提供较好的摩擦力;经碾压养生后的微表处渗水系数为0,防水效果好;同时,微表处的宽度变形率和车辙深度率较小,可用于路面早期压密性车辙填补(不宜用于结构性车辙填补),经过微表处罩面后能显著提高路面的高温抗变形能力,有效恢复路面平整度。

In order to evaluate the performances of micro-surfacing with waterborne epoxy resin modified emulsified asphalt, waterborne epoxy resin modified emulsified asphalt was prepared by the method of emulsification first and then modification. The optimum oil-water ratio, emulsifier content and waterborne epoxy resin content were determined through orthogonal test with three factors and three levels. The 1 h WTAT （wet track abrasion test） and LWT （load wheel test） were conducted on micro-surfacing to measure abrasion values and adhesion sand contents of five groups of different asphalt-aggregate ratios, and the optimum asphalt-aggregate ratio of micro- surfacing was determined by the intersection point which was from curves of abrasion values or adhesion sand contents and the asphalt-aggregate ratios. The 6 h WTAT, the pendulum value test and the seepage test were conducted on micro-surfacing to evaluate the resistance to water damage, skid resistance performance and waterproofness, respectively. Micro-surfacing of water- borne epoxy resin modified emulsified asphalt could be used to fill rutting by the test of wheel rutting deformation, and the rutting resistance of the micro-surfacing was evaluated by the rutting resistance test and overlay rutting test. The results show that the optimum oil-water ratio, emulsifier content and waterborne epoxy resin content of waterborne epoxy resin modified emulsified asphalt are 65：35, 1.4 % and 4% （mass fraction, the same below）, respectively, and the optimum asphalt aggregate ratio of micro-surfacing is very close to 6.7 %. Performance of resistance to water damage of micro-surfacing meets the technical requirements that the abrasion values are not more than 800 g/m^2 , and the skid resistance performance of micro-surfacing also meets the current technical requirements that the pendulum number is no less than 70 BPN. And it is higher than the technical requirements, which can provide better friction for the traffic. The seepage coefficient of micro-surfacing is zero after rolling, which indicates that waterproof effect is good. Furthermore, the width deformation ratio and rutting depth ratio of micro-surfacing is very small, which can be used for filling the early compaction rutting （can not be used for filling the structural rutting）. Micro-surfacing after overlay can significantly improve the high temperature deformation resistance of road and efficiently restore roughness of road. 16 tabs, 4 figs, 24 refs.