水性聚氨酯改性不黏轮乳化沥青制备及其路用性能研究

Preparation of waterborne polyurethane⁃modified trackless emulsified asphalt and its road performance

为了解决沥青路面施工中黏层黏轮和服役中层间黏结不足的问题,制备了一种具有自迁移功能的水性聚氨酯改性不黏轮乳化沥青。通过针入度、软化点及不黏轮效果等实验评价了不黏轮乳化沥青路用性能,研究了水性聚氨酯改性不黏轮乳化沥青黏层微观形貌和流变特性。研究结果表明:水性聚氨酯改性剂在乳化沥青黏层养生过程中自主迁移至黏层表面;水性聚氨酯在不黏轮乳化沥青最佳掺量为3%;在35℃时,水性聚氨酯改性不黏轮乳化沥青黏层养生时间不大于30 min;水性聚氨酯改性不黏轮乳化沥青黏层在60℃时剪切强度大于1 MPa,在70℃时未发生黏轮现象,具有解决沥青路面施工中黏层黏轮和服役中层间黏结不足难题的潜力。水性聚氨酯改性不黏轮乳化沥青路用性能突出和施工过程环境友好,因此其有望在公路建设和养护工程中得到大规模应用,并可提高沥青路面服役寿命,助力公路交通高质量的发展。

To solve the problems resulting from tack coat tracking in the construction of asphalt pavement and its poor bonding in service,a new type of trackless emulsified asphalt(TEA)with self-migration functionality has been prepared.The road performance of the TEA was evaluated by means of penetration,softening point and tracking resistance tests.The micro-morphology and rheological properties of waterborne polyurethane-modified TEA tack coat were studied.The results showed that the waterborne polyurethane migrated to the surface of the emulsified asphalt tack coat during the curing process.The optimal content of waterborne polyurethane modifier in TEA was 3%.The curing time of the waterborne polyurethane-modified TEA tack coat at 35℃was less than 30 min.The shear strength of the polyurethane-modified TEA tack coat was greater than 1 MPa at 60℃,and the tack coat showed no tracking phenomenon at 70℃.This has the potential to solve the problems of tack coat tracking in the construction of asphalt pavement and its poor bonding in service.The polyurethane-modified TEA has an outstanding road performance and an environmentally friendly construction process.Therefore,it can be expected to be employed on a large scale in highway construction and maintenance projects,improving the service life of asphalt pavement,affording highway traffic with high quality.