不同RAP掺量对高模量再生沥青混合料的抗裂性能影响研究

Study on Effect of Different RAP Dosages on Crack Resistance of High-modulus Recycled Asphalt Mixture

摘要:

高模量再生沥青混合料的路用性能取决于废旧回收沥青混合料RAP的掺量。为评估RAP掺量不同时对高模量再生沥青混合料的抗裂性能的影响，通过小梁弯曲试验分析了其不同掺量对抗裂性能的影响以支持公路工程的实际应用。研究结果表明：高模量热再生沥青混合料的马歇尔稳定度在RAP掺量为20%~40%范围内随掺量增加而增大，流值随掺量增大而减小；而在40%~50%范围内马歇尔稳定度随掺量增加而减小，流值随掺量增大而增大；RAP掺量增加的最佳油石比值也随之增加，而新加油石比则随着RAP掺量增加而减少；且随着RAP掺量的增加，其引起的弯拉破坏应变连续减少，弯拉强度和劲度模量却连续增加。试验结果表明天然高模量再生沥青混合料在RAP掺量占比为20%时的抗裂性能最好。

Abstract:

The pavement performance of high-modulus recycled asphalt mixture depends on the dosage of waste recycled asphalt pavement (RAP). In order to evaluate the effect of different RAP dosages on the crack resistance of high-modulus recycled asphalt mixture, the effect of different dosages on the crack resistance of high-modulus recycled asphalt mixture is analyzed by the three-point bending beam test to support the practical application of highway engineering. The results show that the Marshall stability of the high-modulus hot-recycled asphalt mixture increases with the increase of the RAP dosage of 20%~40%, and the flow value decreases with the increase of the RAP dosage, and in the range of 40%~50%, the Marshall stability decreases with the increase of the dosage, and the flow value increases with the increase of the dosage. With the increase of RAP dosage, the value of the optimal asphalt-aggregate ratio also increases, and the ratio of new asphalt and aggregate decreases with the increase of RAP dosage. With the increase of RAP dosage, its bending-tensile failure strain decreases continuously, and the bending-tensile strength and the stiffness modulus increase continuously. The test results show that the natural high-modulus recycled asphalt mixture has the best crack resistance when the RAP dosage is 20%.