橡胶改性沥青纤维加强碎石封层抗污染试验研究和效果评价

Anti-pollution Test Research and Effect Evaluation of Rubber Modified Asphalt Fiber Reinforced Gravel Seal

橡胶改性沥青纤维加强同步碎石封层作为一种层间处置方式,具有强化沥青路面层间黏结、预防反射裂缝的作用。但是在层间界面受到污染的情况下,其是否仍然能够发挥作用,缺乏相应的研究验证。针对橡胶改性沥青纤维加强碎石封层,及两种应用场景(沥青面层与沥青面层之间,沥青面层与水泥稳定碎石基层之间),通过剪切强度试验和剪切疲劳试验对其在层间界面尘土污染、滞留水污染以及冻融循环作用下的性能衰变规律展开试验研究和效果评价。研究结果表明:0.5 mm厚度的界面尘土污染会导致层间剪切疲劳寿命下降95%,层间尘土污染程度需要控制在0.25 mm厚度以内;与不黏轮乳化沥青透层相比,橡胶改性沥青纤维加强碎石封层抵抗层间滞留水污染的能力更佳;冻融循环对层间性能的影响主要体现在前4次循环中,导致最大剪切应力下降40%,剪切疲劳寿命下降83%;研究对比了几种不同的制样方法和测试试验,提出了适用于层间界面污染效果的评价试验。研究结果可以为沥青路面施工技术和层间处置工艺提供参考。

As an interlayer disposal method, rubber modified asphalt fiber reinforced synchronous gravel seal has the function of strengthening the interlayer adhesion of asphalt pavement and preventing reflection cracks. However, under the condition that the interface between layers is contaminated, there is a lack of corresponding research and verification on whether the rubber-modified bitumen asphalt fiber reinforced gravel seal can still work normally. This research focuses on rubber-modified asphalt fiber reinforced gravel seals, relying on two application scenarios(between asphalt surface and asphalt surface, and between asphalt surface and cement stabilized crushed stone base), the shear strength test and the shear fatigue test are carried out to study and evaluate its performance decay law under the interlayer interface dust pollution, stagnant water pollution and freeze-thaw cycles. The research results show that the interface dust pollution with a thickness of 0.5 mm will reduce the shear fatigue life of the interlayer by 95%, and the degree of dust pollution between the layers needs to be controlled within the thickness of 0.25 mm;compared with the non-stick emulsified asphalt permeable layer, the rubber-modified asphalt fiber reinforced gravel seal has better resistance to interlayer water pollution;the effect of freeze-thaw cycles on interlayer performance is mainly reflected in the first 4 disposals, resulting in a 40% reduction in the maximum shear stress and a 83% reduction in the shear fatigue life;and several different sample preparation methods and test methods are compared in the study, and a more suitable test method for evaluating the pollution effect of the interlayer interface is proposed. The research results can provide literature references for asphalt pavement construction technology and interlayer disposal technology.