Nazmey Kareem G, Eisa Mohammed S, Morsi Ahmed Gamal M, Debaiky Ahmed S
Civil Engineering Department, Benha Faculty of Engineering, Benha University, Benha, Egypt.
Sci Rep. 2024 Jul 6;14(1):15599. doi: 10.1038/s41598-024-65615-y.
Porous asphalt mixture is conventional hot mix asphalt (HMA) with substantially decreased fines, which produces an open-graded mixture that enables the water to flow through an interconnected void space. Porous asphalt is a permeable system that has a lot of benefits. However, because of its open structure, the durability of this mixture decreases, and both its stability and resilient modulus are much lower compared to the dense conventional asphalt mixtures. Also, the high void percentage may lead to an increase in the draindown proportion. Fibers (cellulose or mineral) and polymer-modified binders are recommended for porous asphalt mixtures, especially in hot and moderate climates. The objective of this study is to improve the porous asphalt mixture's performance by using ethylene-vinyl acetate (EVA) polymer-modified bitumen. Two types of fibers (cellulose fibers and glass wool fibers) were used, separately to determine the control mixture. Four different proportions of EVA polymer were added to the bitumen (1%, 2%, 3%, and 4%) and Scanning Electron Microscopy (SEM) was used for better investigating of the bitumen microstructure, then The Marshall mix design was used to determine the optimum EVA content (OEC) for the porous asphalt mixture. Several performance tests were conducted to investigate the characteristics of the porous asphalt mixture, such as the infiltration rate, binder draindown, the wheel track and the cantabro abrasion tests. The findings of the study conclude that the addition of EVA polymer to the porous asphalt mixtures enhances the performance as it increases stability by 20.8% and the infiltration rate by 20.6%. It decreases binder draindown proportion by 33.3%, cantabro abrasion loss by 25.1% and the rut depth at 5,000 cycles and 10,000 cycles by 29.8% and 19.7%, respectively.
多孔沥青混合料是一种细料大幅减少的传统热拌沥青（HMA），它形成一种开级配混合料，能使水通过相互连通的空隙空间流动。多孔沥青是一种具有诸多优点的透水系统。然而，由于其开放结构，这种混合料的耐久性降低，与密实的传统沥青混合料相比，其稳定性和回弹模量都要低得多。此外，高空隙率可能导致析漏比例增加。对于多孔沥青混合料，推荐使用纤维（纤维素或矿物纤维）和聚合物改性粘结剂，尤其是在炎热和温和气候条件下。本研究的目的是通过使用乙烯-醋酸乙烯酯（EVA）聚合物改性沥青来改善多孔沥青混合料的性能。使用了两种类型的纤维（纤维素纤维和玻璃棉纤维），分别用于确定对照混合料。向沥青中添加了四种不同比例的EVA聚合物（1%、2%、3%和4%），并使用扫描电子显微镜（SEM）来更好地研究沥青微观结构，然后采用马歇尔混合料设计来确定多孔沥青混合料的最佳EVA含量（OEC）。进行了多项性能测试，以研究多孔沥青混合料的特性，如渗透速率、粘结剂析漏、车辙和坎塔布罗磨耗试验。研究结果表明，向多孔沥青混合料中添加EVA聚合物可提高其性能，因为它使稳定性提高了20.8%，渗透速率提高了20.6%。它使粘结剂析漏比例降低了33.3%，坎塔布罗磨耗损失降低了25.1%，在5000次循环和10000次循环时的车辙深度分别降低了29.8%和19.7%。
