Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt

Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR–asphalt mixes prepared using the wet process. Mechanical testing on the ENR–asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR–asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR–asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.道路病害会带来高昂的养护成本。然而，随着对沥青行为与性能的认知不断深化，加之技术进步，道路工程技术人员得以探究添加外加剂与改性剂的诸多益处。为此，聚合物作为改性剂以提升沥青混合料性能的方案已得到广泛应用。本研究针对环氧化天然橡胶（epoxidized natural rubber, ENR）改性热拌沥青的性能特征展开探究。本研究采用湿法工艺制备ENR改性沥青混合料并开展相关试验。对ENR改性沥青混合料的力学试验结果表明，混合料的回弹模量受试验温度与加载频率的影响极为显著。另一方面，尽管ENR改性沥青混合料因弹性提升，在高温环境下的车辙性能有所下降，但相较于基质沥青混合料，其在中等温度区间的抗疲劳性能得到了改善。不过耐久性试验结果显示，ENR改性沥青混合料对水分存在轻微的敏感性。综上，通过掺入ENR作为改性剂，可提升沥青路面的整体性能，从而应对主要道路病害问题。