Studies show that warm mix asphalt (WMA) technology is a practical solution against the high production temperature of rubberized-asphalt (RA) mixtures. RA mixture containing WMA additive is considered as an eco-friendly technology contributing to noise reduction and performance optimization of asphalt mixtures. This study aims to introduce two organic WMA additives called slack wax (SW) and polypropylene wax (PPW) which are used to lower the production temperatures by reducing the viscosity of RA mixtures. Rotational viscosity (RV) as a common bitumen test (Equiviscous, ZSV, and S-ZSV methods), as well as tests related to mixtures including resilient modulus ( M r ) and moisture susceptibility (TSR and MRR methods), were carried out on binder and mixture specimens. According to the results, 6% (by the binder’s weight) of both WMA additives reduced the mixing and compaction temperatures of the RA binder by about 20–25 °C. Also, CRM and both WMA additives improved the stiffness of mixtures by increasing the resilient modulus ( M r ). In terms of moisture susceptibility, although nearly all specimens could pass the minimum requirement of SCDOT, both WMA additives and CRM caused a reduction in ITS value of wet mixtures and final TSR value. MRR test results followed a similar trend, though resilient modulus was more sensitive to moisture damage compared to ITS. The results suggest that PPW and SW are suitable and cost-effective warm additives that can be used in combination with CRM in areas with hot climates and low precipitation. Nevertheless, additional experiments should be done to further validate the performance of CRM mixtures with these two warm additives.

中文翻译：

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两种温拌沥青 (WMA) 添加剂改性橡胶沥青混合料的生产温度和机械性能

研究表明，温拌沥青 (WMA) 技术是解决橡胶沥青 (RA) 混合物生产温度高的实用解决方案。含有 WMA 添加剂的 RA 混合料被认为是一种有助于沥青混合料降噪和性能优化的环保技术。本研究旨在介绍两种称为松散蜡 (SW) 和聚丙烯蜡 (PPW) 的有机 WMA 添加剂，它们用于通过降低 RA 混合物的粘度来降低生产温度。旋转粘度 (RV) 作为一种常见的沥青测试（等粘度、ZSV 和 S-ZSV 方法），以及与包括弹性模量 (M r ) 和湿敏度在内的混合物相关的测试（TSR 和 MRR 方法）粘合剂和混合物试样。根据结果​​，6%（按粘合剂重量计）的两种 WMA 添加剂将 RA 粘合剂的混合和压实温度降低了约 20–25 °C。此外，CRM 和两种 WMA 添加剂通过增加弹性模量 (M r ) 来改善混合物的刚度。在湿气敏感性方面，尽管几乎所有样品都可以通过 SCDOT 的最低要求，但 WMA 添加剂和 CRM 都会导致湿混合物的 ITS 值和最终 TSR 值降低。MRR 测试结果遵循类似的趋势，尽管与 ITS 相比，弹性模量对湿损更敏感。结果表明，PPW 和 SW 是合适且具有成本效益的暖添加剂，可在气候炎热和降水量少的地区与 CRM 结合使用。尽管如此，