Department of Civil and Environmental Engineering, University of Sharjah, Sharjah, UAE.
Jordan University of Science and Technology, Irbid, Jordan.
Sci Prog. 2020 Oct-Dec;103(4):36850420959876. doi: 10.1177/0036850420959876.
Major distresses such as rutting, fatigue, and thermal cracking are facing asphalt pavement structures due to continuous heavy traffic loading and climate change. The modification of asphalt binders (one of the main components of the asphalt paving mix) has the potential to mitigate distresses through using different additives. Polymer modified asphalt (PMA) binders showed a noticeable resistance to pavement distresses as reported in previous studies. The present study aims to evaluate the effect of polymer modification on the rheological properties of asphalt binders through laboratory tests. The polymers included styrene-butadiene-styrene (SBS) and epolene emulsifiable (EE2) types. The 60/70 binder was used as a control for comparison. The Mechanistic-Empirical Pavement Design Guide (MEPDG) was also utilized to simulate the effect of PMA binders on the rheological properties under different climatic conditions and structural capacities. Additionally, the MEPDG was further utilized to compare the effect of asphalt binders on rheological properties using four different binder input levels. Findings of the study showed that laboratory tests experienced varying outcomes regarding the most efficient asphalt binder by means of distresses resistance. However, the MEPDG evaluation showed that the overall ranking of asphalt binders positively impacting the rheological properties was as following: (1) 4.5% EE2 PMA, (2) 4% EE2 PMA, (3) 60/70 binder, (4) 5% SBS PMA, and (5) 4% SBS PMA binders. Furthermore, statistical analysis illustrated that the effect of using different binder input levels on the performance of pavement varied relatively to the evaluated distresses. The analysis showed that using different binder input levels would affect, to a certain extent, the asphalt binder influence on rheological properties only when evaluating rutting and fatigue distresses. Therefore, it is recommended that precise asphalt binder inputs, that is, shear complex modulus (G*) and phase angle (δ) are used when designing pavement structures in regions with hot and mild climate conditions.
由于持续的重载交通和气候变化，沥青路面结构面临着车辙、疲劳和热开裂等主要病害。通过使用不同的添加剂，改性沥青结合料（沥青混合料的主要组成部分之一）具有减轻病害的潜力。如先前的研究报告所述，聚合物改性沥青（PMA）结合料显示出对路面病害有明显的抵抗力。本研究旨在通过实验室试验评估聚合物改性对沥青结合料流变性能的影响。所使用的聚合物包括苯乙烯-丁二烯-苯乙烯（SBS）和可乳化的乙丙橡胶（EE2）。60/70 基质沥青被用作对比的控制材料。还利用力学-经验路面设计指南（MEPDG）模拟不同气候条件和结构能力下 PMA 结合料对流变性能的影响。此外，还利用 MEPDG 比较了四种不同的结合料输入水平对沥青结合料流变性能的影响。研究结果表明，实验室试验在通过抵抗病害来确定最有效的沥青结合料方面得出了不同的结果。然而，MEPDG 的评估结果表明，对流变性能有积极影响的沥青结合料的总体排名如下：（1）4.5%EE2 PMA；（2）4%EE2 PMA；（3）60/70 基质沥青；（4）5%SBS PMA；（5）4%SBS PMA 结合料。此外，统计分析表明，使用不同的结合料输入水平对路面性能的影响与评估的病害相对应而有所不同。分析表明，仅在评估车辙和疲劳病害时，使用不同的结合料输入水平会在一定程度上影响沥青结合料对流变性能的影响。因此，建议在炎热和温和气候条件下设计路面结构时，使用精确的沥青结合料输入值，即剪切复合模量（G*）和相位角（δ）。
