Ishaq Muhammad Aakif, Giustozzi Filippo
Civil and Infrastructure Engineering, School of Engineering, RMIT University, Melbourne, VIC 3001, Australia.
Materials (Basel). 2021 Dec 17;14(24):7839. doi: 10.3390/ma14247839.
Accurate characterisation and appropriate binder selection are essential to increase the load-induced cracking resistance of asphalt mixtures at an intermediate temperature. Hence, the primary goal of this study was to correlate the cracking resistance exerted by the binder with the cracking performance of asphalt mixtures. The laboratory-based experimental plan covered various types of laboratory tests specified by various agencies and road authorities to study the correlation of a neat bitumen and five polymer-modified binders with their corresponding asphalt mixtures. The fatigue life of the binders was assessed through a Linear Amplitude Sweep (LAS) test and statistically correlated with various load-induced cracking parameters from the indirect tensile test, semi-circular bending (SCB) test, and four points bending beam test (FPBB) of asphalt mixtures at 25 °C. Binders and mixes were further grouped depending on their polymeric family (i.e., modified with a particular type of polymer) to validate their statistical correlation. The indicator that mostly correlated the binder properties with the asphalt mixture properties is the secant modulus from the SCB test. Fatigue parameters obtained through LAS better explain the asphalt fatigue performance obtained through FPBB; specifically, asphalt tests at high strain levels (e.g., 400 micro strain) better correlate to the LAS fatigue parameter (Nf).
准确表征和选择合适的粘结剂对于提高沥青混合料在中温下的荷载诱导抗裂性至关重要。因此，本研究的主要目标是将粘结剂的抗裂性与沥青混合料的抗裂性能相关联。基于实验室的试验计划涵盖了各机构和道路管理部门规定的各类实验室测试，以研究一种纯沥青和五种聚合物改性粘结剂与其相应沥青混合料之间的相关性。通过线性振幅扫描（LAS）试验评估粘结剂的疲劳寿命，并与25℃下沥青混合料间接拉伸试验、半圆弯曲（SCB）试验和四点弯曲梁试验（FPBB）的各种荷载诱导开裂参数进行统计关联。根据聚合物类型（即采用特定类型聚合物改性）对粘结剂和混合料进行进一步分组，以验证它们的统计相关性。将粘结剂性能与沥青混合料性能关联度最高的指标是SCB试验的割线模量。通过LAS获得的疲劳参数能更好地解释通过FPBB获得的沥青疲劳性能；具体而言，高应变水平（如400微应变）下的沥青试验与LAS疲劳参数（Nf）的相关性更好。
