Huang Tuo, Li Mi, Huang Mou-Ying, Jiang Hao-Hao, Tang Yao, Liu Hong-Fu
National Engineering Laboratory for Highway Maintenance Technology, School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China.
School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China.
Materials (Basel). 2020 Jun 3;13(11):2541. doi: 10.3390/ma13112541.
Strength is an important parameter for the design of asphalt pavement materials and structures. To study the influence of various factors on the three-dimensional strength of asphalt mixtures, three aggregate gradations (dense-graded bituminous mixture AC-13, stone mastic asphalt SMA-13 and bituminous stabilization aggregate paving mixture OGFC-13) and two binders (SBS modified bitumen and 70# base bitumen) were used to prepare the asphalt mixture specimens. Among them, SBS+SMA-13 asphalt mixture has the best performance. On this basis, the uniaxial compressive test, uniaxial tensile test and confining triaxial test were conducted on the SBS+SMA-13 asphalt mixture under six oil-stone ratios conditions (5.5%, 5.7%, 5.9%, 6.1%, 6.3%, and 6.5%), six temperatures conditions (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C), and five loading rates conditions (1 mm/min, 2 mm/min, 3 mm/min, 4 mm/min, and 5 mm/min). In addition, a unified three-dimensional strength calculation model considering the influence of temperature, loading rate, and oil-stone ratio was proposed, and the change law of the three-dimensional strength with these above factors was revealed. Furthermore, two sets of three-factor three-level orthogonal tests were carried out on the SMA-13 asphalt mixture. The sensitivity analysis and strength regulation research between three-dimensional strength and each factor were carried out. The results show that the type of asphalt has the greatest influence on the strength of the mixture, the temperature has the second most influence, the loading rate has less influence, and the oil-stone ratio has the least influence. The strength regulations proposed to improve the strength of the asphalt mixture include the use of modified asphalt, high-temperature stability high-quality asphalt, and the lower oil-stone ratio than the Marshall optimal oil-stone ratio. The strength control measures proposed from the perspective of the three-dimensional stress state, the joint failure of each stress components and real stress states are taken into consideration.
强度是沥青路面材料与结构设计的一个重要参数。为研究各种因素对沥青混合料三维强度的影响，采用三种集料级配（密级配沥青混合料AC - 13、沥青玛蹄脂碎石混合料SMA - 13和开级配沥青稳定碎石排水式路面混合料OGFC - 13）和两种结合料（SBS改性沥青和70#基质沥青）制备沥青混合料试件。其中，SBS + SMA - 13沥青混合料性能最佳。在此基础上，对SBS + SMA - 13沥青混合料在六种油石比条件（5.5%、5.7%、5.9%、6.1%、6.3%和6.5%）、六种温度条件（5℃、10℃、15℃、20℃、25℃和30℃）以及五种加载速率条件（1mm/min、2mm/min、3mm/min、4mm/min和5mm/min）下进行了单轴压缩试验、单轴拉伸试验和围压三轴试验。此外，提出了考虑温度、加载速率和油石比影响的统一三维强度计算模型，揭示了三维强度随上述因素的变化规律。进一步地，对SMA - 13沥青混合料进行了两组三因素三水平正交试验。开展了三维强度与各因素之间的敏感性分析和强度规律研究。结果表明，沥青类型对混合料强度影响最大，温度次之，加载速率影响较小，油石比影响最小。提出的提高沥青混合料强度的强度规律包括使用改性沥青、高温稳定性优质沥青以及低于马歇尔最佳油石比的油石比。从三维应力状态、各应力分量的联合破坏以及实际应力状态的角度提出了强度控制措施。
