Characterisation of temperature and loading rate dependent bond strength on the Bitumen-aggregate interface using direct shear test
Characterisation of temperature and loading rate dependent bond strength on the Bitumen-aggregate interface using direct shear test
复制标题
使用直接剪切试验表征沥青-骨料界面上的温度和加载速率相关的粘结强度
DOI：
10.1016/j.conbuildmat.2023.132284
复制
发表时间：
2023
影响因子：
7.4
通讯作者：
Dong M
中科院分区：
文献类型：
--
作者：
Dong M
研究了沥青-集料界面粘结强度随温度和加载速率的变化规律。首先采用集料-沥青-集料夹层样品，使用应变控制的直接剪切试验来量化其在四种不同温度（15、25、35和45 °C）和四个加载速率水平（5、10、15和20 mm/min）下的粘结强度。然后，通过传统上用于确定聚合物基材料的温度依赖性复模量的时间-温度叠加原理（例如，沥青粘合剂或混合物）。通过对沥青-集料界面的SEM观察，分析了温度和加载速率对沥青-集料界面剥离的影响。最后，在不同的温度下的内聚和粘合剂剥离的百分比进行了量化。结果表明，时间-温度叠加原理适用于不同温度和加载速率下沥青粘结强度的量化。通过对直剪试验中所测粘结强度的对比分析，其主曲线能较好地反映沥青-集料界面在较宽温度和加载速率范围内的粘弹特性。在15 °C和25 °C时，界面裂纹主要表现为内聚和粘着脱粘的组合;而在35 °C和45 °C时，则以内聚脱粘为主。这一观察结果归因于这样的事实，即随着温度升高，沥青分子的链网络变得松散并且其运动活性增强，这导致沥青分子之间在经受剪切载荷时的脱粘和更高百分比的内聚破坏。
The objective of this paper is to characterise the temperature and loading rate dependences of bond strength on the bitumen-aggregate interface. An aggregate-bitumen-aggregate sandwich sample was first employed to quantify its bond strength under four different temperatures (15, 25, 35, and 45 °C) and four levels of loading rate (5, 10, 15, and 20 mm/min) using a strain-controlled direct shear test. Then, a master curve of bond strength on the bitumen-aggregate interface was constructed via the time–temperature superposition principle traditionally used to determine the temperature-dependent complex modulus of polymer-based material (e.g., asphalt biner or mixture). After that, the impacts of temperature and loading rate on interfacial debonding were analysed based on SEM observation of the cracked bitumen-aggregate interface after the direct shear test. Lastly, percentages of cohesive and adhesive debonding at different temperatures were quantified. Results show that the time–temperature superposition principle applies to the quantification of bond strengths of bitumen under different temperatures and loading rates. Based on the comparative analysis of bond strength measured in the direct shear test, its master curve can well reflect the viscoelastic properties of the bitumen-aggregate interface over a wide range of temperatures and loading rates. At 15 °C and 25 °C, the interfacial crack mainly exhibits a combination of cohesive and adhesive debonding; however, at 35 °C and 45 °C, it is dominated by cohesive debonding. This observation is attributable to the fact that as the temperature rises, the chain network of bitumen molecules gets loosened and its kinematic activity enhances, which leads to the debonding between the bitumen molecules when subjected to shear loads and a higher percentage of cohesive failure.