ABSTRACT

To explore the fatigue characteristics of self-compacting rubberized concrete (SCRC) pavement, notched slabs with a 10% rubber content were fabricated. Monotonic and fatigue tests were carried out, including incremental amplitude tests controlled by crack mouth opening displacement (CMOD), load, and alternative constant and incremental amplitude loads. Meanwhile, the fracture process was dynamically monitored with acoustic emission (AE), and the failure characteristics were analyzed based on AE parameters. Under monotonic loads, cracks mainly develop along with the interface between aggregates or rubber particles and cement. The cumulative ring counts and damage evolution show a three-stage distribution. The b-value fluctuates dramatically initially and less in the middle and later stages under monotonic tests. Under fatigue loads, brittle fractures are significant and fatigue life increases. Only one inflection point appears in the cumulative ringing counts curve and damage evolution curve, the critical damage is lower. The fluctuation range of the b-value are higher. The cumulative ringing counts, AE signal intensity, damage parameter based on AE energy, and b-value can dynamically reflect the crack growth and damage evolution of SCRC slabs. The fracture mode analysis based on AF-RA manifests cracks are mainly tensile, and the fracture mode is the type I.

摘要

为了探究自密实橡胶混凝土 (SCRC) 路面的疲劳特性，制作了橡胶含量为 10% 的缺口板。进行了单调和疲劳试验，包括由裂纹张口位移 (CMOD)、载荷以及交替的恒定和增量振幅载荷控制的增量振幅试验。同时，利用声发射（AE）动态监测断裂过程，并基于AE参数分析失效特征。在单调载荷下，裂缝主要沿着骨料或橡胶颗粒与水泥的界面发展。累积环数和损伤演化呈现三阶段分布。b _-value 在单调测试下初期波动较大，中后期波动较小。在疲劳载荷下，脆性断裂显着，疲劳寿命增加。累积振铃次数曲线和损伤演化曲线仅出现一个拐点，临界损伤较低。b值的波动幅度较大。累积振铃次数、AE信号强度、基于AE能量的损伤参数和b值可以动态反映SCRC板的裂纹扩展和损伤演化。基于AF-RA的断裂模式分析表明裂纹以拉伸为主，断裂模式为Ⅰ型。