ABSTRACT

The Tensile Strength Ratio (TSR) test is commonly used to quantify the moisture susceptibility of asphalt mixtures. This test method is based on the indirect tensile strength, which is not a fundamental property and hence cannot be used in the asphalt mixture design process. Therefore, alternative test methods that use a fundamental property to quantify moisture sensitivity of asphalt mixtures are needed. This study investigates if the linear impact resonance shift and frequency spectrum bandwidth changes measured using Axisymmetric Flexural Vibration (AFV) technique can be used to quantify moisture damage. This test enables calculation of the dynamic elastic modulus of the disk, based on measured resonance frequency as well as quantification of vibration energy dissipation in the specimens based on the change in bandwidth of frequency spectrum. AFV test is used to quantify moisture damage susceptibility of asphalt mixture specimens with different moisture conditioning levels and different mixture designs. The results of the AFV test are compared with the TSR test. Also, the sensitivity of the AFV test to quantify the effect of thixotropic aging due to storage and temperature are discussed. The results show that the AFV technique can successfully quantify moisture damage and the effect of aging and temperature change.

摘要

拉伸强度比 (TSR) 测试通常用于量化沥青混合料的水分敏感性。该测试方法基于间接拉伸强度，这不是基本属性，因此不能用于沥青混合料设计过程。因此，需要使用基本特性来量化沥青混合物的水分敏感性的替代测试方法。本研究调查使用轴对称弯曲振动 (AFV) 技术测量的线性冲击共振偏移和频谱带宽变化是否可用于量化水分损害。该测试能够根据测量的共振频率计算圆盘的动态弹性模量，并根据频谱带宽的变化量化试样中的振动能量耗散。AFV 测试用于量化具有不同湿度调节水平和不同混合料设计的沥青混合料试样的湿气损伤敏感性。将 AFV 测试的结果与 TSR 测试进行比较。此外，还讨论了 AFV 测试对量化由于储存和温度引起的触变老化影响的敏感性。结果表明，AFV 技术可以成功量化水分损害以及老化和温度变化的影响。