This study presents a new mechanistic procedure for determining the critical cracking temperature of asphalt concrete (AC) using data from bending beam rheometer (BBR) test of asphalt binder and indirect tension (IDT) test of AC. This new procedure uses BBR creep data to generate the mixture relaxation modulus mastercurve by utilizing the Hirsch model, time-temperature superposition principle, and Prony series-based interconversion method. The Hirsch model parameters are calibrated by comparing creep data from BBR and IDT creep tests performed at the same temperature. Boltzmann hereditary integral and second-order heat equation are then used to calculate thermal stress from the developed relaxation modulus mastercurve. IDT strength data is transferred from test strain rate to thermal strain rate using the viscoelastic continuum damage model. Since a strain gauge is not attached for traditional laboratory IDT strength testing, this study derived an analytical equation based on the Hondros solution to compute the horizontal strain rate from the applied vertical displacement rate. Finally, the critical cracking temperature is determined by coupling the thermal stress and strength profiles. Using the procedure presented in this paper, the critical cracking temperatures of four AC mixtures were predicted from BBR and IDT data. Their actual critical cracking temperatures were measured using thermal stress restrained specimen test performed in the laboratory to validate the method. The predicted critical cracking temperatures are found to be very close to the laboratory measured values. The developed procedure has substantial practical and technical importance in predicting the critical cracking temperature of AC because it utilizes widely available BBR and IDT tests.

本研究提出了一种新的机械程序，用于使用沥青结合料的弯曲梁流变仪 (BBR) 试验和 AC 的间接拉伸 (IDT) 试验的数据确定沥青混凝土 (AC) 的临界开裂温度。这个新程序使用 BBR 蠕变数据，通过利用 Hirsch 模型、时间-温度叠加原理和基于 Prony 级数的相互转换方法生成混合物松弛模量主曲线。Hirsch 模型参数通过比较在相同温度下进行的 BBR 和 IDT 蠕变试验的蠕变数据进行校准。然后使用 Boltzmann 遗传积分和二阶热方程从发展的松弛模量主曲线计算热应力。使用粘弹性连续介质损伤模型将 IDT 强度数据从测试应变率转换为热应变率。由于传统实验室 IDT 强度测试没有附加应变计，因此本研究基于 Hondros 解导出了一个解析方程，以根据应用的垂直位移率计算水平应变率。最后，临界开裂温度是通过耦合热应力和强度曲线来确定的。使用本文介绍的程序，根据 BBR 和 IDT 数据预测了四种 AC 混合物的临界裂解温度。它们的实际临界开裂温度是使用实验室中进行的热应力约束试样测试来测量的，以验证该方法。发现预测的临界开裂温度非常接近实验室测量值。