ABSTRACT

Owing to a reasonable correlation with field performance, dynamic modulus ($\left|E^{\ast }\right|$) has been used as an input in pavement design specifications. With experimental determination of $\left|E^{\ast }\right|$ issues, researchers have resorted to the use of predictive models. This study evaluates the underlying patterns in prediction error in these models using $\left|E^{\ast }\right|$ database developed during NCHRP 1-40D study. The significant difference between the global and mixture-wise dataset observed in the correlation analysis was substantiated by the T-test. Thus, predictive models were recalibrated, and statistical indicators indicated improvement with mixture-wise calibration compared to global calibration. Q-Q and cumulative distribution plots constructed using ‘difference parameter (DP)’ introduced in this study indicated highest and lowest error with Al-Khateeb and Original Witczak models, respectively. Finally, the entire range of measured $\left|E^{\ast }\right|$ was divided to analyze the error patterns in detail. In general, lower prediction error was observed in the middle range where all the predictive models showed comparable performance. However, they showed significant prediction error at the extreme values of $\left|E^{\ast }\right|$, and the DP showed skewed and flatter distribution. In this region, Hirsch and Al-Khateeb models performed poorly whereas Original Witczak and South Korean models performed well. Sensitivity analysis identified binder properties as highest sensitive.

摘要

由于与现场性能的合理相关性，动态模量（$\left|{乙}^{*}\right|$) 已被用作路面设计规范的输入。用实验测定$\left|{乙}^{*}\right|$问题，研究人员求助于使用预测模型。本研究使用以下方法评估这些模型中预测误差的潜在模式$\left|{乙}^{*}\right|$NCHRP 1-40D 研究期间开发的数据库。T 检验证实了在相关分析中观察到的全局和混合数据集之间的显着差异。因此，预测模型被重新校准，统计指标表明，与全局校准相比，混合校准的改进。使用本研究中引入的“差异参数 (DP)”构建的 QQ 和累积分布图分别表明 Al-Khateeb 和原始 Witczak 模型的误差最高和最低。最后，整个测量范围$\left|{乙}^{*}\right|$被划分来详细分析错误模式。一般来说，在所有预测模型都表现出可比性能的中间范围内观察到较低的预测误差。然而，他们在极值处显示出显着的预测误差$\left|{乙}^{*}\right|$, DP 呈现偏态和更平坦的分布。在该地区，Hirsch 和 Al-Khateeb 模型表现不佳，而 Original Witczak 和韩国模型表现良好。敏感性分析将粘合剂特性确定为最高敏感性。