沥青混合料松弛和延迟时间谱的确定与换算

Determination and Conversion of Relaxation and Retardation Time Spectrum of Asphalt Mixtures

为了分析沥青混合料不同时间谱的确定方法和相互换算关系,采用Prony级数和积分变换表达式分别对沥青混合料的离散松弛和延迟时间谱及连续松弛和延迟时间谱进行确定,并将连续时间谱进行离散化表示,建立了由连续时间谱换算离散时间谱的关系式,由时间域、Laplace变换域和频率域内本构关系分别导出了离散松弛与延迟时间谱之间的换算线性方程组,并通过动态模量和蠕变柔量主曲线试验结果对本研究确定和换算方法的有效性进行了验证.结果表明,沥青混合料的4种时间谱可以通过试验主曲线同时确定,松弛与延迟时间谱之间的换算结果与试验结果吻合较好,该方法能够为沥青混合料黏弹性参数的全面分析提供有效工具.

To analyze the method of determining different time spectra of asphalt mixture and the conversion relationship mutually,the discrete relaxation and retardation time spectrum and continuous relaxation and retardation time spectrum were determined by using Prony series and integral transformation expression,respectively.The relationship of discrete time spectrum converted from continuous time spectrum was established based on the discretization of continuous time spectrum,the conversion linear equations of discrete relaxation and retardation time spectrum were obtained from constitutive relation in time domain,Laplace transform domain,and frequency domain,respectively,and the validity of determination and conversion methods were verified by the test results of dynamic modulus and creep compliance master curves.Results show that four kinds of time spectrum of asphalt mixtures can be determined simultaneously by the master curve,and the relaxation and retardation time spectrum obtained from conversion are consistent with test results.The method provides effective means to comprehensive viscoelastic parameters analysis of asphalt mixtures.