Research of Method for Solving Relaxation Modulus Based on Three-Point Bending Creep Test

Materials (Basel). 2019 Jun 24;12(12):2021. doi: 10.3390/ma12122021.

Abstract

A method was developed for solving the relaxation modulus of high viscosity asphalt sand (HVAS) based on the three-point bending creep test, and was verified by comparison with experimental results. In this method, firstly, a transcendental equation was obtained by the convolution, and then equations were obtained by Taylor's formula, which were solved by Mathmatica to obtain the relaxation modulus by Newton's method. Subsequently, the laboratory investigations of the viscoelastic parameters of the Burgers model for the HVAS by three-point bending creep tests were carried out. In addition, the method was verified by comparing the relaxation moduli with the indoor relaxation experiments. Results showed that the numerical calculation and the test data were in good agreement, and the relaxation characteristics of the HVAS were reflected more accurately. The method can be used to study the relaxation characteristics of the asphalt mixtures effectively. In addition, this study provides a research basis for road crack prevention.

Keywords: Boltzmann superposition principle; HVAS; Newton’s method; convolution; creep compliance; relaxation modulus; transcendental equation.