Determination of complex modulus gradients of flexible pavements using falling weight deflectometer and artificial intel
- PDF / 1,066,847 Bytes
- 17 Pages / 547.087 x 737.008 pts Page_size
- 87 Downloads / 187 Views
(0123456789().,-volV) ( 01234567 89().,-volV)
ORIGINAL ARTICLE
Determination of complex modulus gradients of flexible pavements using falling weight deflectometer and artificial intelligence Yong Deng . Xue Luo . Yazhou Zhang . Robert L. Lytton
Received: 11 March 2020 / Accepted: 4 July 2020 RILEM 2020
Abstract The modulus gradient of asphalt concrete (AC) layers is an important feature of flexible pavements. The variation of the modulus with depth results from the synthetical effect of material properties, the service time of pavements, loading and environmental conditions. Since the modulus gradient directly affects critical responses and performance of pavements, the determination of the modulus gradient of AC layers is necessary for the evaluation,
Y. Deng R. L. Lytton Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA e-mail: [email protected] R. L. Lytton e-mail: [email protected] X. Luo (&) College of Civil Engineering and Architecture, Zhejiang University, 866 Yuhangtang Road, An-Zhong Bldg., Hangzhou 310058, China e-mail: [email protected] X. Luo National Engineering Laboratory of Highway Maintenance Technology, Changsha University of Science & Technology, Changsha 410114, Hunan, China Y. Zhang CCCC Second Highway Consultants Co., Ltd, Wuhan 430052, Hubei, China e-mail: [email protected]
maintenance and rehabilitation of flexible pavements. This paper aims to propose a method to obtain layer moduli of flexible pavements at different loading frequencies, which include a power function describing the modulus gradient of AC layers. The method utilizes results from a typical nondestructive test in the field applying the falling weight deflectometer and techniques of the fast Fourier transform, finite element model updating, kriging model and artificial intelligence. The method is validated by comparing layer moduli obtained from the proposed method and other backcalculation softwares. Keywords Complex modulus gradient Pavement structure Nondestructive testing Kriging model Artificial intelligence Finite element model updating
1 Introduction The modulus gradient of asphalt concrete (AC) layers is a characteristic of flexible pavements, which refers to a continuous change (increase or decrease) in the modulus value with layer depth. Numerous studies have revealed that it results from the synthetical effect of material properties, the service time of pavements, loading and environmental conditions. As viscoelastic materials, material properties of AC layers are sensitive to the temperature and the frequency of the applied load [1]. The temperature gradient in AC
100
Page 2 of 17
layers was observed and studied in many researches [2–5]. It has been considered in the pavement design and evaluation for its effects on the modulus and critical responses of the AC layer [6–8]. Similarly, the loading frequency significantly affects AC layers in terms of the stiffness and distress modes. Different from the laboratory cond
Data Loading...
