Relating asphalt binders response to LAS and LAOS tests at intermediate temperatures
- PDF / 1,364,288 Bytes
- 15 Pages / 439.37 x 666.142 pts Page_size
- 15 Downloads / 186 Views
Relating asphalt binders response to LAS and LAOS tests at intermediate temperatures Nikhil Saboo1 · Mayank Sukhija1 · Mohit Chaudhary1
Received: 15 March 2020 / Accepted: 4 August 2020 © Springer Nature B.V. 2020
Abstract This study is an attempt to quantify the nonlinear rheological behavior of four different asphalt binders using linear amplitude sweep (LAS) test and large amplitude oscillatory shear (LAOS) test at intermediate temperatures (10 °C, 20 °C, and 30 °C) in unaged (UA) and short-term aged (STA) conditions. Additionally, the present study also relates the response of the asphalt binders under increasing strain amplitude, obtained from both test methods. LAS test results indicated improvement in the fatigue life of asphalt binders with an increase in temperature. The effect of ageing on fatigue life was found to be binder dependent. Lissajous–Bowditch (LB) plots and higher-order harmonic ratio I3 /I1 were found to be imperative analysis procedures to study the LAOS test results. The effect of instrument inertia at low strain and higher frequency, along with the deterioration of the binder at high strain amplitudes, led to distorted stress-strain LB curves, which resulted in ambiguous values of strain stiffening ratio S. It was found that I3 /I1 can be appreciably correlated with the fatigue life Nf obtained from LAS test using the relationship Nf = 0.2 × ( II31 )−1.42 . The relationship validated in the study is found to be independent of temperature, type of binder, and ageing condition. Keywords LAS · LAOS · Fatigue · Ageing · DSR
1 Introduction Fatigue cracking is one of the primary distresses, which occurs in flexible pavements at intermediate temperatures due to repeated vehicular loads (Shen and Carpenter 1929;
B M. Sukhija
[email protected] N. Saboo [email protected] M. Chaudhary [email protected]
1
Department of Civil Engineering, Indian Institute of Technology (BHU), Varanasi, Uttar Pradesh, 221005, India
Mech Time-Depend Mater
Ziari et al. 2014). High localized tensile strain, which occurs in the binder phase of the asphalt mixture, has been considered responsible for the development of microcracks in the binder course of flexible pavements (Bahia et al. 1999; Hintz and Bahia 2013a). These microcracks, when subjected to repeated loads, lead to the development of macrocracks, which finally deteriorate the pavement infrastructure. Much research has been done to understand and characterize the fatigue behavior of asphalt binders. A comprehensive review on the development of various fatigue criteria for asphalt binders has been presented by Hajj and Bhasin (2018). Currently, the linear amplitude sweep (LAS) test, which uses the viscoelastic continuum damage (VECD) protocol for characterization of fatigue behavior of asphalt binders at intermediate temperatures, is in use (Johnson et al. 2009; Saboo and Kumar 2016; Singh et al. 2017a; Singh et al. 2017b). Numerous studies have been done using the LAS test procedure for studying and comparing
Data Loading...
