EVALUATING FATIGUE BEHAVIOR OF ASPHALT BINDERS AND MIXES CONTAINING DATE SEED ASH

Ali Foroutan Mirhosseini,Amir Kavussi,Abolfazl Hassani,Mohammad Mehdi Khabiri,Mohammad Hossain Jalal Kamali

doi:10.3846/13923730.2017.1396560

Abstract

Fatigue is one of the most occurring distresses in asphalt pavements. Asphalt binder plays a critical role in fatigue behavior of asphalt mixes. Modelling and predicting fatigue behavior of binders will result in more fatigue resistant mixes. In this research, possibility of using Date Seed Ash alongside two commonly used additives (namely, a siliceous and a limestone) as bitumen modifier were investigated. Then, the influence of these additives on fatigue behavior of asphalt binders and mixes was investigated. Linear Amplitude Sweep (LAS) test was carried out and Viscoelastic Continuum Damage (VECD) parameter was determined. In addition, Indirect Tensile Fatigue Test (ITFT) was performed on mixes containing these additives. Correlation equations were developed to link fatigue behavior of binders to those of mixes. The results showed acceptable agreement between binders and mixes fatigue testing results. In addition, with predicted models it was able to obtain the asphalt binders contribution to mixes fatigue resistance. However, in the case of ash modified samples, no good correlation was observed between fatigue behavior of binders and that of mixes.

Highlights

Fatigue failure in asphalt mixes occurs as a result of accumulation of damages under repeated loading
As asphalt binder plays a key role in fatigue behavior of asphalt mixtures, many researchers investigated the application of additives in order to improve characteristics of binders in mixes (Khattak et al 2013; Capitão et al 2012; Yang et al 2014)
The efforts in determining fatigue resistance of binders resulted in two tests; namely Binder Yield Energy Test (BYET) which is a monotonic shear test, performed under constant strain rate loading condition and Linear Amplitude Sweep test (LAS) (Hintz et al 2011a; AASHTO-TP101 2014)

Summary

Introduction

Fatigue failure in asphalt mixes occurs as a result of accumulation of damages under repeated loading. In order to improve PG specifications, Time Sweep test (TS) which is performed using DSR device was introduced in NCHRP Project 9-10 This is different than the SHRP proposed PG tests that consist of applying repeated cyclic loading at fixed amplitude mode in either stress or strain controlled conditions (Safaei et al 2016; Bahia et al 2001a; Martona, Bahia 2008; Hintz et al 2011a). The efforts in determining fatigue resistance of binders resulted in two tests; namely Binder Yield Energy Test (BYET) which is a monotonic shear test, performed under constant strain rate loading condition and Linear Amplitude Sweep test (LAS) (Hintz et al 2011a; AASHTO-TP101 2014). Amplitude or strain sweep runs after the frequency sweep, where loading begins and increases linearly with 100 cycles at a rate of 1% increased and the application of stress until 30% strain level is achieved as shown in Figure 1 (Safaei et al 2016; Hintz, Bahia 2013; AASHTO-TP101 2014)

Objectives

Results

Conclusion