Linear viscoelastic behaviour of thermosetting epoxy asphalt concrete – Experiments and modeling Bo Yao ⇑ , Gang Cheng, Xiao Wang, Cheng Cheng, Songyu Liu School of Transportation, Southeast University, 35 Jinxianghe Road, Nanjing 210096, China highlights  The linearity strain limit for EAC is 150 (10 6 ) strain.  Increasing air void contents lead to lower dynamic modulus and higher phase angles.  EAC with binder content of 6.5% has the lowest phase angle master curve.  The Huet–Sayegh model can describe the linear viscoelastic behaviour of EAC. article info Article history: Received 28 April 2013 Received in revised form 28 June 2013 Accepted 21 July 2013 Available online 14 August 2013 Keywords: Epoxy asphalt concrete Linear viscoelastic behaviour Complex modulus test Linearity limits Master curve Huet–Sayegh model abstract This paper presents an investigation into the linear viscoelastic behaviour and rheological model for epoxy asphalt concrete (EAC). The complex modulus test was used to characterize the linear viscoelastic properties including dynamic modulus and phase angle. Strain sweeps were performed to determine the linearity limits of EAC at various temperatures and frequencies. Complex modulus tests were conducted at strain level well inside the linear region at temperatures of 5, 20, 30, 40, and 60 °C and frequencies of 0.1, 0.5, 1, 5, 10, and 25 Hz for each temperature. Master curves of dynamic modulus and phase angle were developed based on time–temperature superposition principle, respectively. Effects of air void con- tent and binder content on the master curves of dynamic modulus and phase angle of EAC were evalu- ated. The linear viscoelastic behaviour of EAC over the range of frequencies was modeled by Huet– Sayegh rheological model. Results show that EAC exhibits typical linear viscoelastic behaviour at low strain magnitude. The linearity limits are temperature and frequency dependent. A strain magnitude of 150 (10 6 ) can be accepted as the linearity limit of EAC at various temperatures and frequencies. EAC shows considerable susceptibility to air void content and binder content. The increasing air void con- tents result in lower dynamic modulus and higher phase angles. EAC with binder content of 6.5% has the lowest phase angle master curve. The results also show that there is good agreement between the mea- sured complex modulus values and results of analytical calculations obtained from the Huet–Sayegh model. Hence, the Huet–Sayegh model can be successfully used in describing the linear viscoelastic behaviour of EAC over a wide range of frequencies. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Epoxy asphalt concrete (EAC) is a polymer concrete made from a curing binder mixed with aggregates. The epoxy asphalt binder is a two-phase chemical system in which the continuous phase is a thermosetting epoxy and the discontinuous phase is a mix of spe- cialized asphalt and epoxy cross-linker [1–3]. The thermosetting polymer binder ensures that EAC will not melt after it is cured over the range of expected pavement service temperatures. The advan- tage of this is that it avoids rutting, making EAC an extremely sta- ble and waterproof material. Furthermore, EAC has high stability and good resistance to cracking and damage from moisture and fuel erosion [4–6]. The use of EAC as a surfacing material on steel bridge deck is increasing from 1967 when it was firstly used to strengthen the sur- face of San Mateo-Hayward Bridge [7]. Since then, EAC has been used extensively on orthotropic steel bridge decks in North America and East Asia [8]. It also has been considered to be suitable as long- lasting pavements for heavily trafficked roads and under evaluation by the International Transport Forum of The Organisation for Eco- nomic Co-operation and Development (OECD) in a multi-country research program seeking long life pavements for strategic roads. With increasing use of EAC as a long-lasting pavement material on both bridge decks and normal roads, research into its 0950-0618/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.conbuildmat.2013.07.066 ⇑ Corresponding author. Tel.: +86 25 83795911. E-mail addresses: blade@seu.edu.cn (B. Yao), chengg@seu.edu.cn (G. Cheng), wangxiao65@126.com (X. Wang), drcheng1983@126.com (C. Cheng), liusy@ seu.edu.cn (S. Liu). Construction and Building Materials 48 (2013) 540–547 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat