Evaluation of fracture resistance of warm mix asphalt containing jute fibers Ahmad Mansourian a,⇑ , Ali Razmi b , Mahmoud Razavi b a Department of Bitumen and Asphalt, Road, Housing and Urban Development Research Center, Tehran, Iran b Department of Highway Engineering, College of Engineering, Ahar Branch, Islamic Azad University, Iran highlights  Fracture resistance (FR) of WMA with jute fibers, increases with decreasing Temp.  The Max. and Min. improvements of FR of modified WMA are observed in pure modes.  Addition of jute fibers increases FR of WMA in mode I and mixed-mode (M e = 0.5).  When shear load increases, the K eff of modified WMA decreases and then increases. graphical abstract article info Article history: Received 26 January 2016 Received in revised form 16 April 2016 Accepted 26 April 2016 Keywords: Warm mix asphalt Jute fibers Fracture resistance Semi-circular bend (SCB) abstract This study investigates the low temperature performance of warm mix asphalt (WMA) reinforced by ran- domly distributed jute fibers. WMA is a kind of asphalt mixture that is produced at 20–55 °C lower than typical hot mix asphalt (HMA). Finite element (FE) analysis was carried out to obtain the geometry factors of semi-circular bend (SCB) specimens under pure mode I, pure mode II and mixed mode (I/II) loading. Then the fracture resistance of the WMA mixtures containing Sasobit and reinforced by different percent- ages of jute fibers (0, 0.3, 0.5 and 0.7%) were measured at 0 °C, 10 °C and 20 °C. The results of this research show that jute fibers improve the fracture resistance of the WMA mixtures under pure mode I and mixed mode with a higher proportion of the tension. Meanwhile, the results indicate when shear load increases, the fracture resistance of the modified WMA mixtures first decreases and then increases. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Warm mix asphalt (WMA) is a kind of asphalt mixture that is produced at 20–55 °C lower than typical hot mix asphalt (HMA). Studies indicate that use of WMA may have benefits such as: reduction in plant emissions, fuel saving, the ability to pave in cooler temperatures, the ability to haul the asphalt mixture longer distances, the ability to compact asphalt mixture with less effort and reduction in worker exposure compared to HMA [1]. Further- more warm mix technologies extend the paving season in colder climates [2]. At low temperature asphalt mixture often behaves as a brittle material and the stress intensity factors can be used as fundamen- tal parameters in order to characterize the asphalt mixture failure due to brittle fracture [3]. A number of researchers have used prin- ciples of fracture mechanics to evaluate the fracture resistance of the asphalt mixtures at low temperatures. Fracture may occur under mode I (opening or tension mode), mode II (sliding or in- plane shear mode), mode III (tearing or anti-plane shear mode) or a combination of them (Fig. 1). http://dx.doi.org/10.1016/j.conbuildmat.2016.04.128 0950-0618/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: a.mansourian@bhrc.ac.ir (A. Mansourian). Construction and Building Materials 117 (2016) 37–46 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat