An experimental laboratory study of fiber-reinforced asphalt mortars with polyolefin-aramid and polyacrylonitrile fibers

Abstract

Promising results have been found in the literature through use of synthetic fibers in hot mix asphalt. However, few research works have focused on studying the effect of these fibers at asphalt mortar scale. In this research, the reinforcing effect of polyolefin-aramid (POA) fibers and polyacrylonitrile (PAN) fibers is investigated in asphalt mortars through indirect tensile testing. Fiber-Reinforced Asphalt Mortar (FRAM) specimens were prepared with different fiber contents (0.1 wt%, 0.2 wt% and 0.3 wt%) and tested at three temperatures (15 °C, 0 °C, ?15 °C). Indirect tensile strength, fracture energy, post-cracking energy and toughness were the parameters obtained and analyzed from the test in order to understand the behavior of the different FRAM designs. Moreover, the failure types obtained were also analyzed. According to the experimental results, a significant improvement of strength at low temperature (?15 °C) was observed when adding 0.3% of POA or PAN fibers. Furthermore, the fracture energy properties were enhanced due to the addition of fibers.This work has received funding from the CEDR Transnational Road Research Program - call 2017 427 under the contract N. 867481, “Fostering the implementation of fiber-reinforced asphalt mixtures 428 by ensuring its safe, optimized and cost-efficient use (FIBRA)”. Scientific support from the 429 consortium partners University of Cantabria (Spain), Technical University of Braunschweig 430 (Germany), BAM (Netherlands) SINTEF and Veidekke (Norway) is gratefully acknowledged. 43