Effects of the addition of date palm fibers on the physical, Theological and thermal properties of bitumen

摘要

This paper investigated the contribution of plant fibers recovered from date palm waste to modify bitumen properties. Palm fibers were characterized to determine their chemical composition, structure, mass loss by heating and tensile strength and the properties of the bitumen-fiber mixtures were evaluated before and after aging using consistency (penetration, Ring and Ball softening point), rheological and thermal tests. The experiments were completed with binder drainage tests on asphalt mixtures to assess the ability for palm fibers to retain bitumen.The results pointed out that the addition of until 6 wt% fibers to neat bitumen conferred a slightly greater consistency, an increase in viscosity by 50% and complex modulus norm by 40% at service life temperatures, before and after aging. These last trends allow to predict the behavior of the asphalt mixtures towards permanent deformations. Thermal analysis on the different mixtures showed that the addition of fibers induced the increase in bitumen crystallinity. The existence of a semi-crystalline fiber network in the bitumen matrix improves the physico-mechanical characteristics of bitumen. The binder drainage tests performed on asphalt mixtures highlighted bitumen absorption by the fibers: this could be correlated to their microstructure and roughness. The results found in this study are encouraging for a potential use of date palm fibers at asphalt mixture scale. (C) 2019 Elsevier Ltd. All rights reserved.