Influence of Wood Fiber on the Laboratory Road Performance of Recycled Asphalt Pavement (RAP) Asphalt Mixture

Abstract

The influence of wood fiber content on the road performance of asphalt mixture with high recycled asphalt pavement (RAP) content was studied based on the Marshall test, high temperature rutting test, low temperature crack resistance test and water stability test. And the optimum wood fiber content in RAP asphalt mixture with high RAP content was recommended. The results show that the dynamic stability and low temperature bending strain of RAP asphalt mixture increased and then decreased with the increase of wood fiber content. When the content of wood fiber is 0.3 %, the road performance of RAP asphalt mixture is the best. Compared with RAP asphalt mixture without wood fiber, the Marshall stability and low temperature flexural tensile strain of RAP asphalt mixture with 0.3% wood fiber increase by 7.1% and 4.6%, respectively, and the high temperature rutting resistance and water stability decreases.

Mechanical performance of sustainable asphalt mixtures manufactured with copper slag and high percentages of reclaimed asphalt pavement

“…Researchers have studied the incorporation of different types of materials and design methodologies to avoid an excessive increase in the stiffness modulus, which is a characteristic of mixtures with high RAP content that can affect long-term performance, turning them into a brittle material susceptible to the appearance and propagation of cracks. The use of rejuvenating additives (oils and waxes) [24,25], polymer modified binders [26,27] or lower grade PG (stiffness compensation) [10], the use of warm mixtures (reduction of short-term aging of RAP) [28,29] and the use of stabilizing additives (slag, fibers, and minerals) [30][31][32][33][34][35] are some of them. On the one hand, these techniques make it possible to counteract the aging of RAP by controlling its viscoelasticity and, on the other hand, to stabilize the behavior of RAP mixtures against the phenomena of loss of adhesiveness due to moisture conditions, fatigue damage, and permanent deformation, the main causes of deterioration of this type of mixtures [36].…”