Increase of Recycled Asphalt Proportion through Use of SBR (Styrene-Butadiene Rubber) Latex

摘要

Styrene-butadiene rubber latex (SBR) was added to asphalt pavement mixes consisting of 50 percent reclaimed asphalt pavement and 50 percent new aggregate and new asphalt, and to 70 percent reclaimed - 30 percent new mixes, in order to determine improvement of properties of treated materials over those of untreated recycled mixes of the same propertions. Statistical analysis of variance of the output of the VESYS pavement analysis computer program demonstrated a reduction of asphalt cracking of the treated pavement materials compared to untreated materials when 4 or 5 percent SBR was added. Addition of latex caused little difference in predicted rutting. Since the VESYS program rewards an increase in pavement stiffness, and addition of rubber and use of reclaimed pavement both increase stiffness, comparison of improvements between the 50-50 and 70-30 mixes was not practically significant. Use of SBR latex to improve performance of recycled mixes, and to allow increase of percent of reclaimed pavement, is feasible.