Abrasion Loss and Binder Draindown of Porous Asphalt with Nanosilica-Modified Binder

Abstract

This paper details the performance evaluation of porous asphalt (PA) with nanosilica (NS)-modified binder in terms of binder draindown and abrasion loss. Both tests are widely used to evaluate the lower limit and upper limit of the design binder content for porous asphalt. The existence of nanoparticle with different proportions can affect binder draindown and abrasion resistance behavior of PA. Six different percentages of nanosilica were mixed with PEN 60–70 type of binder in this study. Then, all these blended modified binders were used to prepare PA samples using Marshall mix design method. Nanoparticle used in this study was nanosilica with the average size of 10–15 nm. Binder Draindown test was performed using a metal basket with 3 mm perforation. Then, abrasion loss value was evaluated using Los Angeles Abrasion Machine without steel ball. In accordance to PWD of Malaysia Specification for Road Works, which states that binder draindown for PA should not be more than 0.3 % of total weight of sample, while abrasion loss should not be more than 15 % also by weight of total sample. Based on Cantabro loss Test and Binder draindown test, 2–5 % NS are considered as the effective amounts of NS to be mixed with binder in order to reduce the abrasion loss and binder draindown of PA. In addition, 4 % NS is also considered as the optimum NS proportion. The existence of NS is capable to enhance the physical and rheological properties of asphalt binder, while at the same time it disperses well in asphalt binder. Thus, the performance of PA is also enhanced with the addition of NS in the binder.