POLYPROPYLENE FIBERS AS MODIFIER FOR ASPHALT MIXTURE PRODUCTION

Abstract

Pavement issues are common across the country; rutting and fatigue cracking are the most common issues. Improper construction methods, estimating traffic volume, the characteristics of the materials, and the design of the mix can all contribute to the issues described. Recently, studies have been conducted on the use of propylene fibers (PPF), which have been used in pavement engineering for a few decades, to mitigate issues with pavements. This current study examined PPF use in asphalt mixtures and then conducted analyses on the Marshall stability, rut resistance, moisture susceptibility, FTIR, and XRD. For the PPF fibers, ranging from 1% to 5% the weight of optimum binder content (OBC), were added to the asphalt mixture at a mixing temperature of 160 oC following the guidelines from ASTM D1559. The Marshall stability and flow analysis on the conventional mix determined an OBC content of 4.42% by weight of the Marshall specimen. The optimum addition of PPF was determined to be 4% on Marshall stability of 16.22 KN with a flow value of 2.3 mm. With 4% additive content, the modified asphalt mixture had a low rut depth of 5.2 mm, indicating good rut resistance when compared to the control sample's rut depth of 11.55 mm, indicating low rut resistance. The values of tensile strength ratio (TSR) showed an increasing trend with the increase of PPF content from 1% to 4%. Modified asphalt caused the stiff asphalts to become softer, thus the asphalt mix with 5% PPF having a TSR decline compared to conventional asphalt mixes. Therefore, the industry should use asphalt mixture modified with 4% PPF fibers as per wet method to mitigate permanent deformation and moisture damage on asphalt pavements.