Pengaruh Penggunaan Crumb Rubber dan Low Density Polyethylene (LDPE) terhadap Karakteristik Campuran Lapisan Asphalt Concrete Wearing Course (AC-WC)

Abstract

Modified asphalt is an innovation in asphalt where additives are added to bitumen with the aim of improving asphalt quality and reducing the use of asphalt in flexible pavement construction. The addition of rubber or plastic additives to asphalt mixtures has been widely researched. The addition of rubber to asphalt mixtures results in a decrease in the specific gravity of the mix due to the flexibility of the rubber, leading to the formation of voids in the mix after bearing loads at high temperatures. Adding plastic to the asphalt mixture provides higher strength and durability but does not meet the criteria for elastic recovery; hence, it is recommended that elastomeric polymer materials be added to help improve cracking resistance at low temperatures. This study aims to investigate the effect of the simultaneous addition of Crumb Rubber and Low-Density Polyethylene (LDPE) on the characteristics of the AC-WC mixture as an effort to improve asphalt mixture quality and reduce waste. Crumb Rubber added to the asphalt mixture has 6% and 7% variations, and LDPE added to the asphalt mixture has variations of 1% and 2% by weight of asphalt. The number of specimens prepared was divided into three parts: Marshall Test specimens to determine the Optimum Asphalt Content (OAC), Marshall Test specimens using OAC with the addition of Crumb Rubber and LDPE, and specimens for testing using the Wheel Tracking Machine (WTM). The mixing of asphalt, Crumb Rubber, and LDPE was carried out using the wet mixing method. The tests performed included the Marshall test and WTM testing. The study's results show that adding Crumbs Rubber and LDPE simultaneously to the asphalt mixture affects the asphalt properties, namely the increase in softening point and specific gravity and the decrease in asphalt penetration value. It also affects Marshall parameters, such as the increase in stability, VFB, and MQ values. The optimum combination of additive content variations is 6% Crumbs Rubber and 1% LDPE.