DEVELOPMENT OF WARM MIX ASPHALT (WMA) MODIFIED WITH LIQUID NATURAL RUBBER CONTAINING RECLAIMED ASPHALT PAVEMENT (RAP)

• Main Author: IRFAN
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/62395
• Institution: Institut Teknologi Bandung

Economic growth is directly proportional to the increase in demand for infrastructure networks both in quality and quantity, which can improve the quality of the road network, especially asphalt pavement—the limitations of the conventional asphalt pen. 60/70 properties are easy to deform at high temperatures and fatigue at low temperatures. Plus, heavy-loaded vehicles can trigger and damage roads that impact costs. Has encouraged modified asphalt to improve asphalt qualities such as penetration, softening point, viscosity, and elasticity. Modified asphalt that is commonly used uses polymer. How many types of polymer used are imported materials, which burden the country's foreign exchange. It is necessary to look for other alternative materials such as liquid natural rubber. Liquid natural rubber is widely available in Indonesia. Most of this rubber is exported. Currently, the demand for liquid natural rubber exports is decreasing. Therefore, through the Ministry of Public Works and Housing, the government encourages liquid natural rubber as an asphalt modification material to absorb farmers' rubber. The use of liquid natural rubber has the advantage that it is easier to mix with asphalt because this rubber is in the form of a liquid. Liquid natural rubber modified asphalt has been used on several roads in Indonesia. The advantages of using liquid natural rubber modified asphalt increase the durability of road pavement to extend the service life of the road. The problem with using liquid natural rubber is the increase in the mixing temperature and compaction of the asphalt mixture, which reaches ± 175 C. At this temperature, the asphalt is susceptible to damage because the asphalt has begun to evaporate and can accelerate the aging process of the asphalt. From the problems above, research was conducted to improve the method of using liquid natural rubber as a material for asphalt modification at lower mixing and compaction temperatures, using the Warm Mix Asphalt (WMA) technology with the chemical additive. Furthermore, evaluation of the application of Warm Mix Asphalt technology on modified asphalt mixtures, on the characteristics of modified asphalt, volumetric analysis, analysis of Marshall parameters, further tests in the form of Resilient Modulus and Permanent Deformation. The test results show that the use of liquid natural rubber on asphalt pen. 60/70 decreases the penetration value of modified asphalt so that the asphalt becomes harder, and the softening point increases so that the asphalt is more resistant to high temperatures. These viscosity increases make the asphalt thicker and increase the asphalt's elasticity due to the good adhesion and cohesion properties of the modified asphalt. Chemical additives on liquid natural rubber modified asphalt provide a new equilibrium that makes the asphalt less hard with a penetration value below the rubber modified asphalt and above the chemical additives modified asphalt and for the softening point viscosity and elasticity asphalt. This balance is needed to reduce mixed production temperature with mixed performance that is still good. Workability test analysis on a mixture of WMA and WAR shows that the use of chemical additives can reduce the mixing and compaction temperature by 30°C. The percentage of chemical additives in the asphalt mixture depends on the percentage of liquid rubber content. For liquid natural rubber content of 0%, 3%, 5% and 7%, the chemical additive requirements are 0.5%, 0.5%, 0.75% and 1% (by weight of asphalt). The Resilience Modulus of the WMA mixture is almost equivalent when compared to the HMA mixture. The use of liquid natural rubber increases the value of the Resilience Modulus of the HAR and WAR mixtures. In asphalt mixtures containing RAP, the value of the Resilience Modulus of the mixture is higher, especially for WAR mixtures. Permanent Deformation Testing using the Hamburg Wheel Tracking tool showed that the use of liquid natural rubber increased the deformation resistance of the asphalt mixture. However, the deformation resistance of the WAR mixture was lower when compared to HAR. Still, the WAR mixture had the advantage because it was produced at a lower temperature of 30 C. The use of RAP material in a mixture of WMA and WAR further increases the deformation resistance.