Optimization of lawele granular asphalt (LGA) performance in cold paving hot mix asbuton (CPHMA) with candlenut oil modifier

Abstract

Lawele Granular Asphalt (LGA) is a Buton asphalt product derived from the Lawele area in Central Sulawesi, Indonesia. Although it possesses great potential, LGA utilization has not been fully maximized. One of the challenges is the need for a modifier to extract asphalt from the minerals within LGA. Candlenut oil is a potential modifier that can be used with LGA in Cold Paving Hot Mix Asbuton (CPHMA) due to its similar polarity. Therefore, the aim of this research is to evaluate the performance of Lawele Granular Asphalt (LGA) with candlenut oil as a modifier in Cold Paving Hot Mix Asbuton (CPHMA). The Marshall test was conducted to assess the performance of CPHMA with candlenut oil as a modifier. Furthermore, several variations were examined, including the quantity of the modifier, duration of heating and compaction, heating temperature, and storage duration, using seven different mixtures and three storage periods. The optimal composition produced a Marshall value of 687.68 kg, which increased with a longer mixing duration and higher heating temperature. The results showed that the Marshall value met the standards for CPHMA in Indonesia, as well as for VIM, VMA, VFB, and Flow values. The low flow indicated the density of the CPHMA pavement, while the MQ value showed its ability to withstand deformation of 200.13 kg/1 cm. The behavior of Marshall resistance was supported by Fourier transform infrared (FTIR) spectra, which exhibited similar compound groups between asphalt and the leached results of LGA with candlenut oil, indicating the presence of asphalt (binder). There was a slight decrease in the Marshall value after a 7-day duration, showing an increase after a 21-day storage period. Therefore, candlenut oil served as a viable alternative modifier for LGA