Evaluation on the usage natural asphalt asbuton as modifier of crude asphalt on ITS characteristic

NUGROHO, Yusuf Edi, Ir. Djoko Murwono, M.Sc

2009 | Tesis | S2 Magister Sistem dan Teknik Transportasi

Most of roads in Indonesia use flexible pavement. The damage of this kind of roads is much caused by overload truck and high temperature that sometimes exceeds the softening point of asphalt commonly used in the pavement. These situations encourage the engineers to develop better asphalt. The other problems are the deficiency of asphalt in Indonesia. Extensive construction and maintenance of the Indonesian road network involves the use of very large quantities of bitumen-bound materials. On the other hand, Indonesia has Asphalt Buton, rock asphalt from Buton Island, as natural resource with a large amount of deposit, but they have not been effectively utilized. This research was conducted in laboratory, and the objectives are to modify Pertamina crude oil asphalt with Buton Extraction Asphalt (BEA), and make evaluation on the usage of natural asphalt asbuton as modifier of crude oil asphalt on its characteristic. Homogenization is an important issue in modifying asphalt. To get homogeneous mix, Homogenates test is designed using design tube then determine by Penetration test and Softening Point test. To determine the optimal composition of crude oil asphalt and Asbuton extraction in this research is using three parameters, Penetration, softening point, and Penetration Index. Variation of solvent (TCE and CCL4), variation of temperature for penetration test (25°C, 30°C, 40°C), Variation of Buton Extraction Asphalt from 1%, 2%, 3%, 4%, 5% to 25% and variation of mixing time were done for evaluation. Empirical approach was used to determine stiffness modulus of mixtures. The results of the research show that Homogenizations are influenced by mixing time and temperature; preheating during 30 minutes and mixing with stirrer during 30 minutes at temperature 130oC are optimum time and temperature for homogeneous mixture. CasmentonT5; Abbreviation from “Campuran Aspal Murni dengan Extracts Asbuton 5% dengan Solvent TCE”, is fulfilling all criteria. This mix has penetration number 55, softening point 50oC, and Penetration index using penetration at two temperatures, and also temperature and softening point in between -1100. Elastic recovery of the bitumen increase from 2.5 % to 3%, hence casmenton5 is more elastic compared with ordinary asphalt. The stability and Marshall Quotient HRS mix using casmenton5 has higher value than HRS mix using conventional asphalt. Casmentont5 give higher stiffness modulus than conventional asphalt pen 60/70. The stiffness modulus of casmentont5 at temperature 25°C and 35°C exceeds 5 MPa and higher compared with conventional asphalt of pen 60/70. At temperature 25°C and loading time 0.02 sec stiffness modulus of camentont5 is 22.85 Mpa while Asphalt pen 60/70 pertamina only 17.8 Mpa.

Kata Kunci : Homogenization,Buton extraction asphalt,Stiffness modulus