LABORATORY EVALUATION OF SPLIT MASTIC ASPHALT (SMA) WITH RETONA-60 ADDITIV

• Main Author: Sarosa, Handri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2965
• Institution: Institut Teknologi Bandung

LABORATORY EVALUATION OF SPLIT MASTIC ASPHALT (SMA) WITH RETONA-60 ADDITIVE, Handri Sarosa, 1999, Program Magister Sistem dan Teknik Jalan Raya, Program Pascasarjana, Institut Teknologi Bandung. Indonesia currently uses 1.2 million tonnes(MT) of bitumen annually, about 50% of which is locally produced and 50% is imported. The local product consists of 83% petroleum bitumen and 17% natural rock asphalt (Asbuton). Asbuton until now has been produced in the form of solid particles. Retona-60, a more recent development is produced through a refining and extraction process on Asbuton. The process does not remove all the minerals from the Asbuton , but only to the extent that refined Buton Asphalt (Retona) with an asphalt content of 60% and a filler content of 40% is obtained. This thesis describes a laboratory investigation of blends of Retona-60 bitumen and 60/70 pen petroleum bitumen and of SMA mixes made with 0%, 30%, 40%, and 50% Retona-60 by weight of total binder. For purposes of comparison an asphalt concrete surfacing mix was also investigated. Investigations showed that the effect of adding Retona-60 bitumen to petroleum bitumen was to increase the softening point and reduce the penetration of the binder, thereby indicating a reinforcing effect. Marshall analysis of the SMA mixes showed that the mixes made with 40% and 50% Retona-60 were satisfactory in terms of Bina Marga design criteria and had optimum bitumen contents that were almost identical. Specimens of these mixes prepared at optimum bitumen content were investigated using the Marshall immersion, indirect tensile strength and wheel tracking tests. With the exception of the wheel tracking test almost identical performance was observed for the mixes made with 40% and 50% Retona-60. In the wheel tracking test at 60 °C the performance of the mix made with 50% Retona-60 was superior, with rate of deformation and dynamic stability values of 0.009 mm/min and 4510 passes/mm as compared with values of 0.012 mm/min and 3543 passes/mm observed for the mix made with 40% Retona-60. The asphalt concrete mix complied with Bina Marga design criteria at a bitumen content of 6.0%. The stability of the mix was about 22% higher than that of the SMA mixes but its performance in the wheel tracking at test 60 °C was poorer; permanent deformation after 2520 passes of the wheel was 4.41 mm as compared to 1.98 mm for the SMA with 50% Retona-60. The tensile strength of the mix was lower than that of SMA mixes with 40% and 50% Retona-60 but it had superior resistance to water damage. SMA mix with Retona-60 additive appears to offer a feasible technical alternative to mix containing cellulose fibre as the additive. However the susceptibility of the mix to drainage of the binder could not be evaluated directly