The Assessment of Natural Rock Asphalt for Thin Surfacing Mixture Design

¹ Roadmate Research Group, Universitas Sebelas Maret, Surakarta 57126, Indonesia
² Civil Engineering Department, Universitas Sebelas Maret Surakarta 57126, Indonesia

^* Corresponding author: arysetyawan@staff.uns.ac.id

Abstract

Thin surfacing hot mixed asphalt is one of the alternatives to anticipate the problem of thickness on overlay that are being developed as environment-friendly pavement, but the use of thin surfacing was still not maximum with some weakness. One way to improve the qualities of bitumen is by the use of the modification which has been available in the market. A new materials available in market is retona. Retona (Refined Buton Asphalt) is produced by the extraction of the natural asphalt from Buton island, Indonesia that were developed with a distillation process and extraction. The study has been carried out to define optimum bitumen content and characteristic in hot mix thin surfacing by using retona blend 55 and asphalt penetration 60 / 70 with the experimental method using the Marshall to define the stability, flow, density, percentage number of pores, Marshal Quotient (MQ). Result of Marshall test thin sufacing hot mix asplhat for optimum bitumen content retona belnd 55 asphalt is 5,87%, using the same gradations achieved optimum bitumen content of asphalt penetration 60/70 of 5.80%. In each of the asphalt on the conditions of optimum bitumen content obtained difference for characteristic and properties. Stability value retona blend 55 asphalt 525,61 kg, and asphalt penetration of 60/70 is 651,16 kg. The density value of retona blend 55 asphalt 2,06%, and asphalt penetration 60/70 is 2,11%. The percentage of the pores value of retona blend 55 asphalt is 18,45%, and asphalt penetration 60/70 is 15,8%. Flow value retona blend 55 asphalt is 2,11mm, and asphalt penetration 60/70 is 2,23mm. Thus asphalt penetration have resistance to traffic loads which is stronger, with a more solid density value, the value of smaller pores and higher flow values than the natural rock asphalt blend retona 55 asphalt.