TYPES OF ASPHALT
Modified Asphalt
Another name for Modified Asphalt is Polymer Modified Asphalt (PMA) or Polymer Modified Bitumen (PMB). In Indonesia, there is awareness to use modified asphalt because the following things are needed:
- Asphalt that is more heat resistant (increasing the softening point), used additives based on plastomer, elastomer, cellulose, filler or addition of asphaltene such as asbuton, gilsonite, Trinidad asphalt, or special additives with various properties (certain types of polymers). Polymer asphalt is usually a downstream product from oil refineries.
- Stickier asphalt (increasing adhesion) so that the aggregate is not easily dispersed, additives that are sticky and flexible are used, namely rubber-based additives.
- Asphalt that is more UV resistant so as not to age easily.
As an illustration, in the market we know modified asphalt that has been sold in Indonesia (and this has been since 1996) such as: High Bonding Asphalt, Mexphalt, Cariphalt, Bituplus, Superflex, Superphalt, Starbit, Asphalt Prima 50, Retona etc.
Buton Asphalt
Buton Asphalt Is natural asphalt found on the island of Buton, in the form of rock containing asphalt (rock asphalt) which was found since 1920, with reserves of more than 600 million tons, the largest in the world. There are two mine sites in Buton, namely in Kabungka and Lawele. The differences between Kabungka asphalt and Lawele asphalt are as follows:
- Buton Kabungka Asphalt, the parent rock is limestone, and the asphalt seeps into the pores of the rock by 12-20%, therefore mining uses explosives. Rock is broken into small pieces with a stone crusher (stone crusher). Kabungka's natural asphalt in bulk is sent by barge and dump truck to the project that will utilize it. Furthermore, the asphalt activation process is to mix the bulk asphalt with a modifier (special solvent oil) with the aim of picking up Kabungka natural asphalt from its shell through curing for 2-5 days. The result of the curing is that mastic is ready to be mixed with aggregate into a ready-to-level asphalt mixture.
- Buton Lawele Asphalt, the parent rock is Silica rock, where the asphalt does not permeate but sticks to the rock as much as 20 – 35%, so it is easier to activate (no need for curing as in the asphalt activation process in Kabungka asphalt). The difficulty in handling Buton Lawele asphalt lies in its stickiness which is too high (clumps) so that it is difficult to measure according to the required amount.
