The 89 kilometers of roads had been successfully constructed with chip seal as surfacing pavement layer by PT. Harap Panjang. This is part of rehabilitation of critical road project in Chevron Pacific Indonesia operations at Minas and Duri, Riau periode of 2004 – 2012. Spray seal or Chipseal known in Indonesia as burtu (laburan aspal satu lapis) and burda (laburan aspal dua lapis) is the aplication to a pavement surface of a thin surface layer of bituminous binder into which aggregate is incorporated.
As the surfacing layer, the fungtions of Chipseal are:
- To protect the underlaying pavement (base to subgrade layer) from water and other damaging effects of the environment.
- To provide a wearing surface resistance to abrasion by vehicle; and
- To provide an economical, durable and skid resistance surface on which it is safe and confortable to travel under normal conditions.
Chipseal consist of two main materials are binder (bitumen) which was sprayed in hot condition and aggregate that meet with required specification. The function of bitumen is to serve as a binder which hold the aggregate in position and to provide a waterproof membrane. The function of aggregate in chip seal is to resist abrasion by traffic and to transmit the wheel loads to the base layer of pavements. Aggregate is retained in position by the binder. The aggregate should be durable and possess the necesary hardness, thoughness, wearing resistance, crushing stregth and polishing resistance to withstand the type of traffic conditions to which it is subjected.