Drain Asphalt construction process It is known to use the tire roller for drain pavement construction, however [Asphalt pavement design, construction guideline(KRTA, 1998)] says that tire roller shall not be used in drain pavement, which contradicts existing standards. Therefore, the construction process of drain pavement needs to be clearly be provided by layers. Drain pavement construction   1. Manufacture and transport 1) 1) Drain pavement mixture don't have much fine powder, therefore caution is necessary in controlling temperature when heating and mixing the aggregate. If the aggregate is overheated, the asphalt will age, which will lower the adhesiveness of the viscosity, thus causing problem in the durability of the pavement. 2) 2) Drain pavement mixture uses dry-type method, which puts mixed additives(rubber powder of waste tire, thermoplastic resin powder) directly into the mixer. The mixing time and temperature should be more carefully managed than general asphalt mixture in order to mix the additives uniformly. 3) 3) Even drain pavement is open grade mixture with high porosities, and so the temperature tends to drop easily. Therefore, devices such as thermal insulation cover should be employed according to the temperature. The transport distance to the construction site is under 40Km and under an hour in general, in which temperature control is possible.   2. Pavement and Compaction   1) Drain pavement needs experienced workers according to the special qualities of the material. 2) Tack coating should be done after cleaning the surface of the waterproof layer of oil, dust and dirt. 3) To prevent cooling of the drain pavement mixture, Compaction should be done as soon as possible after the pavement. 4) If a vertical joint occurs while paving drain pavement mixture, the asphalt may weaken. Using several finishers simultaneously can prevent this. 5) Drain pavement is open graded mixture and so its volume decreases less than conventional mixtrures when being tamped down. Therefore, the amount used for pavement should be carefully decided. Test pavement is required in case of a large scale construction. 6) Since fine powder is not much in the drain pavement, Compaction does not add to much adhesiveness. 7) If the drain pavement is thick, the outer layer's thickness should be decided after a test pavement. The noise reduction effect gets better as it gets thicker or if there are many pavement layers. 8) Drain pavement mixture is of open grade. Therefore, when voltage is too low, the adhesiveness will not get better with Compaction. When there is too high voltage, the mixture may get shoved or the aggregate may get damaged. So,the combination of equipment should be carefully dealt with, and test pavement for large scale constructions is necessary to achieve satisfactory adhesiveness. 9) 9) For the equipment used for drain pavement, the same equipments used in general asphalt construction such as Mechedum roller, tanndum roller, tire roller are used. If too much weight is loaded on the roller, drain pavement mixture may move or the aggregate may get damaged., therefore...... The Compaction of the tire roller can stabilized the mixture compared to other rollers with the increase of intersecting aggregates. Vegetable oil is a good choice to prevent drain pavement mixture from sticking to the tire. Therefore, tire roller, combined roller with tandum roller function can be used without difficulty in small scale constructions such as maintenance of drain pavement. Tandum roller (8~10 ton) is used for the third Compaction, removing the tire mark of the tire roller and finishing up the work .