The lack of clay borrow sources at the Meijaran dam site, along with a high annual precipitation rate in the area, led consulting engineers to replace the clay core with an asphalt concrete core (ACC) at the rockfill dam. The steps taken for the project from the start, i.e. the selection of suitable aggregate sources for the asphalt concrete (AC) and the adjacent filter materials to the end, i.e. ACC placement in the dam body, are briefly discussed. AC mix design parameters, which were finalized upon completion of laboratory tests are presented, as well as the scope of trial placements conducted for optimizing the hand - and machine - placement of the ACC. Proper results were gained both in the final trial placement and in the dam body, in accordance with the quality control program. The air void contents measured in the AC cores were all below three percent. Construction of the dam took about 18 months which, when compared with the placement of a clay core, is a very short length of time for dam construction activities along the northern coastal region of Iran. The Yangtze Three Gorges Technology & Economy Development Co (TGDC) supervised the whole work.
