关键词: 道路工程, 水损坏, 路面内部排水, 垫层, 渗透系数, 级配设计

Abstract: In order to get appropriate composition of the graded crushed stone, the indoor studies of heavy compaction, California bearing ratio (CBR), coefficient of permeability and water stability test on six kinds of the graded crushed stone were conducted. Results show that penetration can change the gradation distribution of the graded crushed stone. Permeability coefficient will be stabilized with the increase of the penetration frequency. Permeability coefficient of the graded crushed stone with 0.075 mm passive rate （P0.075）is smaller than that of 3% graded crushed stone; and smaller CBR strength is >0.011 6 cm3/s. The discrepancy of P0.075 of the graded crushed stone in the range of 3.6%~5.0% is small, and selecting the upper limit of passive rate can coordinate the confliction between the permeability and the strength. CBR of the graded crushed stone whose P0.075 is 7.6% can be up to 196% and is hardly permeable. P0.075 of the graded crushed stone with the drainage requirement is less than 5%, as the reduction of the filler causes the compaction of the material insensitive to the variation of water content, and there is no the optimum compaction water content. Heavy compaction breaks the aggregate seriously when P0.075 of the graded crushed stone is less than 3%. The abnormal increase of dry density is not suitable to be the compaction standard. Graded crushed stone at the early stage after forming is slightly collapsible, and its water stability is significantly associated with strength. CBR of the graded crushed stone is higher and the water stability is stronger.

Key words: highway engineering, water damage, pavement internal drainage, bed course, permeability coefficient, gradation design