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

摘要： 为得到垫层级配碎石的合理组成，用重型击实、承载比（CBR）、渗透系数和水稳定性试验对6种级配碎石进行了室内研究。结果表明：渗透力会改变级配碎石的级配分布，渗透系数随渗透次数增加趋于稳定，0.075 mm通过率（P0.075）＜3%的级配碎石渗透系数大于0.011 6 cm3/s但CBR较小；P0.075在3.6%~5.0%范围的级配碎石渗透系数差别很小，选择上限通过率可协调渗水与强度的矛盾；P0.075为7.6%的级配碎石CBR达196%但已基本不透水。有排水要求的级配碎石P0.075＜5%，填料数量减少使得材料的可压实性对含水率变化不敏感，已不存在最佳压实含水率；重型击实使得P0.075＜3%的级配碎石严重破碎，干密度异常提高不宜作为压实标准。级配碎石在成型后初期具有轻微的湿陷性，其水稳定性与强度明显相关，CBR越高的级配碎石水稳定性也越好。

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