本文经对三种开级配的沥青稳定碎石进行了试验研究，得出ATPB的沥青用量应在2.5%以上，空隙率在18%以上的结论。

Based on the experiment results on three kinds of open graded ATPB, it is concluded that asphalt content should be above 2.5% and porosity should be above 18%.

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开级配沥青稳定碎石基层（ATPB）是一种路面内部排水结构。

Asphalt-treated permedble base(ATPB)is a kind of pavement internal draining water structure.

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