1.1 本规范涵盖用于地下排水沟的多孔无钢筋混凝土管。 1.2 本规范是规范的公制对应项 C654型 . 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

1.1 This specification covers porous nonreinforced concrete pipe for use in underdrains. 1.2 This specification is the metric counterpart of Specification C654 . 1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.