Material of lower cover的意思|示意

Its construction is divided into two parts, one is the lower part of the manhole cover, ensure that the level of it, it needs to be placed in the asphalt material, dealing with rigid cap.

它的施工分为两个部分，一是沙井盖下部部分，保证它的水平性，它需要被安置在沥青材料上，做好刚性盖的处理。

A laminated composite bar of rectangular cross section consists of a middle portion of one material as well as upper and lower identical cover plates of another material.

一矩形横截面的叠层复合材料杆，由以一种材料为中心部分，及另一种材料的上下两相同的盖板所组成。