Cement well cover, which was originally used more, is mostly used in residential areas and less obvious occasions. The cement well cover has obvious advantages, low cost, active anti-theft and is not easy to lose. Moreover, the cement well cover is generally thick and anti-theft. The disadvantage is that the cement well cover is bulky, it is relatively difficult to open, the bearing capacity is limited, and it is easy to crack and drop corners after heavy vehicle rolling. Some well covers are intact and broken after opening, and the sewer is blocked. Most of them are caused by the broken cement well covers falling into the well, so the cement well covers are not suitable for roads and inspection wells that often need to be opened.

Composite well cover. The composite well cover is made of non-metallic materials supported by steel bars or bamboo strips in the middle. Generally, there are polymer materials, glass fiber materials and resin materials. The composite well cover has the characteristics of bright color and active anti-theft, and is more and more widely used. The disadvantage is that the bearing capacity is small and the corrosion resistance is poor. The “bamboo strip well cover” and “fragile cover” exposed on the network refer to this kind of well cover. The high temperature in summer and the low temperature in winter make the composite well cover age quickly, and some snow removal chemicals are the natural enemies of the composite well cover. Therefore, the composite manhole cover is not suitable for cold areas in the north, let alone on large motor vehicle roads. In addition, due to its light weight and no connection, the composite well cover is easy to be washed away by water in rainy days, resulting in pedestrians falling into the wellhead and casualties.