Manholes are a significant construction element which plays some roles. They are built to allow maintenance workers to access the underground piping and the telecommunication lines laid out under the roads. Manholes also serve as an access point for meters which measure which measure the liquid flow in the sewer lines. Learn more about different manhole materials here. But, manholes must be covered to prevent accidents from taking place involving pedestrians walking on the sidewalk. Also, manhole covers help vehicles run smoothly on the road without fearing their tires can get stuck in the holes.
Manhole covers are available in different materials and designs. Each of them provides various features and benefits. The materials they are made of determine the amount of load the cover can bear and the length of their lifecycle. These days, composite manhole covers are getting attention because of their ability to hold a great amount of load and a higher lifespan than conventional iron manhole covers. Below are the different kinds of composite plastic manhole covers:
Fiber Reinforced Plastic (FRP)
This composite material has elements such as glass fiber, unsaturated polyester resin, various kinds of additives, and quartz. They are a bit complex to make. These manhole covers boast a great surface and are resistant to wear. Also, they have a very high load ability.
Bulk Molding Compound (BMC) Manhole Covers
The elements used in making BMC covers include glass fiber, unsaturated polyester resins, steel bars, trasys, and calcium carbonate. The process of making them is quite simple and doesn’t cost much. BMC covers have a smooth surface and a uniform color. But, they have a lower load ability than FRP covers and are susceptible to friction.
Sheet Moulding Compound (SMC)
These manhole covers are made using elements such as unsaturated polyester resins, trasys, calcium carbonate, glass fiber, and a small amount of additive. The process of making them is a bit complex and costly. SMC manhole covers come with a smooth surface and a better load ability than BMC covers. But, as with BMC, they are also susceptible to friction.
If you are looking to purchase manhole covers, keep in mind that your choice of material will tell how long will your covers last and how effective they are ensuring public safety. As you browse through choices of manhole covers, consider both of their pros and cons and choose that one that offers the most benefits and suits your specific requirements.