Fiber reinforced plastic manholes can reduce corrosion & deter theft
According to a study by the National Assn. of Corrosion Engineers (NACE), the direct cost of infrastructure corrosion was more than $22 billion in 2002 in the U.S. alone. Adjusted for inflation, the direct cost of corrosion in 2013 was estimated to be more than $42 billion on an annual basis. It has been estimated that at least 25% to 30% of annual corrosion costs could be saved if proper corrosion management practices were employed.
Today, composite materials are used in wind energy, marine, construction, aerospace, military and defense, automotive, pipes, access covers, tanks and many more applications. Composites offer several advantages over traditional materials: higher tensile strength, lighter weight, greater corrosion resistance, no resale value, better surface finish and easier processing.
Fiber reinforced plastic (FRP) products are now being widely used for applications where corrosion can destroy underground infrastructure. The corrosion resistance of FRP is a function of both the molding technology and the specific resin used in the laminate. Today, various resin systems are available which can provide long-term resistance to almost every chemical and temperature environment.
One application in which FRP is being adopted worldwide is with manhole access and service trench covers. By helping to reduce the costs of corrosion, composite covers can allow utilities and other operators of underground infrastructure to improve the financial strength of their enterprises.
With recent statistics attributing over half of injuries (resulting in absence from work) to manual handling it’s already known that reducing hazards in this area is a priority on a global scale. Because of legislation restricting acceptable manual handling weights, there is a global trend towards lighter weight FRP composite manhole and access covers, which also have the benefits of ease of handling.
Lightweight composite covers that provide safe and easy access eliminating unsafe manual handling issues are replacing aging concrete and heavy cast iron access covers all over the world. By using lighter materials, operational injuries are prevented, work sites are made safer and ease of installation and maintenance is made available to utility workers and contractors.
Additionally, the metal theft epidemic is not going away. There are few industries that can hide from the thieves and the water industry is still being severely affected. Cast iron and steel manhole covers and drainage grates are routinely stolen for the scrap value of the metal cover or grate. While the financial cost of replacement is quite high, the thefts also lead to open manholes, which create significant hazards. Composite covers can solve this problem as the fiberglass material used has no inherent scrap value. With the inability to melt down composite covers into quick cash at the junk yard; there is no incentive for thieves to steal the covers in the first place.