
Manhole covers or pit lids or access covers are used to close the openings of manholes or pits in order to prevent people and unwanted materials from falling into manholes and to avoid people from injuring themselves. Manhole Covers are manufactured in a variety of shapes such as circles, rectangles, etc.. Materials that are used for manufacturing manhole covers include metals (cast iron, ductile iron, and steel), concrete (conventional concrete and steel fiber reinforced concrete), and composites (FRP/GRP and others). Metal and concrete are the most widely used materials for making manhole covers. However, these traditionally used types are being widely replaced by composite manhole covers, which are the emerging type of manhole covers across the world.