This frame and cover is made of a patented new super high strength concrete (HSC). HSC is designed for years of maintenance-free street and highway duty. It helps the products resist cracking, abrasion, and corrosion. Since the frame and cover are cast in this material, the need for webs around the circumference of the frame is eliminated, making road material compaction around the unit easy. HSC allows the skid resistance of the cover to be almost identical to that of asphalt. This eliminates the need for raised surfaces on the cover, helping create a safe design and comfortable ride.
The frame and cover dimensions are similar to conventional units, allowing direct and simple replacement of worn out iron covers in existing iron frames or direct new construction substitutions with HSC covers and frames. There are only two holes on the cover, which reduces storm sewer cover infiltration. The frame is slightly tapered to help distribute the traffic load to the surrounding upper road material.
Evcorp (Evangineering Corporation), 140 Sackville St., Toronto, ON M5A 3E7. Tel: 416-828-5454; Fax: 416-368-8507.