The Cretex PRO-RING™ manhole grade adjustment system is a lightweight alternative to concrete grade rings or brick and mortar used in the construction of manholes and other utility structures. PRO-RING is made from expanded polypropylene, a high-strength, impact-absorbing plastic that meets AASHTO HS-25 load requirements. PRO-RING also meets the requirements of ASTM C969 (exfiltration test) and C1244 (vacuum test), has excellent chemical resistance, and is approximately 1/20th the weight of concrete grade rings.
Cretex Specialty Products
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