We have 2 types of pull boxes:
Polymer Concrete:
Made from a combination of sand, aggregates and polymer bonding resin. Precast polymer concrete boxes are reinforced with fiberglass for added strength. They are lighter weight than concrete boxes, have excellent strength, resistance to freeze and thaw, impact resistance, and corrosion resistance. They are non-conductive, so no grounding is required for the box or cover.
Polymer Concrete/Fiberglass Combination
Some of our underground splice boxes have a polymer concrete cover and supporting ring molded to a fiberglass body. This reduces weight, while supporting incidental traffic.