Structures
Manholes and Wet Wells
Design
P3 Polymers manholes and wet wells are cast with our 12,000 psi, styrene free, corrosion resistant polymer concrete blend. Our design varies only slightly from the traditional concrete manhole. Our high strength polymer concrete allows for thinner walls, which reduces weight and makes handling them in the field easier. We also use a bell-up design for ease of installation. Other than those slight differences, there is no need to learn a new installation method or handling requirements.
There is currently no standard for polymer concrete manholes or wet wells, but we design our structures to meet and exceed the existing standards for concrete structures- ASTM C857, ASTM C478, and ACI 350-06.
Reinforcement
We typically reinforce our structures with steel rebar in accordance with ASTM C478 rather than Fiber Reinforced Polymer Bar or FRP. This is for several reasons. For one, the issue of rebar corrosion is negated by the polymer matrix encapsulating it- it's similar in theory to epoxy coated rebar. Secondly, the standards and design practices are better developed and tested for steel rebar than they currently are for FRP. Lastly, there is evidence that FRP only performs best under prestressed conditions where the impact of the lower elastic modulus can be mitigated. However, we are able to design for FRP reinforcement per ACI 440.1R-15 if requested.
Riser Joints and Pipe Connections
We join our riser sections with butyl rubber joint sealant rope meeting ASTM C990. We ship our manholes with pipe boots conforming to ASTM C923 installed. We can also do doghouse style bases with the bench and invert cast-in-place.
Box Structures
We design all of our large boxes and sumps with an engineer certified in the state, and we involve the customer every step of the way. We've designed and built large boxes for the wastewater industry, recycling, and chemical processing plants. We can design for H-20 or pedestrian loading, include weirs or other special features, and even combine precast and cast-in-place for unique situations.
