The following example is used to illustrate key differences between B-303 and CCFRPM pipe.
CCFRPM Pipe is a less dense and less rigid system than B-303 pipe.
CCFRPM Pipe yielded lower stresses and higher deflections in finite element analysis than did the B-303 pipe with the same inside diameter subjected to the same internal pressure and external loading conditions.
Wilson Okamoto specified only two products for the microtunneled pipes--concrete steel cylinder, or prestressed concrete cylinder pipe (the pressure version of regular reinforced concrete pipe), and CCFRPM.
The CCFRPM pipes performed 100% reliably in jacking with no breaks and maximum loads of only 200 tons even on the longest push of more than 1000 feet.
The completed system easily passed the installed 100 psi field hydrotest with no leaks or breaks in any of the CCFRPM pipes or gasket-sealed jacking joints.
The pipe specifications required the CCFRPM pipes to meet ASTM D3262 with minimum stiffness classes of 36, 46, and 72 psi depending on the depth of cover and the installation means.
As an installer, Taylor prefers the CCFRPM pipe due to the versatility and ease of installation.
The quick assembly of the FWC joints and the lightweight CCFRPM pipe sections provided installation ease that helped in meeting the completion goal.
CCFRPM had been used in this area for both sliplining and above-ground installations, although little had been installed by direct bury, so the design engineers had little prior experience.
An added benefit of the CCFRPM pipe is the ability to be structurally repaired in place.
The high stiffness CCFRPM
pipe had no perceptible deformation from the uplift forces.