Frequently Asked Questions (FAQ)

In the Draft Revise January 10, 2008 of the Updated Structure Design Manual, April 1982, Section I - Reinforced Concrete Pipe, Page I-6, the first paragraph of Section I-4 Concrete Cover for Reinforcement does not comply with Section 207-2.4.2 Location of Reinforcement of the Standard Specifications for Public Works Construction (Greenbook).

After revisited both documents. The answer is :
The cover for reinforcement in updated Section I-4 is used for the pipe design (1" for =/> 2.5" wall, 0.75" for <2.5" wall). The Greenbook Section 207- [pages 129~130 on 2009 version](cover = 0.75"+/-0.25"= 1"~0.5" & 1.25"+/-0.25"= 1.5" ~ 1" for >2.25" wall, cover = half of wall thickness for =/< 2.25" wall, also based on sizes of pipe dia. as well)are the allowance ranges for the products to be accepted.
Our interpretation - These two documents are compatible and supported each other.
Thanks for feedback and call me for questions.

-Peter Chang-

Reinforced Concrete Pipe