AASHTO M 176M/M 176-20 PDF Download

The AASHTO M 176M/M 176-20 standard deals with the specifications for porous nonreinforced concrete pipe used in underdrains. This standard aligns with the ASTM C 654M-05a and C 654-05a standards, with the exception of a few variations.

One significant difference is that the absorption test is limited to the 5-hour boil method, unlike the ASTM standards, which provide alternative methods for conducting this test. Additionally, the standard does not allow the manufacturer to provide inch-pound sized pipe when the order is placed in SI units. Lastly, the use of fibers in Section 6.5 is optional, and it is at the discretion of the owner whether to include them or not.