พลาสติก
เอกสารมาตรฐาน
สหรัฐอเมริกา
AASHTO
M 278-22
Class PS46 Poly(Vinyl Chloride) (PVC) Pipe
2022
11
HM42-2022 part 1
This specification covers the requirements and methods of test for smooth-wall perforated and unperforated poly(vinyl chloride) (PVC) plastic pipe, couplings, and fittings for use in subsurface drainage and surface drainage (culverts) of transportation facilities, where soil support is given to its flexible walls in all applications ...