I need to specify bitumen coating thickness on steel pipe piles and the surface preparation of the steel pipes in order to reduce downdrag. Anybody knows where I can get some references on these?
FHWA publication FHWA DP-66-1 Manual on Design and Construction of Driven Pile Foundations includes a sample bituminous coating specification in Appendix C.
The specification calls for 3/8" coating that conforms to ASTM D2521 Canal Liner Bitumen. It also specifies a primer conforming to AASHTO M116.