Dowel Bar Specifications for Concrete Pavement

[jropert]

I am working on a Army Corps project that requires us to construct concrete pavements (typically 8-inch thick) with both smooth and deformed dowels ("tie bars").

For the smooth dowels the contract specifications state, "[Dowel] Bars shall conform to ASTM A615/A615M, Grade 40 for plain billet-steel bars of size and length indicated" (typically 20-inches on the drawings in our case).

For the deformed dowels the contract specifications state, "[Tie] Bars shall be billet or axle steel deformed bars and conform to ASTM A615/A615M or ASTM A966/A966M Grade 40."

Both types of bars will also need to be epoxy coated.

Our supplier is telling us that there are no such smooth dowels that are made (i.e. no industry standard available, only custom orders from a foundry which is way beyond budget). They are trying to supply us with ASTM A36 smooth bar dowels and ASTM A615 Grade 60 rebar (for deformed bars). Our supplier says they have talked with their foundry suppliers and have found that A36 steel is the only type of smooth dowel commonly produced and stocked, and grade 60 steel is only used for rebar, no grade 40 is produced for either type of bar nowadays.

Does anyone have experience in this type of issue with ASTM and grade types for smooth dowels and deformed dowels? The Army Corps will allow grade 60, but only for both types of bars (smooth bars being in question still since supposedly only A36 steel is available). We would like some "back-up" information to our suppliers statements before telling the Army Corps that their contract specifications don't make sense (if this is the case).

Thanks,
Josh

 

[TXStructural]

ASTM A1078 is the new standard specification for epoxy-coated dowels, which specifies smooth A615 Grade 60 bar stock.
Grade 40 is not generally available in larger sizes, but thousands of tons of grade 40 rebar are produced every year in the US. However, there is no reason to require grade 40 when the available grade 60 also meets the requirements for grade 40. In any case, the yield strength of dowels is not relevant to the design, only the stiffness (which is the same for all grades of steel having the same section.)