new bonded topping on top of new repair concrete

[ajk1]

We are repairing corroded top rebar in a slab. In some cases the top rebar has only 1/2" or less cover. The top bars were designed by WSD in 1956, so there are lots of bars and in negative column strip areas they are quite close together.

One way of doing it is to make the new topping and the new repair concrete a monolithic pour.

The other way is to make the new topping a separate but bonded pour to the new repair concrete, but I wonder if there is a weakness in bonding to concrete that has only 1/2" or less of concrete cover to the top rebar. Any comment?

 

[Ron]

ajk1...make it monolithic! If you put a topping over a thin fill, you stand a chance of breaking both bonds, just from differential shrinkage. No point in having two bond lines when one will be better.

 

[ajk1]

To Ron - yes that is what I told the contractor (we did it successfully during the now completed phase 1), and he has now agreed. Thanks for your input. Much appreciated.