Cheating Cover With Galvanized Rebar 1

[KootK]

I'm doing a minor outdoor parking slab in a norther climate where deicing chemicals will be used. The Canadian code for parking structures contains some great stuff with respect to durability for these kinds of structures. In a perfect world, this would lead me to using some great concrete as well as 40mm/30mm top and bottom cover.

Unfortunately, on this project, I am limited to using a very thin slab. And the high covers kill me for that. One option that I'd considered was using galvanized rebar and then relaxing the cover requirements somewhat. However, I've been unable to track down any guidance for what combination of cover + galvanized might produce an equivalent level of durability.

Anybody have any ideas? Also, if anyone feels that this is simply a bad idea, I'd be interested in hearing that as well.

 

[Settingsun]

FRP would be a good option for durability and I presume readily available since we use the Canadian code here in Aust. But I think it requires 50mm min cover from memory. That combined with lower modulus and you'd have massive deflection for sure in a 127mm slab.

Without knowing your concrete, I'd hazard 600gsm (85 micron) galv is about 10mm equivalent cover.

 

[Ron]

The first slab had insufficient cover and didn't work (see photos). Obviously you don't want to repeat the same mistake, so that's a good excuse to change the parameters and increase the thickness.

 

[TehMightyEngineer]

It's worth mentioning that the client appears to be a budget minded individual. Something tells me they'll accept something with a reduced service life as long as a lasts a reasonable amount of time and the durability is sufficient such that they can anticipate repairs well in advance.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL, HI)