Leading a concrete crack with cams

Anyone here ever lead a parallel crack in concrete with cams?  Two giant concrete slabs come together to form part of a bridge about 40 feet high...just curious if anyone has experience with gear placed in concrete.  Think it would break or crumble under the force of a lead fall?

concrete will most likely bust under your weight on a fall. it is a sediment mixture and isn't as strong as regular rock the cams are designed for. 

Aplenty of times. Make sure it doesn't have the anti-graffiti coating on it. ( like a high gloss candy coating)  you can try out the friction of the cams by aiding a section of it first-

Bob Westman wrote: concrete will most likely bust under your weight on a fall. it is a sediment mixture and isn't as strong as regular rock the cams are designed for. 

That's the silliest thing I've heard. 

Edit: @Bob Westman. I see you're local. I lead a concrete restoration practice area within one of the largest structural engineering companies in the city. I'm happy to discuss material properties of concrete and any other reservations you have about its strength and durability! 

There is a gym in Wichita, Kansas with concrete splitters on the outside. People lead them and whip on it. 

Not me. Pitons and small slider nuts only. BTW, later climber zippered, landed in the mud bank or a fall into the river would have been fatal. Turned out the concrete was expanding. Wish there were cams that small then as the under the bridge climbing was sustained, interesting, very parallel, and dry when it rained. Overdriving the pitons could lead to spalling on the edges and we tryed to avoid creating pin scars.

Leading a concrete crack with cams

Yer gunna die.  

Definitely good if the surface is rough enough.

If it is smooth or polished concrete I'd be very careful and stay away from BD cams which have lower holding force than most others.

Bob Westman wrote: concrete will most likely bust under your weight on a fall. it is a sediment mixture and isn't as strong as regular rock the cams are designed for. 

It probably has a strength of 5000-10000 psi so you are probably fine as long as others have said it isn't smooth and pulls out.

This building no longer exists in this form, but all of the walls were constructed like this, and there were several areas that were lead-able and protectable with cams. The “cracks” were even slightly flared.