Visit Concrete.Com

Visit Concrete.Com | Advertising | Contact Us | Concrete Calculators

Topic Options
#8559 - 03/06/05 04:40 AM !/4" minus mix
steve in ca Offline
Junior Member

Registered: 03/05/05
Posts: 2
Loc: norcal
I'm looking for a small aggregate (1/4 minus concrete sand) mix suitable for decorative, non structural, no load, cast in place wall cap. Cap will be approx. 3" thick by 11"wide with 2 #4 bars, poured on 8" cmu retaining walls. We will be batching on site in a 1/2 sack mixer. The hard way, but all that logistics permit.

I cast some samples out of 6 sack pea gravel grout. The customer loves the shape, but wants a very coarse sponge float finish with no rock showing. We'll have to strip forms asap and sponge away. A 1-3 mortar type mix with minimum water would be plenty strong enough, but I'm more concerned about cracking than strength.

Any suggestions?

#8560 - 04/29/05 11:34 PM Re: !/4" minus mix
BRfromPA Offline

Registered: 05/23/02
Posts: 221
Loc: Emmaus Pennsylvania
You can control shrinkage cracking by keeping the mix water to a minimum, so the mortar mix might be ok. Maybe you can add a layer or two of chicken wire or other lathe in there? The ferrocement people make structures out of mortar mix that do not crack. Use super-p to reduce water. Pozzolan can reduce shrinkage (and just makes darn good concrete)