Browse Forums Paving & Concreting 1 Mar 27, 2010 8:15 am It has been explained to me by concretors that there is 2 ways to colour concrete. One way is to put the colour through the concrete and the other is to put the colour on the top. Some concretors say that colour through is not as strong as colour on top and is more susceptible to cracking while other concretors say this is nonsense. I do like the look of decorative saw so coloured through concrete is my preference. Anyone have any views on this? Troy Re: Coloured Concrete - Through or on Top? 2Mar 27, 2010 10:39 am Colour through Colour on top is weaker IMHO because it displaces cement from the 'working' surface. Colour through is homogenous, will it crack more readily...? No. If the correct amount of water is used and some curing method is used and the control jointing is well placed and deep it will be fine. Where you are coming from is where you are going to... Re: Coloured Concrete - Through or on Top? 3Mar 27, 2010 11:01 am onc_artisan Colour through Colour on top is weaker IMHO because it displaces cement from the 'working' surface. Colour through is homogenous, will it crack more readily...? No. If the correct amount of water is used and some curing method is used and the control jointing is well placed and deep it will be fine. Excellent response. Confirms what a concretor was telling me yesterday. Re: Coloured Concrete - Through or on Top? 4Mar 30, 2010 7:32 pm we did both on ours... colour through and then a colour sealer on top. The colour on top has all scratched and appears to be back down to the normal concrete, whilst it is coloured, it is a lot lighter than the "same" colour that we chose for the sealer on top. (We had all of our mulch and top soil delivered for our landscaping onto our driveway... it was the shovels that scratched the surface colour... won't be doing that in the new house ) Sleven Moved into our Atlantique MkII 36 by Carlisle Homes Re: Coloured Concrete - Through or on Top? 5May 26, 2010 8:45 pm Colour thru does weaken the concrete mix to a limited extent - you are only adding pigment to the mix - thus reducing the cement ratio, only by a small amount though. We do have cracking problems mainly on hot days with dark colours - black charcoal etc. Around here concreters nearly always go this way - its easy for them they bring it to our plant and we throw it into the agitator before loading the concrete. Throw on Colour is also known as colour hardener - the companies selling it claim that it strengthens the part of the concrete that it penetrates into - however I don't have enough experience with it to say yay or ney. This method is extremely messy - the concretor throws the powder onto the concrete at a specific point after pouring and then works it into the surface. Another point to consider with throw on is that if the concrete chips or breaks - the colour is only at the very top, you'll see the underlying plain concrete. Coloured Concrete Sealer which is what Sleven appears to have used on the top rolled onto cured concrete in a similar way to paint. It is thin and wears over time, it will need to be resealed approx very 18 months. It normally provideds a very bright fresh finish. I would personally go for pigment in the mix, however you will need to be vigilant and make sure the concreter doesn't pour the concrete too wet (ask for 80 Slump), provides adequate concrol joints (keyjoints, crack a joints, saw cuts etc) and that the concrete is cured properly. Any way you go, make sure you seal the concrete and reseal it to retain the finish, many driveways around here never get resealed - they end up looking worse then having plain concrete after time. Re: Coloured Concrete - Through or on Top? 6Feb 26, 2011 8:53 pm So which one should be more expensive? The pre-mixed coloured, or the one where they throw the oxide over the top and then slightly mix it in ?? Also, how do you know what has been delivered if it's all ordered and handled by your contractor? I mean the right slump, strength etc? We just have to trust ??? My signature is distracting people from my wise posts ... Re: Coloured Concrete - Through or on Top? 7Feb 28, 2011 8:08 am I think I'm sold on a colour-thru driveway. Maybe with some imprinted stencil pattern too. Strange how many concretors talked us out of it initially . But, as far as my information goes, this combination would be the most expensive finish for "plain" decorative concrete ... not sure how it compares with pebblecrete My signature is distracting people from my wise posts ... Re: Coloured Concrete - Through or on Top? 8Mar 01, 2011 12:21 pm Colour through will be more expensive but IMHO a superior choice. I do the sprinkled on method often, only because I seem to have the stuff around the place, I do it more for the hell of it, novelty factor. Its not easy to get the timing right of application, for if it does not bond into the concrete it cracks away. It fades in the sun and sealing would be better, have not found a great sealer yet, "seal a crete" looks interesting I could not imagine how much weaker the concrete strength would be with the colour all the way through, very minor, you could always increase specs from 25mpa to 32mpa keeping the slump to 80 (good Luck) and curing well is way more important. I would tend to believe either method has almost no effect on structural integrity although the surface is more likely to be compromise with the sprinkled method. Re: Coloured Concrete - Through or on Top? 9Mar 01, 2011 2:14 pm Thanks for your comments Pulpo ... I take it you are in the business ? BTW, is there a concrete strength between 25mpa and 32mpa ? In regards to curing ... what curing!? ALL our concretors are leaving it up to us, ie. sprinkle with water all day long for 5 days. I reckon the chemical curing with the agent is way too expensive and nobody knows when exactly they need to apply it after the pour My signature is distracting people from my wise posts ... Re: Coloured Concrete - Through or on Top? 10Mar 01, 2011 10:26 pm Not really in the concrete game too bloody hard, just seem to be doing some of late and helping a few friends but done plenty over the years. I have only ordered 20mpa, 25mpa, and 32mpa, give the concrete plants a call they might offer more options I know they go higher but never used, 25mpa should be fine, cure and slump more important. Cure is critical hot windy day like today could really bugger a concrete slab. Concrete gets quite warm when setting I forget the term some sort of hydration process. Water evapouration from sun and wind is not good, I forget the sums but strength varies dramatically from slump and cure duration Foam the best cover, stops sun and wind, but most just spray water which should be ok although I have seen top layers split. Good luck Pulpo Re: Coloured Concrete - Through or on Top? 11Mar 02, 2011 7:05 am I just noticed that the colour on top method keeps talking about "colour hardener" - what is that? Does it mean that the oxide in this method has some special chemical added that makes this top layer stronger than the rest of the concrete (actually - if it's stronger, does it mean the MPa goes up for that 1-2 mm on top?? )? While the oxide that's added into the mix does not have this "hardener" added?? Or yes? Confusing!! My signature is distracting people from my wise posts ... Re: Coloured Concrete - Through or on Top? 12Mar 04, 2011 11:57 am I think it does mention hardener for the on top products. I have done no research "why is that so" They must be hanging their hat on some bit of theory. Personally from my experience that is just BS, never ocurred to me it would be any hardener. Add Silica Fume to the mix or other types of admixtures to increase strength. Maybe even Seal-a Crete (I have my doubts). But I have seen how this stuff is applied and there is no way it adds to strength of concrete in any way. If you had two slabs poured side by side one just normal concrete the other having the top colour added most of the time the first slab would be stronger because few get the timing. Add top layer too late, it does not bond, add it too early and it just does not colour the top lots more used. DIY, Home Maintenance & Repair Are you doing this with a building permit? Conversion of a non habitable room into a habitable room requires building permit. 3 17311 yep sounds good make the footing bigger to to allow for the pipe in the middle 3 7296 Hi When it rains in a particular direction water comes through the security door. It hits the main door and the bottom swells and jams. There is already a cover over the… 0 38438 |