HOW TO PLACE, FINISH, AND CURE CHROMIX® G INTEGRALLY COLORED CONCRETE
Jarco Supply is proud to partner with Sika Decorative Concrete to bring the premier and most versatile decorative concrete products to the North Carolina and surrounding construction markets. Our branches are stocked with both Scofield and Butterfield products ranging from made-to-order integral color, concrete hardeners, antiquing release agents, stains, polishes, sealers, and decorative concrete tools. Come to Jarco Supply and learn why Scofield is the brand most specified by architects and engineers and Butterfield is the brand most preferred by contractors.
Recently, we blogged about the proper way to batch concrete using CHROMIX® G admixtures. If you missed this first, crucial step of the decorative concrete process, please visit our website blog.
Today’s blog is designed to help our professional contractor friends expand their knowledge of how to place, finish, and cure CHROMIX® G integrally colored concrete. As we all know, the goal of this process is to create #prettyconcrete and like most things, there is a RIGHT WAY to do it. Jarco Supply is your supplier of choice for the best decorative concrete products in the industry AND the expertise to help you become a premier decorative concrete contractor!
PLACING CHROMIX® G INTEGRALLY COLORED CONCRETE
SOME GENERAL GUIDELINES:
Some of the most important factors in the successful placement of concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete are scheduling, timing, and weather. Although construction delays are never welcomed, a little planning ahead can go far in alleviating issues down the road. Here are some basic guidelines for dealing with these placement considerations.
Scheduling
When scheduling a concrete pour, try to split the loads as evenly as possible. Many discoloration problems can be avoided by having loads of the same size; short loads (especially those under 3 cubic yards) are greatly affected by any water added.
Timing
If your color job will have more than one placement, it is best to place integral colored concrete in as short of time as possible. This will avoid any wide swings in ambient temperatures that can affect the water content in the mix. Warmer temperatures will typically require more water for a given slump than cooler temperatures.
Weather
It is recommended NOT to pour integrally colored concrete when it is raining or will rain within three days of pouring. Rain will likely result in discoloration of the concrete surface. If it is imperative to pour under these conditions, take precautions to keep rain or other moisture from falling on the poured surface.
TEN TIPS for SUCCESSFUL PLACEMENT (Chute or Pump)
1. Concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete should be placed as close to its final position as possible to avoid segregation due to rehandling.
2. When pumping concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete, make sure all pump priming materials are pumped outside of the placement area. Include at least 2 wheelbarrows of integral colored concrete. This will prevent any discoloration from occurring due to priming materials coming to the surface of the slab.
3. Concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete must be placed at a consistent slump throughout the pour, with a maximum slump of 5 inches. If any water is added after the color-conditioned concrete has begun to discharge, the color will lighten and variation will occur. Water-reducing admixtures or mid-range water reducing admixtures may be added to increase the slump. Calcium Chloride should never be used in integral colored concrete.
4. Once the concrete truck arrives on the job, any water needed to improve the placement of the integral colored concrete should be added only once, and before the first discharge of the load. If any water is added after this, discoloration may result, as more water will lighten your color. Do not add water into the pump or onto tools or brooms. Most importantly, Do not exceed the design water for the mix.
5. The established mix design must not be changed at any time throughout the pour. Any changes to aggregate sizes, cementitious content, and amount of chemical admixtures or water can affect the color consistency of the resulting hardened concrete. Whatever mix you start with, finish with. Always do a mock-up sample to determine the look of the color to be placed. The color charts or chips are to be viewed as an approximate match to the actual concrete placed. A job site mock-up is required. A minimum of 3 yards is recommended.
6. The subgrade should be well drained and properly consolidated. Concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete should never be placed on subgrade that has freestanding water, is muddy, frozen, or has soft spots as this will affect set time and final concrete color.
7. Grade the subgrade so that the integral colored concrete is of uniform thickness and properly sloped for drainage.
8. If a portion of the concrete is placed in the shade, variations in color may occur. This is normal and will subside over time.
9. Consolidate and spade the concrete adjacent to forms.
10. Vibrate, tamp or screed the concrete, then float it to the specified finished grade, flatness and levelness.
FINISHING CHROMIX®G INTEGRALLY COLORED CONCRETE
The finishing of surfaces integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete should take place within a reasonable time period after placement. It is recommended that wood floats be used in this process instead of magnesium floats to avoid sealing the surface and causing moisture to be trapped in the concrete. Always wait for bleed water “sheen” to disappear before starting floating and troweling.
Use only slip-resistant textures, such as broom, swirl, sponge float, exposed aggregate, stamped or sandblasted for integral colored concrete flatwork.
Water should not be sprinkled or added to the surface of the integral colored concrete while finishing. Don’t add water to tools or brooms. Adding water causes the surface to pale or discolor. Sika® Film can be used to help retard surface moisture evaporation.
Long–handled Fresnos should not be used, and hard steel troweling should be minimized to avoid trowel burns. Finish all the edges first, and do all final hand-finishing in the same direction.
When concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete is placed in hot, dry, and windy conditions, precautions must be taken to prevent plastic shrinkage cracking. Use an evaporation retarder.
CURING CHROMIX®G INTEGRALLY COLORED CONCRETE
All concrete integrally colored with CHROMIX® Admixtures for Color-Conditioned® Concrete must be cured. For best results, we recommend using one of Sika Scofield’s color-matched curing materials such as LITHOCHROME® Colorwax™ or SCOFIELD® Cureseal™. The type of material will depend on the kind of work you are doing, whether it is exterior or interior concrete, and if a regular maintenance program is necessary. If integral colored concrete is not cured color WILL NOT be uniform. When all these steps are followed, your integrally colored concrete job will be one of beauty and satisfaction.
Until it is completely cured, the color of concrete is normally less uniform and appears darker than the final color.
Apply the curing compound by airless sprayer at a rate of 300 – 400 ft2 /gal. When the concrete is hard enough to walk on gently without marring, surface moisture has evaporated and no condensation has occurred.
For water-based curing with SCOFIELD® Cureseal-W™ or SCOFIELD® Selectseal™ Plus, pump spraying and back-rolling is recommended.
Protect the coated surfaces from damage by other trades and traffic to keep the surface water from evaporating.
NEVER CURE WITH WATER or any type of wet covering such as burlap, plastic sheeting, or other liquid membrane type curing compounds, as mottling, staining, and discoloration will occur.
IMPROPER CURING OF CHROMIX®G INTEGRALLY COLORED CONCRETE
Over cure or improper curing can result from any of the following:
Applying the cure too early while condensation is on surface.
Applying the cure too heavy will produce a cloudy to white appearance.e on surface.
Curing compound peels off due to over applying curing compound
Non-uniform application of curing compound.
Applying curing compounds when outside temperatures are below 42° F and will freeze overnight will cause curing materials to whiten.
Using water curing.
Cure or sealer doesn’t match. The wrong tint cup was used, or only a partial amount of the tint cup was used.
Using a roller or Hudson sprayer.
How to Remedy Poorly Cured Integral Colored Concrete:
If discoloration occurs due to trapped moisture, follow the guidelines established for removing trapped moisture problems on the following pages.
To remove curing compounds that have whitened due to over application the cure must be stripped. This can be accomplished by using a citrus based stripper/cleaner to take off the curing compound. Follow the manufacturer’s recommendation for use and dilution rates.
Failure to remove all contaminants and coatings can cause the curing compound to loss adhesion, peel, and reduce its durability due to lack of bond.
Always use an airless sprayer to apply curing compounds, such as LITHOCHROME® Colorwax™ or SCOFIELD® Cureseal™.
When using curing compounds that are tinted, always use color-tinted curing compounds at full strength. Make sure the full amounts of Part A and Part B have been mixed at full strength together.
YOU’RE ON YOUR WAY TO DECORATIVE CONCRETE EXCELLENCE!
When you partner with Jarco Supply for your decorative concrete projects, you have made a conscious decision to achieve decorative concrete excellence. Our team is ready to help you determine which products are right for your next decorative concrete project and give you the tools and knowledge you need to do it successfully. Visit or call your local Jarco Supply today!
Tune in for our next decorative concrete blog post soon: Troubleshooting CHROMIX®G Integrally Colored Concrete.