- Integral Color Home
- Integral Color vs. Color Hardener for Stamped Concrete
- Tips for Getting the Best Results
- Common Integral Color Issues: Troubleshooting Tips from Expert Chris Sullivan
- Tips for Achieving Consistent Color
- Changing the Color of Integral Concrete
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- Comparison Chart of Concrete Coloring Products
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INTEGRAL COLOR CONCRETE PIGMENTSGet the inside scoop on using integral pigments to color concrete mix, including buying tips and how to achieve the best results
One of the most popular methods for coloring newly placed concrete is integral coloring admixtures. These admixtures infuse concrete with rich, long-lasting, fade-resistant color. Stamped concrete contractors often use this coloring medium to produce a backdrop for contrasting accent or antiquing colors, such as pigmented release agents and stains or dyes. This layering of color is what enables them to so closely replicate the variegated, multi-tonal appearance of natural stone.
CONCRETE PIGMENTS IN INTEGRAL COLOR
A concrete pigment is an iron oxide pigment used in integral concrete coloring. They can come in either powder or liquid form. With integral coloring, there are a wide variety of concrete color options available. Many manufacturers offer over 20 standard concrete color additives and custom color matching services. Also, concrete pigments have a low likelihood of fading.
Since the introduction of the repulpable bag, which dissolves when tossed into the concrete mix, using powdered integral coloring has never been easier. Ready Mix suppliers simply toss in the entire bag of color, cutting down on work and mess. Following are product links to integral coloring in repulpable bags:
- Davis Colors™ in Mix-Ready® Disintegrating Bags
- Butterfield Color DECORATIVE CONCRETE COLORS UNI-MIX® Integral Color
- Solomon Colors Dry Integral Color
The use of liquid color pigments has also gotten easier since the introduction of concrete color systems. Concrete color systems are PC operated systems designed to help ready mix suppliers use liquid pigments.
ADVANTAGES OF INTEGRAL COLOR
With integrally colored concrete, the entire batch of concrete is colored all the way through, similar to adding food coloring to cake icing. Integral colors are available in powdered, granular and liquid forms. All types are generally a blend of synthetic or natural iron-oxide pigments that are formulated to disperse evenly when mixed into fresh concrete, either at the ready-mix plant or at the jobsite. The palette for integral pigments consists primarily of soft earth tones that integrate well with most landscapes and architectural elements. (See this color chart for Mix-Ready pigments from Davis Colors.)
The chief advantage of integral pigments is that the color extends throughout the entire concrete slab, so even if surface abrasion occurs, the color will not wear away. The pigments in integral coloring admixtures also are chemically stable and won't fade over time from exposure to the weather or ultraviolet light.
Another big advantage is convenience and labor savings. Because the integral color is mixed into the concrete, you can simply place and finish the concrete as usual. There's no need to dust the color onto the surface and float it in during finishing, as is the case with shake-on hardeners.
INTEGRAL COLOR LIMITATIONS
The main disadvantage of integral color is that the hues are subtle and less intense than what you can achieve with color hardeners. Cost can be another drawback. Because you're coloring the entire batch of concrete rather than just applying color to the surface, you may pay 10% to 30% more for integrally colored concrete than for plain concrete. But generally the cost for labor won't be any higher, since integrally colored concrete is mixed and finished just like conventional concrete.
WHERE TO USE CONCRETE PIGMENTS
Integral pigments can be added to just about any type of new concrete. Popular applications include exterior flatwork, floors, walls and countertops. Integral color is ideal for achieving uniform tones with no variations. It also works well as a contrasting base shade for creating layers of color. For example, stamped concrete contractors often start out with integrally colored concrete and then enhance it with color hardeners, stains and other surface-applied treatments. Indoors, integral color is a good alternative to shake-on color hardeners if mess and cleanup are concerns.
CHECKLIST FOR INTEGRALLY COLORED CONCRETE FLATWORK
- Verify that no calcium chloride or other incompatible admixture will be used in the mix.
- Pour a sample to make sure the color meets the designer and owner's specifications (different finishing textures can change the look of the concrete)
- Order concrete with substantial lead times as not all colors are kept in stock at all times
- Avoid delays in placement or excessive mixing at the job site
- Check that the type and brand of cement, the aggregate source, and the coloring agent will not change during the job
- Keep the water content and slump consistent from load to load
- Verify the color matching curing or clear cure is available for the selected color-conditioning admixture
- Ponding, fogging, and wet coverings such as burlap should not be used on colored concrete
- Protect colored concrete from damage from construction traffic
WHAT TO CONSIDER BEFORE BUYING COLORING PIGMENTS
Only use products that meet or exceed ASTM C 979 standards for pigments for integrally colored concrete. You can usually find this information on the technical data sheet for the product.
Most integral pigments on the market today are made from synthetic rather than natural iron oxides. While you can still buy the natural form, synthetics offer two to three times the tinting strength, says technical expert Chris Sullivan.
When it comes to powdered versus liquid forms of integral color, one is really no better than the other, according to Sullivan. "They are really the same product and offer the same tinting strength. One just happens to be suspended in water," he says. A downside of liquid pigments is that you'll end up paying more because they contain 30 to 40 percent water. "One pound of dry pigment equals 1.3 to 1.4 pounds of liquid pigment,' he says. Liquid pigments may offer advantages during mixing, however, because they are less messy to handle than bulk powders and they blend in faster. They also can be dispensed with computer-controlled metering systems, which some ready-mix producers use in their plants for more precise dosing and to simplify the blending of custom concrete colors.
Ask your ready-mix producer or integral color supplier about the effects other admixtures could have on the workability, set times, and color consistency of integrally colored concrete. Manufacturers say that most admixtures have no detrimental effects on colored concrete, with the exception of calcium-chloride-based accelerators, which can cause discoloration and blotchiness. Some admixtures, however, may shift the color slightly lighter or darker.
Because the dosage rate of integral color is based on the cement content of the concrete, some manufacturers warn against using cement substitutes, such as pozzolans and fly ash, because the final color could be affected.
In addition to straight integral pigments, you can find "engineered" integral colors that contain admixtures such as water reducers, set retarders, and conditioners. These products are designed to improve the finishability of the colored concrete. Examples include Chromix Admixtures from L.M. Scofield.
If you plan to add the integral color to the concrete mix yourself, be sure to consult with the color supplier for guidance on the proper dosage per sack of cement and the required mixing times. Most suppliers offer dry pigments in disintegrating bags of various sizes, ranging from 1 to 25 pounds or more, so you can buy the exact quantity needed for a particular project.
Ready-mix producers generally use integral color from one supplier, which may limit your options somewhat. However, Sullivan says that shouldn't be a big concern because the integral colors from the various manufacturers are chemically similar and there's a lot of overlap in color options. "What it comes down to is service and availability," he emphasizes.
Find Local Suppliers: Decorative Concrete Stores
HOW TO FIX INTEGRAL COLOR
Integral color - dry pigments vs liquid color
Question: I am aware that integral color is available in both dry and liquid forms. Is there an advantage to using one over the other? If so, what are they and which is better?
Answer: The short answer is: It depends. Both dry and liquid integral colors use the same type of pigments (typically synthetic or natural iron oxides). Liquid color just happens to be suspended in water. The decision of which type to use comes down to user preference, availability, and price.
Powdered pigments have been around for 60 years, and they are still the most popular coloring medium, although liquid color has grown in popularity over the last 10 years. Advantages of using dry color in bags or in bulk include wider availability, greater tinting strength, and lower cost. However, liquid pigments offer advantages when it comes to mixing and storing. They are less messy to handle, easier to store, and blend in faster than powders. They also can be dispensed with computer-controlled metering systems, which some ready-mix producers use in their plants for more precise dosing and to simplify the blending of custom concrete colors. The downside is cost. Liquid color is 30% to 40% water on average, so you must buy 1.3 to 1.4 pounds of liquid color to obtain the same results as 1 pound of dry color.
While this discussion is not going to end the debate on the merits of dry vs. liquid integral pigments, it should shed some light on the differences. No matter what form of color you choose for your concrete (powder or liquid), the end result will be the same.
Fixing discoloration in concrete with integral color
Question: What caused this last pour of integrally colored concrete to be off-color?
Answer: Asking a few basic questions turned up the following. This was the last of multiple pours, which ran over many weeks. All were tightly controlled for slump and color. A clear water-based curing compound was used on all the slabs. The last slab was rushed a bit since the deadline for opening this area had already passed.
Looking more closely at the other areas of the slab revealed a few blotchy gray areas like the large area in question. This led me to believe that possibly the curing compound was covering the true color. In an effort to save time and money from costly rip out and replacement of the slab (which was the general contractors' first and only recommendation), a simple chemical stripper was used to remove any surface coatings. Sure enough, once a small test area was stripped, the correct color was revealed.
The curing compound had been applied too early and at too high a coverage rate in an effort to save time and cure the concrete faster. This actually backfired by trapping too much moisture, causing the curing compound to haze and turn white. The use of a colored curing compound would have helped in this situation, even at the higher application rate. More information on proper curing of concrete is available from your local ready mix association or from the American Society of Concrete Contractors.
Admixture effects on integral color
Question: How do common concrete admixtures affect integrally colored concrete?
Answer: For decades, the rule of thumb has been that the only admixtures that should not be used with integrally colored concrete are calcium-chloride-based accelerators. The chloride ions attack the color, causing it to fade and turn blotchy.
While all other admixtures have been tested and found to have no long-term detrimental effects on colored concrete, they may shift the color lighter or darker. This makes it that much more important to maintain batch-to-batch consistency.
Never switch admixtures or stop using them in the middle of a colored concrete project! The accompanying chart shows the effects of common admixtures on colored concrete.