03300 – INTEGRALLY COLORED CAST-IN-PLACE CONCRETE
1. PRODUCT NAME
Pigments for Integrally Colored Cast-in-Place Concrete
Pigments for Integrally Colored Concrete paving
7101 Muirkirk Road
Beltsville, MD 20705
301-210-3400 In Maryland
3700 E. Olympic Boulevard
Los Angeles, CA 90023
323-269-7311 In California
3. PRODUCT DESCRIPTION
Davis Colors are made with pure concentrated pigments especially processed for mixing into portland cement concrete. They are lightfast, alkali-resistant, weather-resistant, and formulated to give long-lasting appeal to concrete. Davis Colors give concrete the added design dimension of color.
Use Davis Colors in cast-in-place concrete buildings, and structures. Davis Colors can also be used in concrete paving and slabs, precast and tilt-up concrete, concrete masonry units, concrete unit pavers, masonry mortar, shotcrete, plaster, and other concrete products.
Davis Colors are color admixtures made from metal or mineral oxides either recycled from iron or refined from the earth. Most Davis Colors are made from iron oxide, an abundant and environmentally safe material. (Davis Colors 807 and 8084 are concentrated carbon black, treated in a proprietary process for extra tint strength and dispersability. They are economical alternatives where concrete is not air-entrained and is sealed against water damage.)
Davis Colors are manufactured to exact quality control standards to maintain uniformity of color from bag-to-bag and year-to-year. They are mechanically milled to microscopic particle size to obtain high tinting strength.
Davis Colors are packed in Mix-Ready® disintegrating bags. Mix-Ready bags can be tossed into concrete mixers without opening or pouring. They are made of special paper and adhesive which get soggy when wet and disintegrate during mixing. The bags release Davis Colors deep in the mixer to disperse uniformly. Color handling is clean and there are no empty sacks to litter the job-site. Mix-Ready is the original disintegrating bag for concrete colors and has been used successfully in millions of yards of concrete.
Do not use with admixtures containing calcium chloride. Davis Colors are for mix-in use only; do not sprinkle or dust onto concrete surfaces.
4. TECHNICAL DATA
Davis Colors meet or exceed ASTM C979-82 (Reapproved 1993) – Pigments for Integrally Colored Concrete. This standard establishes criteria for the alkali resistance, stability, and lightfastness of pigments and for their compatibility with concrete.
Davis Colors are available in a wide spectrum of standard colors and can be custom blended to meet special design requirements.
The keys to successful concrete, whether colored or not, include consistency in materials and craftsmanship and careful planning and detailing of the project. Follow industry standards for high quality architectural concrete work and observe the following recommendations.
Concrete Mix Design:
Determine pigment number and pigment dosage rate from the Davis color card. Custom shades are made by varying the amount of color added to the mix. Typical dosage rates range from one to five pounds of Davis Colors per 94 pound sack (1 cu. ft.) of cement content. (With metric mix designs, typical dosage rates range from one to five percent of cement content.) Maximum dosage rate of color should not exceed 10% of weight of cement content. Cement content includes portland cement, fly ash, silica fume, lime and other cementitious materials but not aggregate or sand. Use the same pigment-to-cement ratio for each mix design on a job.
For consistent color throughout a job, each component of the concrete should be from a single source, uniform in color, and consistently proportioned. Maintain 5″ (13 cm) maximum slump unless otherwise specified. If higher slump is required, use water-reducing or plasticizing admixtures instead of added water. A low water water-cement ratio minimizes shrinkage and cracking, maximizes hardness and promotes a richer, darker concrete color. Adding water causes concrete to pale or “wash out”. Schedule deliveries for consistent mixing times for each load. Clean mixer thoroughly before batching colored concrete and after pour to prevent color carry-over.
Davis Colors in Mix-Ready bags may be used in combination with vinsol resin-type air-entraining agents, water-reducing or plasticizing admixtures, and reinforcing fibers. They are expected to be compatible with other commercially available admixtures but have not been tested with all admixtures and mix designs.
Mix-Ready bags have no negative effect on typical concrete mix designs when used at recommended dosage rates. At high addition rates, they have a slight water-reducing effect which can improve workability by slightly increasing slump. However, this is not the intended use for Mix-Ready bags. Use the lowest number of bags required for the batch.
The pure pigments in Davis Colors are not blended with the fillers, additives or admixtures used in some other brands of concrete colors. Pre-blended admixtures, sometimes called “color-conditioned” admixtures, add unnecessary expense and could be incompatible with the concrete mix specified for a particular project. Instead of pre-blended admixtures, Davis Colors recommends using admixtures which are stocked by and familiar to the concrete producers in your area. These admixtures will have a proven performance record with the concrete producer’s materials and can be mixed separately, as required, into the concrete batch.
Adding Davis Colors:
Read label on Mix-Ready bags. Make sure the pigment number and amount added to mixer matches the batch ticket or mix design.
Batch mixer truck with at least three cubic yards of concrete.
Toss in Mix-Ready bags and mix at charging speed for at least 5 minutes (7 minutes for pea-gravel mixes).
Use if satisfactory results are not obtained with standard method.
First, wet mixer drum with approximately 1/2 to 2/3 of total batch water and some of the aggregate.
Toss in Mix-Ready bags and mix at charging speed for one or two minutes to break bags and disperse pigment.
Add cement and remaining aggregate and batch water. Continue mixing at charging speed for 5 minutes (7 minutes for pea-gravel mixes).
In mixes with small aggregate, dry low-slump mixes, or batches with short mixing duration, bags may not completely disintegrate. With sand-blasted or mechanically-exposed aggregate finishes, use smaller bag sizes (15 lbs. maximum) to reduce possibility that small pieces of bag could be exposed.
Provide mock-up to establish that proposed materials and construction techniques provide acceptable visual effect. Construct at least one month before start of concrete work to allow concrete to cure before final inspection. Materials used for mock-up should be those proposed for actual construction; retain samples of cement and aggregates used.
Pick a section or sections of building which typify the most difficult areas to build. Include full allocation of reinforcing steel to be used in project. Erect forming that consists of all formed conditions in project. Use the same placement and finishing techniques that will be used in project. Include repaired areas to demonstrate the color and texture of patching materials.
Design forms to prevent pillowing and deflection of forms.
Steel and high density overlaid plywood forms and plastic formliners are recommended. Avoid porous form materials. Lumber forms can affect color of concrete surface through variation in absorption of different portions of the board unless sealed with a non-porous coating.
Release agents should be non-staining.
Specify tight joints; surface blemishes occur when water containing cement is allowed to leak from forms. Seal joints with tape or foam rubber to avoid leakage. Forms must be secured against the previous pour and sealed to prevent leakage. Multiple horizontal pours should also have tight fitting forms, sealed against the previous pours. In multiple lift vertical pours, rustication strips are recommended.
Form ties manufactured from fiberglass rods are available in colors to match Davis Colors. When ground flush with wall, they are rust-proof and virtually invisible, and reduce the need to plug and patch recesses for formwork ties.
Place in accordance with ACI-301. Keep concrete temperature consistent. Temperatures between 65 degrees and 85 degrees F (18 to 29 C) will normally produce more uniform color. Schedule trucks to arrive just before concrete is required. Deposit concrete in lifts 12″ to 18″ (300 to 460 mm) thick. Layers should be fairly level so that vibrator does not need to move the concrete laterally. Insert vibrator at about 18″ (460 mm) on center depending on concrete mix and vibrator used. Vibrator should penetrate at least 6″ (150 mm) into preceding layer.
Do not over vibrate.
Remove forms in accordance with ACI-347. Different color hues may be expected between two surfaces where adjacent formwork is stripped at different ages.
Use only curing compounds specifically recommended for colored concrete. Davis Colors W-1000 Clear Cure & Seal’ allows the natural appearance of concrete to show. Davis Colors Color Seal II’ covers concrete with a thin colored coating, creating a more uniform appearance. Curing with water, membranes, or non-approved compounds can discolor concrete.
Finishes for Slabs:
Concrete can be finished with a variety of attractive finishes, including broomed, swirled, troweled, rock salt pocked, exposed aggregate, sandblasted, or pattern stamped.A separate product data sheet, available from Davis Colors, has more information about finishes for slabs.
Textured surfaces produce more uniform looking concrete than smooth formed surface. Sandblasting, high pressure water jet, bushhammering, and surface retarders can be used to expose the fine or coarse aggregate. Sandblasted finishes can be brush, light medium or heavy depending on texture desired. If retarders are used, exercise caution and follow manufacturer’s instructions explicitly.
The use of a high quality sealer or water repellent treatment may help preserve the beauty of colored concrete by reducing efflorescence and staining. Follow manufacturer’s instructions.
Patching Colored Concrete:
Fill holes and defects in concrete surface within a few days after form removal. This allows patches and surrounding concrete to age together and reduces the possibility of color variations. Use the same patching materials and techniques that were approved on mock-up.
Make patches with materials from the same sources as the concrete. Because the stiff mortar used for patching typically has a lower water/cement ratio than the rest of the concrete, it will normally dry darker. To overcome this, white cement should be added to the mortar mix. Determine mix proportions by trial and error; a good starting mix is 3 parts sand, 1 part gray cement, and 1 part white cement. Add enough color to create the same color/cement mix rate used on the job, but the white cement used to lighten the patch should not be included when figuring the color/cement mix rate for patching. If necessary, add aggregate to mortar mix so patches will have the same texture and appearance as adjacent concrete.
Color of cured concrete can vary from color cards or samples due to differences in mix water content; forming, finishing and curing methods; weather conditions; and variations in base color of cement or other concrete materials. As with all natural materials, minor variations in appearance are an accepted feature of concrete, both colored and uncolored.
Observe industry practices for quality concrete. Check a test batch to see if it meets specifications before finalizing mix design. Sample concrete throughout pour to assure it meets specifications.
Efflorescence, a salt deposit that forms a white stain on concrete, can be particularly objectionable on colored concrete. Reduce efflorescence by using a low water-cement ratio, using curing compound, and designing concrete mix for less permeability. Seal concrete against water penetration and leaks. Keep de-icing salts away from slabs which are not fully cured. Remove efflorescence as soon as possible. If removal is delayed, deposits convert to calcium carbonate which is removed with a dilute acid wash that will affect the surface appearance.
Davis Colors are not hazardous and are non-toxic if accidentally ingested. Protect against breathing dust and contact with eyes, skin or clothing. Wash thoroughly after use. See label on bag and Material Safety Data Sheet. Store bags in a dry, cool place away from sources of heat or open flame.
Install integrally colored concrete in accordance with applicable building codes, appropriate safety procedures, and good industry practices. Comply with latest editions of the following unless otherwise specified:
ACI 301 – Standard Specification for Structural Concrete.
ACI 303R – Guide to Cast-In-Place Architectural Concrete Practice.
PCA Publication SP021A – Color and Texture in Architectural Concrete.
6. AVAILABILITY & COST
Davis Colors are available through ready-mix concrete producers. They can deliver concrete with Davis Colors already mixed direct to the job site. When it is necessary to add colors at the job site, Davis Colors are also available through leading building material dealers and a nationwide network of distributors. Contact Davis Colors for the nearest suppliers.
Convenient one, five, and 25-pound Mix-Ready bags are standard; batch-sized, metric, and specially-sized packages can also be ordered. Davis Colors are also available in bulk SuperSacks and in liquid or granular forms to meet the needs of special concrete manufacturing operations.
Compared to surface-applied coatings, Davis Colors are an economical way to color concrete. Integral colors are part of the concrete and eliminate the extra costs such as surface preparation, scaffolding, and labor associated with coatings. Because Davis Colors are permanent, the ongoing costs of maintaining and reapplying coatings are eliminated. Contact Davis Colors or your local Davis Colors dealer for additional pricing information.
Since the condition of use and application of our products are beyond our control, Davis Colors makes NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE, and expressly disclaims liability for consequential or incidental damages, whether based on warranty or negligence. Buyer’s sole remedy shall be refund of color purchase price from point of sale.
Cured concrete may be cleaned using power washing or commercially available cleaning solutions; contact the cleaner manufacturer for instructions. Strong acids can cause discoloration. Test the cleaning method in an inconspicuous location before application and rinse thoroughly with clean water.
9. TECHNICAL SERVICES
Call Davis Colors for color samples, guide specifications, additional product literature, and other assistance. A complete concrete color laboratory is available to provide technical assistance and match custom colors. Davis Colors sales representatives are available nationwide.
10. FILING SYSTEMS
Architect’s First Source
Landscape Architecture’s OneSource Directory
Sweet’s General Building and Renovation file 03010/DAV.
Additional product information available upon request:
Material Safety Data Sheets
Data sheets for other colored concrete applications.