Concrete Powder Pigment

1. Scope — the colors this data sheet covers

This data sheet applies to the twenty-nine iron oxide color codes listed below. Each is a dry powder pigment for integrally coloring concrete, cement, mortar, stucco and grout.

118 · 202 · 203 · 204 · 205 are covered by separate data sheets. Each carries its own chemistry and its own safety data sheet. No statement in this document — including the ASTM C979 statement in §4 — applies to those codes. Ask for the data sheet that names the code you are specifying.

2. Product description

Direct Colors concrete pigment is a dry powder colorant added to a cement-based mixture during batching. Color is distributed through the material rather than applied to its surface. There is no surface color layer that can peel or flake; appearance change comes from wear and weathering of the concrete itself rather than from loss of a coating. Supplied in 34 standard colors across the full range; twenty-nine of those are covered by this document.

The colors are blended to Direct Colors formulations rather than resold as stock pigment.

3. Composition

Specifiers: iron oxide describes the codes in the §1 table only. It does not describe 202, 203, 204 or 205. Confirm the specific code before submittal.

4. ASTM C979 conformance

Direct Colors concrete pigments in the codes listed in §1 comply with ASTM C979, Pigments for Integrally Colored Concrete.

What this statement is. A declaration of conformance made by Direct Colors against the criteria of the standard, on documentation held on file. It is not a third-party certificate — no certification scheme for ASTM C979 exists. It covers the twenty-nine color codes listed in §1 and no others, and it speaks to the pigment rather than to finished concrete, whose color depends on the variables in §9.

How to obtain it. A signed Statement of Conformance is issued separately and is available to specifiers on request — write to cs@directcolors.com with the color codes and the project name.

What the standard covers. ASTM C979 sets criteria for the alkali resistance, resistance to light, water-soluble content, calcium chloride solubility, effect on setting time, effect on 28-day compressive strength, and uniformity against a reference standard of pigments for integrally colored concrete. The conformance statement above speaks to those criteria. It is not a statement about the finished concrete, whose color depends on the variables in §9.

What ASTM C979 is. ASTM C979 is a specification. There is no third-party certification scheme for it — no body certifies conformance. Conformance is a declaration made against the criteria of the standard, not a certificate issued by a third party. Any supplier describing its pigment as certified to ASTM C979 is describing something that does not exist.

5. Packaging

Pack sizes above 25 lb are quoted individually and are not catalog items.

6. Dosage

Pigment is dosed as a percentage of the weight of cementitious material — cement plus any supplementary cementitious materials. It is never calculated on the weight of the total concrete, and never on the volume of the pour.

6.1 The shade code carries the dose

Each finished shade is written as base–step, and the step is the dose in pounds of pigment per 94 lb sack of cement. 102-5 Smokestack is base color 102 at 5 lb per 94 lb sack.

Both the sack column and the cubic-yard column assume the cement is the whole of the cementitious content — a five-sack mix is 470 lb cementitious per cubic yard on that basis. Where fly ash, slag or any other supplementary cementitious material replaces part of the cement, dose on total cementitious weight using the percentage column, and ignore the sack and yardage columns.

6.2 Cement base

Every shade rendering published by Direct Colors is produced on gray Portland cement. White Portland cement with the same pigment and the same dose produces a different, brighter result. State which cement the work will use before selecting a shade.

7. Mixing

1. Add pigment to the mix, not to the surface. This is not a dry-shake or broadcast color hardener. Do not sprinkle pigment onto finished concrete.
2. Charge the pigment with the aggregate and cement, before the full water charge, so it disperses through the dry materials.
3. Central mix — typical starting point: approximately two-thirds of the water and one-third of the aggregate, then three minutes at charging speed, then 8–12 minutes or 120–150 revolutions.
4. Site mix — typical starting point: 10–12 minutes after all materials are in.
5. Keep the batch sequence, mixer, mixing time and materials identical across every batch on a job. Under-mixing is the most common cause of streaking and mottling.

The charging split and the mixing times in items 3 and 4 are typical starting points, not specifications. Water and aggregate proportions, mixing time and revolution count depend on the mix design and on the plant's own established practice, and should be confirmed against both before the first batch. Items 1 and 5 do not vary with the mix or the plant: pigment is batched into the mix rather than applied to the surface, and whatever sequence and mixing time the job settles on is held constant across every batch.

8. Limitations

• Do not use calcium chloride or any chloride-based accelerator. It causes mottling and discoloration in colored concrete.
• Do not add water after batching. Water has a substantial effect on final color and adding it lightens and washes out the result. The effect is not recoverable.
• Do not exceed 10% of cementitious weight.
• Maintain a consistent water/cement ratio and a 4–6 inch slump across the job.
• Do not sprinkle or dust pigment onto the surface of the concrete. This product is an integral color and is batched into the mix. Broadcasting it onto a finished surface will not color the slab through and will not hold.
• Color cannot be corrected after placement. Approve the color before the pour.

Two things worth remembering on site. Color follows the cure — where a slab dries evenly, it colors evenly. And every variable you hold constant from load to load is one that cannot move the color.

9. What determines the finished color

Pigment is one variable among many, and the others are controlled on site. The same pigment at the same dose produces a different result if any of these change:

• Cement color, brand and source. Gray cement mutes every color; the effect is strongest on bright shades
• Water content and water/cement ratio — the largest single cause of batch-to-batch variation
• Aggregate and sand color · supplementary cementitious materials such as fly ash or slag
• Curing method, timing and temperature. Even curing and even drying give even color
• Finishing technique and timing · sealers, cures and surface treatments, which generally darken the apparent color
• Efflorescence, a whitish surface deposit arising from the concrete itself, which makes the apparent color paler or patchy wherever it is present

Holding the mix design, the materials and the methods constant throughout a job — including cement and aggregate from a single source — reduces variation.

On efflorescence. Efflorescence is a whitish surface deposit that can appear as new concrete cures. Where it is present it makes the apparent color pale or patchy, and it is more noticeable on colored concrete than on gray. It arises from the concrete itself and is not a defect of the pigment. It falls outside the pigment warranty in §11, and this data sheet does not specify a treatment for it.

10. Mock-up

Make a test panel using the actual cement, aggregate, water and finishing method for the work, cured as the work will be cured, and approve the color from the cured panel.

Color cards, screen renderings and samples made with other materials indicate a color. They do not predict it. Direct Colors will prepare a sample against submitted materials on request — send the cement and sand intended for the work and our color lab will work up a match.

11. Warranty

Direct Colors LLC warrants that, at the time of delivery, pigment sold in the color codes listed in §1 conforms to the alkali resistance criterion and the resistance to light criterion of ASTM C979, Pigments for Integrally Colored Concrete. This is a warranty about the pigment. It is not a warranty about finished concrete, whose appearance depends on the variables in §9.

Where a claim under this warranty is established, the remedy is replacement of the nonconforming pigment or a refund of the purchase price paid for it, and Direct Colors' liability is limited to that amount.

Full terms. This section summarizes the warranty. Every sale is governed by the Direct Colors Terms of Service and Refund Policy, which contain the complete warranty, remedy, claim-period and liability terms and which govern in the event of any inconsistency with this data sheet.

12. Document control

Coverage per cubic yard

Figures assume a five-sack cubic yard, which is 470 lb of cementitious material. Confirm the actual sack count with your ready-mix supplier before ordering, since richer and leaner mixes change the pigment required per yard. At Step 5 the arithmetic is convenient: one 25 lb bag colors roughly one cubic yard. Both the sack column and the cubic-yard column assume the cement is the whole of the cementitious content; where fly ash, slag or any other supplementary cementitious material replaces part of the cement, dose on total cementitious weight using the percentage column.

Worked example — a residential driveway

A 20 ft × 40 ft driveway poured 4 in. thick is 800 sq ft, or about 9.9 cubic yards. At Step 5 that is roughly 250 lb of pigment, or ten 25 lb bags. At Step 3 the same driveway takes about 150 lb, or six bags. Order the full quantity in one batch: pigment from a single production run gives the most consistent result across a continuous pour.

Colors used on exterior flatwork

Most pavement work is specified in the grey and black range. Those colors are iron oxide based — the pigment chemistry that has been used in exterior concrete for decades, because it is stable in the alkaline environment of cement and does not wash out.

• 102 Graphite
• 206 Charcoal
• 215 Gray
• 217 Light Charcoal
• 224 Silver Gray
• 231 Eagle Gray

Earth tones — buffs, tans and browns — are also common on aprons, walkways and decorative bands. Colors carrying an ASTM C979 conformance statement are marked in the full color list; ASTM C979 is the standard specification for pigments used in integrally colored concrete. A signed Statement of Conformance is available to specifiers on request.

Working to a numbered color specification

Pavement and flatwork scopes on commercial, retail and multi-site work usually name a color by number rather than by description. 860 and graphite are among the callouts that come up most often on dark grey flatwork.

A number on a plan sheet tells you what the architect approved. It does not tell you the pigment chemistry, the loading, or the mix the approved sample was made from — and those three things decide what your pour actually looks like.

Direct Colors does not publish conversions between one manufacturer's numbering and another's. A chart cannot see your cement, your sand or your water, and a number carried across from one system into another is a guess wearing the clothes of an answer. We match to the physical sample instead:

1. Send us what was approved. The chip, the specification page, a photo of the control pour, or a broken piece of the sample slab.
2. Our color lab reads it and identifies the closest starting point in our range, with a loading in pounds per 94 lb sack.
3. You pour a cured test panel using your own cement, sand, aggregate and finishing method, and approve the color from that panel before the job pour.

Approximations, not exact matches. Any color identified from a submitted sample is a starting point for your test panel. It is not a representation that a finished pour will match a sample made with different materials, and it is not a statement about any other manufacturer's product. Every reference to a third-party color number is for identification of the specification only.

Iron oxide, not carbon black

Worth knowing before you submit: the blacks in our 1xx series are iron oxide, not carbon black. Some pavement specifications exclude carbon black outright, and some dark grey colors in circulation are carbon black based. If your specification carries that exclusion, say so when you send the sample and we will confirm the chemistry in writing.

Higher loadings on commercial pavement

Commercial pavement specifications frequently call for loadings above our published Step 7 — some sit at or slightly above the customary ceiling of ten percent of cementitious weight, which on a five-sack yard is about 47 lb per cubic yard.

Before a full pour

• Final color depends on your cement, sand and aggregate, water content, curing and finish.
• Grey cement mutes and darkens every color; white cement gives a cleaner, more saturated result.
• Do not add water after batching, and do not use calcium chloride or any chloride-based accelerator.
• Approve the color from a fully cured test panel made with your own mix — not from a screen, a chart or a sample poured with other materials.
• Keep the mix design, the dose and the finishing method identical across every truck on the job.