The Constructor

Pigments for Concrete: Types, Purposes, and Influences

Pigments for Concrete types, purpose, and applications

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Pigments are fine dry powder or slurry or aqueous suspension that added to the concrete ingredients to produce colors, other than the normal grey color. It is added during batching as a liquid or finely divided colored inert powder.

Pigments can be natural or synthetic, organic or inorganic. Synthetic pigments are more stable and color fast. Examples of pigments are iron oxide (black, bround, red, yellow of varying particle size and shape), chromix oxide (green), titanium dioxide (white), phthalocyanine (blue, green).

Wetness and alkalinity of concrete can be aggressive environment to pigments. That is why it is very important to use pigments designed for use in concrete.

Plasticizers may be introduced to concrete mixture in which pigments are used in order to reduce water demand and other constituents that reduce the occurrence of surface efflorescence and minimize color fade caused by UV light.

Types of pigments

1. Iron Oxide Pigments 

Iron oxide pigments are widely utilized but it can be costly. Different colors are browns, reds, blacks, and dirty yellows.

2. Special Metal Oxides 

Special metal oxides include some iron oxides are purply red, blue or yellow; chromium oxide is green, and titanium oxide is bright white.

3. Synthetic Pigments 

Synthetic pigments are more expensive than previous pigments but provide the desired colors which are unobtainable from metal oxides. For instance, brilliant violet, pure red, and canary yellow.

4. Powdered Pigments 

Powdered pigments can be either loose or granulated. The former is dustless since its particles are adhere together. The latter is designed for use in mixer trucks where the coarse aggregate and lengthy, vigorous mixing action break the particles up.

5. Liquid Pigments 

Liquid pigments are solid pigment particles suspended in a liquid. The liquid helps to keep the pigment suspended for the duration of the measuring and dosing.

Fig. 1: Types of Pigments

Pigment Dosage

According to ASTM C 979-10, the maximum pigment dosage is equal to or less than 10 % mass of cement. However, a normal range is between 3% and 6%.

When two types of pigments are blended to achieve certain color, the same maximum dosage of single pigments for the total amount of both pigments used.

Effects on Concrete

Fig. 2: Pigmented Concrete

Where to use Pigments?

Fig. 3: Pigmented Exterior Surface of Concrete Structure



It can be costly

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