Available Specs:
| Paving | Cast-In Place | Tilt-Up | Masonry | Precast |
Download Cast-In Place Specs in Microsoft Word format

SECTION 03300

INTEGRALLY COLORED ARCHITECTURAL CAST-IN-PLACE CONCRETE

Davis Colors add color to the design of concrete floors, buildings, and structures. Integral colors are economical to use because they are mixed right into the concrete and require little additional labor to finish. In addition, integral colors are permanent and do not require periodic refinishing as can coatings and applied finishes. Davis Colors are made with pure, concentrated pigments especially milled for mixing into concrete. They are lightfast, alkali-resistant, weather resistant, and formulated to give long-lasting appeal to concrete.

In general, integrally colored concrete is produced the same way as high-quality uncolored concrete. This document suggests specification provisions which pertain to colored concrete. INCORPORATE INFORMATION FROM THIS GUIDE SPECIFICATION INTO A COMPLETE MASTER SPECIFICATION FOR CAST-IN-PLACE CONCRETE. Then edit to meet project requirements. Prepare specification in accordance with ACI recommendations and other applicable industry guidelines. Show locations of colored concrete on Drawings or in Schedules.

This document is available in word processing format on SweetSource and from Davis Colors via the Internet or diskette. For product literature or tech-nical assistance about pigments, con-tact Davis Colors at:

    East: 800-638-4444 (301-210-3400 Maryland).
    West: 800-356-4848 (213-269-7311 California).

 

PART 1 GENERAL

 

1.01 SUMMARY

  1. Section Includes: Integrally colored cast-in-place concrete.

Davis Colors can also be specified in other specification sections. Include the paragraph below if you wish to coordinate cast-in-place concrete colors with colors specified in other sections. Note, however, that an exact color match of cast-in-place concrete and work specified in other sections may not be practical because of the differences in the various manufacturing and construction processes; make final color selections on the basis of product samples or mock-ups.

Guide specifications for other types of colored concrete work are also available from Davis Colors.

  1. Related Sections:
    1. Section [02750 - Cement Concrete Paving]: Coordination of sample submittal [and color selection].
    2. Section [02780 - Concrete Unit Pavers]: Coordination of sample submittal [and color selection].
    3. Section [03400 - Precast Concrete]: Coordination of sample submittal [and color selection].
    4. Section [04200 - Masonry Units]: Coordination of sample submittal [and color selection] for [concrete masonry units] [and] [colored mortar].
    5. Section [07320 - Concrete Roofing Tiles]: Color coordination.
    6. Section [07900 - Joint Sealers]: Colored sealants for joints.

 

1.02 REFERENCES

Edit references to include standards use in Project Specifications. For a copy of ASTM C979, contact Davis Colors.

Other useful publications about colored concrete include:

  • ACI 303R - Cast-In-Place Architectural Concrete Work.
  • PCA PA124.H - Finishing Concrete Slabs with Color and Texture.
  • PCA SP021A - Color and Texture in Architectural Concrete.

  1. American Concrete Institute:
    1. ACI 301 - Structural Concrete for Buildings.
    2. ACI 305R - Hot Weather Concreting.
    3. ACI 306R - Cold Weather Concreting.
  2. American Society for Testing and Materials:
    1. ASTM C309 - Liquid Membrane-Forming Compounds for Curing Concrete.
    2. ASTM C979 - Pigments for Integrally Colored Concrete.

 

1.03 SUBMITTALS

  1. Submit product data and manufacturer's instructions for:
    1. Pigments.
    2. Curing compounds.
    3. Form facing materials.
    4. Form release agents.
    5. Surface retarders.
    6. [________________________.]
  2. Samples:
    1. Submit pigment manufacturer's [color chart] [sample chip set] for color selection; indicate pigment number and required dosage rate. Submittals are for general color selection and may vary somewhat from concrete finished in field according to Specifications.

If color selection has not been made at time specification is issued, include above. If color selection is specified, include below.

    1. Submit sample chip[s] of specified color[s] indicating pigment number[s] and required dosage rate[s]. Submittals are for general verification of color and may vary somewhat from concrete finished in field according to Specifications.
    2. Submit samples of [select aggregate,] [and] [_________].

 

1.04 QUALITY ASSURANCE

  1. Perform work in accordance with ACI 301, Section 6 - Architectural Concrete.
  2. Conform to ACI 305R during hot weather.
  3. Conform to ACI 306R during cold weather.
  4. Obtain each materials from same source and maintain high degree of consistency in workmanship throughout Project.
  5. Installer Qualifications: Concrete work shall be finished by firm with [five] [________] years experience with work of similar scope and quality.

Specify a mock-up to demonstrate that proposed materials and workmanship produce acceptable concrete appearance.

  1. Colored Concrete Mock-Up:
    1. Provide full-scale mock-up under provisions of Section [01400.] [________.] Construct at least one month before start of other concrete work to allow concrete to cure before observation.
    2. [At location on Project selected by [Architect] [________], demonstrate each forming and finishing condition required on Project using materials, workmanship, joint treatment, form ties, curing method, and patching techniques to be used throughout Project.
    3. Retain samples of cements and aggregates used in mock-up for comparison with materials used in remaining Work.
    4. Accepted mock-up provides visual standard for work of Section.
    5. [Mock-up may remain as part of Work.] [Remove when no longer required for comparison with finished work.]

Specify preconstruction conference if job is complex.

  1. Preconstruction Conference:
    1. Comply with Section [01200] [________].
    2. Review organization and procedures for work of this Section.

 

1.05 DELIVERY, STORAGE AND HANDLING

  1. Pigments: Comply with manufacturer's instructions. Deliver pigments to job site or batch plant in original, unopened packaging. Store in dry conditions.

 

PART 2 PRODUCTS

In general, integrally colored concrete can be specified with the same cements, aggregates, reinforcing, forms, and admixtures used in high-quality uncolored concrete.

 

2.01 CONCRETE MATERIALS

  1. Pigments for Integrally Colored Concrete:
    1. Manufacturer:
      1. Davis Colors manufactured by Davis Colors; phone 213-269-7311.
      2. Substitutions: Comply with [Instructions to Bidders] [Section 01600] [________________] for substitution request procedures.
    2. Materials: Pigments shall contain pure, concentrated mineral pigments especially processed for mixing into concrete and complying with ASTM C979.

Mix-Ready disintegrating bags simplify use of pigments. Toss unopened Mix-Ready bags directly into concrete mixer. Bags travel deep into mix and disintegrate under mixing action, so there's less colored dust released into air and no empty sacks to litter job site. Premeasured bags make it easy to add the right amount of pigment without weighing. Additional packaging systems are also available for convenience of ready mix plant operators.

    1. Packaging: If pigments are to be added to mix at Site, furnish pigments in premeasured Mix-Ready disintegrating bags to minimize job site waste.

Select one of three following methods to specify colors. Typical dosage rates range from 1 to 5 percent and must not exceed 10 percent.

    1. Color[s]:
      1. [Provide color[s] to be selected by [Architect] [________] from manufacturer's [standard] [premium] color line. [Allow for up to [two] [________] colors on Project.]
      2. [Concrete mix shall contain [________] percent dosage rate of Davis Colors pigment No. [________]. Dosage rate shall be based on weight of portland cement, fly ash, silica fume, lime and other cementitious materials but not aggregate or sand.]
      3. [Pigment as necessary to match [existing building] [sample in Architect's office.]

Color of cement, sand, and aggregates affect final appearance of colored concrete.

  1. Cement: Color shall be [gray] [white].
  2. Sand: Color shall [be locally available natural sand.] [match sample in [Architect's] [________] office.] [be color required to match approved concrete sample.]
  3. Select Aggregate: [________________________________.]
  4. Admixtures: Do not use calcium chloride admixtures.

 

2.02 FORMS

Porous materials, like lumber or unfaced plywood, can absorb moisture from fresh concrete, causing uneven curing and colors. Decorative form liners provide textured or patterned relief on the concrete surface and increase the design possibilities with colored concrete.

  1. Form Facing Material:
    1. [Provide smooth, non-porous surface such as steel, plastic, or high-density overlaid plywood.]
    2. [Decorative Form Liners: [_________________________.]]

Conventional metal form ties can rust if not properly recessed and plugged. Colored fiberglass ties blend with concrete when ground flush to surface and do not rust.

  1. Form Ties: Fiberglass rods tinted to match concrete.
  2. Joint Sealants: [Tape,] [foam rubber gaskets,] [or] [sealant].

Specify a form release agent that is non-staining and minimizes formation of "bug-holes" in surface of concrete.

  1. Form Release: [_______________________________________.]

 

2.03 ACCESSORIES

Use only curing compounds specifically recommended for use with colored concrete. W-1000 Clear Cure & Seal allows the natural appearance of concrete to show. Color Seal II covers concrete with a thin colored coating, creating a more uniform appearance.

  1. Curing Compound for Colored Concrete: Curing compound shall comply with ASTM C309 and be approved by pigment manufacturer for use with colored concrete. Provide [W-1000 Clear Cure & Seal] [Color Seal II tinted to match colored concrete and] manufactured by Davis Colors.

Surface retarder can be used with exposed-aggregate finishes.

  1. Surface Retarder: [________________________________.]
  2. Sealants: Joint sealers shall be [type specified in Section 07900.] [________________.] Provide in color matching colored concrete.

Use corrosion-resistant chairs and supports to prevent rust stain on face of concrete.

  1. Supports for Reinforcing Bars: Use corrosion-resistant types at locations in contact with exposed surfaces.

 

2.04 MIXES

When specifying concrete mix, 4" slump is recommended. If greater slump is required, use water-reducing or super-plasticizing admixture instead of adding water. Low water-cement ratio promotes richer, darker concrete colors.

  1. Pigments: Mix in accordance with manufacturer's instructions. Mix until pigments are uniformly dispersed throughout mixture and disintegrating bags, if used, have disintegrated.
  2. Schedule delivery of concrete to provide consistent mix times from batching until discharge.

 

PART 3 EXECUTION

 

3.01 FORMS

Leakage around forms changes water-to-cement ratio in concrete surrounding joint, leading to discoloration. Similarly, removing forms when concrete is at various ages can result in color variations.

  1. Provide watertight joints, sealed to prevent leakage.
  2. Stripping: Leave forms in place as long as practical. Remove forms when concrete has reached a consistent age to maintain uniformity of curing conditions throughout Project.

 

3.02 FINISHES ON FORMED SURFACES

See ACI 301 and PCA Color and Texture in Architectural Concrete for more information about formed finishes.

  1. Provided the following finishes in accordance with ACI 301:
    1. As-cast, rough form finish.
    2. As-cast, smooth form finish, smooth rubbed.

The finishes below will have the more uniform color than as-cast finishes.

    1. Textured form liner finish.
    2. Exposed aggregate, scrubbed finish.
    3. Exposed aggregate, blast finish.
    4. Exposed aggregate, tooled finish.

The following are just two of many possible finishes with integrally colored concrete. Finishing Concrete Slabs with Color and Texture published by Portland Cement Association is a useful guide and includes photographs of these and other finishes.

 

3.03 FLOOR FINISHES

Brooming provides an attractive, slip-resistant surface. Applying broomed finish to floated concrete saves the extra step of troweling and can produce a more uniformly colored surface.

  1. Broomed: Pull broom across freshly [floated] [troweled] concrete to produce [fine] [medium] [coarse] texture in [straight] [wavy] lines perpendicular to main line of traffic. Do not dampen brooms.

The smooth, dense surface produced by troweling may not provide adequate slip resistance outdoors or in wet areas. Over-troweling or starting troweling late may produce discolored burns or dark spots.

  1. Trowel: Use steel trowel to produce smooth dense surface. Do not over-trowel or start troweling late.

 

3.04 PATCHING

  1. Fill holes and defects in concrete surface within 48 hours of form re-moval.
  2. Use the same patching ma-terials and techniques that were approved on mock-up.
  3. Make patches with a stiff mortar made with materials from the same sources as the concrete. Adjust mortar mix proportions so dry patch matches dry adjacent concrete. Add white cement to mortar mix if necessary to lighten it. [With exposed aggregate finishes, add aggregate to mortar mix so patches will have the same texture and appearance as adjacent concrete.]

 

3.05 CURING

  1. Maintain concrete between 65 and 85 F (18 to 29 C) degrees during curing.

Curing with water, membranes, or non-approved compounds can discolor concrete.

  1. Colored Concrete: Apply curing compound in accordance with manufacturer's instructions.

 

3.06 TOLERANCES

As with any natural material, some variation in appearance is a normal design feature of concrete, whether colored or not. Note that concrete lightens as it cures; allow up to 28 days for process to occur.

  1. Minor variations in appearance of colored concrete, which are similar to natural variations in color and appearance of unpigmented concrete, are acceptable.

 

3.07 SCHEDULE

If locations of colored concrete are not shown on Drawings, include schedule here. Examples are given below.

LOCATION PIGMENT DOSAGE FINISH
Lobby Floor 61078 5% Troweled.
Retaining Walls 160 1% Sandblasted.
Exterior Walls 160 4% Sandblasted.
Accent Wall 160 4% Form liner.

 

END OF SECTION

Color Seal II, Davis Colors, Mix-Ready, and W-1000 Clear Cure & Seal are trademarks of Davis Colors. Copyright 1996; qualified design and construction professionals may copy for preparation of construction specifications. Issued September 3, 1996.

We welcome questions or comments.
Or call:   West: 800-356-4848   East: 800-638-4444