RMC Pigments Integral Color for Concrete
RMC: Iron oxide pigments are used in ready mix, pre-cast, tilt-up, ornamental concrete, shot-crete, mortar, concrete masonry units, pavers, roof tiles, and retaining wall units. Additional uses are to color stucco, plaster, cast stone, and many other cement-based construction materials.
Materials: RMC Pigments colors do not contain fillers or extenders. All pigments are permanent, light-fast, inert and stable to atmospheric conditions. RMC colors comply with ASTM C979, Pigments for Integrally Colored Concrete. Integral colors are not designed for dust-on application.
Packaging: RMC Pigments are packaged in pre-measured per cubic yard repulpable bags. RMC Pigments may be tossed into mixer without opening or pouring. The mixing action disintegrates the bag allowing the pigment to disperse throughout the mix. Select colors are available in standard 50lb paper bags, 2000lb super sacs, and bulk tanker loads. Quality is assured by a batch label system that tracks the product through production to the warehouse and to your job site. Standard packaging is based on a 5 sack mix (3000psi) per cubic yard.
Mix Design: Make sure to use the same mix design and a consistent water to cement ratio throughout the job with a consistent slump between 4″ to 6″. Color variation may occur if batch proportion and slump are not maintained from load to load. Keep all raw materials (sand, cement, and aggregates especially) as consistent as possible throughout the entire project. Changes in raw materials (size, color, moisture content) affect the final color. Remember water has a vast affect on final color. Adding too much water will lighten the color of the project giving it a pale or washed out look. When better flow ability is required, use a plasticizer or water-reducing admixture. Calcium chloride or any chloride based accelerator should not be used. Chloride based additives will cause discoloration in the finished project.
Mixing Color: Batch Plant – When mixing at batch plant, truck mixers should be thoroughly cleaned prior to use. For best results add two-thirds of the water and one-half of the aggregates to the drum. Add RMC Pigments to the drum. Mix at full charging speed for three minutes or until bags break apart and pigment is dispersed evenly. Add balance of ingredients and mix at full charging speed for 8-12 minutes (120-150 revolutions). Job Site- RMC Pigments Integral Color can also be added at the job site. Add bags to drum and mix for 10-12 minutes (120-150 revolutions). Order concrete at a workable slump (4”-6″) and always keep water addition to a minimum. Make every effort to maintain consistency with multiple loads. Water addition can lead to inconsistent color.
Additional Items for the Contractor
RMC recommends following similar procedures for colored and uncolored concrete regarding base preparation, use of vapor barriers, form placement, reinforcement and joints. Integrally colored concrete should be installed the same way as high quality uncolored concrete. Listed are additional guidelines that should be observed for colored concrete. For more detailed information, please review our color guide.
- Avoid adding extra water at the job site. Do not wet finishing tools or add water to the surface of the colored concrete.
- When the surface becomes wet, stop floating. Allow bleed water to evaporate, then begin troweling. Waiting too long, may allow dark spots or “burn” marks to appear.
- Do not use wet coverings, plastic sheeting, water proof paper, or liquid membrane curing compounds.
- Even curing + even drying = even color.
- Pigment loading should never exceed 10% of the weight of the cement content.
- Consistency = Reliability.
- Do not sprinkle pigment onto the surface of the concrete.
- Complete the job by sealing your project with one of RMC Pigments products.
- Contact your local sales person for pump mix design color requirement.
Efflorescence is a naturally occurring process. It is a white powdery substance that may occur on the surface of the concrete. This is a result of water evaporation and is more noticeable on colored concrete. Proper curing and protection from water penetration will help reduce the effects of efflorescence. If efflorescence occurs, care should be taken to clean the surface. Use RMC Pigments Clean & Etch for cleaning colored concrete and be sure to seal with an RMC Pigments sealer. RMC Cure – Seal 25 is designed to be applied to freshly placed concrete as soon as the finishing process is completed. This product seals and protects, assures proper curing and will help to prevent efflorescence. Please refer to RMC product label and data sheets for proper application. Always follow manufacturer’s recommendations carefully.