Steps can be taken by the contractor, concrete producer, and color supplier to help ensure that attractive and uniform results are obtained with integral color. Either raw pigments or pigments combined with other admixtures can be used to give integral color. Liquid color systems have also been developed. To get good results with integrally colored concrete, pay particular attention to the following details. MIX DESIGN Aim for the lowest slump that can still be placed and finished readily. Avoid using any admixtures that contain calcium chloride. For air-entrained concrete, be aware that some coloring agents will reduce air content. BATCHING AND MIXING Don't add the color pigment first. It may stick to the mixer baffles and not get uniformly distributed. Don't change cement brands in the middle of a job. Watch slump particularly closely during batching. Slump variations often indicate that water content has changed. Changes in water content also cause color variations. FORMING AND PLACING CONCRETE FOR VERTICAL SURFACES Water leakage at joints causes changes in water-cement ration and discoloration near the leak. Use a nonstaining form release agent and thoroughly clean forms before reusing them. Make sure that any steel has at least 1 « inches of concrete cover to prevent stains caused by corrosion. FINISHING AND CURING FLATWORK Don't start finishing colored concrete until the bleed water has evaporated. Use mechanical floats or trowels if possible. Use a liquid membrane curing compound.