Any attempt to categorize and define architectural precast concrete with its myriad expressions and possibilities can have only limited success. Precast concrete is a visually rich material that offers the architect the opportunity to be innovative and obtain design objectives that cannot be accomplished with other materials.
The samples in this search serve only as a visual guide for initial selection of color and texture. It is important to note that the colors seen will vary depending on your monitor settings, as well as by the specific settings for your color printer, should you print the results of your search. Since it is impossible to reproduce exactly on the screen the true colors of precast mix designs (as it is with printing inks), some variation from these samples must be expected.
Additionally, due to different material sources or different techniques in various plants, the architect should not expect to select a photographic sample and obtain exact matching by all precast concrete producers. Samples should be required to ensure that the desired colors and textures can be satisfactorily matched.
Be sure to contact the PCI-certified architectural precaster near you to ask about the colors and textures available in the architectural precast concrete design option! And bear in mind that many architectural precasters ship over wide, multistate areas.
The proper selection of color, form, and texture is critical to the aesthetic appearance of architectural precast concrete. The choice of appropriate aggregates and textures, combined with well conceived production and erection details, can achieve a wide variety of design objectives.
It is recommended that the architect contact local architectural precast concrete producers in the early design stages and throughout the development of the contract documents. This will provide optimum utility and quality of the product and its installation at minimum construction cost. Precast concrete manufactured in a plant under factory-controlled conditions, ensures a uniform, high quality building facade in the desired shapes, colors and textures.
The photographs are numbered and arranged from light to dark colors. Most of the samples have dual finishes and each finish is numbered separately.
Design flexibility is possible in both color and texture of precast concrete by varying aggregate and matrix color, size of aggregates, finishing processes, and depth of exposure. Combining color with texture accentuates the natural beauty of aggregates.
Color and, consequently, color tone represent relative values. They are not absolute and constant, but are affected by light, shadow, density, time and other surrounding or nearby colors.
Color selection should be made under lighting conditions similar to those under which the precast concrete will be used, such as the strong light and shadows of natural daylight. Surface texture influences color. The building's appearance is a function of the architect's use of light, shadow, texture and color.
Cement (plus coloring agent) exerts the primary color influence on a smooth finish because it coats the exposed concrete surface. As the concrete surface is progressively removed and aggregates are exposed, the panel color increasingly exhibits the fine and then the coarse aggregate colors. Nevertheless, the color of the cement always has an effect on the general tone of the panel. Cement may be gray, white, buff or a mixture. All cements have inherent color and shading differences depending on their source.
Pigments and pigmented admixtures often are added to the matrix to obtain colors which cannot be obtained through combinations of cement an fine aggregate alone. White portland cement will produce cleaner, brighter colors and should be used in preference
Fine aggregates have a major effect on the color of white and light buff colored concrete, and can add color tones when the surface is given a shallow profile to increase their exposure.
Coarse aggregate colors become dominant as the surface of the concrete is removed to obtain a medium or deep aggregate exposure profile. Some finishing processes change the appearance of aggregates. Sandblasting will give the aggregate a matte finish, while acid etching may increase their brightness. Exposure by retardation normally leaves the aggregates unchanged.