Precast concrete offers a virtually unlimited palette of options for creating unique aesthetic treatments ranging from a historic appearance to blend with nearby landmarks or a contemporary style that makes a strong statement of its own. The material can provide any appearance desired in a cost-efficient way with added benefits no other material can match.
The options include:
Using inset thin-brick techniques on precast’s panelized systems can create the masonry appearance that building owners seek while adding benefits masonry can’t provide. Precast’s inset brick eliminates the long scheduling needed for laid-up brick while removing several trades from the site. It ensures a high-quality, even-spaced appearance that is difficult to achieve with actual brickwork—while eliminating on-site inspections. Using inset brick with precast panels makes efficient use of materials, minimizes time and construction materials, avoids problems with weep holes from falling mortar and eliminates concerns over inconsistent labor expertise, weak mortar joints, efflorescence and disruptions due to bad weather.
Special mixes and finish techniques are used on panels to mimic limestone, sandstone, granite and any other type of stone desired. The finishes are produced far more economically than real stone can be laid, and they can be erected much quicker. Form liners can replicate unusual pieces such as cut stone or slate, limiting options only to the designer’s imagination.
Replicating Existing Styles
With its ability to replicate such a wide range of materials, precast concrete panels ensure new buildings blend with existing ones. This is particularly true if the original buildings also were made of precast concrete, as previous mixes often can be reproduced.
Precast concrete panels offer a plasticity in shapes, curves and geometries that can create any desired look. They interface smoothly with glass and other modern materials.
Corporate or school names, emblems and other custom touches can be embedded into panels, creating unique accents at an attractive cost. Glass Fiber-Reinforced Concrete (GFRC) can create sculptural forms for custom designs that create a standout facility.
Precasters’ capability to tint concrete and provide several tones by using various surface treatments within one panel allow designers to specify any color they want. A wide range of finish combinations and textures can be achieved easily.
A wide variety of textures can be created in the concrete to add interest. The most common of these are:
- Smooth or off-the-form finishes show the natural look of the concrete without trying to simulate any other building product.
- Exposed-aggregate finishes, via chemical retarders or water washing, are achieved with a non-abrasive process that effectively brings out the full color, texture and beauty of the coarse aggregate.
- Form liners create unique patterns or textures. The liners can be made of wood, steel, plaster, elastomeric, plastic or foam plastic.
- Sand or abrasive blasting provides all three degrees of exposure noted above.
- Acid etching dissolves the surface cement paste to reveal the sand, with only a small percentage of coarse aggregate being visible, providing a light exposure.
- Tooling, usually called bushhammering, mechanically spalls or chips the concrete using any of a number of hand or power tools, exposing the aggregate textures.
- Hammered-rib or fractured-fin designs creates a bold, deeply textured surface by casting ribs onto the surface of the panels and then randomly breaking the ribs to expose the aggregate.
- Sand embedment creates a massive appearance using 1- to 8-inch-diameter stones or flagstones. The stones typically are placed in a sand bed at the bottom of the mold, and finishing reveals the stone face, resulting in the appearance of a mortar joint.
- Honing or polished finishes are achieved by grinding the surface to produce smooth, exposed-aggregate appearances.
- Painting is used purely for decorative purposes. The decision to paint should be made early to ensure the finished concrete surface is not so smooth that pain won’t adhere to it easily.
- Combination Finishes. Two or more finishes can be readily achieved using the same concrete mix. This procedure will raise the cost of the product, but it will be less expensive than producing a separate unit that must be attached to the primary panel, as with an accent sill.
Precast’s plasticity and variety of finishes make it an outstanding choice no matter what style of architecture is desired.
Ensuring the proper look is achieved can be made easy with precast concrete. Precasters can provide finish samples, range samples and large-scale mockups, ensuring design concepts translate into reality.
Designers can inspect window interfaces, joint connections and other critical elements to ensure they are visually acceptable and will properly interface between trades. Plant visits to discuss technical and aesthetic concerns provide control without requiring constant site supervision.
As the single source for so many architectural and structural components, and the source for brickwork or other finishes, the precaster works closely with the construction team to ensure satisfaction. Overlapping trades and gaps in responsibilities are eliminated when the precaster provides the entire exterior design.
For more information, contact a PCI Certified Manufacturer.