The precast concrete industry is gaining quite an excellent reputation for innovations in sound absorptive soundwall designs. With the use of reusable plastic or rubber formliner, manufacturers can create nearly any texture, pattern, or style of finish imaginable. And since precast concrete is essentially comprised of mostly concrete, water, sand, and stone, it’s also very eco-friendly.
Common examples of pre-fabricated formliner include brick, stone, and fluted finishes. However, some soundwall architects prefer a more distinctive aesthetic. For a slight increase in cost, the formliner can be custom manufactured to precise specifications. It can even be designed to include embossed or debossed imagery or individual letters.
Excellence in sound absorptive precast
One rather impressive example of image-embossed soundwall is the State Route 527 Project for the city of Mill Creek, Washington. Initially, the design was to contain a simple, fractured fin finish. However, after multiple discussions, the design team ultimately decided to split the precast concrete soundwall panels into two sections. The top portion is now a smoother finish with artistic wildlife pictographs etched into its surface.
The lead architect for the Washington State Department of Transportation, Alex Young, began hand-sketching wildlife creatures, insects, and leaves, each specifically chosen to represent the rural elements of the region. The final selections would ultimately be used to create the one-of-a-kind formliner unnecessary for the casting of the individual precast panels.
The completed project now consists of beautifully ornate soundwall panels with debossed images of ladybugs, dragonflies, cedar branches, alder leaves, and animal tracks. The Precast Concreate Institute even boasts of the Mill Creek Soundwall in a monthly newsletter from 2004.
Going green with fly ash and blast lag
As far back as the Roman Age, architects have been using volcanic ash to act as a hydraulic binder which only increases the concrete’s strength as it ages over the centuries. Following the basic principles of this ancient technique, precasters today often add different types of fly ash or blast furnace lag into their concrete mixtures.
These additives produce a pozzolanic reaction very much like the Roman’s volcanic ash. Another interesting design quality is that different types of fly ash create varying specks of texture in the finished product. Furthermore, it is very eco-friendly.
Fly ash is a residue manufactured during the coal combustion process of electrical power plants. And blast furnace lag comes from the production of iron. The precast concrete industry has discovered a rather interesting use of these byproducts that would otherwise be considered garbage.
Fly ash and blast lag are just two examples of the many green, eco-friendly properties of precast concrete. Another recent advancement in the precast industry is something called Ultra High-Performance Concrete (UHPC). Structures made of UHPC can exhibit compressive strengths of up to 33,000 psi and tensile strengths up to 7,000 psi. This brand of precast concrete is an excellent choice for bridge work or highway projects where exposure to deicing salts and consistent heavy loading are common.
Precasters can manufacture sound absorptive concrete panels in nearly any style, texture, or pattern imaginable. There are usually certain limitations regarding the depth of debossed imagery, based on the desired sound ratings, but professional precasters are experts at determining these precise depth calculations to ensure that every panel meets the contracted code requirements. To add even more eco-friendliness to the final design, consider using recycled steel beams for the individual soundwall posts.