Sophisticated mix designs and precise manufacturing techniques enable designers to create stunning precast concrete structures.
By Kyle Kerstiens, ASSOC. AIA, LEED AP
Welcome to the second annual architectural issue of Precast Solutions. Architectural precast concrete is one of the most versatile, dynamic building materials in 21st century construction. Computer-generated molds, increasingly sophisticated mix designs and precise manufacturing techniques have enabled designers to create stunning precast concrete structures. For this issue, we have selected a handful of projects that illustrate the wide range of possibilities that can be achieved with precast. We start in East Los Angeles at the Mariachi Station where custom precast veneers beautifully mimic natural stone. Then we move north to Redmond, Wash., to show how bridge abutment panels combine form and function for a sweeping, layered look. While we’re in Redmond, we look at how precast concrete helped achieve LEED Gold status at an office building. Then it’s on to Springville, Utah, to view an incredible home that features more than 1,000 pieces of precast concrete.
Back in Washington, we’ll look at how large block precast concrete combined with a father’s vision to create a lasting memorial to his son whose life was tragically cut short.
We hope you enjoy this issue and agree that when it comes to incredible architectural design, precast concrete makes it possible. For additional examples of the wide range of precast, please visit our website at www.solutions.precast.org.
Arto Brick, Gardena, Calif.
In East Los Angeles stands an historic plaza with a beautiful stone gazebo at the center. Donated by Guadalajara, Mexico, it honors the mariachi bands that congregate in the bustling plaza and offer their music to locals and visitors. When the city was ready to expand its Metro line, Mariachi Plaza became the natural selection for a new Metro Station Gold Line extension from Pasadena to East LA.
Because of the historic nature of the neighborhood, the Mariachi Station was constructed underground with above-ground entrances that complement the natural stone architecture. Specially designed form liners were used to create precast concrete veneers that complement the historic stone gazebo. The 12 in. x 24 in. (305 mm x 610 mm) veneers were given irregularly colored aggregate to further enhance the cantera stone look for a more natural appearance.
The custom veneers simplified construction with a quicker lead time, while also providing the city with a lower-cost project. Not only was the precast concrete veneer less expensive than natural stone, it is also thinner and much lighter than stone, so a smaller and more economical foundation could be used. The Metro Gold Line extension proved to be a home run with the local residents and commuters, while paying homage to the existing architecture of the neighborhood.
New Art Medium Features Form and Function
Olympian Precast, Redmond, Wash.
These days it seems that state Departments of Transportation are looking for projects beyond the traditional – something more inspiring for local motorists. Bridges and sound walls are currently the canvas of choice for architects and designers across North America. Washington State DOT recognized this trend and recently hired an architect to design bridge abutment walls. The architect’s final design consisted of seven layers that form a smooth, sweeping pattern in the center with an adjacent ashlar stone pattern. This level of detail sets a new standard for local transportation projects.
The precaster had several challenges on this project. The girders for the elevated freeway had already been installed, and the headroom above varied from 2 to 4 ft. (0.6 to 1.2 m). The overhead girders eliminated a crane installation, so the contractor built a special eight-pronged front-end loader installation device. At Olympian, the project management and drafting team worked closely with the contractor’s engineering staff to specify the precise location of the lifting device holes to establish a center of gravity on each unique panel. The panels, placed on their sides for shipping, were removed from the truck and rotated 90 degrees for transport to their installation points. The holes were later patched and the panels were painted.
Olympian produced a total of 40 panels for the project: 16 of the central design and 24 ashlar stone panels. The total panel area was 6,600 ft2 (613 m2).
LEEDing with Precast
Olympian Precast, Redmond, Wash.
Located in Redmond, Wash., this LEED Gold-certified building serves as office space along a very prominent corridor of travel. Precast concrete contributed to earning one point toward the recycled content (Materials and Resources credit 4) and two points for the regional materials credit (Materials and Resources credit 5). The precaster was located less than five miles (8 km) from the project site and utilized more than 80% local component materials by weight, making the 500-mile (805 km) limitation of the Regional Materials credit easily
The biggest project challenges were based on obtaining consistency in color and finish. The project’s details were made possible with 100% Self Consolidating Concrete (SCC). The precast at the base of the building featured 12-in. (305 mm) pilasters at the west elevation and returned on the north and south elevations. An 18-in. (460 mm) half-round bull nose accented both dark- and light-colored precast. The upper office partition of the project, the lighter color, featured crushed marble aggregate with white cement and finished with a light acid etch. The parking level, the darker color, features standard aggregates with a gray cement and mineral oxide pigment, finished with a light sandblast. The precast concrete reveals enhance the natural beauty by adding some interest to the simple form of the building facade while also reducing the look of variations in color and texture.
Olympian Precast, as evidenced by the smooth, color-matched precast panels, takes great pride in its architectural precast, which added to the success of this LEED Gold-certified building – proving that precast is an excellent choice for a sustainable project.
Details in Precast
Brailsford Cast Stone, Springville, Utah
Nestled in the Rocky Mountains of Springville, Utah, this residence merges rustic mountain lodge stability with Mediterranean elegance. The inviting entry bridge is entirely encased with custom precast concrete bridge skirts, paneling, newel posts and balustrades. As you proceed up the path from the bridge, you are greeted by the impressive home itself. Despite its grand size, the 60,000-ft.2 (5,574-m2) residence embodies the rich, comforting feel of its surroundings. This massive residential project took nearly three years to complete, with more than $500,000 worth of precast material.
More than 1,000 pieces of precast concrete are integrated throughout the home’s exterior, blending seamlessly with the natural stone and timber finishes. This residence demonstrates the remarkable smoothness of standard mold-finished precast; however, a variety of textures stains, mold materials and flexible anchoring systems enable nearly limitless possibilities with architectural precast concrete. For example, the structural walls of the residence are composed of insulated concrete forms, which presented a unique production challenge in establishing an anchoring system that would work with a non-typical application process.
A Lasting Memorial
Wilbert Precast, Spokane, Wash.
When the life of 16-year-old Andrew S. Rosell was cut tragically short in a traffic accident, his father, Ed, spent a lot of time grieving and dwelling on the past. After the worst of his grief subsided, he funneled his emotions into the organization that had meant so much to his son: the Boy Scouts of America.
Andrew and his father spent many hours together in scouting activities, and Andrew had been working to become an Eagle Scout prior to his untimely death. As a result, Ed felt it was fitting to donate not only his time but also the money he received in a settlement from the accident to Camp Cowell, a Boy Scout Camp located on 400 acres (162 hectares) on Diamond Lake in Washington State.
Looking to revamp a fire pit built of logs and rocks nearly 90 years ago, Ed turned to Wilbert Precast to see if precast concrete could be used to complete the renovation of pit. Although it was not the intended use of plant’s retaining wall product, Wilbert was able to adapt the wall system perfectly to the project. What resulted is a stunning amphitheater with
seating for more than 300 facing the pristine lake, with two fire pits, and a grand entrance bearing the name Andrew S. Rosell Memorial Fire Bowl. The project used 224 wall blocks and 160 wall caps for seating, 27 pavers, two flag pole bases and two manhole riser sections.
Looking to meet a tight timeline of just 45 days, SCC was used to pour forms multiple times a day. The precast pieces proved easy to move around the site and needed less backfill and compaction than traditional landscaping, saving the customer soil and labor costs. But most importantly, it provided the Boy Scouts with a dramatic gathering place and gave Ed Rosell a lasting legacy for his son.
Kyle Kerstiens, Assoc. AIA, LEED AP, is NPCA’s director of sustainability.