Location: Ladue, MO
Architect: Lawrence Group
Structural Engineer: KPFF Consulting Engineers
General Contractor: Paric Corporation
Mason Contractor: John J. Smith Masonry Company
Block Producer: Midwest Block & Brick
But when the architect of a new $19 million performing arts center, which was to be located in the middle of existing buildings on the 47.5-acre (19.22-hectare) campus, looked for a building system with the necessary acoustical and structural properties, the structural concrete masonry system won the day.
The Haertter Center for the Performing Arts is a 76,000-ft2 (7060-m2) facility. The major program elements include a 750-seat performance theater; a 125-seat black box theater; band, choral, and orchestra classrooms; a dance studio; a scene shop; a green room and dressing rooms; and a costume shop with laundry and costume storage.
“Loadbearing masonry was chosen for the project so that we could achieve high acoustic values with a single material,” Tim Rowbottom, AIA, NCARB, LEED AP BD+C said. Rowbottom, principal with the Lawrence Group and design architect on the project, said that a steel frame and gypsum board system was considered as well as precast panels.
Rowbottom added, “The project program required many large volume spaces. The large spaces required height and volume for sound dissipation within rooms, while containing and limiting sound transmission between rooms. The height of the walls required fully grouted cells for structural reasons. The performance of the rooms was enhanced by creating mass which limits sound transmission.”
In the audience chamber, the design team determined that the structural masonry could provide both absorptive and reflective surfaces, according to Rowbottom. Concrete masonry units provided the acoustic characteristics desired, while being more sustainable than a number of other materials considered for this project. And masonry could provide both structural support and acoustical barrier.
“An additional benefit of using the masonry as both a loadbearing element and acoustical element was that it took less footprint for the structure as opposed to using a steel frame and then adding in non-loadbearing partitions for acoustics,” said Robert Daugherty, P.E., associate with KPFF Consulting Engineers, structural engineers for the project.
Tight building team coordination. The flexibility of the loadbearing CMU system accommodated tight construction conditions where the site provided little to no room between existing structures. In addition, site restrictions required close coordination among masons and steel erectors. These constraints resulted in the use of a tower crane to move materials, scaffolding and rigging around the site. The project was sequenced to allow the stage house and audience chamber to be constructed while the rest of the spaces were wrapped around the large masonry volume in clockwise fashion.
Tim Vaughan, project manager for Paric Corporation and the project general contractor said that the performing arts center was one of the most complex projects of his career. Because the structure of other campus buildings had to tie into the performing arts center, Vaughan had to manage a complex schedule – creating masonry pockets for steel, then pulling the masons off the project and installing the steel. “We were able to start and stop at different levels and stages,” he said. Staging of such construction sequencing was further facilitated by the use of loadbearing CMU.
The Performing Arts Center construction began in May of 2012 and was originally scheduled to be completed in October 2013. The project was completed two months ahead of schedule in August 2013 in time for John Burroughs School to occupy the building on the first day of school. “It’s a beautiful building… a complex building,” Vaughan said. “This wasn’t like putting up a gym or a Walmart. I don’t think this building could have been built using any other system.”
50-foot-tall CMU walls. The structural CMU walls of the audience chamber are 50-feet (15.2-m) tall. These walls are 12-inch (305 mm) block with two No.5 (M#16) bars at 16 inches (406 mm) on center. The stage house walls are tied to the concrete foundation at the stage level. The top is 64 feet (19.5 m) above the stage level. The walls are comprised of two 8-inch (203 mm) blocks with two No. 7 (M#22) vertical reinforcing steel bars at 8 inches (203 mm) on center. Bond beams are used at 64 inches (1620 mm) on center with two No.5 (M#16) bars and a header course above each bond beam.
“With NCMA’s help we’re trying taller, thinner walls that are more economical,” said John Smith, Jr., president of John J. Smith Masonry Company, mason contractor on the project. Smith, board chairman of the Mason Contractors Association of America, noted that many younger architects, project managers, and engineers have never seen structural CMU walls on the scale of the JBS performing arts center. For that reason Smith and the Mason Contractors Association of St. Louis encouraged site visits for the next generation of designers and contractors.
“Years ago we used loadbearing masonry for everything,” Smith said. “The designs changed to where they wanted to go to structural steel. Today, young engineering and project managers are all saying, ‘We can’t do it with concrete masonry,’ Smith noted. “We ask them to run the numbers. When they do the calculations, they find out it works.”