Architectural Concrete: Where Art Meets Science
When we think about architecture, for many, concrete restoration rarely comes to mind. For Don Redar, Vice President of Bulley & Andrews Concrete Restoration (BACR), it’s one of the first things he notices. For him, a soundly crafted concrete facade is just as awe inspiring as the interior of Chicago’s iconic Rookery building.
Aesthetics and architecture often go hand-in-hand, but for BACR, structural integrity is equally important. During last year’s joint Structural Engineers Association of Illinois (SEAOI) and International Concrete Repair Institution (ICRI) Assessment and Repair of Concrete Structures Seminar, Redar presented alongside Paul Gaudette, principal at Wiss, Janney, Elstner & Associates (WJE). Together, the two addressed the importance of balancing structural integrity with concrete aesthetics.
Highlighting their recent collaboration at North Shore Congregation Israel in Glencoe, IL, the duo shared in-depth insight on what it took to repair, replace and match a 55-year-old concrete facade on one of the area’s oldest synagogues.
“Marrying art with science was imperative to the success of this project,” said Redar. “We have WJE’s expertise to thank for mastering the science while BACR’s craftsmanship brought artistry to the assignment.”
Off To The Lab
The team’s approach to the restoration, which started in the spring of 2019, was mutli-faceted. Getting to know the building was a bit like dating. Understanding the building’s background, history, architectural significance and materials was critical to the team’s assessment of the damage and their ability to propose an effective solution.
Investigative work proved essential to achieving this understanding and was the first step in determining the best course of action. In this case, WJE observed and documented cracking, delamination and spalling on the facade. After consulting the contractor, the team agreed destructive testing was necessary in order to gauge the performance or material behavior under different loads. This was necessary to better understand the inefficiencies of the original concrete and how to make the repairs last beyond the facade’s previous lifespan.
To achieve this required additional measures, the sample taken from the destructive testing was sent to a laboratory to check for chlorides and other mix impurities. Knowing the composition of the material informed WJE and BACR’s recommendation to conduct a full replacement and repair of over 500 linear feet of precast concrete. The team was confident this approach would ensure longevity while seamlessly matching the original architecture.
Leveraging all team members’ expertise, Redar relied on the rest of the BACR team to ensure no detail was overlooked while creating the new architectural concrete pieces.
A Perfect Match
To get the perfect match, BACR created 20 concrete mock ups for evaluation. Each sample took 21 to 28 days to mold, dry and clean before comparing. Once the team narrowed the samples to the best six options, concrete cylinders samples were sent back to the lab for strength and weather compatibility testing.
After a two-month evaluation process, the owner, guided by BACR’s recommendation, decided to move forward with restoring the historical facade. The deteriorated concrete was removed section by section; the team carefully cataloguing each piece’s shape and size for replication. BACR mixed and molded all concrete onsite and completed the entire restoration in two months.
“This level of restoration requires a team that can be trusted to identify and analyze all the issues, then factor them into developing the best solution,” said Redar. “Everyone involved in this project was committed to finding the right solution that would pay homage to the synagogue’s original grandeur and serve its congregation well into the next decade.”
Although parking garage concrete repairs and vaulted sidewalks make up the majority of BACR’s portfolio, Redar believes architectural concrete repairs will be the division’s next niche. Partnering with firms, such as WJE, that share a commitment to shaping communities through restoration and embracing historical elements, BACR is well positioned to do just that.