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 exposed aggregate 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. BACR assisted WJE who performed testing in order to gauge the material performance. This was necessary to better understand the deterioration of the original concrete and how to make the repairs last beyond the facade’s previous lifespan.
To achieve this required additional measures, the samples removed by BACR were analyzed in WJE’s laboratory to measure for chlorides and perform a petrographic examination to understand the original mix deisgn. After WJE’s evaluation and design, BACR replaced and repaired 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 evaluation. Once WJE selected 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 selected the historical facade. The deteriorated concrete was removed section by section; the team carefully documented each piece’s shape and size for replication. BACR mixed and cast 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.”
Designed in 1964, Yamasaki and Associates’ modernist North Shore Congregation Israel has stood the test of time. With the repairs designed by WJE and installed by BACR, the synagogue will continue to serve the community. Partnering with firms, such as WJE, that share a commitment to shaping communities through restoration and embracing historical elements, BACR looks forward to restoring the next landmark.