Originally constructed in 1895, Milwaukee City Hall is a National Historic Landmark and municipal icon. From 2006 to 2008, the entire building was fully renovated and restored with the replacement of approximately 13,400 terra cotta units.
In February of 2011, a fragment of the replacement terra cotta fell from the building, requiring an assembly of scaffolds with protective coverings to be put in place to protect pedestrians. The quality of the $60 million restoration was the subject of a lawsuit filed by the City of Milwaukee in 2012 against various parties involved in the restoration design and construction work.
CTLGroup was engaged by the law firm of Davis & Kuelthau, S.C. on behalf of the restoration general contractor. The objective of the investigation was to provide opinions as to the cause of the fall and repair recommendations for the reported terra cotta cracking and spalling.
CTLGroup’s approach involved the review of project and industry documentation, on-site field investigations, grout trials, laboratory examinations and testing of selected materials. A particular focus of CTLGroup’s investigation was to effectively refute allegations that the contractor had used excessive water in the terra cotta grout.
Upon completion of the investigation, CTLGroup submitted a detailed report of findings to be used for mediation. Based on CTLGroup’s scope of work, the general contractor was able to successfully negotiate a settlement with the City. carbonation resistance, sulfate resistance, and water-soluble chlorides. In addition, we evaluated the elastic modulus and coefficient of thermal expansion in order to allow for performance-based temperature difference limits for thermal control of mass concrete placements.