CTLGroup performed a condition assessment of thousands of precast concrete channel slabs that comprised the roof over a large filtration building. Deterioration observed during the visual review included spalled flanges with exposed corroded reinforcement, longitudinal cracking in the flanges, web spalls, and excessive web cracking. Based on the assessment. CTLGroup ultimately determined that replacement of distressed channel slabs was the only practical repair solution.
The City of Chicago commissioned a comprehensive removal and replacement program for the roof of the filtration building. As part of the program, CTLGroup was retained to design a more durable channel slab, which included a high performance concrete mix and enhanced concrete cover over the reinforcing steel. CTLGroup also performed submittal reviews and quality assurance reviews at the precast concrete fabrication plant.
