Award of Merit: Industrial Category
University of Missouri Power Plant Concrete Chimneys Rehabilitation
Submitted by ABS Consulting
University of Missouri-
St. Louis, MO
Fibrwrap Construction, Inc.
FYFE Co., LLC
San Diego, CA
Two reinforced concrete chimneys located on the University of Missouri campus in Columbia, MO, service the University’s power plant. The chimneys were constructed between 1980 and 1981 and feature a concrete windscreen and freestanding brick liner. The project objective was to extend their service life for a minimum of 20 years.
During condition assessment, the entire surface of each chimney was visually surveyed using a remote-control helicopter drone equipped with a high-resolution digital camera. A composite image map was prepared by merging the high-resolution images. Using high-resolution digital-zoom technology, the composite image map was used to identify areas of visible deterioration. Structural analysis was performed to evaluate conformity with the design code. Based on the results of the study, structural reinforcement was recommended to restore the strength loss caused by deterioration of the reinforced concrete structures.
The solution involved application of externally bonded fiber-reinforced polymer (FRP) technology. Vertical carbon FRP (CFRP) strip strengthening was used to provide additional flexural strength for the lower one-third of the south chimney. In addition, full height installation of horizontal glass FRP (GFRP) strips was performed at both chimneys to enhance confinement of existing concrete and reinforcement. Finally, a urethane coating was installed at exterior chimney surfaces for ultraviolet (UV) protection and aesthetics. Prior to application of the FRP, delaminated concrete was repaired and a penetrating corrosion inhibitor was applied to the concrete chimneys. The project also included repairs to masonry flue interiors and replacement of service platforms.
The selected solution saved millions of dollars in demolition and new construction costs and enabled a sustainable reuse of an existing facility, while preventing significant operational downtimes.