Missouri S&T Scholar's Mine Research RepositoryMissouri S&T Research
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Experimental Results of One-Way Slabs with Openings Strengthened with CFRP Laminates
One-way RC slabs are very common as a floor system in buildings. It often happens that buildings need to be renovated due to many factors, such as placing new staircases, elevators, additional skylights or (more often) wiring and ducts through the existing floor slabs. In these instances, openings usually need to be created, weakening the existing floor system. Fiber-reinforced polymer (FRP) matrix composites can provide an efficient method for strengthening slabs after installation of cut-outs, but it is important to define guidelines for the designer, particularly when the openings are created in the negative moment region.

This project consists of an experimental program that investigated the behavior of RC one-way continuous flat slabs with openings in both the positive and negative moment regions, strengthened with externally-bonded CFRP laminates following two different schemes of strengthening. The significance of this work is that instead of testing specimens manufactured in the laboratory, the authors had the possibility of using as a research test bed, an old parking garage scheduled for demolition. Experimental results revealed that externally-bonded CFRP sheets can significantly increase the flexural capacity of the system for those specimens containing an opening in the positive moment region. For specimens with an opening in the negative moment region and strengthened using top-surface CFRP laminates, shear failure occurred at a lower load capacity than the original unstrengthened specimen. This has considerable implications for the design of such negative-moment strengthening schemes, and reasons for this behavior are discussed.