Articles

Structural Performance of UHPC Overlays

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Abstract

The use of ultra-high performance concrete (UHPC) as an overlay is quickly becoming a viable option in the maintenance and repair of bridge decks. This method of bridge preservation is advantageous when a bridge deck is structurally sound, but the surface of the deck exhibits excessive deterioration. In such an event, the use of conventional repair techniques may not be adequate because water and deleterious chemicals can still penetrate the concrete and result in further deterioration. UHPC overlays typically remove a layer of the deteriorated concrete and replace it with thixotropic UHPC. The very low permeability of the UHPC provides a durable top surface to the deck and significantly reduces the water and chloride ingress in the substrate concrete, thus extending the lifespan of the bridge deck. These durability advantages make UHPC overlays an intriguing option for bridge owners; however, the structural advantages and limitations of UHPC overlays are less acknowledged. The research presented here considered a series of structural tests on conventional concrete slabs with UHPC overlays. Several variables were considered in the research such as positive or negative moment bending, cold-joint detailing, lap-splice detailing, and overlay depth. Both cyclic and monotonic tests were performed. The results indicate that UHPC overlays can increase the structural capacity of bridge decks. Additionally, adequate cold-joint detailing within the UHPC overlay must be considered to maintain the improved structural performance.

Keywords: UHPC, UHPC overlay, thixotropic UHPC, structural design

How to Cite:

Muzenski, S. & Graybeal, B., (2023) “Structural Performance of UHPC Overlays”, International Interactive Symposium on Ultra-High Performance Concrete 3(1): 89. doi: https://doi.org/10.21838/uhpc.16698

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