Behavior and Repair of Corroded Steel H-Piles - Phase I (Axial Behavior)

Missouri Department of Transportation (MoDOT) is responsible for maintaining 10,400 bridges on the state system. The average age of these bridges is 46 years and they were designed to last 50 years. Therefore, many of them need either replacement or repair. Several of these bridges were built using steel H-piles. This proposal is Phase I of multi-phase project to assess and repair corroded H-piles subjected to earthquake and impact. Multiple repair options, numerical models, comprehensive experimental work will be carried out during this project. Phase I of the project will assess the axial capacity for corroded H-piles. It will also develop fiber reinforced polymer (FRP) wrapping filled with concrete which may or may not be reinforced longitudinally. The project will start with establishing a comprehensive literature review on assessment and repair of corroded H-piles. This will be followed by a comprehensive experimental testing to determine the axial strength of H-piles having different corrosion scenarios. Then, the FRP wrapping filled with either conventional or geopolymer concrete (GC) repair will be optimized. GC is relatively a new high performance concrete that does not include any ordinary Portland cement rather it combines an alumina-silica rich material such as fly ash with non-proprietary alkali activator such as NaOH. GC involves substantially quick chemical process where the alkaline liquid polymerizes the fly-ash creating a new three dimensional strong inorganic polymeric chain. The design and optimization of the GC mixture based on Class C fly ash obtained from five different sources in Missouri will be carried out through another MoDOT/Ameren funding. The fresh properties, hardened properties, durability of the GC will be determined during the MoDOT/Ameren project. It is anticipated that the developed GC will be cheaper and more durable than conventional concrete.