Steel-Free Hybrid Reinforcement System for Concrete Bridge Decks |
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Sequential Number | R52 |
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Matching Research Agency | Missouri Department of Transportation (MoDOT) |
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Principal Investigator | Abdeldjelil Belarbi
Associate Professor
University of Missouri-Rolla
Dept. of Civil Engineering, Room 304
Rolla, Missouri, 65409 | | p | (573) 341-4478 | | f | (573) 341-4729 | | belarbia@mst.edu |
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Student Involvement | One graduate and two undergraduate students |
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Project Objective | The main objective of this collaborative research proposal is to develop nonferrous hybrid reinforcement system for concrete bridge decks using continuous FRP rebars and discrete randomly distributed polypropylene fibers with a view to eliminate corrosion in bridge decks. |
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Project Abstract | The main objective of this collaborative research proposal is to develop nonferrous hybrid reinforcement system for concrete bridge decks using continuous FRP rebars and discrete randomly distributed polypropylene fibers with a view to eliminate corrosion in bridge decks. A typical steel girder bridge will be used to study implementation of this innovative bridge-deck system, although it is anticipated that similar innovation can also be implemented for other bridge types (like prestressed concrete I-girder bridges and concrete slab bridges). Enormous savings in maintenance effort and costs can accrue from this hybrid composite application. Researchers at UMC and UMR will collaborate with MoDOT engineers and private industry (one FRP and one fiber manufacturer) to develop this innovative bridge-deck system. The specific research objectives include: (1) development of procedures for the design of a deck slab system using a combination of FRP rebars and polypropylene fibers, (2) fundamental laboratory study to evaluate the bond, ductility and fatigue performance of small specimens made of such materials, and (3) static and fatigue tests on full-scale hybrid reinforced composite slab systems to validate design and evaluate mechanical performance of the slab system. Following successful completion Phase I of this project comprising the above three objectives, Phase II of the project will be undertaken. Field implementation and performance monitoring of the steel-free bridge deck system on one typical steel girder bridge will constitute Phase II of the project. |
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Anticipated Benefits | Cracking in concrete decks under service loads and consequent ingress of chlorides from deicing salts is common in most states requiring snow removal. When chlorides reach the steel rebars, local electrochemical cells are set up due to potential differences. Oxidation and pitting of steel rebars results from electrochemical action. Oxidation (rusting) of steel rebars has two detrimental effects. Firstly, the rebars loose cross-sectional area, and hence it's tensile capacity due to rusting. Secondly, the rust products have a volume of 600-800% of the volume of steel that they replace, resulting in extremely large tensile pressures on the concrete at the location of steel. These pressures cause splitting failures and spalling of concrete. Thus, corrosion of reinforcing steel in concrete decks constitutes the most common and expensive component of bridge maintenance. Associated maintenance effort is also perhaps very time-intensive. It is expected that when steel rebars are replaced with a hybrid system of FRP rebars and short discrete polypropylene fibers, the problem of corrosion in reinforced concrete bridge decks can be entirely eliminated. This would result in enormous savings in maintenance efforts and costs. Inconvenience from frequent lane closures and associated costs can also be avoided. |
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Modal Orientation | N/A |
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Milestones | | Project Start Date: | 07/01/2002 | | Project End Date: | 12/31/2004 |
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Relationship to other Research/Projects | Related to on-going research on the use of FRP in bridges |
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Technology Transfer Activities | Conference and journal publications and final reports to MoDOT and UTC |
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Transportation Research Board Keywords | Polypropylene fibers |
