The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Jonathan Kunin - One of the best experts on this subject based on the ideXlab platform.
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In-service evaluation of a reinforced concrete T-Beam Bridge FRP strengthening system
Composite Structures, 2004Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan KuninAbstract:Abstract In November 1999, bonded fiber-reinforced polymer (FRP) laminates were used to strengthen a single span, reinforced concrete T-Beam Bridge in New York State. The laminate system was installed to strengthen the structure in flexure and shear, and to contain observed freeze–thaw cracking. The Bridge was then instrumented and load tested before and after installation of the laminates, to evaluate effectiveness of the strengthening FRP system. In November 2001, the load test was repeated to monitor in-service performance of the system. The test results indicated that the quality of bond between the laminates and concrete, and effectiveness of the system have not deteriorated after two years of service. Further inspection using an Infrared thermography camera did not show any significant delamination in the system, in agreement with the test results.
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Application of FRP laminates for strengthening of a reinforced-concrete T-Beam Bridge structure
Composite Structures, 2001Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan KuninAbstract:This paper describes application of fiber-reinforced polymer (FRP) composite laminates to strengthen an aging reinforced-concrete T-Beam Bridge in South Troy, Rensselaer County, New York. Leakage at the end joints of this single-span structure led to substantial moisture and salt infiltration in the Bridge superstructure. Presence of efflorescence was observed, and freeze-thaw cracking and concrete delamination at some locations on the beams were noted. Concerns about integrity of the steel reinforcing and overall safety of the Bridge were raised. These concerns were heightened by the absence of any documents pertaining to the Bridge design, such as rebar size, steel type, concrete strength, and design loads. Thus, a decision was made to strengthen the Bridge using bonded FRP-laminates. Load tests were conducted to evaluate effectiveness of the strengthening system and investigate its effect on structural behavior, and tests results were compared with those obtained using classical analysis.
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Strengthening of a Concrete T-Beam Bridge Using FRP Composite Laminates
Advanced Technology in Structural Engineering, 2000Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan Kunin, Timothy ConwayAbstract:This paper describes application of Fiber Reinforced Polymer (FRP) composite laminates to strengthen a seventy-year old reinforced concrete T-Beam Bridge in Rensselaer County, New York. Leakage at the joints of this single-span Bridge lead to substantial moisture and salt infiltration in the superstructure -- manifested in efflorescence , freeze-thaw cracking, and delamination at some locations. Integrity of the steel reinforcing and overall safety of the Bridge was suspected. This concern was heightened by the absence of any documents pertaining to the Bridge design, such as bar size, steel type, concrete strength, and design loads. The Bridge was strengthened using bonded FRP laminates. Load tests were conducted before and after the FRP laminates were installed to assess effectiveness of the strengthening system. Test results are also compared with those obtained analytically using classical approaches.
Tamara M Cortez - One of the best experts on this subject based on the ideXlab platform.
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Load Rating a Prestressed Concrete Double T-Beam Bridge without Plans by Field Testing
Transportation Research Record: Journal of the Transportation Research Board, 2020Co-Authors: Carlos V Aguilar, David V Jauregui, Craig M Newtson, Brad D Weldon, Tamara M CortezAbstract:Bridges with no design plans are an issue in New Mexico because of the many that exist throughout the state. Conventional load rating techniques cannot be used because these Bridges have limited or no design documentation. This lack of information has created uncertainties regarding the load-carrying capacity of these structures. Only a few states have formal procedures on how these particular Bridges should be load rated. A project was conducted for the New Mexico Department of Transportation to develop a procedure for load rating Bridges without plans, including prestressed concrete Bridges. In accordance with the AASHTO Manual for Bridge Evaluation, a prestressed concrete double T-Beam Bridge was evaluated with advanced analyses and experimental methods (including load testing and nondestructive material evaluation techniques). A four-step load rating procedure was implemented that included estimating the prestressing steel by Magnel diagrams, verifying the estimate with a rebar scanner, testing the Bridge at both diagnostic and proof loads based on strain measurements, and using the proof test results to rate the Bridge. Rating factors and posting loads were determined for AASHTO and New Mexico legal loads. Because of the poor condition of the shear keys (some of which were broken), it is shown that the load distribution between beams was adversely affected and the Bridge should be load posted.
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load rating a prestressed concrete double t beam Bridge without plans by field testing
Transportation Research Record, 2015Co-Authors: Carlos V Aguilar, David V Jauregui, Craig M Newtson, Brad D Weldon, Tamara M CortezAbstract:Bridges with no design plans are an issue in New Mexico because of the many that exist throughout the state. Conventional load rating techniques cannot be used because these Bridges have limited or no design documentation. This lack of information has created uncertainties regarding the load-carrying capacity of these structures. Only a few states have formal procedures on how these particular Bridges should be load rated. A project was conducted for the New Mexico Department of Transportation to develop a procedure for load rating Bridges without plans, including prestressed concrete Bridges. In accordance with the AASHTO Manual for Bridge Evaluation, a prestressed concrete double T-Beam Bridge was evaluated with advanced analyses and experimental methods (including load testing and nondestructive material evaluation techniques). A four-step load rating procedure was implemented that included estimating the prestressing steel by Magnel diagrams, verifying the estimate with a rebar scanner, testing the br...
Dan M Frangopol - One of the best experts on this subject based on the ideXlab platform.
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service life prediction of deteriorating concrete Bridges
Journal of Structural Engineering-asce, 1998Co-Authors: Michael P Enright, Dan M FrangopolAbstract:Experience has demonstrated that highway Bridges are vulnerable to damage from environmental attack, such as alkali-silica reaction, corrosion, and freeze-thaw. To make rational decisions in a life-cycle cost perspective, reliable prediction of the service life of deteriorating highway Bridges is necessary. To obtain an accurate insight into this problem, time-variant reliability methods have to be used. The application of these methods in the performance and safety assessment of deteriorating structures is relatively new. In this study, the reliability of reinforced concrete highway girder Bridges under aggressive conditions is investigated using a time-variant series system reliability approach in which both load and resistance are time-dependent. Monte Carlo simulation is used to find the cumulative-time system failure probability. An existing reinforced-concrete T-Beam Bridge located near Pueblo, Colo., is investigated. The effects of various parameters such as variabilities in dead and live loads, li...
Osman Hag-elsafi - One of the best experts on this subject based on the ideXlab platform.
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In-service evaluation of a reinforced concrete T-Beam Bridge FRP strengthening system
Composite Structures, 2004Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan KuninAbstract:Abstract In November 1999, bonded fiber-reinforced polymer (FRP) laminates were used to strengthen a single span, reinforced concrete T-Beam Bridge in New York State. The laminate system was installed to strengthen the structure in flexure and shear, and to contain observed freeze–thaw cracking. The Bridge was then instrumented and load tested before and after installation of the laminates, to evaluate effectiveness of the strengthening FRP system. In November 2001, the load test was repeated to monitor in-service performance of the system. The test results indicated that the quality of bond between the laminates and concrete, and effectiveness of the system have not deteriorated after two years of service. Further inspection using an Infrared thermography camera did not show any significant delamination in the system, in agreement with the test results.
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Application of FRP laminates for strengthening of a reinforced-concrete T-Beam Bridge structure
Composite Structures, 2001Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan KuninAbstract:This paper describes application of fiber-reinforced polymer (FRP) composite laminates to strengthen an aging reinforced-concrete T-Beam Bridge in South Troy, Rensselaer County, New York. Leakage at the end joints of this single-span structure led to substantial moisture and salt infiltration in the Bridge superstructure. Presence of efflorescence was observed, and freeze-thaw cracking and concrete delamination at some locations on the beams were noted. Concerns about integrity of the steel reinforcing and overall safety of the Bridge were raised. These concerns were heightened by the absence of any documents pertaining to the Bridge design, such as rebar size, steel type, concrete strength, and design loads. Thus, a decision was made to strengthen the Bridge using bonded FRP-laminates. Load tests were conducted to evaluate effectiveness of the strengthening system and investigate its effect on structural behavior, and tests results were compared with those obtained using classical analysis.
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Strengthening of a Concrete T-Beam Bridge Using FRP Composite Laminates
Advanced Technology in Structural Engineering, 2000Co-Authors: Osman Hag-elsafi, Sreenivas Alampalli, Jonathan Kunin, Timothy ConwayAbstract:This paper describes application of Fiber Reinforced Polymer (FRP) composite laminates to strengthen a seventy-year old reinforced concrete T-Beam Bridge in Rensselaer County, New York. Leakage at the joints of this single-span Bridge lead to substantial moisture and salt infiltration in the superstructure -- manifested in efflorescence , freeze-thaw cracking, and delamination at some locations. Integrity of the steel reinforcing and overall safety of the Bridge was suspected. This concern was heightened by the absence of any documents pertaining to the Bridge design, such as bar size, steel type, concrete strength, and design loads. The Bridge was strengthened using bonded FRP laminates. Load tests were conducted before and after the FRP laminates were installed to assess effectiveness of the strengthening system. Test results are also compared with those obtained analytically using classical approaches.
Carlos V Aguilar - One of the best experts on this subject based on the ideXlab platform.
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Load Rating a Prestressed Concrete Double T-Beam Bridge without Plans by Field Testing
Transportation Research Record: Journal of the Transportation Research Board, 2020Co-Authors: Carlos V Aguilar, David V Jauregui, Craig M Newtson, Brad D Weldon, Tamara M CortezAbstract:Bridges with no design plans are an issue in New Mexico because of the many that exist throughout the state. Conventional load rating techniques cannot be used because these Bridges have limited or no design documentation. This lack of information has created uncertainties regarding the load-carrying capacity of these structures. Only a few states have formal procedures on how these particular Bridges should be load rated. A project was conducted for the New Mexico Department of Transportation to develop a procedure for load rating Bridges without plans, including prestressed concrete Bridges. In accordance with the AASHTO Manual for Bridge Evaluation, a prestressed concrete double T-Beam Bridge was evaluated with advanced analyses and experimental methods (including load testing and nondestructive material evaluation techniques). A four-step load rating procedure was implemented that included estimating the prestressing steel by Magnel diagrams, verifying the estimate with a rebar scanner, testing the Bridge at both diagnostic and proof loads based on strain measurements, and using the proof test results to rate the Bridge. Rating factors and posting loads were determined for AASHTO and New Mexico legal loads. Because of the poor condition of the shear keys (some of which were broken), it is shown that the load distribution between beams was adversely affected and the Bridge should be load posted.
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load rating a prestressed concrete double t beam Bridge without plans by field testing
Transportation Research Record, 2015Co-Authors: Carlos V Aguilar, David V Jauregui, Craig M Newtson, Brad D Weldon, Tamara M CortezAbstract:Bridges with no design plans are an issue in New Mexico because of the many that exist throughout the state. Conventional load rating techniques cannot be used because these Bridges have limited or no design documentation. This lack of information has created uncertainties regarding the load-carrying capacity of these structures. Only a few states have formal procedures on how these particular Bridges should be load rated. A project was conducted for the New Mexico Department of Transportation to develop a procedure for load rating Bridges without plans, including prestressed concrete Bridges. In accordance with the AASHTO Manual for Bridge Evaluation, a prestressed concrete double T-Beam Bridge was evaluated with advanced analyses and experimental methods (including load testing and nondestructive material evaluation techniques). A four-step load rating procedure was implemented that included estimating the prestressing steel by Magnel diagrams, verifying the estimate with a rebar scanner, testing the br...
