Infrastructure Research Institute Scholarly Workshttps://hdl.handle.net/1808/197392024-03-28T10:17:21Z2024-03-28T10:17:21ZLong-term Implications of Redecking Bridges with Prestressed Concrete GirdersAdhikari, BeevaLequesne, Rémy D.Collins, Williamhttps://hdl.handle.net/1808/349662024-03-13T06:06:57Z2024-03-01T00:00:00ZLong-term Implications of Redecking Bridges with Prestressed Concrete Girders
Adhikari, Beeva; Lequesne, Rémy D.; Collins, William
Precast/prestressed concrete girders with cast-in-place decks are commonly used for bridge construction throughout the United States. There is a need to replace concrete decks on many of these bridges because girders last much longer than concrete decks. This study surveyed United States Department of Transportation (DOT) engineers to determine common deck removal practices. Survey results showed that, although most states have a need to replace bridge decks, few states have comprehensive plans for assessing the long-term effects of deck replacement on girder behavior. This study developed a Python model to estimate girder behavior over its lifespan that accounts for the effects of deck replacement, changes in loading conditions, changes in restraint conditions, and concrete deformations. Time-step analysis was used to calculate incremental changes in girder behavior throughout time, considering several lifespan stages delineated by changes in loading or boundary conditions. The B4 model (Wendner et al., 2013) was used to estimate the creep and shrinkage strain in the concrete. The model was validated against examples in the literature and applied to an example bridge to illustrate function. Modelling results suggest that deck replacement had minimal effect on long-term girder behavior for the bridge considered. A parametric study was also conducted to evaluate the influence of input parameter variations on long-term prestress loss, deflections, and stresses and strains for the example bridge. Parametric study results showed that girder behavior varies widely based on input parameters, suggesting that more research is needed to determine whether other bridge configurations would also be insensitive to deck replacement.
2024-03-01T00:00:00ZBond Behavior of Epoxy-Coated Reinforcing Bars in Non-Proprietary UHPCDarwin, DavidO'Reilly, MatthewLequesne, Rémy D.Thapa, Sanjeebhttps://hdl.handle.net/1808/349502024-01-31T07:07:20Z2023-10-01T00:00:00ZBond Behavior of Epoxy-Coated Reinforcing Bars in Non-Proprietary UHPC
Darwin, David; O'Reilly, Matthew; Lequesne, Rémy D.; Thapa, Sanjeeb
Non-proprietary ultra-high-performance concrete (UHPC) mixtures were developed for use in closure strips between precast members on reinforced concrete bridges. The mixtures contained ODOT approved Type I portland cement, slag cement, silica fume, graded fine aggregate, two high-range water-reducers (HRWRs), one of which incorporated a viscosity modifying admixture, and 2% by volume of 0.5-in. steel fibers. Several HRWRs of each type were included in the evaluations. Mixtures were evaluated based on flow, fiber distribution, flexural properties, compressive strength, and effect on bond strength using a modified pullout test and the ASTM A944 beam-end test for No. 5 uncoated, ASTM A755 epoxy-coated, and ASTM A1124 textured-epoxy-coated reinforcing bars. The UHPC mixture with the best properties was used to cast a closure strip between two precast sections to determine the splice strength of No. 4, No. 5, and No. 8 uncoated, epoxy-coated, and textured-epoxy-coated reinforcing bars with minimum clear covers ranging from 1.00 to 2.63 in. The results of the splice test were used to develop design recommendations. The study showed that UHPC can be made using ODOT approved materials. The splice strength of reinforcing bars in UHPC is two times the value in conventional concrete. The negative effects of epoxy coating on bond strength are lower in UHPC than in conventional concrete. ASTM A1124 textured epoxy-coated bars have the same bond strength as uncoated bars. The design procedures described in this report are based on UHPC with a minimum compressive strength at the time of load application of not less than 12 ksi, with a flow between 8 and 10 in. and good fiber distribution.
2023-10-01T00:00:00ZConstruction of Low-Cracking High-Performance Bridge Decks Incorporating New Technology Phase IIBahadori, AlirezaDarwin, DavidO'Reilly, MatthewSalavati-Khoshghalb, Mohsenhttps://hdl.handle.net/1808/349482024-01-30T17:08:00Z2023-12-01T00:00:00ZConstruction of Low-Cracking High-Performance Bridge Decks Incorporating New Technology Phase II
Bahadori, Alireza; Darwin, David; O'Reilly, Matthew; Salavati-Khoshghalb, Mohsen
The construction, crack surveys, and evaluation of 12 bridge decks with internal curing provided by prewetted fine lightweight aggregate and supplementary cementitious materials following internally cured low-cracking high-performance concrete (IC-LC-HPC) specifications of Minnesota or Kansas are described, as well as those from two associated Control decks without IC (MN-Control). Nine IC-LC-HPC decks and one Control deck were monolithic, while three IC-LC-HPC decks and one Control deck had an overlay. The internally cured low-cracking high-performance concrete had paste contents between 23.8 and 25.8 percent by volume. Of the 12 IC-LC-HPC decks, nine were constructed in Minnesota between 2016 and 2020, and three were constructed in Kansas between 2019 and 2021. The performance of the decks is compared with that of earlier IC-LC-HPC bridge decks and low-cracking high-performance concrete (LC-HPC) bridge decks without internal curing. The effects of construction practices on cracking are addressed. The results indicate that the use of overlays on bridge decks is not beneficial in mitigating cracking. The IC-LC-HPC decks constructed exhibited lower average crack densities than those without internal curing. Good construction practices are needed for low-cracking decks. If poor construction practices, which may include poor consolidation and disturbance of concrete after consolidation, over-finishing, delayed application of wet curing, are employed, even decks with low paste contents and internal curing can exhibit high cracking. Delayed curing and over-finishing can also result in scaling damage to bridge decks.
2023-12-01T00:00:00ZDATASET: Test Results from Shake Table Tests of Reinforced Concrete Frames with Grade 60 or 100 (420 or 690) ReinforcementChin, Chin-HsuanCheng, Min-YuanLepage, AndrésLequesne, Rémy D.https://hdl.handle.net/1808/348722023-12-28T18:01:23Z2023-12-13T00:00:00ZDATASET: Test Results from Shake Table Tests of Reinforced Concrete Frames with Grade 60 or 100 (420 or 690) Reinforcement
Chin, Chin-Hsuan; Cheng, Min-Yuan; Lepage, Andrés; Lequesne, Rémy D.
This dataset reports the acceleration and displacement data collected during tests of two reinforced concrete frames that differed in one way: the longitudinal bars were Grade 60 (420) in C1 and Grade 100 (690) in H1. The frames were placed side-by-side on the NCREE shake table in Taipei, Taiwan, and subjected to 16 earthquake simulations. Details of the specimens and ground motions are reported in references [1] and [2], along with inferences made by the authors.
This dataset includes one image file (“Instrument Locations”), which shows the locations and IDs of the instruments used during testing, and 39 excel files. The excel file named “Description of Runs” identifies the excitation type associated with each of the 38 runs, which include low-amplitude excitation recorded to determine dynamic properties before and after each earthquake simulation. Excel files named “Run 1” to “Run 38” each contain the recorded displacement (mm) and acceleration (g) data versus time.
References:
[1] Chin, C.-H., Cheng, M.-Y., Lepage, A., & Lequesne, R. D., (2024). Shake Table Tests to Compare the Seismic Response of Concrete Frames with Conventional and High-Strength Reinforcement. Earthquake Engineering and Structural Dynamics, 53(1), 89-115. doi: 10.1002/eqe.4008
[2] Chin, C.-H., (2022). Shaking Table Test of RC Column Using High-Strength Flexural Reinforcement Under Low Axial Load. M.S. Thesis, National Taiwan University of Science and Technology, Taipei, Taiwan, 175 pp. (In Chinese)
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