This online appendix provides an extensive catalog of geometric properties for the girder sections considered in the study "Saint-Venant Torsion Constant of Modern Precast Concrete Bridge Girders” in PCI Journal 66 (3): 23-31, https://doi.org/10.15554/pcij66.3-01. This appendix is online only.
{"title":"Appendix: Section Properties of Standard Precast Concrete Girders","authors":"R. Brice, Richard D. Pickings","doi":"10.15554/pcij66.3-04","DOIUrl":"https://doi.org/10.15554/pcij66.3-04","url":null,"abstract":"This online appendix provides an extensive catalog of geometric properties for the girder sections considered in the study \"Saint-Venant Torsion Constant of Modern Precast Concrete Bridge Girders” in PCI Journal 66 (3): 23-31, https://doi.org/10.15554/pcij66.3-01. This appendix is online only.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Precast concrete members need to be connected effectively to form an integral structural system. Use of unstressed strands provides a cost-effective and practical solution to reinforce the connection regions of precast concrete members, especially for precast concrete bridge girder applications. With the limited understanding of bonding characteristics for unstressed strands, a combination of experimental and analytical programs, which focused on unstressed strands as a connection between precast concrete girders and cap beams for seismic applications, was designed to investigate the fundamental load-transfer characteristics of unstressed strands anchored in grout and concrete based on pullout tests. The relationship between strand stress and loaded-end displacement was developed, and the bond stress of unstressed strands embedded in concrete and grouted duct was examined. The average bond stress of unstressed strands anchored in concrete and grouted duct is recommended to be five and seven times the square root of concrete compressive strength, respectively. The results of this research provide qualitative embedment length requirements to design connections between precast concrete members using unstressed strands.
{"title":"Use of unstressed strands for connections of precast concrete members","authors":"Xiao Liang, S. Sritharan","doi":"10.15554/PCIJ66.3-03","DOIUrl":"https://doi.org/10.15554/PCIJ66.3-03","url":null,"abstract":"Precast concrete members need to be connected effectively to form an integral structural system. Use of unstressed strands provides a cost-effective and practical solution to reinforce the connection regions of precast concrete members, especially for precast concrete bridge girder applications. With the limited understanding of bonding characteristics for unstressed strands, a combination of experimental and analytical programs, which focused on unstressed strands as a connection between precast concrete girders and cap beams for seismic applications, was designed to investigate the fundamental load-transfer characteristics of unstressed strands anchored in grout and concrete based on pullout tests. The relationship between strand stress and loaded-end displacement was developed, and the bond stress of unstressed strands embedded in concrete and grouted duct was examined. The average bond stress of unstressed strands anchored in concrete and grouted duct is recommended to be five and seven times the square root of concrete compressive strength, respectively. The results of this research provide qualitative embedment length requirements to design connections between precast concrete members using unstressed strands.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"49-66"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Nafadi, G. Lucier, Tuğçe Sevil Yaman, H. Gleich, S. Rizkalla
■ The applied fatigue testing did not affect the ultimate performance of the panels and had a minimal effect on the composite action between the wythes. Precast concrete sandwich panels are typically used to construct high-performance, energy-efficient building envelopes. These panels typically consist of two concrete wythes separated by rigid foam insulation, such as expanded polystyrene (EPS) or extruded polystyrene (XPS). The panels are designed to resist floor loads as well as wind or seismic lateral loads while providing efficient insulation to the structure. They are often fabricated with heights over 45 ft (13.7 m) and widths up to 15 ft (4.6 m). Wythe thickness commonly ranges from 2 to 6 in. (50.8 to 152.4 mm), and overall panel thickness may be from 6 to over 12 in. (304.8 mm). Longitudinal prestressing is normally provided in both concrete wythes to control cracks.
{"title":"Long-term behavior of precast, prestressed concrete sandwich panels reinforced with carbon-fiber-reinforced polymer shear grid","authors":"M. Nafadi, G. Lucier, Tuğçe Sevil Yaman, H. Gleich, S. Rizkalla","doi":"10.15554/pcij66.5-01","DOIUrl":"https://doi.org/10.15554/pcij66.5-01","url":null,"abstract":"■ The applied fatigue testing did not affect the ultimate performance of the panels and had a minimal effect on the composite action between the wythes. Precast concrete sandwich panels are typically used to construct high-performance, energy-efficient building envelopes. These panels typically consist of two concrete wythes separated by rigid foam insulation, such as expanded polystyrene (EPS) or extruded polystyrene (XPS). The panels are designed to resist floor loads as well as wind or seismic lateral loads while providing efficient insulation to the structure. They are often fabricated with heights over 45 ft (13.7 m) and widths up to 15 ft (4.6 m). Wythe thickness commonly ranges from 2 to 6 in. (50.8 to 152.4 mm), and overall panel thickness may be from 6 to over 12 in. (304.8 mm). Longitudinal prestressing is normally provided in both concrete wythes to control cracks.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
■ Recommended updates to design guidelines and connection details to preserve structural integrity in precast concrete modular construction are presented. The American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19) contains structural integrity provisions for precast concrete panel buildings but does not address the structural integrity of precast concrete modules. ACI 318 requires spaced steel ties in all directions to tie the precast concrete panel elements together. These criteria are impractical for precast concrete modules due to the construction methods and the overall rigidity of each module. Precast concrete modules are inherently stable, even when subjected to General Services Administration (GSA) criteria for partial removal of structural walls or corners, which require that if a portion of a wall or an entire module is removed, the remaining portions must have sufficient capacity to carry the resulting gravity loads. This paper examines the stress increases due to partial wall removal and the possibility of total module removal. It discusses strength reserves, provides recommendations for future editions of ACI 318 and the PCI Design Handbook: Precast and Prestressed Concrete, and presents conceptual connections that provide the continuity and ductility needed to maintain structural integrity following total module removal.
{"title":"Structural integrity of precast concrete modular construction","authors":"Jeff M. Wenke, C. Dolan","doi":"10.15554/PCIJ66.2-02","DOIUrl":"https://doi.org/10.15554/PCIJ66.2-02","url":null,"abstract":"■ Recommended updates to design guidelines and connection details to preserve structural integrity in precast concrete modular construction are presented. The American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19) contains structural integrity provisions for precast concrete panel buildings but does not address the structural integrity of precast concrete modules. ACI 318 requires spaced steel ties in all directions to tie the precast concrete panel elements together. These criteria are impractical for precast concrete modules due to the construction methods and the overall rigidity of each module. Precast concrete modules are inherently stable, even when subjected to General Services Administration (GSA) criteria for partial removal of structural walls or corners, which require that if a portion of a wall or an entire module is removed, the remaining portions must have sufficient capacity to carry the resulting gravity loads. This paper examines the stress increases due to partial wall removal and the possibility of total module removal. It discusses strength reserves, provides recommendations for future editions of ACI 318 and the PCI Design Handbook: Precast and Prestressed Concrete, and presents conceptual connections that provide the continuity and ductility needed to maintain structural integrity following total module removal.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"58-70"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
■ This article summarizes the research of various sources dating from the 1950s on prestressing strand bonding to concrete in support of the publication of “Recommended Practice to Assess and Control Strand/Concrete Bonding Properties of ASTM A416 Prestressing Strand.” The transfer of prestressing force from prestressed strand to concrete over a predictable length is essential for the reliable performance of prestressed concrete.
{"title":"Bond of prestressing strand to concrete","authors":"A. Osborn, M. Lanier, N. Hawkins","doi":"10.15554/pcij66.1-04","DOIUrl":"https://doi.org/10.15554/pcij66.1-04","url":null,"abstract":"■ This article summarizes the research of various sources dating from the 1950s on prestressing strand bonding to concrete in support of the publication of “Recommended Practice to Assess and Control Strand/Concrete Bonding Properties of ASTM A416 Prestressing Strand.” The transfer of prestressing force from prestressed strand to concrete over a predictable length is essential for the reliable performance of prestressed concrete.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"28-48"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many bridge owners have developed new precast, prestressed concrete bridge girder sections that are optimized for high-performance concrete and pretensioning strands with diameters greater than 0.5 in. (12.7 mm). Girder sections have been developed for increased span capacities, while others fill a need in shorter span ranges. Accurate geometric properties are essential for design. Common properties, including cross-sectional area, location of centroid, and major axis moment of inertia, are generally easy to compute and are readily available in standard design references. Computation of the torsion constant is a different matter. This paper presents the methods and results of a study to determine the torsion constant for many of the modern precast, prestressed concrete bridge girders used in the United States and compares the results with values from the approximate methods of the AASHTO LRFD specifications.
{"title":"Saint-Venant torsion constant of modern precast concrete bridge girders","authors":"R. Brice, Richard D. Pickings","doi":"10.15554/PCIJ66.3-01","DOIUrl":"https://doi.org/10.15554/PCIJ66.3-01","url":null,"abstract":"Many bridge owners have developed new precast, prestressed concrete bridge girder sections that are optimized for high-performance concrete and pretensioning strands with diameters greater than 0.5 in. (12.7 mm). Girder sections have been developed for increased span capacities, while others fill a need in shorter span ranges. Accurate geometric properties are essential for design. Common properties, including cross-sectional area, location of centroid, and major axis moment of inertia, are generally easy to compute and are readily available in standard design references. Computation of the torsion constant is a different matter. This paper presents the methods and results of a study to determine the torsion constant for many of the modern precast, prestressed concrete bridge girders used in the United States and compares the results with values from the approximate methods of the AASHTO LRFD specifications.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A typical 1200 mm (48 in.) wide × 200 mm (8 in.) deep prestressed concrete hollow-core unit is analyzed and designed in order to make a comparison between Eurocode 2 and ACI 318-08. This includes calculations for serviceability limit state of stress and moment of resistance, ultimate moment of resistance, ultimate shear capacities, flexural stiffness (that is, for deflection), and cover to pretensioning tendons for conditions of environmental exposure and fire resistance. Concrete cylinder strength is 40 MPa (5.8 ksi), and concrete cube strength is 50 MPa (7.3 ksi). The hollow-core unit is pretensioned using seven-wire helical strands. Worked examples are presented in parallel formation according to Eurocode 2 and ACI 318. For uniformly distributed loads, the design criterion between the service moment to service moment of resistance (Ms/Msr for EC2 and Ms/Msn for ACI 318) and the ultimate design bending moment to ultimate moment of resistance (MEd/MRd for EC2 and Mu/φMn for ACI 318) is well balanced for this example. Usually the service moment is critical unless the amount of prestress is small. For EC2-1-1, flexurally uncracked shear capacity VRd,c is only limiting when the span-to-depth ratio in this example is less than about 35. For ACI 318, flexurally cracked shear capacity φVci is limiting when span-to-depth ratio is 42, showing that shear cracked in flexure will often be the governing criterion.
{"title":"Comparison of the design of prestressed concrete hollow-core floor units with Eurocode 2 and ACI 318","authors":"K. Elliott","doi":"10.15554/PCIJ66.2-01","DOIUrl":"https://doi.org/10.15554/PCIJ66.2-01","url":null,"abstract":"A typical 1200 mm (48 in.) wide × 200 mm (8 in.) deep prestressed concrete hollow-core unit is analyzed and designed in order to make a comparison between Eurocode 2 and ACI 318-08. This includes calculations for serviceability limit state of stress and moment of resistance, ultimate moment of resistance, ultimate shear capacities, flexural stiffness (that is, for deflection), and cover to pretensioning tendons for conditions of environmental exposure and fire resistance. Concrete cylinder strength is 40 MPa (5.8 ksi), and concrete cube strength is 50 MPa (7.3 ksi). The hollow-core unit is pretensioned using seven-wire helical strands. Worked examples are presented in parallel formation according to Eurocode 2 and ACI 318. For uniformly distributed loads, the design criterion between the service moment to service moment of resistance (Ms/Msr for EC2 and Ms/Msn for ACI 318) and the ultimate design bending moment to ultimate moment of resistance (MEd/MRd for EC2 and Mu/φMn for ACI 318) is well balanced for this example. Usually the service moment is critical unless the amount of prestress is small. For EC2-1-1, flexurally uncracked shear capacity VRd,c is only limiting when the span-to-depth ratio in this example is less than about 35. For ACI 318, flexurally cracked shear capacity φVci is limiting when span-to-depth ratio is 42, showing that shear cracked in flexure will often be the governing criterion.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"21-57"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ahmed Almohammedi, C. Murray, Canh N. Dang, W. Hale
Inaccurate prediction of prestress losses leads to inaccurate predictions for camber, deflection, and concrete stresses in a bridge girder. This study aims to improve the prediction of prestress losses and provides bridge designers with insights into the differences between design and actual concrete properties. Prestress losses, compressive strength, modulus of elasticity, shrinkage, and creep were measured for several American Association of State Highway and Transportation Officials (AASHTO) Types II, III, IV, and VI girders. The investigation revealed that the measured total prestress losses at the time of deck placement were lower than the design losses calculated using the refined estimates method of the 2017 AASHTO LRFD Bridge Design Specifications. This was mainly attributed to the actual concrete compressive strength at transfer being greater than the design compressive strength. This discrepancy was as high as 73% for some girders. It was also determined that the 2017 AASHTO LRFD specifications’ refined estimates method for estimating prestress losses overestimates the total prestress losses at the time of deck placement for AASHTO Types II and III girders.
{"title":"Investigation of measured prestress losses compared with design prestress losses in AASHTO Types II, III, IV, and VI bridge girders","authors":"Ahmed Almohammedi, C. Murray, Canh N. Dang, W. Hale","doi":"10.15554/PCIJ66.3-02","DOIUrl":"https://doi.org/10.15554/PCIJ66.3-02","url":null,"abstract":"Inaccurate prediction of prestress losses leads to inaccurate predictions for camber, deflection, and concrete stresses in a bridge girder. This study aims to improve the prediction of prestress losses and provides bridge designers with insights into the differences between design and actual concrete properties. Prestress losses, compressive strength, modulus of elasticity, shrinkage, and creep were measured for several American Association of State Highway and Transportation Officials (AASHTO) Types II, III, IV, and VI girders. The investigation revealed that the measured total prestress losses at the time of deck placement were lower than the design losses calculated using the refined estimates method of the 2017 AASHTO LRFD Bridge Design Specifications. This was mainly attributed to the actual concrete compressive strength at transfer being greater than the design compressive strength. This discrepancy was as high as 73% for some girders. It was also determined that the 2017 AASHTO LRFD specifications’ refined estimates method for estimating prestress losses overestimates the total prestress losses at the time of deck placement for AASHTO Types II and III girders.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"32-48"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Very little experimental data have been published relating to the pullout capacity of prestressing strand lifting loops. To address this gap in knowledge, 13 pullout tests were conducted on strand lifting loops with 0.6 in. (15.24 mm) diameter, 270 ksi (1860 MPa) strand. Straight and bent orientations were tested for single loops at different embedment depths. Loops were embedded in 12 in. (304.8 mm) wide and 44 in. (1117.6 mm) deep concrete blocks and subjected to monotonic, static loading until failure. Marginal bond quality of the strand (18.2 kip [81 kN]), Mohs hardness (3.6), and concrete strength (3000 psi [20.7 MPa]) resulted in an average bond stress value of 400 psi (2758 kPa) at failure. Most tests exhibited pullout failure modes and adequate ductility. Three loops tested at 32 in. (812.8 mm) embedment with 6 in. (152.4 mm), 90-degree bends experienced brittle side-face blowout failures. These failures were due to inclination of the lifting, which led to a reduced edge distance. A safe uniform bond stress of 199 psi (1372 kPa) is recommended for 0.6 in. diameter strand.
{"title":"Experimental investigation of 0.6 in. diameter strand lifting loops","authors":"Sandip Chhetri, R. Chicchi, A. Osborn","doi":"10.15554/PCIJ66.2-03","DOIUrl":"https://doi.org/10.15554/PCIJ66.2-03","url":null,"abstract":"Very little experimental data have been published relating to the pullout capacity of prestressing strand lifting loops. To address this gap in knowledge, 13 pullout tests were conducted on strand lifting loops with 0.6 in. (15.24 mm) diameter, 270 ksi (1860 MPa) strand. Straight and bent orientations were tested for single loops at different embedment depths. Loops were embedded in 12 in. (304.8 mm) wide and 44 in. (1117.6 mm) deep concrete blocks and subjected to monotonic, static loading until failure. Marginal bond quality of the strand (18.2 kip [81 kN]), Mohs hardness (3.6), and concrete strength (3000 psi [20.7 MPa]) resulted in an average bond stress value of 400 psi (2758 kPa) at failure. Most tests exhibited pullout failure modes and adequate ductility. Three loops tested at 32 in. (812.8 mm) embedment with 6 in. (152.4 mm), 90-degree bends experienced brittle side-face blowout failures. These failures were due to inclination of the lifting, which led to a reduced edge distance. A safe uniform bond stress of 199 psi (1372 kPa) is recommended for 0.6 in. diameter strand.","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"71-87"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67574513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of precast concrete members with jointed connections for seismic applications has gained momentum recently; however, these systems may have limited application in seismic regions. This is because their dominant mechanism of impact damping is considered to be inadequate to dissipate the seismic energy imparted to them. With no hysteresis elements, precast concrete members with jointed connections may undergo long durations of motion and large lateral drifts when subjected to seismic loads. This paper investigates a method that can allow these members to dissipate the seismic energy efficiently by having them rock on a thin rubber layer that is placed at the jointed connection. Experiments that examine the use of various classes and layer thicknesses of rubber show that this method can improve damping in these members. Using experimental and numerical data, this paper quantifies the energy dissipation and seismic responses associated with this use of rubber. It is shown that rubber layers with high shore hardness of 90 and thickness between 6.35 and 25.4 mm (0.25 and 1 in.) improve the amount of damping in lateral-load-resisting systems using precast concrete members and produce satisfactory seismic response for these systems. Disciplines Geotechnical Engineering Comments This article is published as Kalliontzis, Dimitrios, and Sri Sritharan. "Seismic behavior of unbonded posttensioned precast concretemembers with thin rubber layers at the jointed connection. PCI Journal 66, no. 1 (2021): 60-76. DOI: 10.15554/pcij66.1-02. Posted with permission. This article is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/ccee_pubs/284
{"title":"Seismic behavior of unbonded post-tensioned precast concrete members with thin rubber layers at the jointed connection","authors":"D. Kalliontzis, S. Sritharan","doi":"10.15554/pcij66.1-02","DOIUrl":"https://doi.org/10.15554/pcij66.1-02","url":null,"abstract":"The use of precast concrete members with jointed connections for seismic applications has gained momentum recently; however, these systems may have limited application in seismic regions. This is because their dominant mechanism of impact damping is considered to be inadequate to dissipate the seismic energy imparted to them. With no hysteresis elements, precast concrete members with jointed connections may undergo long durations of motion and large lateral drifts when subjected to seismic loads. This paper investigates a method that can allow these members to dissipate the seismic energy efficiently by having them rock on a thin rubber layer that is placed at the jointed connection. Experiments that examine the use of various classes and layer thicknesses of rubber show that this method can improve damping in these members. Using experimental and numerical data, this paper quantifies the energy dissipation and seismic responses associated with this use of rubber. It is shown that rubber layers with high shore hardness of 90 and thickness between 6.35 and 25.4 mm (0.25 and 1 in.) improve the amount of damping in lateral-load-resisting systems using precast concrete members and produce satisfactory seismic response for these systems. Disciplines Geotechnical Engineering Comments This article is published as Kalliontzis, Dimitrios, and Sri Sritharan. \"Seismic behavior of unbonded posttensioned precast concretemembers with thin rubber layers at the jointed connection. PCI Journal 66, no. 1 (2021): 60-76. DOI: 10.15554/pcij66.1-02. Posted with permission. This article is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/ccee_pubs/284","PeriodicalId":54637,"journal":{"name":"PCI Journal","volume":"66 1","pages":"60-76"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67573825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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