The use of high strength concrete has been increasing in the construction of high-rise earthquake resistant buildings in Japan. However, design guidelines have not been fully developed for reinforced concrete buildings with concrete compressive strengths higher than 35.3 MPa. Therefore the Japanese Building Research Institute initiated "New RC Project" aimed at establishing design guidelines for buildings constructed using high strength concrete. The project started in 1988 and extensive research has been conducted at several research institutes and universities. Shear tests on beams and columns with high strength concrete were also conducted as part of program to establish the shear design method for them. This paper summarizes findings from the New RC tests and others on shear strength of reinforced concrete beams and columns with high strength concrete and high strength shear reinforcement. The accuracy of currently available shear strength equations are then examined. The shear design method proposed by the Shear Working Group of the New RC project is also introduced in this paper.
{"title":"Shear Strength of RC Members with High-Strength Concrete","authors":"F. Watanabe, T. Kabeyasawa","doi":"10.14359/5908","DOIUrl":"https://doi.org/10.14359/5908","url":null,"abstract":"The use of high strength concrete has been increasing in the construction of high-rise earthquake resistant buildings in Japan. However, design guidelines have not been fully developed for reinforced concrete buildings with concrete compressive strengths higher than 35.3 MPa. Therefore the Japanese Building Research Institute initiated \"New RC Project\" aimed at establishing design guidelines for buildings constructed using high strength concrete. The project started in 1988 and extensive research has been conducted at several research institutes and universities. Shear tests on beams and columns with high strength concrete were also conducted as part of program to establish the shear design method for them. This paper summarizes findings from the New RC tests and others on shear strength of reinforced concrete beams and columns with high strength concrete and high strength shear reinforcement. The accuracy of currently available shear strength equations are then examined. The shear design method proposed by the Shear Working Group of the New RC project is also introduced in this paper.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130338852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent research on confinement of high-strength concrete (HSC) is reviewed. The emphasis is placed on the effects of confinement parameters and related experimental research. A review of analytical models proposed for HSC is also presented. The results indicate that for similar strength and deformability, HSC requires higher confinement pressure than normal-strength concrete. The level of lateral pressure required can be provided by increasing the volumetric ratio and grade of confinement reinforcement. The efficiency of pressure can be improved by reducing the spacing of lateral reinforcement in both the longitudinal and cross-sectional planes. When properly confined, HSC exhibits ductile stress-strain characteristics. The analytical models developed for normal -strength concrete cannot be used to describe stress-strain characteristics of HSC. A number of models have been proposed for HSC that produce good correlations with experimental data.
{"title":"Confinement of High-Strength Concrete","authors":"M. Saatcioglu, P. Paultre, S. Ghosh","doi":"10.14359/5897","DOIUrl":"https://doi.org/10.14359/5897","url":null,"abstract":"Recent research on confinement of high-strength concrete (HSC) is reviewed. The emphasis is placed on the effects of confinement parameters and related experimental research. A review of analytical models proposed for HSC is also presented. The results indicate that for similar strength and deformability, HSC requires higher confinement pressure than normal-strength concrete. The level of lateral pressure required can be provided by increasing the volumetric ratio and grade of confinement reinforcement. The efficiency of pressure can be improved by reducing the spacing of lateral reinforcement in both the longitudinal and cross-sectional planes. When properly confined, HSC exhibits ductile stress-strain characteristics. The analytical models developed for normal -strength concrete cannot be used to describe stress-strain characteristics of HSC. A number of models have been proposed for HSC that produce good correlations with experimental data.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123172134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-Strength Concrete Beam-Column Joints of Moment Resisting Frames","authors":"R. Park, H. Tanaka, Xin Xin","doi":"10.14359/5907","DOIUrl":"https://doi.org/10.14359/5907","url":null,"abstract":"","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122406505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Strength and deformability of High-Strength Concrete (HSC) columns are presented based on recent experimental and analytical research. HSC columns under concentric compression and under combined axial compression and lateral load reversals are discussed. Experimentally observed column strengths are compared with those computed based on the provisions of ACI 318 (1) building code and analytical models proposed for HSC columns. The results indicate that the rectangular stress block currently used for normal-strength concrete is not applicable to HSC, especially for columns under high compression where the overall response is dominated by concrete. A triangular and a modified rectangular stress block is presented. Column capacity under concentric compression is illustrated with due considerations given to early spalling of cover concrete. Axial and lateral deformabilities of HSC columns are discussed with emphasis placed on the parameters of confinement. It is shown that HSC columns conforming to the current building code requirements may exhibit ductile behavior under moderate and low levels of axial compression. Higher grade lateral reinforcement can be utilized effectively to confine HSC columns to produce improved inelastic deformability under higher levels of axial compression.
{"title":"Performance of High-Strength Concrete (HSC) Columns Confined with Rectilinear Reinforcement","authors":"A. Azizinamini, M. Saatcioglu","doi":"10.14359/5901","DOIUrl":"https://doi.org/10.14359/5901","url":null,"abstract":"Strength and deformability of High-Strength Concrete (HSC) columns are presented based on recent experimental and analytical research. HSC columns under concentric compression and under combined axial compression and lateral load reversals are discussed. Experimentally observed column strengths are compared with those computed based on the provisions of ACI 318 (1) building code and analytical models proposed for HSC columns. The results indicate that the rectangular stress block currently used for normal-strength concrete is not applicable to HSC, especially for columns under high compression where the overall response is dominated by concrete. A triangular and a modified rectangular stress block is presented. Column capacity under concentric compression is illustrated with due considerations given to early spalling of cover concrete. Axial and lateral deformabilities of HSC columns are discussed with emphasis placed on the parameters of confinement. It is shown that HSC columns conforming to the current building code requirements may exhibit ductile behavior under moderate and low levels of axial compression. Higher grade lateral reinforcement can be utilized effectively to confine HSC columns to produce improved inelastic deformability under higher levels of axial compression.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122048013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Possible applications of the use of high strength concrete in structures designed to respond to the strong ground shaking of earthquakes is discussed. The basis of the building code requirements is discussed and various limitations are explored. The need for detailing of members to ensure ductility is discussed and how the high stresses that can be present in high strength concrete members will require more stringent confinement reinforcement as well as other detailing procedures. The paper urges caution when designing with high strength concrete in seismic regions.
{"title":"Application of High-Strength Concrete in Seismic Regions","authors":"L. Wyllie","doi":"10.14359/5909","DOIUrl":"https://doi.org/10.14359/5909","url":null,"abstract":"Possible applications of the use of high strength concrete in structures designed to respond to the strong ground shaking of earthquakes is discussed. The basis of the building code requirements is discussed and various limitations are explored. The need for detailing of members to ensure ductility is discussed and how the high stresses that can be present in high strength concrete members will require more stringent confinement reinforcement as well as other detailing procedures. The paper urges caution when designing with high strength concrete in seismic regions.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121301614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flexural behavior of high strength concrete (HSC) beams was investigated based on the experimental work of a number of researchers. The effects of HSC on mechanical properties such as modulus of elasticity, tensile strength, limiting concrete compressive strain, and Poisson's ratio were reviewed. The applicability of current ACI design guidelines and suggested modifications were compared with experimental data in terms of strength, ductility, and serviceability.
{"title":"Effect of High-Strength Concrete (HSC) on Flexural Members","authors":"C. Fasching, C. French","doi":"10.14359/5898","DOIUrl":"https://doi.org/10.14359/5898","url":null,"abstract":"Flexural behavior of high strength concrete (HSC) beams was investigated based on the experimental work of a number of researchers. The effects of HSC on mechanical properties such as modulus of elasticity, tensile strength, limiting concrete compressive strain, and Poisson's ratio were reviewed. The applicability of current ACI design guidelines and suggested modifications were compared with experimental data in terms of strength, ductility, and serviceability.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129940997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The first purpose of this report is to introduce experiments on 91 square confined concrete specimens and 59 circular ones with high strength materials subjected to monotonic and concentric axial loading conducted in Japan recently. The concrete strength of specimens ranged from 27 MPa to 132 MPa and the strength of transverse reinforcement ranged from 173 MPa to 1360 MPa. Small size specimens with section dimension of about 200 mm have been conducted mainly but it is notable that four quasi-real size specimens with 470 mm square section were tested through the New RC Projects. The second purpose of this report is to introduce the recent research works on models, examining their feasibility. Conclusions included the following: (1) Regarding the maximum strength of the square confined specimens, the predictions with the models proposed by Sakino et al. and Watanabe et al. were accurate enough especially for quasi-real size specimens. However, the accuracy of the prediction for the axial strain became much worse compared with that for maximum strength in each model. (2) Regarding the stress-strain curves, the relations of the model by Sakino were quite similar to the observed curves until the end of the loading of quasi-real size specimens. (3) Regarding the effects of the material strengths, assuming that the model by Sakino was true, it was concluded that the stress increase was independent of the concrete strength and proportional to the strength of transverse reinforcement as far as it reached 687 MPa. On the other hand, the strain increase depended on the concrete strength: it decreased with the increasing value of the concrete strength.
本报告的第一个目的是介绍最近在日本进行的91个方形约束混凝土试件和59个高强度材料圆形约束混凝土试件在单调和同心轴向加载下的试验。试件混凝土强度范围为27 ~ 132 MPa，横向配筋强度范围为173 ~ 1360 MPa。主要进行的是截面尺寸约为200 mm的小尺寸试件，但值得注意的是，通过新RC项目进行了4个470mm方形截面的准真实尺寸试件的试验。本报告的第二个目的是介绍最近对模型的研究工作，检查其可行性。结论如下:(1)对于方形约束试件的最大强度，Sakino et al.和Watanabe et al.提出的模型预测是足够准确的，特别是对于准真实尺寸的试件。然而，各模型中轴向应变预测的精度比最大强度预测的精度差得多。(2)在应力-应变曲线方面，Sakino模型在准真实尺寸试件加载结束前与观测曲线的关系非常接近。(3)对于材料强度的影响，假设Sakino的模型成立，当达到687 MPa时，应力增加与混凝土强度无关，与横向钢筋强度成正比。另一方面，应变增量与混凝土强度有关，随混凝土强度的增大而减小。
{"title":"Confined Concrete with High-Strength Materials","authors":"D. Kato, F. Watanabe, M. Nishiyama, H. Sato","doi":"10.14359/5896","DOIUrl":"https://doi.org/10.14359/5896","url":null,"abstract":"The first purpose of this report is to introduce experiments on 91 square confined concrete specimens and 59 circular ones with high strength materials subjected to monotonic and concentric axial loading conducted in Japan recently. The concrete strength of specimens ranged from 27 MPa to 132 MPa and the strength of transverse reinforcement ranged from 173 MPa to 1360 MPa. Small size specimens with section dimension of about 200 mm have been conducted mainly but it is notable that four quasi-real size specimens with 470 mm square section were tested through the New RC Projects. The second purpose of this report is to introduce the recent research works on models, examining their feasibility. Conclusions included the following: (1) Regarding the maximum strength of the square confined specimens, the predictions with the models proposed by Sakino et al. and Watanabe et al. were accurate enough especially for quasi-real size specimens. However, the accuracy of the prediction for the axial strain became much worse compared with that for maximum strength in each model. (2) Regarding the stress-strain curves, the relations of the model by Sakino were quite similar to the observed curves until the end of the loading of quasi-real size specimens. (3) Regarding the effects of the material strengths, assuming that the model by Sakino was true, it was concluded that the stress increase was independent of the concrete strength and proportional to the strength of transverse reinforcement as far as it reached 687 MPa. On the other hand, the strain increase depended on the concrete strength: it decreased with the increasing value of the concrete strength.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121583668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article points out the requirement of ACI 318(1) and the Uniform Building Code (2) concerning the confinement of concrete in beams, columns and shearwalls that are part of the lateral force resisting system of structure in a region of high seismicity. It reviews available research to assess the adequacy of these requirements when high-strength concrete is used in the structural members. ACI 318 notation is used throughout this article.
{"title":"Confinement of High-Strength Concrete for Seismic Performance","authors":"S. Ghosh","doi":"10.14359/5895","DOIUrl":"https://doi.org/10.14359/5895","url":null,"abstract":"This article points out the requirement of ACI 318(1) and the Uniform Building Code (2) concerning the confinement of concrete in beams, columns and shearwalls that are part of the lateral force resisting system of structure in a region of high seismicity. It reviews available research to assess the adequacy of these requirements when high-strength concrete is used in the structural members. ACI 318 notation is used throughout this article.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114900324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An overview is presented on New Zealand applications and design concepts for the utilization of high strength concrete (concrete compressive strength greater than 55 MPa (8,000 psi)) in various forms of structures that are required to withstand seismic loading. In order to take advantage of the high concrete compressive strengths and enhanced durability designers and researchers are investigating various structural applications. The performance of elements of these structures ranges from remaining elastic during a major seismic event through to being required to exhibit significant ductility in the major events.
{"title":"Design Concepts and Applications of High-Strength Concrete in New Zealand","authors":"D. Bull","doi":"10.14359/5911","DOIUrl":"https://doi.org/10.14359/5911","url":null,"abstract":"An overview is presented on New Zealand applications and design concepts for the utilization of high strength concrete (concrete compressive strength greater than 55 MPa (8,000 psi)) in various forms of structures that are required to withstand seismic loading. In order to take advantage of the high concrete compressive strengths and enhanced durability designers and researchers are investigating various structural applications. The performance of elements of these structures ranges from remaining elastic during a major seismic event through to being required to exhibit significant ductility in the major events.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114086681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A theoretical study was carried out to investigate the effects of increasing concrete strength on the depth of rectangular beams. Two series of beams were investigated. Th first series comprised reinforced concrete beams with spans from 6 to 15 m, and the second comprised prestress concrete beams with spans from 12 to 30 m. The concrete strength ranged from 20 to 120 MPa and from 30 to 120 MPa for the reinforced and prestressed concrete beams, respectively. The results show that for rectangular concrete beams, an increase in concrete strength results in a rather significant reduction in the beam depth, whereas for rectangular prestressed concrete beams no significant reduction in the beam depth is gained from increasing the concrete strength because the deflection governs the design.
{"title":"Effects of Increasing Concrete Strength on the Dimension of Beams","authors":"H. Pam, H. Tanaka, R. Park","doi":"10.14359/5900","DOIUrl":"https://doi.org/10.14359/5900","url":null,"abstract":"A theoretical study was carried out to investigate the effects of increasing concrete strength on the depth of rectangular beams. Two series of beams were investigated. Th first series comprised reinforced concrete beams with spans from 6 to 15 m, and the second comprised prestress concrete beams with spans from 12 to 30 m. The concrete strength ranged from 20 to 120 MPa and from 30 to 120 MPa for the reinforced and prestressed concrete beams, respectively. The results show that for rectangular concrete beams, an increase in concrete strength results in a rather significant reduction in the beam depth, whereas for rectangular prestressed concrete beams no significant reduction in the beam depth is gained from increasing the concrete strength because the deflection governs the design.","PeriodicalId":208613,"journal":{"name":"SP-176: High-Strength Concrete in Seismic Regions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115356195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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