The study used a standard instrumented ring test method, ASTM C 1581 to quantify the restrained shrinkage behavior of several conventional concrete and self consolidating concrete (SCC) mixtures. The instrument ring method involves the measurement of the strain developed in a steel ring as the concrete shrinks. The measured strain is an indication of the level of stress developed in the concrete. The rate at which the stress develops in the concrete, as well as the time after initiation of drying when the test specimen cracks, can be used to classify the cracking potential of the concrete.
该研究使用ASTM C 1581标准环测试方法来量化几种常规混凝土和自固结混凝土(SCC)混合物的约束收缩行为。仪表环法是测量混凝土收缩时钢环中产生的应变。测得的应变是混凝土中产生的应力水平的指示。应力在混凝土中发展的速率，以及试样开裂时开始干燥后的时间，可以用来对混凝土的开裂潜力进行分类。
{"title":"Performance of Self-Consolidating Concrete Under Restrained Shrinkage","authors":"H. T. See, E. Attiogbe","doi":"10.14359/14436","DOIUrl":"https://doi.org/10.14359/14436","url":null,"abstract":"The study used a standard instrumented ring test method, ASTM C 1581 to quantify the restrained shrinkage behavior of several conventional concrete and self consolidating concrete (SCC) mixtures. The instrument ring method involves the measurement of the strain developed in a steel ring as the concrete shrinks. The measured strain is an indication of the level of stress developed in the concrete. The rate at which the stress develops in the concrete, as well as the time after initiation of drying when the test specimen cracks, can be used to classify the cracking potential of the concrete.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122190405","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}
As concrete shrinks and steel does not, the resistance of reinforcement to shrinkage causes deflection of slabs and beams and shortening of columns and walls. In this paper, the current methods of calculating shrinkage curvature and deflection in reinforced sections are examined and compared, concluding that the American Concrete I method seems realistic but the UK and European methods overestimate the deflection significantly. Shrinkage is also significant in concrete roads and industrial ground floors, but the paper is limited to typical structural elements in buildings.
{"title":"\"Managing Deflection, Shortening and Cracking Arising from Restrained Contraction\"","authors":"S. Alexander","doi":"10.14359/14423","DOIUrl":"https://doi.org/10.14359/14423","url":null,"abstract":"As concrete shrinks and steel does not, the resistance of reinforcement to shrinkage causes deflection of slabs and beams and shortening of columns and walls. In this paper, the current methods of calculating shrinkage curvature and deflection in reinforced sections are examined and compared, concluding that the American Concrete I method seems realistic but the UK and European methods overestimate the deflection significantly. Shrinkage is also significant in concrete roads and industrial ground floors, but the paper is limited to typical structural elements in buildings.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131098805","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 Australian Standard for Concrete Structures, AS3600, is currently being reviewed, with amendments introduced to facilitate the use of 500 MPa reinforcing steel in the design of concrete structures. This paper is primarily concerned with the instantaneous and time dependent strength and deformation characteristics of concrete up to 100 MPa. The factors that have been considered in the current review are discussed and the models that have been developed for predicting the tensile strength, the elastic modulus, the creep coefficient and the shrinkage strain for the full range of applicable concrete strengths are presented.
{"title":"AS3600 Creep and Shrinkage Models for Normal and High Strength Concrete","authors":"R. Gilbert","doi":"10.14359/14424","DOIUrl":"https://doi.org/10.14359/14424","url":null,"abstract":"The Australian Standard for Concrete Structures, AS3600, is currently being reviewed, with amendments introduced to facilitate the use of 500 MPa reinforcing steel in the design of concrete structures. This paper is primarily concerned with the instantaneous and time dependent strength and deformation characteristics of concrete up to 100 MPa. The factors that have been considered in the current review are discussed and the models that have been developed for predicting the tensile strength, the elastic modulus, the creep coefficient and the shrinkage strain for the full range of applicable concrete strengths are presented.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123085639","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 paper discusses a study that considered constant load and incremental restrained load cases got measurement and modeling of early age tensile creep and shrinkage of concrete. The experimental program measured early age tensile creep and shrinkage and the results were used to develop suggestions for improving existing models. The experimental results showed good agreement for restrained creep deformation, indicating that they are valid for early age tensile creep in addition to mature compressive creep.
{"title":"Modeling Early Age Tensile Creep and Shrinkage of Concrete","authors":"Matthew D. D'Ambrosia, D. Lange","doi":"10.14359/14439","DOIUrl":"https://doi.org/10.14359/14439","url":null,"abstract":"The paper discusses a study that considered constant load and incremental restrained load cases got measurement and modeling of early age tensile creep and shrinkage of concrete. The experimental program measured early age tensile creep and shrinkage and the results were used to develop suggestions for improving existing models. The experimental results showed good agreement for restrained creep deformation, indicating that they are valid for early age tensile creep in addition to mature compressive creep.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127955736","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}
Integral abutment bridges are becoming popular among a number of transportation agencies owing to the benefits arising from elimination of expensive joints, installation, and reduced maintenance costs. The purpose of this study is to quantify the time dependent effects of creep, shrinkage and temperature using an analytical model to ensure efficient and reliable design, and give a rationale for the adoption of integral abutment bridges. An analytical procedure incorporating the time dependent behavior of the superstructure will aid in getting the appropriate forces transmitted to the substructure system of the integral abutment bridge rather than assuming the superstructure and substructure as separate systems.
{"title":"Design Implications of Creep and Shrinkage in Integral Abutment Bridges","authors":"M. Arockiasamy, M. Sivakumar","doi":"10.14359/14427","DOIUrl":"https://doi.org/10.14359/14427","url":null,"abstract":"Integral abutment bridges are becoming popular among a number of transportation agencies owing to the benefits arising from elimination of expensive joints, installation, and reduced maintenance costs. The purpose of this study is to quantify the time dependent effects of creep, shrinkage and temperature using an analytical model to ensure efficient and reliable design, and give a rationale for the adoption of integral abutment bridges. An analytical procedure incorporating the time dependent behavior of the superstructure will aid in getting the appropriate forces transmitted to the substructure system of the integral abutment bridge rather than assuming the superstructure and substructure as separate systems.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132123622","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 North Halawa Valley Viaduct (NHVV) is a 1.5 km box girder viaduct with span lengths up to 110 m. It is part of a new freeway on the island of Oahu in Hawaii. The paper discusses a 10-year instrumentation program that was designed to provide long term monitoring of the structural performance of the viaduct. The measurements obtained include concrete strains, span shortening, tendon forces, span deflections, and support rotations. In order to perform the measurements, over 200 instruments were installed. The paper presents results from the vibration wire stain gauges, span longitudinal and vertical deflection measurements, and tendon prestress forces. The results of the study have been incorporated into the development of an instrumentation system for a planned bridge on the Island of Hawaii.
{"title":"Shrinkage and Creep Predictions Evaluated using 10-Year Monitoring of the North Halawa Valley Viaduct","authors":"I. Robertson, Xiaopeng Li","doi":"10.14359/14429","DOIUrl":"https://doi.org/10.14359/14429","url":null,"abstract":"The North Halawa Valley Viaduct (NHVV) is a 1.5 km box girder viaduct with span lengths up to 110 m. It is part of a new freeway on the island of Oahu in Hawaii. The paper discusses a 10-year instrumentation program that was designed to provide long term monitoring of the structural performance of the viaduct. The measurements obtained include concrete strains, span shortening, tendon forces, span deflections, and support rotations. In order to perform the measurements, over 200 instruments were installed. The paper presents results from the vibration wire stain gauges, span longitudinal and vertical deflection measurements, and tendon prestress forces. The results of the study have been incorporated into the development of an instrumentation system for a planned bridge on the Island of Hawaii.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"165 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116390708","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 paper reports on a study that conducted a sensitivity analysis on shrinkage of conrete in five categories: relative humidity, specimen size, compressive strength, cement type, and type of curing. The maximum value of sensitivity for each model was compared in order to determine the most sensitive model.
{"title":"Sensitivity of the Models for Predicting Shrinkage of Concrete","authors":"A. Al-Manaseer, Snezana Ristanovic","doi":"10.14359/14425","DOIUrl":"https://doi.org/10.14359/14425","url":null,"abstract":"The paper reports on a study that conducted a sensitivity analysis on shrinkage of conrete in five categories: relative humidity, specimen size, compressive strength, cement type, and type of curing. The maximum value of sensitivity for each model was compared in order to determine the most sensitive model.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131687665","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}
Creep acts both positively and negatively on the long term service conditions of modern reinforced or prestressed concrete structures that are subjected to complex histories of loading and restraint conditions. Creep substantially modifies stress and strain patterns, increasing the load induced deformation, relaxing the stresses and activating the delayed restraints.. This paper illustrates how the use of the four fundamental theorems of the theory of viscoelasticity for aging materials , and the related fundamental functions, offers a reliable and rational approach for estimating these effects.
{"title":"A Rational Approach to the Analysis of Structural Effects due to Creep","authors":"M. A. Chiorino","doi":"10.14359/14428","DOIUrl":"https://doi.org/10.14359/14428","url":null,"abstract":"Creep acts both positively and negatively on the long term service conditions of modern reinforced or prestressed concrete structures that are subjected to complex histories of loading and restraint conditions. Creep substantially modifies stress and strain patterns, increasing the load induced deformation, relaxing the stresses and activating the delayed restraints.. This paper illustrates how the use of the four fundamental theorems of the theory of viscoelasticity for aging materials , and the related fundamental functions, offers a reliable and rational approach for estimating these effects.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"209 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133926205","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 focus of this study is on deviations from the linear viscoelastic behavior of concrete occurring at high stress levels, at early age loading and in case of unloading implying strain reversal. Paper describes the series of creep tests that was performed on high strength concrete specimens undergoing creep under constant stress, followed by a period of recording of the creep recovery after complete unloading.The experiment data show that the creep recovery deviates strongly from the numerical predictions obtained by the application of the principle of superposition but seems to conform rather well to the recovery model proposed.
{"title":"Deviations from the Principle of Superposition and their Consequences on Structural Behavior","authors":"S. Staquet, B. Espion","doi":"10.14359/14426","DOIUrl":"https://doi.org/10.14359/14426","url":null,"abstract":"The focus of this study is on deviations from the linear viscoelastic behavior of concrete occurring at high stress levels, at early age loading and in case of unloading implying strain reversal. Paper describes the series of creep tests that was performed on high strength concrete specimens undergoing creep under constant stress, followed by a period of recording of the creep recovery after complete unloading.The experiment data show that the creep recovery deviates strongly from the numerical predictions obtained by the application of the principle of superposition but seems to conform rather well to the recovery model proposed.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125960227","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}
Mauricio Lopez, L. Kahn, K. Kurtis, B. S. Buchberg
The advantages of high performance concrete (HPC) have long been recognized, particularly bridge structures. Structural lightweight concrete (SLC), usually defined as a concrete with an air dried density at 28 days, has three key advantages:reduction in structure dead load; reduction in member size; and development of a precast technology as a result of self weight reduction that facilitates the transport and lifting of structural members. High performance lightweight concrete (HPLC) can be conceptualized a concrete possessing the characteristics of both HPC and SLC. Current design standards do not specifically consider HPLC. High strength and high performance lightweight concrete is a relatively new material and its long term performance, especially creep, is not well known. This might be one barrier to the use of HPLC. The objective of this research was to investigate the time dependence behavior of high performance, lightweight concrete for its potential use in precast, prestressed bridge girders.
{"title":"Long-Term Creep and Shrinkage in High-Strength Lightweight Concrete","authors":"Mauricio Lopez, L. Kahn, K. Kurtis, B. S. Buchberg","doi":"10.14359/14437","DOIUrl":"https://doi.org/10.14359/14437","url":null,"abstract":"The advantages of high performance concrete (HPC) have long been recognized, particularly bridge structures. Structural lightweight concrete (SLC), usually defined as a concrete with an air dried density at 28 days, has three key advantages:reduction in structure dead load; reduction in member size; and development of a precast technology as a result of self weight reduction that facilitates the transport and lifting of structural members. High performance lightweight concrete (HPLC) can be conceptualized a concrete possessing the characteristics of both HPC and SLC. Current design standards do not specifically consider HPLC. High strength and high performance lightweight concrete is a relatively new material and its long term performance, especially creep, is not well known. This might be one barrier to the use of HPLC. The objective of this research was to investigate the time dependence behavior of high performance, lightweight concrete for its potential use in precast, prestressed bridge girders.","PeriodicalId":254369,"journal":{"name":"SP-227: Shrinkage and Creep of Concrete","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131121486","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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