Drying shrinkage cracking can adversely affect the aesthetics, durability, and serviceability of reinforced concrete structures, thereby negating some of the benefits provided by high-performance concretes. Developed years ago but relatively new to the construction industry, shrinkage-reducing admixtures (SRAs) have been shown to provide significant reductions in concrete drying shrinkage and subsequent cracking. The potential benefits that SRAs provide have resulted in increased use of these products in the past few years. In this paper, data from laboratory testing and field investigations of SRA-treated concrete mixtures and their use in a few projects where watertightness was desired are presented and discussed. The findings of visual inspections of the projects performed shortly after construction and after a year in service will also be presented. The information to be presented verify the drying shrinkage reduction characteristics of SRAs and show that these innovative admixtures can provide substantial benefits with regards to improving watertightness and overall serviceability of reinforced concrete structures.
{"title":"Improving Watertightness of Reinforced Concrete Structures with Shrinkage-Reducing Admixtures","authors":"J. Buffenbarger, C. Nmai, M. Miltenberger","doi":"10.14359/10821","DOIUrl":"https://doi.org/10.14359/10821","url":null,"abstract":"Drying shrinkage cracking can adversely affect the aesthetics, durability, and serviceability of reinforced concrete structures, thereby negating some of the benefits provided by high-performance concretes. Developed years ago but relatively new to the construction industry, shrinkage-reducing admixtures (SRAs) have been shown to provide significant reductions in concrete drying shrinkage and subsequent cracking. The potential benefits that SRAs provide have resulted in increased use of these products in the past few years. In this paper, data from laboratory testing and field investigations of SRA-treated concrete mixtures and their use in a few projects where watertightness was desired are presented and discussed. The findings of visual inspections of the projects performed shortly after construction and after a year in service will also be presented. The information to be presented verify the drying shrinkage reduction characteristics of SRAs and show that these innovative admixtures can provide substantial benefits with regards to improving watertightness and overall serviceability of reinforced concrete structures.","PeriodicalId":130124,"journal":{"name":"SP-204: Design and Construction Practices to Mitigate Cracking","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124316827","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 reconnaissance visit was conducted to Turkey shortly after the August 17, 1999 Earthquake to investigate the performance of concrete structures. The dominant form of construction in the area was reinforced concrete frames, infilled with masonry walls. Extensive cracking and damage was observed in most structures located in the disaster area. This paper presents an overview of the types of cracking that can be expected after a seismic activity, as well as those observed after the August 17, 1999 Earthquake in Turkey. Causes of seismic damage are discussed with examples. A brief review of the seismological aspects of the earthquake and the overall performance of reinforced concrete buildings are provided.
{"title":"\"Cracking in Concrete Structures During the August 17,1999 Earthquake in Turkey\"","authors":"M. Saatcioglu","doi":"10.14359/10824","DOIUrl":"https://doi.org/10.14359/10824","url":null,"abstract":"A reconnaissance visit was conducted to Turkey shortly after the August 17, 1999 Earthquake to investigate the performance of concrete structures. The dominant form of construction in the area was reinforced concrete frames, infilled with masonry walls. Extensive cracking and damage was observed in most structures located in the disaster area. This paper presents an overview of the types of cracking that can be expected after a seismic activity, as well as those observed after the August 17, 1999 Earthquake in Turkey. Causes of seismic damage are discussed with examples. A brief review of the seismological aspects of the earthquake and the overall performance of reinforced concrete buildings are provided.","PeriodicalId":130124,"journal":{"name":"SP-204: Design and Construction Practices to Mitigate Cracking","volume":"566 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114089787","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 American Concrete Institute (ACI) building code has adopted a new design method for the control of flexural cracking. This design method is intended for structures containing steel reinforcement and not requiring specialized crack control procedures. It is the objective of this paper to explore the background for this method, highlight the assumptions, and develop design tools that can be applied for special design cases. This paper presents a summary of a physical model for cracking that was the basis for the new design method, illustrates the development and limitations of the design method, and develops design tools that are applicable for the control of cracking in structures requiring increased levels of crack control and in structures incorporating alternative reinforcement materials. Examples illustrating the use of the new design method as well as tools extending its applicability are presented.
{"title":"Flexural Crack Control in Reinforced Concrete","authors":"R. Frosch","doi":"10.14359/10817","DOIUrl":"https://doi.org/10.14359/10817","url":null,"abstract":"The American Concrete Institute (ACI) building code has adopted a new design method for the control of flexural cracking. This design method is intended for structures containing steel reinforcement and not requiring specialized crack control procedures. It is the objective of this paper to explore the background for this method, highlight the assumptions, and develop design tools that can be applied for special design cases. This paper presents a summary of a physical model for cracking that was the basis for the new design method, illustrates the development and limitations of the design method, and develops design tools that are applicable for the control of cracking in structures requiring increased levels of crack control and in structures incorporating alternative reinforcement materials. Examples illustrating the use of the new design method as well as tools extending its applicability are presented.","PeriodicalId":130124,"journal":{"name":"SP-204: Design and Construction Practices to Mitigate Cracking","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131478031","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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