SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures最新文献_第3页

Prehydrated High-Alumina Cement- Based Admixture For Compensating Autogenous Shrinkage in High-Performance Concrete 补偿高性能混凝土自收缩的预水合高铝水泥基掺合料

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5548

W. L. Repette, N. Mailvaganam

{"title":"Prehydrated High-Alumina Cement- Based Admixture For Compensating Autogenous Shrinkage in High-Performance Concrete","authors":"W. L. Repette, N. Mailvaganam","doi":"10.14359/5548","DOIUrl":"https://doi.org/10.14359/5548","url":null,"abstract":"One of the limitations of high-performance concrete is its susceptibility to autogenous shrinkage, which can considerably compromise its durability and mechanical strength despite diligent cure during the hardening stage. Although calcium-sulfoaluminate admixture (CSA) and shrinkage-reducing admixture (SRA) can play a role in reducing autogenous shrinkage, rapid set and low effectiveness have been associated with their use in concrete with low water content. Recently, an innovative type of CSA admixture based on pre-hydrated high alumina cement (H-HAC) has been developed, but its potential in reducing autogenous shrinkage has not yet been evaluated. In this paper, the effects of H-HAC expansive admixture in decreasing the shrinkage during the early hardening and hardening stages are described. It was hoped that the expansion generated from hydration of the expansive components would offset the volume reduction due to autogenous shrinkage. The influences of particle size distribution, dosage and type of H-HAC hydrates in determining expansion are evaluated and discussed. Microstructural and chemical aspects are studied through XRD and SEM techniques. Tests on the evaluation of the H-HAC admixture to offset autogenous shrinkage are described and preliminary results are presented. The results show that in specific dosage and particle size distribution, H-HAC is a suitable admixture for compensating shrinkage, although autogenous shrinkage in high-performance concrete has not been prevented by the use of this admixture","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120949219","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}

引用次数: 2

Concrete Sulphate Attack in a Sulfate-Free Environment 无硫酸盐环境下混凝土硫酸盐侵蚀

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5546

M. Collepardi

{"title":"Concrete Sulphate Attack in a Sulfate-Free Environment","authors":"M. Collepardi","doi":"10.14359/5546","DOIUrl":"https://doi.org/10.14359/5546","url":null,"abstract":"This paper provides an example of the application of the holistic model to the study of one of the most complex phenomenon in the science of concrete durability, namely the deterioration caused by delayed ettringite formation (DEF) in a sulfate-free environment. By adopting the holistic approach, a new model to explain this damage is proposed. The model is based on three essential elements: late-sulfate release, microcracking, and exposure to water. Late-sulfate release, from a cement with high-sulfate content (especially that with high content of clinker sulfate in less available form) can cause the delayed deposition of ettringite in pre-existing microcracks after sulfate ions diffuse through the pore solution in concrete, either intermittently, or continuously exposed to environmental water. Microcracking may be promoted by alkali-silica reaction, steam curing at high temperatures, localized high stress in prestressed concrete structures or other causes. Theoretically, the DEF-induced damage occurrence can be reduced or prevented by controlling at least one of the above three parameters. In practice, the best way of reducing the DEF-induced damage risk is either to avoid cements with high clinker sulfate that are responsible for the late-sulfate release, or to adopt lower and more homogeneous stress distribution derived from the prestressing process in precast elements, such as concrete ties.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122528750","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}

引用次数: 4

Development of Research and Application of High-Performance Concrete in Bridge Engineering in Poland 波兰高性能混凝土在桥梁工程中的研究与应用进展

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5576

W. Radomski

{"title":"Development of Research and Application of High-Performance Concrete in Bridge Engineering in Poland","authors":"W. Radomski","doi":"10.14359/5576","DOIUrl":"https://doi.org/10.14359/5576","url":null,"abstract":"The needs concerning improvement in durability of existing and new bridges in Poland are briefly presented. The requirements to ensure a high durability of new bridge structures constructed on a new network of motorways are especially emphasized. Material possibilities to produce high-performance concrete in Poland are presented. Application of high-performance concrete to construct bridge structures with the use of modern erection methods (e.g. incremental launching, cast-in-place cantilever balance) is analyzed and exemplified in the light of technical and economical aspects. Special attention is given to the development of the research on high-performance concrete in Poland. Some chosen problems are presented in particular, namely: testing and technological problems, hydration and thermal effects and their influence on material properties, bond strength, strength tests of structural members subjected to different type of loading. Design problems concerning structural applications of high-performance concrete are also listed and discussed, focusing on bridge structures. A lack of the relevant requirements in existing design standards or codes is emphasized and a consequence of it for engineering practices is discussed. Concluding remarks summarizing research of high-performance concrete in Poland and its up-to-date and future potential structural applications are formulated.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"274 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116069294","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}

引用次数: 0

Applications of High-Performance Concrete for Ultra -Thin Pavement Overlays (White-Topping) 高性能混凝土在超薄路面覆盖层(白顶)中的应用

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5588

J. Balbo

{"title":"Applications of High-Performance Concrete for Ultra -Thin Pavement Overlays (White-Topping)","authors":"J. Balbo","doi":"10.14359/5588","DOIUrl":"https://doi.org/10.14359/5588","url":null,"abstract":"Employment of High Performance Concrete (HPC) for thin overlays construction for aged flexible pavements has become a reality during the 90's, especially in the U.S.A. and some northwest European countries. While whitetopping old pavements was a technique employed from earlier decades of the twentieth century, the construction of ultra-thin concrete overlays (of 100 mm) for rehabilitation of pavements has been enhanced by the availability of technology for manufacturing HPC and the possibility of fast tracking. Ultra-thin whitetopping is a technique requiring several field conditions to be met concerning the old asphalt pavement in order to perform well as an overlay. They are full bond condition at the interface of HPC and asphalt concrete (generally provided by milling), asphalt concrete without fatigue cracking and rational joint spacing. All these factors, on the other hand, must be taken into account on the basis of the peculiar resistance of the HPC to be used. Within this context, this paper presents a study with regard to the HPC strength to be achieved for ultra-thin whitetopping purposes. It is supported by a numerical analysis based on a finite element solution for slabs-on-grade and takes into account the elastic properties for both HPC and old asphalt, as well as slab dimensions and the load critical position. An international review of HPC applied on whitetoppings around the world, that includes recent work in this field, is also presented.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132317478","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}

引用次数: 5

"Use Of Locally Available Aggregates For High-Strength, High Abrasion-Resistant Concrete in Slovenia SLOVENIA" 《在斯洛文尼亚使用本地可获得的高强度、高耐磨性混凝土集料》

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5557

M. Simon, J. Šelih

引用次数: 1

High-Strength Concrete With Limestone Filler Cements 石灰石填料水泥高强混凝土

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5578

V. Bonavetti, H. Donza, V. Rahhal, E. Irassar

{"title":"High-Strength Concrete With Limestone Filler Cements","authors":"V. Bonavetti, H. Donza, V. Rahhal, E. Irassar","doi":"10.14359/5578","DOIUrl":"https://doi.org/10.14359/5578","url":null,"abstract":"For high strength concrete, the use of superplasticizer and high cement content leads to a very low water to cement ratio. In this concrete, the cement used cannot complete its hydration due to the unavailable space to locate the reaction products. In this case, the addition of limestone filler can modify the packing of cement grains, and it increases the hydration degree of portland clinker leading to the same strength level. In Europe, a vast experience has been developed with limestone blended cements. However, the use of limestone filler is a recent practice in South American countries. In this paper, the effect of a limestone filler in the production of high strength concrete was studied using 0, 9.3, and 18.1 percent of replacement by mass of clinker. Concretes were designed to achieve 50 MPa compressive strength at 28 days (450 kg/(m cubed) of cement content and a water-to-cementitious material ratio of 0.34). The mechanical properties, including compressive strength, split tensile strength and elasticity modulus were evaluated at 1, 3, 7, 28, and 150 days. The results show that limestone filler increases concrete strength at very early ages due to enhanced clinker grains hydration. It did not affect significantly the mechanical strength of concrete containing 9.3 percent of replacement while for concretes with 18.1 percent of filler, a relative strength reduction was observed after seven days. At all ages, limestone filler replacement improves clinker efficiency but, it decreases with hydration progress.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131360107","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}

引用次数: 18

High-Strength Concrete Deep Beams With Web Openings 带腹板开口的高强度混凝土深梁

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5580

Andressa Almeida, N. Pinto

引用次数: 9

Study of Influence of Rice-Husk Fly Ash on Compressive Strength of Concrete at Different Ages 稻壳粉煤灰对不同龄期混凝土抗压强度影响的研究

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5558

G. R. Sensale, D. Molin

引用次数: 2

Concrete Mix Proportioning to Meet Durability Concerns For Confederation Bridge 满足联邦大桥耐久性要求的混凝土配合比

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5553

W. Langley

引用次数: 1

Design and Properties of High-Volume Fly Ash High- Performance Concrete 大掺量粉煤灰高性能混凝土的设计与性能研究

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5547

J. Cabrera, C. Atiş

引用次数: 18