SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures最新文献_第5页

Admixture Compatibility in Special Concretes 掺合料在特殊混凝土中的相容性

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5581

N. Mailvaganam

引用次数: 5

Reliability Updating of Deteriorating Concrete Floor Slabs 劣化混凝土楼板的可靠性更新

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5575

T. DaSilva, P. Roca

引用次数: 1

Synergic Action of Fly Ash In TernaryMixtures of High-Performance Concrete 粉煤灰在高性能混凝土三元混合料中的协同作用

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1999-05-01 DOI: 10.14359/5573

G. C. Isaia

{"title":"Synergic Action of Fly Ash In TernaryMixtures of High-Performance Concrete","authors":"G. C. Isaia","doi":"10.14359/5573","DOIUrl":"https://doi.org/10.14359/5573","url":null,"abstract":"The scope of this work is to quantify the synergic action of fly ash when mixed with other pozzolans, through the performance of microstructural and durability parameters of high-performance concrete (HPC). Eleven mixture proportions were tested with fly ash, rice husk ash and silica fume in binary and ternary mixtures, with cement substitution, in mass, from 10% to 50%. The following tests related to HPC durability were made: axial compression strength, elasticity modulus, shrinkage, total chloride content, Cl-/OH- ionic relationship, water penetration and accelerated carbonation. Some microstructural parameters were determined such as bound water, amount of C-S-H, remaining (C3S + C2S) and C-H. The results were calculated related to the unitary mass of cement, compared to each other in compressive strength equality of 70 MPa. Practically all the variables linked to the durability presented better performance in the ternary mixtures, than the arithmetic sums of the respective binary mixtures and this behavior is validated with microstructural evidence. It is suggested that the fly ash has a synergic action in ternary mixtures, probably due to the higher dispersion of the cement grains, similar of plasticizing mixture action, resulting in additional nucleation sites and larger amounts of hydration products. A synergic action model of fly ash in ternary mixtures is provided.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"34 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":"126128103","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: 8

Mechanical Behavior of Repaired Beams Under Static Loading 静力荷载作用下修复梁的力学性能

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1900-01-01 DOI: 10.14359/5549

K. Ong, W. Xu, P. Paramasivam

{"title":"Mechanical Behavior of Repaired Beams Under Static Loading","authors":"K. Ong, W. Xu, P. Paramasivam","doi":"10.14359/5549","DOIUrl":"https://doi.org/10.14359/5549","url":null,"abstract":"A total of 15 repaired and unrepaired reinforced concrete beams were tested under static loading in this study. The beams were of rectangular cross-section, 100 x 120 mm, and tested in flexure in simply supported mode on a span of 600 mm under a line load at mid-span. These include control beams, which were unrepaired, and beams repaired by shotcreting prepacked material, shotcreting mortar, casting prepacked material and casting prepacked material with steel fibres. The performance of the repaired beams statically-loaded to failure was monitored. The influence of differential shrinkage between repair material and substrate, bonding strength, casting method and the presence of steel fibres on the mechanical behaviour of repaired beams are discussed in this paper. The test results indicated that the mechanical properties of the repaired beams were significantly affected by differential shrinkage, the mechanical properties and the mix proportions of the repair materials used, and the repairing methods employed. The flexural stiffness of the repaired beams could be increased by using steel fibres, improving the bond quality between substrate and repair materials, and selecting appropriate repair method.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","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":"130726656","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

Composite Columns Steel Pipes With Square and Rectangular Sections and High-Strength Concrete Core 方、矩形截面组合柱、钢管及高强混凝土芯

SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures Pub Date : 1900-01-01 DOI: 10.14359/5566

J. Fernández, R. Agostini

{"title":"Composite Columns Steel Pipes With Square and Rectangular Sections and High-Strength Concrete Core","authors":"J. Fernández, R. Agostini","doi":"10.14359/5566","DOIUrl":"https://doi.org/10.14359/5566","url":null,"abstract":"High-strength concrete columns, usually reinforced, require high rates of confined transverse reinforcement to obtain ductile fracture. In this paper the composite columns of steel pipes with square and rectangular sections, and cores consisting of high-strength concrete, are analyzed with the objective of changing the usual confining reinforcement. The metal pipes were fabricated with steel plates with 5,0 mm and 6,9 mm thickness, on cold cutting and folded in \"U\" form, and then subsequently compounding pipes with transverse sections of 60 mm x 60 mm and 60 mm x 100mm, and 460 mm height. The wall cross-section of steel pipes was determined by section of transverse and longitudinal reinforcement used in the square and rectangular columns reinforced conventionally. In the design the differences between yield strain of steel plates and yield strain of the reinforcement concrete columns were computed. To define the yield strain of steel plates, specimens were tested and analyzed under axial tension. With the mechanical properties of the metal pipes and the mixture of the high-strength concrete core, eight models were tested - four with square transverse sections and four with rectangular transverse sections. The specimens were tested under concentric compression loading, on a rigid hydraulic press with load controlled capabilities, having a maximum compression load of 10.000 kN. It is concluded from the investigation that composite columns with square sections were efficient in the confinement of high-strength concrete core and presented global instability. However, the composite columns with rectangular sections presented localized instability near the extremities, probably due to compression of the concrete core.","PeriodicalId":299049,"journal":{"name":"SP-186: High-Performance Concrete: Performance and Quality of Concrete Structures","volume":"127 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":"116443056","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