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"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete"最新文献

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Using Natural Pozzolans to Improve the Sulfate Resistance of Cement Mortars 天然火山灰提高水泥砂浆抗硫酸盐性能的研究
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6021
R. E. Rodriguez-Camacho
{"title":"Using Natural Pozzolans to Improve the Sulfate Resistance of Cement Mortars","authors":"R. E. Rodriguez-Camacho","doi":"10.14359/6021","DOIUrl":"https://doi.org/10.14359/6021","url":null,"abstract":"Concrete in contact with a sulfate environment can severely degrade due to expansion accompanying the formation reaction products such as ettringite. The use of portland-pozzolan cement has been successful in mitigating this expansion. However, it is important to study the effectiveness of natural pozzolans to improve the resistance to attack by sulfates. This paper reports results of different portland-pozzolan cements containing different natural pozzolans and ASTM Types I, II, and V portland cements. The pozzolanic activity and composition of each pozzolan was evaluated. The susceptibility to sulfate attack was studied by measuring the expansion in mortar bars at different ages according to ASTM Method 1012 for 78 weeks. It was found that cements containing pozzolans with high activity or low alumina content improved the sulfate resistance. Also, the pozzolan content in the cement was found to be important.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"1221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133116194","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: 11
Influence of Silica Fume on Permeability of Concrete to Oxygen for Temperatures up to 500 C 温度高达500℃时硅粉对混凝土透气性的影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6018
M. S. Zadeh, G. Debicki, P. Clastres, Y. Billard
{"title":"Influence of Silica Fume on Permeability of Concrete to Oxygen for Temperatures up to 500 C","authors":"M. S. Zadeh, G. Debicki, P. Clastres, Y. Billard","doi":"10.14359/6018","DOIUrl":"https://doi.org/10.14359/6018","url":null,"abstract":"","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127649607","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: 3
Influence of Temperature on Strength Development of Fly-Ash and Silica-Fume Concretes 温度对粉煤灰和硅粉混凝土强度发展的影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5972
H. Saricimen, M. Maslehuddin, A. Eid
{"title":"Influence of Temperature on Strength Development of Fly-Ash and Silica-Fume Concretes","authors":"H. Saricimen, M. Maslehuddin, A. Eid","doi":"10.14359/5972","DOIUrl":"https://doi.org/10.14359/5972","url":null,"abstract":"The reduction in the useful service life of reinforced concrete structures in the coastal areas of the Arabian Gulf is of major concern to the construction industry. Since the concrete deterioration phenomena are strongly permeability dependent, mineral admixtures and industrial by-products, such as natural pozzolan, fly-ash, blast-furnace-slag, and silica-fume are increasingly used to improve its durability. Among the mineral admixtures and industrial by-products, fly-ash and silica-fume are considered to be more beneficial due to their superior performance in improving concrete durability. In this study, the effect of temperature and drying as well as different curing conditions on the compressive strength development in normal portland, silica-fume and fly-ash cement concretes was evaluated. The test specimens were cured in the laboratory and under field conditions, and tested 1,3,7,14,28,60 and 90 days after casting to evaluate the compressive strength development. The results indicated an increase in the compressive strength, in both the normal, fly-ash and silica-fume cement concrete specimens with the period of curing. Field curing had more negative effect on the strength development in concrete specimens containing fly-ash and silica-fume than in the plain concrete specimens. High temperature casting and curing increased the compressive strength in both plain and fly-ash concretes. Drying during curing produced the highest strength in the silica-fume concrete specimens compared to plain and fly-ash concretes.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121849309","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
Microstructural Study of Hydration Reactions of a Fly Ash-Belite Cement 粉煤灰-白石水泥水化反应的微观结构研究
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5980
S. Goñi, M. P. Luxán, A. Guerrero, M. Hernández, A. Macías
{"title":"Microstructural Study of Hydration Reactions of a Fly Ash-Belite Cement","authors":"S. Goñi, M. P. Luxán, A. Guerrero, M. Hernández, A. Macías","doi":"10.14359/5980","DOIUrl":"https://doi.org/10.14359/5980","url":null,"abstract":"The evolution of the microstructure of a hydrated fly ash-belite cement (HFABC) has been studied during a period of 90 days after mixing. The cement was synthesized from a mixture of fly ash (ASTM Class F), lime and water by a hydrothermal procedure. The microstructure characterization at different times was followed by mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and EDS, X-ray diffraction (XRD), thermogravimetry (TG) and analytical techniques. Besides, the compressive strength was determined and correlated to the microstructure characteristics. The pore solution was expressed and analyzed at different periods of the hydration reaction.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121862572","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
Utilization of Coal Ash Produced from Pressurized Fluidized Bed Combustion Power Plant as a Concrete Mineral Admixture 加压流化床燃烧电厂粉煤灰作为混凝土矿物掺合料的利用
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5997
K. Fukudome, N. Shintani, T. Saitoh, T. Kita, H. Sasaki
{"title":"Utilization of Coal Ash Produced from Pressurized Fluidized Bed Combustion Power Plant as a Concrete Mineral Admixture","authors":"K. Fukudome, N. Shintani, T. Saitoh, T. Kita, H. Sasaki","doi":"10.14359/5997","DOIUrl":"https://doi.org/10.14359/5997","url":null,"abstract":"A pressurized fluidized-bed combustion power plant (PFBC) is a coal-fired thermal power plant specially developed for the enhancement of generating efficiency and the reduction of environmental loads. The physico-chemical properties of coal ash produced from this type of power plant (PFBC ash) are different from those of ordinary fly ash, because coal is mixed with pulverized limestone and burnt at a lower temperature than that in the conventional power generation system. This study explores the feasibility of utilizing PFBC ash as a concrete mineral admixture. It has been found that the coal ash from a secondary cyclone dust collector enhances the strength of concrete although it cannot improve the fluidity. A series of tests, including those for durability and changes in length, show that the durability of concrete containing the coal ash so produced is adequate for practical applications.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122856673","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
"Effects of Fine Aggregate Replacement on the Rheology, Compressive Strength and Carbonation Properties of Fly Ash and Mortar" 细骨料置换对粉煤灰和砂浆流变学、抗压强度及碳化性能的影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5990
K. Hwang, T. Noguchi, F. Tomosawa
{"title":"\"Effects of Fine Aggregate Replacement on the Rheology, Compressive Strength and Carbonation Properties of Fly Ash and Mortar\"","authors":"K. Hwang, T. Noguchi, F. Tomosawa","doi":"10.14359/5990","DOIUrl":"https://doi.org/10.14359/5990","url":null,"abstract":"Recently, the amount of fly ash generated from electric power plants and other industries in Japan was about 6.4 million tons per year, and it is expected to increase to 12 million tons per year in 2010. Hence, there is a great need to investigate solutions on how to utilize fly ash more effectively. One of the promising solutions is to use high amounts of fly ash in concrete as replacement of the fine aggregate, instead of replacing portland cement. When replacing a part of the cement by a high amount of fly ash, changes in strength development and resistance to carbonation may cause problems in the applications of the concrete to actual building construction in respect to the structural and durability requirement. Though the replacement of a part of fine aggregate by fly ash reduces low strength development, higher rates of carbonation of the concrete may remain as a problem, as calcium hydroxide will be consumed by pozzolanic reactions with the fly ash. This study aims to clarify the effects of high level of replacement of fine aggregate by fly ash on the properties of concrete in the fresh state as well as in the hardened state, and investigate the limit of the replacement in view of the practical application of this type of concrete. Rheological properties, compressive strength and rate of carbonation of mortars of water to portland cement ratio of 0.3, 0.4 and 0.5 in which the fine aggregate was replaced with fly ash at 25 and 50% levels were evaluated experimentally. It was found that the rheological constants increased with higher replacement level of fly ash and that, when water to portland cement ratio was maintained the strength development and carbonation properties were improved.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123113541","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: 22
Chemical Development of the Fluid from Pores of Admixture-Bearing Mortars Affected by the Alkali-Aggregate Reaction 碱-骨料反应对含外加剂砂浆孔隙流体的化学发展影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6025
J. Sota, R. Iasi, R. Pérez, O. Batic
{"title":"Chemical Development of the Fluid from Pores of Admixture-Bearing Mortars Affected by the Alkali-Aggregate Reaction","authors":"J. Sota, R. Iasi, R. Pérez, O. Batic","doi":"10.14359/6025","DOIUrl":"https://doi.org/10.14359/6025","url":null,"abstract":"Hardened concrete contains interconnected pores if, during its production, the quantity of water used is higher than that required to do away with capillary continuity of the paste. These pores contain ions in solution from the chemical reactions that take place. The major ionic components involved in the reactions may vary in concrete affected by the alkali-silica reaction (ASR), in contrast with concrete with no ASR. By applying the fundamentals of the Longuet et. al. method, the composition of the liquids contained in the pores of specially proportioned mixtures has been studied. This paper presents the results of the research work carried out up to the age of 180 days in order to know the chemical composition of the liquid contained in the pores of hardened mortars, whether affected or not by the ASR, and that of others to which pozzolans had been added so as to prevent excessive expansion due to ASR.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"59 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114040573","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
The Influence of Physical Properties of Aggregate on Shrinkage in High Strength Slag Cement Concrete 骨料物理性能对高强矿渣水泥混凝土收缩性能的影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6003
H. Matsushita, H. Tsuruta, K. Nakae
{"title":"The Influence of Physical Properties of Aggregate on Shrinkage in High Strength Slag Cement Concrete","authors":"H. Matsushita, H. Tsuruta, K. Nakae","doi":"10.14359/6003","DOIUrl":"https://doi.org/10.14359/6003","url":null,"abstract":"In order to investigate the influence of aggregate on autogenous shrinkage and drying shrinkage in high-fluidity, high-strength concrete containing ground granulated blast-furnace slag (GGBFS), a study was made of the water-binder ratio (W/B), quality of coarse aggregate and replacement ratio of GGBFS (replacement ratio of slag) at different levels. In this test, W/B was 23, 28, 33 and 43%, replacement ratio of slag was 0, 50 and 75%, five types of coarse aggregates were used. The authors investigated the relationships between W/B and autogenous shrinkage or drying shrinkage, physical properties of aggregate and concrete shrinkage, and replacement ratio of slag and concrete shrinkage. Particularly in this study, the authors paid attention to aggregate crushing value of physical properties of aggregate. The aggregate crushing value was measured by method which was defined in British Standard. The following findings were obtained. (a) The smaller the W/B, the greater the percentage of autogenous shrinkage in drying shrinkage. (b) The aggregate crushing value is a critical factor in concrete shrinkage. (c) An increase in replacement ratio of slag leads to an increase in the percentage of autogenous shrinkage in drying shrinkage. (d) The practical significance of these data is that we should consider the aggregate crushing value in evaluating autogenous shrinkage of high-strength, high-fluidity concrete.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127506197","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
Potential of Blast Furnace Slags to Immobilize Toxic Wastes 高炉炉渣固定化有毒废物的潜力
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6014
A. Macías, S. Goiii, J. Madrid, J. M. Díez, E. Castillo
{"title":"Potential of Blast Furnace Slags to Immobilize Toxic Wastes","authors":"A. Macías, S. Goiii, J. Madrid, J. M. Díez, E. Castillo","doi":"10.14359/6014","DOIUrl":"https://doi.org/10.14359/6014","url":null,"abstract":"Waste disposal has become a major concern in most industrial countries because of limited sites and strict environmental standards for landfilling. The common cementing materials, widely available and used, are normal portland cement, lime and high-calcium fly ashes from coal combustion. Ground granulated blast-furnace slag is also a component in binder formulation of general interest because of its potential for metal immobilization, based on its physical and chemical properties. The present work analyzes the immobilization of toxic wastes containing cadmium, lead and chromium in portland cement matrices with 80% of blast-furnace slag in comparison with plain portland cement matrices. The results show that lower levels of toxic ions in pore solution are obtained for blast-furnace blended cements due to differences in phases formed and the reduction of species to less toxic ones that occurs at the redox potential of slags. Differences in porosity may also cause a reduction in metal leaching from slag-blended cements.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131616345","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: 3
Effects of Superplasticizers in Highly Alkaline Model Suspensions Containing Silica Fume 高效减水剂对含硅粉高碱性悬浮液的影响
"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6015
R. Flatt, Y. F. Houst, P. Bowen, H. Hofmann, J. Widmer, U. Sulser, U. Mäder, T. A. Bürge
{"title":"Effects of Superplasticizers in Highly Alkaline Model Suspensions Containing Silica Fume","authors":"R. Flatt, Y. F. Houst, P. Bowen, H. Hofmann, J. Widmer, U. Sulser, U. Mäder, T. A. Bürge","doi":"10.14359/6015","DOIUrl":"https://doi.org/10.14359/6015","url":null,"abstract":"Synopsis: The behavior of superplasticizers has been studied in highly alkaline suspensions of magnesium hydroxide and silica fume, which can be considered as good model system for cementitious systems containing silica fume. Rheology showed that as superplasticizer dosage is increased, suspensions pass from behaving as Bingham fluids to Newtonian fluids. Beyond a critical concentration large dispersed particles sediment due to the absence of yield stress. The critical concentrations required to obtain Newtonian fluids has allowed to elucidate the dependence between adsorption and dispersion. Indeed, dispersion appears to be only linked to adsorbed polymers and can therefore be attributed either to electrostatic or steric repulsion mechanisms. On the other hand, superplasticizer requirement increases with silica fume fraction in particular with the less ionic polymer. This indicates important electrostatic interactions with the surface in the process of adsorption.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131040412","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: 15
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