SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete最新文献

Investigation of Physico-Chemical Aspects of Air Entrainment in Cementitious Systems 胶凝系统中夹带空气的物理化学方面的研究

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12940

C. Jolicoeur, Thi To, T. Nguyen, R. Hill, M. Pagé

{"title":"Investigation of Physico-Chemical Aspects of Air Entrainment in Cementitious Systems","authors":"C. Jolicoeur, Thi To, T. Nguyen, R. Hill, M. Pagé","doi":"10.14359/12940","DOIUrl":"https://doi.org/10.14359/12940","url":null,"abstract":"A method for measuring air entrainment in cement pastes was developed and validated against mortars and concrete air entraining protocols with commercially available air-entraining admixtures (AEA). The paste method was found to adequately reflect variations in air content as a function of AEA dosage observed in mortars and concrete; it thus provides a useful means for extensive studies of the relative performance of AEA's, or of the air entrainment mechanism using a series of reference surfactants. The paste method was employed to investigate air entrainment by several homologous surfactants in the series: n-alkylcarboxylates (n-RCOO-); n-alkysulfonates (n-RSO3-); and n-alkylsulfates (n-RSO4-). Sodium salts of the latter, with hydrocarbon chain lengths between C7 and C12 were used to investigate the influence of anionic head group and hydrocarbon chain length on the performance of these surfactants as AEA. Parallel measurements were also performed on the solubility of these surfactants in various systems, namely lime solutions, dilute cement slurries, cement pastes and solution pre-extracted from cement slurries. The study included three different cements. The combined results provide a basis for understanding the mode of action of surfactants in terms of a balance between the inherent surface activity (ability to reduce the surface tension of water) and the solubility of the surfactant homologs in alkaline solutions containing Ca ions.","PeriodicalId":387601,"journal":{"name":"SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete","volume":"130 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124957989","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

Performance and Compatibility of Permeability Reducing and Other Chemical Admixtures in Australian Concretes 澳大利亚混凝土中减渗剂和其他化学外加剂的性能和相容性

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12925

R. Munn, G. Kao, Z. Chang

引用次数: 16

Empirical and Fundamental Methods for Measuring Rheological Properties of Cement-Based Materials 水泥基材料流变性能测量的经验和基本方法

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12919

B. G. Petersen, K. Reknes

引用次数: 0

Performance of a Multifunctional and Multipurpose Superplasticizer for Concrete 一种多功能多用途混凝土减水剂的性能研究

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12923

H. Nakanishi, S. Tamaki, M. Yaguchi, K. Yamada, M. Kinoshita, M. Ishimori, S. Okazawa

{"title":"Performance of a Multifunctional and Multipurpose Superplasticizer for Concrete","authors":"H. Nakanishi, S. Tamaki, M. Yaguchi, K. Yamada, M. Kinoshita, M. Ishimori, S. Okazawa","doi":"10.14359/12923","DOIUrl":"https://doi.org/10.14359/12923","url":null,"abstract":"Recently, due to demands for higher strength and retention of flowability in concrete, polycarboxylate-based superplasticizers (PC) have attracted much attention.Polycarboxylate-based superplasticizers above all, have been recognized to show superior water reducing ability and ability to retain workable consistence. PC has also been an indispensable material for various kinds of high performance concrete, especially for making extremely low water-cement ratios (W/C) possible. Because of a shortage of quality aggregate in Japan and a need to adhere to the maximum water content regulation for concrete durability in which the upper value is limited and the use of PC for water reduction has been increasing. The significance of cracks on durability of concrete has been pointed out in many studies. In order to reduce the effect of cracks, it is important to reduce the autogenous and drying shrinkage. To answer these concerns, a new multi-function and multi-purpose PC has been invented, PC incorporating both shrinkage and water reducing effects in wide range of W/C; the performance of which is described in this study. The new PC can be applied to numerous scenarios ranging from high W/C to very low W/C requirements. This multipurpose makes it's a candidate for a new generation of superplasticizers.","PeriodicalId":387601,"journal":{"name":"SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115898405","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: 10

The Electrostatic Potential of Highly Filled Cement Suspensions Containing Various Superplasticizers 含各种高效减水剂的高填充水泥悬浮液的静电势

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12907

O. Blask, D. Honert

{"title":"The Electrostatic Potential of Highly Filled Cement Suspensions Containing Various Superplasticizers","authors":"O. Blask, D. Honert","doi":"10.14359/12907","DOIUrl":"https://doi.org/10.14359/12907","url":null,"abstract":"One of the most challenging tasks in cement chemistry is to understand exactly how superplasticizers work and why they occasionally fail. The higher fluidity of superplasticized concrete is considered to be caused by an increased dispersive force. This dispersive force can be increased in two ways, either by electrostatic repulsion or by steric repulsion. The way in which dispersive forces are increased depends on the kind of superplasictizer used. It is commonly know that sulfonate-based admixtures increase electrostatic repulsion while polycarboxylate-based admixtures increase steric repulsion. This paper analyzes the influence of various superplasticizers, mixing energy and adding time of superplasticizers on the electrostatic potential of different cement pastes. The electrostatic potential has been observed by measuring the zeta-potential of cement pastes using the electro kinetic sonic amplitude method (ESA). Additionally, suspensions of cement and silica have been used to study the dispersing mechanisms of different superplasticizers. The results lead to a better understanding of the way sulfonate polycarboxylate-based admixtures work.","PeriodicalId":387601,"journal":{"name":"SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113959948","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: 9

Performance of an Advanced Polycarboxylate-Based Powder Superplasticizer 一种新型聚羧酸基粉状高效减水剂的性能研究

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12927

K. Tsukada, M. Ishimori, M. Kinoshita

引用次数: 4

Studies of Cement-Admixture Interactions Related to Aluminate Hydration Control by Isothermal Calorimetry 用等温热法研究水泥-外加剂相互作用对铝酸盐水化控制的影响

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12936

P. Sandberg, L. Roberts

引用次数: 20

The Influence of Mineral Additions on the Rheology of Self-Compacting Concrete 矿物掺量对自密实混凝土流变学的影响

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12916

Corinaldesi, G. Moriconi

{"title":"The Influence of Mineral Additions on the Rheology of Self-Compacting Concrete","authors":"Corinaldesi, G. Moriconi","doi":"10.14359/12916","DOIUrl":"https://doi.org/10.14359/12916","url":null,"abstract":"The development of concrete, which need not be vibrated, and which consolidates under its own weight, is a challenge to the building industry. In order to achieve this behavior, fresh concrete must show high fluidity and good cohesiveness. For the propose of evaluating these properties, comes concretes were prepared with a water to cement ratio of 0.45 by alternatively adding two different kinds of acrylic-based superplasticizer to the mixture at a dosage of about 1% by weight of cement. Either fly ash or limestone powder or rubble powder (that is a powder obtained from the recycling process of rubble from building demolition) were used as mineral admixture, in order to ensure adequate rheological properties to the self-compacting concretes in the absence of viscosity modifying agents. Preliminary rheological tests were carried out of pastes in which cement was partially replaced by these fine materials. The fresh concrete properties were evaluated through both the slump flow and the L-box tests. The segregation resistance was also determined. Compressive strength was also measured on hardened concretes after 1, 3, 7 and 28 days of wet curing.","PeriodicalId":387601,"journal":{"name":"SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete","volume":"255 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132895690","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

Effects of Increasing Dosages of an Alkali-Free Accelerator on the Physical and Chemical Properties of a Hydrating Cement Paste 增加无碱促进剂用量对水化水泥浆体理化性能的影响

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12915

A. Bravo, T. Cerulli, C. Maltese, C. Pistolesi, D. Salvioni

引用次数: 6

Development of Concrete with High Early-Stage Strength 高早期强度混凝土的研制

SP-217: Seventh CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete Pub Date : 2003-09-01 DOI: 10.14359/12918

J. Ambroise, J. Pera

引用次数: 0