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1、This document has been approved for usebyagen- cies of the Department of Defense andforlistingIn the DoDIndex of Specifications and Standards. ACI 211.1-91, (Reapproved 2009) Standard PracticeforSelecting Proportionsfor Normal, Heavyweight, and Mass Concrete An ACI Standard Reported by ACI Committee
2、 211 Donald E. Dixon, Chairman Edward A. Abdun-Nur“ Stanley G. Barton Leonard W.Bell Stanley J. BIas, Jr. Ramon1.Carrasquillo Peggy M. Carrasquillo Alan C. Carter Martyn T. Conrey James E. Cook Russet A. Cook“ William A. Cordon Wayne J. Costa David A. Crocker Kenneth W. Day Calvin1.Dodl Thomas A. Fo
3、x Donald A. Graham George W. Hollon William W. Hotaling, Jr. Robert S. Jenkins Paul Klieger Frank J. Lahm Stanley H. Lee Gary R.Mass“ Jack R. Prestrera, Secretary Mark A. Mearing RichardC.Meininger“ Richard W. Narva Leo P. Nicholson James E. Oliverson James S. Pierce Sandor Popovics“ Steven A. Ragan
4、 Harry C. Robinson JereH. Rose“ James A. Scherocman James M. Shilstone* George R. U. Burg,“ Chairman, Subcommittee A George B. Southworth Alfred B. Spamer Paul R. Stodola Michael A. Taylor Stanely J. Vigalitte William H. Voelker Jack W. Weber“ DeanJ. WhiteII Milton H. Willis, Jr. Francis C. Wilson R
5、obert Yuan Committee Members Voting on 1991 Revision Gary R. Masst Chairman George R. U.Burgf Chairman, Subcommittee A Edward A.Abdun-Nurt William1.Barringert Stanley G. Barton Leonard W.Bellt James E. Bennett, Jr. J. Floyd Best Ramon L Carrasquillo James E.Cookt Russell A. Cook David A. Crocker Lui
6、s H. Diaz Donald E. Dixont Calvin L Dodl Thomas A. Fox George W. Hollon Tarif M. Jaber Stephen M. Lane Stanley H. Lee Richard C. Meiningert James E. Oliverson James S. Pierce Sandor Popovics Steven A. Ragan JereH.Roset DonaldL.Schlegel James M. Shilstone, Sr. Paul R. Stodola William S. Sypher Ava Sz
7、ypula Jimmie L Thompsont Stanley J. Virgalitte Woodward1.Vogt Jack W. Weber Dean J. White,III Marshall S. Williams John R. Wilsont Describes, with examples, two methods for selecting and adjusting proportions for normal weight concrete, both withandwithout chemical admixtures, poz- zolanic,andslag m
8、aterials. Onemethodis based on an estimated weightofthe concrete per unit volume; the other is based on calculationsofthe absolute volume occupiedbythe concrete ingredients.Theprocedures take into consid- eration the requirements forplaceability,consistency, strength, and durability. Example calcula
9、tions areshown for both methods, including adjustments based on the characteristicsofthe first trial batch. Theproportioningofheavyweight concrete for such purposes as radiation shielding and bridge counterweight structures is described in an appendix. This appendix uses the absolute volume method;
10、which is generally accepted and is more convenient for heavyweight concrete. There is also an appendix that provides information on the proportioning ofmassconcrete.Theabsolute volumemethodis used becauseofits general acceptance. Keywords:absorption;admixtures;aggregates;blast-furnaceslag;cementitio
11、us materials;concretedurability; concretes; consistency;durability;exposure;fine aggregates;flyash; heavyweight aggregates; heavyweight concretes;massconcrete; mix proportioning; pozzolans; quality control; radiation shielding; silica fume; slump tests; volume;water-cementratio: water-cementitious r
12、atio: workability. ACI Committee Reports, Guides, Standard Practices. and Commentaries are intended for guidance in planning, designing, executing, and inspecting construction.Thisdocument is intendedforthe use of individuals whoarecompetenttoevaluatethe significanceand limitationsof itscontentandre
13、commendationsandwho willaccept responsibility for the application of the materialitcontains. The AmericanConcreteInstitutedisclaimsany andallresponsibilityforthe stated principles. The Instituteshallnotbeliableforanylossor ?;e=i8:tr:-eJr:mentshall notbemade in contract documents.Ifitems found in thi
14、sdocumentaredesiredbythe ArchitectlEngineertobeapartofthecontractdocuments, theyshallbe restated inmandatory languageforincorporationbythe ArchitectlEngineer. 211.1-1 CONTENTS Chapter1-Scope,p.211.1-2 Chapter2-lntroductlon,p. 211.1-2 Chapter3-Baslcrelationship, p.211.1-2 Chapter4-Effectsofchemical a
15、dmixtures, pozzolanlc, and othermaterials on concrete proportions, p. 211.1-4 MembersofSubcommitteeA whopreparedthis standard.Thecommittee acknowledges the significant contribution of William L.Barringerto theworkofthe subcommittee. tMembersofSubcommitteeA whopreparedthe 1991 revision. Thisstandards
16、upersedesACI211.1-89.Itwas revisedby theExpedited Standardizationprocedure.effective Nov. 1, 1991.Thisrevision incorporates provisions related to the use of themineraladmixture silica fumeinconcrete.Chapter4hasbeen expandedto cover in detail the effects of the use of silica fume on the proportions o
17、f concretemixtures.Editorialchanges have alsobeenmadeinChapters2through4, andChapters6through8. Copyright1991.AmericanConcreteInstitute. All rights reserved including rights ofreproductionand use in any form or by any means, includingthemaking of copies by anyphotoprocess, or by any electronic or me
18、chanical device, printed, written, ororalorrecording for sound or visual reproductionor for use in any knowledge or retrieval system or device, unless permission in writingisobtainedfrom the copyright proprietors. 211.1-2 ACI COMMITTEE REPORT Chapter 5-Background data, p. 211.1-7 Chapter 6-Procedure
19、, p. 211.1-7 Chapter 7-Sample computations, p. 211.1-13 Chapter 8-References, p. 211.1-18 Appendix 1-Metric system adaptation Appendix 2-Example problem in metric system Appendix 3-Laboratory tests Appendix 4-Heavyweight concrete mix proportioning Appendix 5-Mass concrete mix proportioning CHAPTER 1
20、 - SCOPE 1.1 This Standard Practice describes methods for selecting proportions for hydraulic cement concrete made with and without other cementitious materials and chemical admixtures. This concrete consists of normal and/or high- density aggregates (as distinguished from lightweight aggregates) wi
21、th a workability suitable for usual cast-in-place construction (as distinguished from special mixtures for concrete products manufacture). Also included is a descrip- tion of methods used for selecting proportions for mass concrete. Hydraulic cements referred to in this Standard Practice are portlan
22、d cement (ASTM C 150) and blended cement (ASTM C 595). The Standard does not include pro- portioning with condensed silica fume. 1.2 The methods provide a first approximation of pro- portions intended to be checked by trial batches in the lab- oratory or field and adjusted, as necessary, to produce
23、the desired characteristics of the concrete. 1.3 U.S. customary units are used in the main body of the text. Adaption for the metric system is provided in Appendix 1 and demonstrated in an example problem in Appendix 2. 1.4 Test methods mentioned in the text are listed in Appendix 3. CHAPTER 2 - INT
24、RODUCTION 2.1 Concrete is composed principally of aggregates, a portland or blended cement, and water, and may contain other cementitious materials and/or chemical admixtures. It will contain some amount of entrapped air and may also contain purposely entrained air obtained by use of an ad- mixture
25、or air-entraining cement. Chemical admixtures are frequently used to accelerate, retard, improve workability, reduce mixing water requirements, increase strength, or alter other properties of the concrete (see ACI 212.3R). De- pending upon the type and amount, certain cementitious materials such as
26、fly ash, (see ACI 226.3R) natural pozzolans, ground granulated blast-furnace (GGBF) slag (see ACI 226.1R),and silica fume may be used in con- junction with portland or blended cement for economy or to provide specific properties such as reduced early heat of hydration, improved late-age strength dev
27、elopment, or in- creased resistance to alkali-aggregate reaction and sulfate attack, decreased permeability, and resistance to the in- trusion of aggressive solutions (See ACI 225R and ACI 226.1R). 2.2 The selection of concrete proportions involves a balance between economy and requirements for plac
28、eability, strength, durability, density, and appearance. The required characteristics are governed by the use to which the concrete will be put and by conditions expected to be encountered at the time of placement. These characteristics should be listed in the job specifications. 2.3 The ability to
29、tailor concrete properties to job needs reflects technological developments that have taken place, for the most part, since the early 1900s. The use of water- cement ratio as a tool for estimating strength was recognized about 1918. The remarkable improvement in durability resulting from the entrain
30、ment of air was recognized in the early 1940s. These two significant developments in concrete technology have been augmented by extensive research and development in many related areas, including the use of admixtures to counteract possible deficiencies, develop special properties, or achieve econom
31、y (ACI 212.2R). It is beyond the scope of this discussion to review the theories of concrete proportioning that have provided the background and sound technical basis for the relatively simple methods of this Standard Practice. More detailed information can be obtained from the list of references in
32、 Chapter 8. 2.4 Proportions calculated by any method must always be considered subject to revision on the basis of experience with trial batches. Depending on the circumstances, the trial mixtures may be prepared in a laboratory, or, perhaps pre- ferably, as full-size field batches. The latter proce
33、dure, when feasible, avoids possible pitfalls of assuming that data from small batches mixed in a laboratory environment will predict performance under field conditions. When using maximum- size aggregates larger than 2 in., laboratory trial batches should be verified and adjusted in the field using
34、 mixes of the size and type to be used during construction. Trial batch procedures and background testing are described in Appendix 3. 2.5 Frequently,existing concrete proportions not containing chemical admixtures and/or materials other than hydraulic cement are reproportioned to include these ma-
35、terials or a different cement. The performance of the re- proportioned concrete should be verified by trial batches in the laboratory or field. CHAPTER 3 - BASIC RELATIONSHIP 3.1 Concrete proportions must be selected to provide PROPORTIONS FOR NORMAL, HEAVYWEIGHT, AND MASS CONCRETE 211.1-3 necessary
36、 placeability, density, strength, and durability for the particular application. In addition, when mass concrete is being proportioned, consideration must be given to gen- eration of heat. Well-established relationships governing these properties are discussed next. 3.2 Placeability - Placeability (
37、including satisfactory finishing properties) encompasses traits loosely accumulated in the terms “workability” and “consistency.” For the purpose of this discussion, workability is considered to be that property of concrete that determines its capacity to be placed and consolidated properly and to b
38、e finished without harmful segregation. It embodies such concepts as mold- ability, cohesiveness, and compactability. Workability is affected by: the grading, particle shape, and proportions of aggregate; the amount and qualities of cement and other cementitious materials; the presence of entrained
39、air and chemical admixtures; and the consistency of the mixture. Procedures in this Standard Practice permit these factors to be taken into account to achieve satisfactory placeability economically. 3.3 Consistency y - Loosely defined, consistency is the relative mobility of the concrete mixture. It
40、 is measured in terms of slump - the higher the slump the more mobile the mixture -and it affects the ease with which the concrete will flow during placement. It is related to but not synonymous with workability. In properly proportioned concrete, the unit water content required to produce a given s
41、lump will depend on several factors. Water requirement increases as ag- gregates become more angular and rough textured (but this disadvantage may be offset by improvements in other char- acteristics such as bond to cement paste). Required mixing water decreases as the maximum size of well-graded ag
42、gregate is increased. It also decreases with the en- trainment of air. Mixing water requirements usually are reduced significantly by certain chemical water-reducing admixtures. 3.4 Strength - Although strength is an important characteristic of concrete, other characteristics such as durability, per
43、meability, and wear resistance are often equally or more important. Strength at the age of 28 days is frequently used as a parameter for the structural design, concrete proportioning, and evaluation of concrete. These may be related to strength in a general way, but are also affected by factors not
44、significantly associated with strength. In mass concrete, mixtures are generally proportioned to provide the design strength at an age greater than 28 days. However, proportioning of mass concrete should also pro- vide for adequate early strength as may be necessary for form removal and form anchora
45、ge. 3.5 Water-cement or water-cementitious ratio w/c or w/(c + p) -For a given set of materials and conditions, con- crete strength is determined by the net quantity of water used per unit quantity of cement or total cementitious materials. The net water content excludes water absorbed by the aggreg
46、ates. Differences in strength for a given water- cement ratio w/c or water-cementitious materials ratio w/(c + p) may result from changes in: maximum size of ag- gregate; grading, surface texture, shape, strength, and stiffness of aggregate particles; differences in cement types and sources; air con
47、tent; and the use of chemical admixtures that affect the cement hydration process or develop cemen- titious properties themselves. To the extent that these effects are predictable in the general sense, they are taken into account in this Standard Practice. In view of their number and complexity, it
48、should be obvious that accurate pre- dictions of strength must be based on trial batches or experience with the materials to be used. 3.6 Durability -Concrete must be able to endure those exposures that may deprive it of its serviceability - freezing and thawing, wetting and drying, heating and cool
49、ing, chemicals, deicing agents, and the like. Resistance to some of these may be enhanced by use of special ingredients: low- alkali cement, pozzolans, GGBF slag, silica fume, or ag- gregate selected to prevent harmful expansion to the alkali-aggregate reaction that occurs in some areas when concrete is exposed in a moist environment; sulfate-resisting cement, GGBF slag, silica fume, or other pozzolans for con- crete exposed to seawater or sulfate-bearing soils; or aggregate composed of hard minerals and free of excessive soft particles where resistance to surface abrasion i
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