ACI 211 1-1991 Standard Practice for Selecting Proportions for Normal Heavyweight and Mass Concrete《标称无钢筋重混凝土比例选择标准规范》.pdf

1、This document has been approved for use by agen cies of the Department of Defense and for listing Inthe DoD Index of Specifications and Standards.ACI 211.1-91,(Reapproved 2009)Standard Practice for Selecting Proportions forNormal, Heavyweight, and Mass ConcreteAn ACI StandardReported by ACI Committe

2、e 211Donald E. Dixon,ChairmanEdward A. Abdun-Nur“Stanley G. BartonLeonard W. BellStanley J. BIas, Jr.Ramon 1. CarrasquilloPeggy M. CarrasquilloAlan C. CarterMartyn T. ConreyJames E. CookRusset A. Cook“William A. CordonWayne J. CostaDavid A. CrockerKenneth W. DayCalvin 1. DodlThomas A. FoxDonald A. G

3、rahamGeorge W. HollonWilliam W. Hotaling, Jr.Robert S. JenkinsPaul KliegerFrank J. LahmStanley H. LeeGary R. Mass“Jack R. Prestrera,SecretaryMark A. MearingRichard C. Meininger“Richard W. NarvaLeo P. NicholsonJames E. OliversonJames S. PierceSandor Popovics“Steven A. RaganHarry C. RobinsonJere H. Ro

4、se“James A. ScherocmanJames M. Shilstone*George R. U. Burg,“Chairman, Subcommittee AGeorge B. SouthworthAlfred B. SpamerPaul R. StodolaMichael A. TaylorStanely J. VigalitteWilliam H. VoelkerJack W. Weber“Dean J. White IIMilton H. Willis, Jr.Francis C. WilsonRobert YuanCommittee Members Voting on 199

5、1 RevisionGary R. MasstChairmanGeorge R. U. BurgfChairman, Subcommittee AEdward A. Abdun-NurtWilliam 1. BarringertStanley G. BartonLeonard W. BelltJames E. Bennett, Jr.J. Floyd BestRamon L CarrasquilloJames E. CooktRussell A. CookDavid A. CrockerLuis H. DiazDonald E. DixontCalvin L DodlThomas A. Fox

6、George W. HollonTarif M. JaberStephen M. LaneStanley H. LeeRichard C. MeiningertJames E. OliversonJames S. PierceSandor PopovicsSteven A. RaganJere H. RosetDonald L. SchlegelJames M. Shilstone, Sr.Paul R. StodolaWilliam S. SypherAva SzypulaJimmie L ThompsontStanley J. VirgalitteWoodward 1. VogtJack

7、W. WeberDean J. White, IIIMarshall S. WilliamsJohn R. WilsontDescribes, with examples, two methods for selecting and adjusting proportionsfor normal weight concrete, both with and without chemical admixtures, poz zolanic, and slag materials. One method is based on an estimated weight oftheconcrete p

8、er unit volume; the other is based on calculations of the absolutevolume occupied bythe concrete ingredients. Theprocedures take into consid eration the requirements for placeability, consistency, strength, and durability.Example calculations areshown for both methods, including adjustments basedon

9、the characteristics of the first trial batch.Theproportioning ofheavyweight concrete for such purposes as radiationshielding and bridge counterweight structures is described in an appendix. Thisappendix uses the absolute volume method; which is generally accepted and ismore convenient for heavyweigh

10、t concrete.There is also an appendix that provides information on the proportioningof mass concrete. The absolute volume method is used because of its generalacceptance.Keywords: absorption; admixtures; aggregates; blast-furnace slag; cementitiousmaterials; concrete durability; concretes; consistenc

11、y; durability; exposure; fineaggregates; flyash; heavyweight aggregates; heavyweight concretes; mass concrete; mixproportioning; pozzolans; quality control; radiation shielding; silica fume; slump tests;volume; water-cement ratio: water-cementitious ratio: workability.ACI Committee Reports, Guides,

12、Standard Practices. and Commentaries are intended forguidance in planning, designing, executing, and inspecting construction. This document isintended for the use of individuals who arecompetent to evaluate the significance andlimitations of its content and recommendations and who will accept respon

13、sibility forthe application of the material it contains. The American Concrete Institute disclaims anyand all responsibility for the stated principles. The Institute shall not beliable for any loss or?;e=i8:tr:-eJr:mentshall not be made in contract documents. If items found inthisdocument aredesired

14、by the ArchitectlEngineer to be a partof thecontract documents,they shall be restated in mandatory language for incorporation by the ArchitectlEngineer.211.1-1CONTENTSChapter 1-Scope, p.211.1-2Chapter 2-lntroductlon, p. 211.1-2Chapter 3-Baslc relationship, p.211.1-2Chapter 4-Effects of chemical admi

15、xtures, pozzolanlc,and other materials on concrete proportions, p. 211.1-4 Members of Subcommittee A who prepared this standard. The committeeacknowledges the significant contribution of William L. Barringer to the work of thesubcommittee.t Members of Subcommittee A who prepared the 1991 revision.Th

16、is standard supersedes ACI 211.1-89. It was revised by the ExpeditedStandardization procedure. effective Nov. 1, 1991. This revision incorporates provisionsrelated to the use of the mineral admixture silica fume in concrete. Chapter 4has beenexpanded to cover in detail the effects of the use of sili

17、ca fume on the proportions ofconcrete mixtures. Editorial changes have also been made in Chapters 2 through 4,and Chapters 6 through 8.Copyright 1991. American Concrete Institute.All rights reserved including rights of reproduction and use in any form or byany means, including the making of copies b

18、y any photo process, or by any electronicor mechanical device, printed, written, or oral or recording for sound or visualreproduction or for use in any knowledge or retrieval system or device, unlesspermission in writing is obtained from the copyright proprietors.211.1-2 ACI COMMITTEE REPORTChapter

19、5-Background data, p. 211 .1-7Chapter 6-Procedure, p. 211 .1-7Chapter 7-Sample computations , p. 211 .1-13Chapter 8-References, p. 211.1-18Appendix 1-Metric system adaptationAppendix 2-Example problem in metric systemAppendix 3-Laboratory testsAppendix 4-Heavyweig ht concrete mix proportioningAppend

20、ix 5-Mass concrete mix proportioningCHAPTER 1 - SCOPE1.1 This Standard Practice describes methods forselecting proportions for hydraulic cement concrete madewith and without other cementitious materials and chemicaladmixtures. This concrete consists of normal and/or high-density aggregates (as disti

21、nguished from lightweightaggregates) with a workability suitable for usual cast-in-placeconstruction (as distinguished from special mixtures forconcrete products manufacture). Also included is a descrip-tion of methods used for selecting proportions for massconcrete. Hydraulic cements referred to in

22、 this StandardPractice are portland cement (ASTM C 150) and blendedcement (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 adjust

23、ed, as necessary, to produce thedesired characteristics of the concrete.1.3 U.S. customary units are used in the main body ofthe text. Adaption for the metric system is provided inAppendix 1 and demonstrated in an example problem inAppendix 2.1.4 Test methods mentioned in the text are listed inAppen

24、dix 3.CHAPTER 2 - INTRODUCTION2.1 Concrete is composed principally of aggregates, aportland or blended cement, and water, and may containother cementitious materials and/or chemical admixtures. Itwill contain some amount of entrapped air and may alsocontain purposely entrained air obtained by use of

25、 an ad-mixture or air-entraining cement. Chemical admixtures arefrequently used to accelerate, retard, improve workability,reduce mixing water requirements, increase strength, or alterother properties of the concrete (see ACI 212.3R). De-pending upon the type and amount, certain cementitiousmaterial

26、s such as fly ash, (see ACI 226.3R) naturalpozzolans, 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 toprovide specific properties such as reduced early heat ofhydration, improved late-age streng

27、th development, or in-creased resistance to alkali-aggregate reaction and sulfateattack, decreased permeability, and resistance to the in-trusion of aggressive solutions (See ACI 225R and ACI226.1R).2.2 The selection of concrete proportions involves abalance between economy and requirements for plac

28、eability,strength, durability, density, and appearance. The requiredcharacteristics are governed by the use to which the concretewill be put and by conditions expected to be encountered atthe time of placement. These characteristics should be listedin the job specifications.2.3 The ability to tailor

29、 concrete properties to job needsreflects technological developments that have taken place,for the most part, since the early 1900s. The use o f water-cement ratio as a tool for estimating strength was recognizedabout 1918. The remarkable improvement in durabilityresulting from the entrainment of ai

30、r was recognized in theearly 1940s. These two significant developments in concretetechnology have been augmented by extensive research anddevelopment in many related areas, including the use ofadmixtures to counteract possible deficiencies, developspecial properties, or achieve econom y (ACI 212.2R)

31、. It isbeyond the scope of this discussion to review the theories ofconcrete proportioning that have provided the backgroundand sound technical basis for the relatively simple methodsof this Standard Practice. More detailed information can beobtained from the list of references in Chapter 8.2.4 Prop

32、ortions calculated by any method must alwaysbe considered subject to revision on the basis of experiencewith trial batches. Depending on the circumstances, the trialmixtures may be prepared in a laboratory, or, perhaps pre-ferably, as full-size field batches. The latter procedure, whenfeasible, avoi

33、ds possible pitfalls of assuming that data fromsmall batches mixed in a laboratory environment will predictperformance under field conditions. When usin g maximum-size aggregates larger than 2 in., laboratory trial batchesshould be verified and adjusted in the field using mixes ofthe size and type t

34、o be used during construction. Trial batchprocedures and background testing are described inAppendix 3.2.5 Frequently ,existing concrete proportions notcontaining chemical admixtures and/or materials other thanhydraulic cement are reproportioned to include these ma-terials or a different cement. The

35、 performance of th e re-proportioned concrete should be verified by trial batches inthe laboratory or field.CHAPTER 3 - BASIC RELATIONSHIP3.1 Concrete proportions must be selected to providePROPORTIONS FOR NORMAL , HEAVYWEIGHT, AND MASS CONCRETE211.1-3necessary placeability, density, strength, and d

36、urability forthe particular application. In addition, when mass concreteis being proportioned, consideration must be given t o gen-eration of heat. Well-established relationships governingthese properties are discussed next.3. 2 Placeability - Placeability (including satisfactoryfinishing properties

37、) encompasses traits loosely accumulatedin the terms “workability” and “consistency.” For the purposeof this discussion, workability is considered to be thatproperty of concrete that determines its capacity to beplaced and consolidated properly and to be finished withoutharmful segregation. It embod

38、ies such concepts as mold-ability, cohesiveness, and compactability. Workability isaffected by: the grading, particle shape, and proportions ofaggregate; the amount and qualities of cement and othercementitious materials; the presence of entrained air andchemical admixtures; and the consistency of t

39、he mixture.Procedures in this Standard Practice permit these factors tobe taken into account to achieve satisfactory placeabilityeconomically.3.3 Consistenc yy- Loosely defined, consistency is therelative mobility of the concrete mixture. It is measured interms of slump - the higher the slump the mo

40、re mobile themixture - and it affects the ease with which the concrete willflow during placement. It is related to but not synonymouswith workability. In properly proportioned concrete, the unitwater content required to produce a given slump will dependon several factors. Water requirement increases

41、 as ag-gregates become more angular and rough textured (but thisdisadvantage may be offset by improvements in other char-acteristics such as bond to cement paste). Required mixingwater decreases as the maximum size of well-gradedaggregate is increased. It also decreases with the en-trainment of air.

42、 Mixing water requirements usually arereduced significantly by certain chemical water-reducingadmixtures.3.4 Strength - Although strength is an importantcharacteristic of concrete, other characteristics such asdurability, permeability, and wear resistance are oftenequally or more important. Strength

43、 at the age of 28 days isfrequently used as a parameter for the structural design,concrete proportioning, and evaluation of concrete. Thesemay be related to strength in a general way, but are alsoaffected by factors not significantly associated with strength.In mass concrete, mixtures are generally

44、proportioned toprovide 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 forform removal and form anchorage.3.5 Water-cement or water-cementitious ratio w/c or w/(c+ p) -For a given set of m

45、aterials and conditions, con-crete strength is determined by the net quantity of waterused per unit quantity of cement or total cementitiousmaterials. The net water content excludes water absorbed bythe aggregates. Differences in strength for a give n water-cement ratio w/ c or water-cementitious ma

46、terials rati o w/(c+ p) may result from changes in: maximum size of ag-gregate; grading, surface texture, shape, strength, andstiffness of aggregate particles; differences in cement typesand sources; air content; and the use of chemical admixturesthat affect the cement hydration process or develop c

47、emen-titious properties themselves. To the extent that thes e effectsare predictable in the general sense, they are taken intoaccount in this Standard Practice. In view of their numberand complexity, it should be obvious that accurate pre-dictions of strength must be based on trial batches orexperie

48、nce with the materials to be used.3.6 Durability - Concrete must be able to endure thoseexposures that may deprive it of its serviceability - freezingand thawing, wetting and drying, heating and cooling,chemicals, deicing agents, and the like. Resistance to someof these may be enhanced by use of spe

49、cial ingredients : low-alkali cement, pozzolans, GGBF slag, silica fume, or ag-gregate selected to prevent harmful expansion to thealkali-aggregate reaction that occurs in some areas whenconcrete is exposed in a moist environment; sulfate-resistingcement, GGBF slag, silica fume, or other pozzolans for con-crete exposed to seawater or sulfate-bearing soils; oraggregate composed of hard minerals and free of excessivesoft particles where resistance to surface abrasion isrequired Use of low water-cement or cementitious materialsratio w/c or w/(c + p) will prolong the life of c