ACI 225R-1999 Guide to the Selection and Use of Hydraulic Cements《水硬性水泥的选择和使用指南》.pdf

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1、ACI 225R-99 became effective September 7, 1999.Copyright 1999, American Concrete Institute.All rights reserved including rights of reproduction and use in any form or by anymeans, including the making of copies by any photo process, or by electronic ormechanical device, printed, written, or oral, or

2、 recording for sound or visual reproduc-tion or for use in any knowledge or retrieval system or device, unless permission inwriting is obtained from the copyright proprietors.225R-1ACI Committee Reports, Guides, Standard Practices, andCommentaries are intended for guidance in planning,designing, exe

3、cuting, and inspecting construction. Thisdocument is intended for the use of individuals who arecompetent to evaluate the significance and limitations of itscontent and recommendations and who will acceptresponsibility for the application of the material it contains.The American Concrete Institute d

4、isclaims any and allresponsibility for the stated principles. The Institute shall notbe liable for any loss or damage arising therefrom.Reference to this document shall not be made in contractdocuments. If items found in this document are desired by theArchitect/Engineer to be a part of the contract

5、 documents, theyshall be restated in mandatory language for incorporation bythe Architect/Engineer.Claude Bedard Michael S. Hammer Colin L. LoboGlen E. Bollin Eugene D. Hill Kenneth MackenzieMichael M. Chehab R. Doug Hooton Bryant MatherJames R. Clifton*Kenneth G. Kazanis Walter J. McCoyChristopher

6、Crouch Paul Klieger Leo M. Meyer, Jr.Marwan A. Daye Steven H. Kosmatka James S. PierceGeorge R. Dewey Jim Kuykendall Sandor PopovicsRichard D. Gaynor Bryce P. Simons*DeceasedBecause cement is the most active component of concrete and usually hasthe greatest unit cost, its selection and proper use is

7、 important in obtainingthe balance of properties and cost desired for a particular concretemixture. Selection should take into account the properties of the availablecements and the performance required of the concrete. This report summa-rizes information about the composition and availability of co

8、mmercialhydraulic cements, and factors affecting their performance in concrete.Following a discussion of the types of cements and a brief review of cementchemistry, the influences of admixtures (both chemical and mineral) andthe environment on cement performance are discussed. The largest part ofthi

9、s report covers the influence of cement on the properties of concrete.Cement storage and delivery, and the sampling and testing of hydrauliccements for conformance to specifications, are reviewed briefly.This report will help users recognize when a readily available, general-purpose (ASTM C 150 Type

10、 I) cement will perform satisfactorily, or whenconditions require selection of a cement that meets some additionalrequirements. It will also aid cement users by providing general informa-tion on the effects of cements on the properties of concrete. Some chemicaland physical characteristics of cement

11、 affect certain properties of concretein important ways. For other properties of concrete, the amount of cementis more important than its characteristics.This report is not a treatise on cement chemistry or concrete. For thosewho need to know more, this report provides many references to the tech-ni

12、cal literature, including ACI documents.Guide to the Selection and Use of Hydraulic CementsReported by ACI Committee 225ACI 225R-99(Reapproved 2009)Keywords: admixtures; blended cements; calcium-aluminate cements;cements; cement storage; chemical analysis; concretes; hydraulic cements;mineral admixt

13、ures; physical properties; portland cements; sampling;selection; tests.CONTENTSChapter 1Introduction, p. 225R-21.1The need for a rational approach to selecting cements1.2Purpose of the reportChapter 2Cement types and availability, p. 225R-32.1Portland and blended hydraulic cements2.2Special-purpose

14、cementsChapter 3Cement chemistry, p. 225R-53.1Portland cements3.2Blended hydraulic cements3.3Shrinkage-compensating expansive cements3.4Calcium-aluminate cementsChapter 4Influence of chemical and mineral admixtures and slag on the performance of cements, p. 225R-84.1Air-entraining admixtures4.2Chemi

15、cal admixtures4.3Mineral admixtures4.4Ground granulated blast-furnace slagsGregory S. BargerChair225R-2 ACI COMMITTEE REPORTChapter 5Influence of environmental conditions on the behavior of cements, p. 11Chapter 6Influence of cement on properties of concrete, p. 116.1Thermal cracking 6.2Placeability

16、 6.3Strength 6.4Volume stability 6.5Elastic properties 6.6Creep 6.7Permeability 6.8Corrosion of embedded steel 6.9Resistance to freezing and thawing 6.10Resistance to chemical attack 6.11Resistance to high temperatures 6.12Cement-aggregate reactions 6.13Color Chapter 7Cement storage and delivery, p.

17、 21Chapter 8Sampling and testing of hydraulic cements for conformance to specifications, p. 238.1The cement mill test report8.2Sealed silos8.3Cement certification8.4Quality managementChapter 9References, p. 259.1Recommended references 9.2Cited references AppendixCalcium-aluminate cements, p. 29CHAPT

18、ER 1INTRODUCTION 1.1The need for a rational approach to selecting cements Cement paste is the binder in concrete or mortar that holdsthe fine aggregate, coarse aggregate, or other constituents to-gether in a hardened mass. The term hydraulic is associatedwith the word cement in this document to poin

19、t out to theconsumer that the basic mechanism by which the hardeningof the concrete or mortar takes place is the reaction of the ce-ment material with water. The word hydraulic also differen-tiates this type of cement from binder systems that are basedon other hardening mechanisms.The properties of

20、concrete depend on the quantities andqualities of its constituents. Because cement is the most activecomponent of concrete and usually has the greatest unit cost,its selection and proper use are important in obtaining mosteconomically the balance of properties desired for a particularconcrete mixtur

21、e. Most cements will provide adequate levelsof strength and durability for general use. Some providehigher levels of certain properties than are needed in specificapplications. For some applications, such as those requiringincreased resistance to sulfate attack, reduced heat evolution,or use with ag

22、gregates susceptible to alkali-aggregate reac-tion, special requirements should be imposed in the purchasespecifications. While failure to impose these requirementsmay have serious consequences, imposing these requirementsunnecessarily is not only uneconomical but may degrade oth-er more important p

23、erformance characteristics. For example,moderate sulfate resistance may be specified for certain plant-manufactured structural elements that require strength gain inthe production process. Because the compositional variationsthat impart sulfate resistance tend to reduce the rate ofstrength gain, som

24、e compromise must be made.The goal of the specifier is to provide specifications thatwill ensure that the proper amounts and types of cement areobtained to meet the structural and durability require-mentsno more, no less. Due to gaps in our knowledge, thisgoal is seldom, if ever, fully achieved; eco

25、nomies, however,can often be obtained with little or no decrease in perfor-mance in service, if specifications are aimed at this goal. For a long time, there have been virtually no economic pen-alties to discourage users and others from overspecifying ce-ment characteristics. For example, even thoug

26、h a fullysatisfactory ASTM C 150 Type I cement has been available,users have often chosen to specify an ASTM C 150 Type IIcement or a low-alkali cement on the basis that it could do noharm and its special characteristics might be beneficial. Theyhave not had to worry about possible shortages of supp

27、ly orincreased cost. The effects of increased attention to pollutionabatement and energy conservation, however, are changingthe availability and comparative costs of all types of cement.This brings about a need for greater understanding of factorsaffecting cement performance than was previously nece

28、ssary. It is usually satisfactory and advisable to use a general-pur-pose cement that is readily obtainable locally. General-pur-pose cements are described in ASTM C 150 as Type I or TypeII, in ASTM C 595 as Type IP or IS, and in ASTM C 1157 asType GU. When such a cement is manufactured and used inl

29、arge quantity, it is likely to be uniform and its performanceunder local conditions will be known. A decision to obtain aspecial type of cement may result in the improvement of oneaspect of performance at the expense of others. For this rea-son, a strong justification is usually needed to seek a cem

30、entother than a commonly available ASTM C 150 Type I orType II portland cement, or corresponding blended cement. 1.2Purpose of the report This report summarizes current information about thecomposition, availability, and factors affecting the perfor-mance of commercial hydraulic cements. Although th

31、eamount of information given may make it appear that select-ing cement for a specific purpose is complicated, this is onlytrue in unusual circumstances. The purpose of this report is to provide users with generalinformation on cements to help them recognize when a readilyavailable general-purpose ce

32、ment will perform satisfactorilyor when conditions may require selection of a special ce-ment. It will also aid the cement user by providing general in-formation on the effects of cements on the properties ofconcrete. Some chemical and physical characteristics of a ce-ment affect certain properties

33、of concrete in important ways.For other properties, the amount of cement is more important225R-3GUIDE TO THE SELECTION AND USE OF HYDRAULIC CEMENTSthan its characteristics. The report is not a treatise on cementchemistry or concrete; for those who need to know more,however, it provides references to

34、 the technical literature, in-cluding many ACI documents. CHAPTER 2CEMENT TYPES AND AVAILABILITY Before discussing the factors affecting cement perfor-mance, many types of inorganic cements will be mentioned.The purpose is to define the scope of this report by indicatingthose that will and will not

35、be included, as well as indicatingthe relationships among various types of cement. 2.1Portland and blended hydraulic cements Perhaps 99% of the cement used for concrete constructionin the U.S. is either a portland cement, as specified in ASTMC 150, or a blended cement, as specified in ASTM C 595 orC

36、 1157. Similar specifications are published by the Ameri-can Association of State Highway and Transportation Offi-cials (AASHTO) such as M85 for portland cements andM240 for blended cements, and by the Canadian StandardsAssociation (CSA). CAN/CSA 3A5M88 portland ce-ments are designated as Types 10,

37、20, 30, 40, or 50 and cor-respond in intended use to ASTM C 150 cement Types I, II,III, IV, or V, whereas CAN/CSAA362 covers blended hy-draulic cements.Portland cements are manufactured by a process that be-gins by combining a source of lime such as limestone, asource of silica and alumina such as c

38、lay, and a source ofiron oxide such as iron ore. The properly proportioned mix-ture of the raw materials is finely ground and then heated toapproximately 1500 C (2700 F) for the reactions that form ce-ment phases to take place. The product of the cement kiln isknown as portland-cement clinker. After

39、 cooling, the clinkeris ground with an addition of approximately 6% calcium sul-fate (gypsum) to form a portland cement. Blended hydraulic cements are usually made by grindingportland-cement clinker with calcium sulfate (gypsum) and aquantity of a suitable reactive material such as granulatedblast-f

40、urnace slag fly ash, silica fume, or raw or calcined nat-ural pozzolans. They may also be made by blending the finelyground ingredients.For specification purposes, portland and blended hydrau-lic cements are designated by type depending on their chem-ical composition and properties. The availability

41、 of a giventype of cement may vary widely among geographical re-gions. An appreciation of the relative consumption percent-ages and commonly used descriptions of portland andblended cements can be gained from the information givenin Tables 2.1 and 2.2. The use of blended cements, thoughTable 2.1Char

42、acteristics and consumption of portland cements*Type*DescriptionOptional characteristics% of totalU.S. shipments (1995)I General use 1, 5 86.6IIGeneral use; moderate heat of hydration and moderate sulfate resistance1, 4, 5 III High-early-strength 1, 2, 3, 5 3.3IV Low heat of hydration 5(Not availabl

43、ein U.S.)V High sulfate resistance 5, 6 2.1Optional characteristics1. Air entraining (A).2. Moderate sulfate resistance: C3A maximum, 8%.3. High sulfate resistance: C3A maximum, 5%.4. Moderate heat of hydration: maximum heat of 290 kJ/kg (70 cal/g) at7 days, or sum of C3S and C3A, maximum 58%.5. Low

44、 alkali: maximum of 0.60% alkalies, expressed as Na2O equivalent.6. Alternative limit of sulfate resistance is based on expansion tests ofmortar bars.*For cements specified in ASTM C 150.% of all cement types, including masonry cement.Reference: U.S. Cement Industry Fact Sheet, PCA, 1995.Table 2.2Ch

45、aracteristics of blended hydraulic cements*Type NameBlended ingredientsrangeOptional characteristics% of total U.S. cement shipments (1995)Pozzolan SlagI (PM)Pozzolan-modified portland cement0 to 15 1, 2, 3 IPPortland-pozzolan cement15 to 40 1, 2, 3, 5 PPortland-pozzolan15 to 40 1, 2, 4, 5 1.1I (SM)

46、Slag-modified portland cement 0-25 1, 2, 3 ISPortland-blast furnace slag 25-70 1, 2, 3, 5 S Slag cement 70-100 1, 5 Type Name OptionalGU General use 6HE High early strength 6MSModerate sulfate resistance6HSHigh sulfate resistance6MHModerate heat of hydration6LHLow heat of hydration6Optional characte

47、ristics1. Air-entraining (A).2. Moderate sulfate resistance (MS): must be made with Type II portland-cement clinker.3. Moderate heat of hydration (MH): maximum heat of 290 kJ/kg (70 cal/g) at7 days.4. Low heat of hydration (LH): maximum heat of 249 kJ/kg (60 cal/g) at 7 days.5. Suitablilty for use w

48、ith alkali-silica reactive aggregate: mortar bar expan-sion less than 0.02% at 14 days, 0.06% at eight weeks.6. Option R: mortar bar test for determining potential for alkali-silica reaction.*For cements specified in ASTM C 595.Concretes comparable to blended cement concretes may be made at the batc

49、h plant byadding the individual components, i.e., portland cement and either or both of a poz-zolan and slag, to the concrete mixture.These cements may be blends of pozzolans with either portland or slag-containingcements. Certain combinations with slag cement will reduce alkali-silica reactions andsulfate attack.For use in combination with portland cement in making concrete and in combinationwith hydrated lime in making masonry mortar.225R-4 ACI COMMITTEE REPORTpresently small, is growing in response to needs for use