1、ACI 302.2R-06 became effective August 15, 2006.Copyright 2006, 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 reproductionor for use in any knowledge or retrieval system or device, unless permission in writingis obtained from the copyright proprietors.302.2R-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.Guide for Concrete Slabs that ReceiveMoisture-Sensitive Flooring MaterialsReported by ACI Committee 302ACI 302.2R-06This guide contains materials, design, and construction recommendationsfor concrete s
6、labs-on-ground and suspended slabs that are to receive mois-ture-sensitive flooring materials. These flooring materials include sheetrubber, epoxy coatings, vinyl composition tile, sheet vinyl, carpet, athleticflooring, laminates, and hardwood. Chapters 1 through 8 provide anunderstanding of concret
7、e moisture behavior and drying, and show howrecommended construction practices can contribute to successful perfor-mance of floor covering materials. This background provides a basis forthe recommendations in Chapter 9 to improve performance of floorcovering materials in contact with concrete moistu
8、re and alkalinity.Because this guide is specific to floor moisture problems and solutions,refer to the most current editions of both ACI 302.1R, “Guide for ConcreteFloor and Slab Construction,” and ACI 360R, “Design of Slabs-on-Ground,” for general information. These two documents contain guidanceon
9、 floor design and construction that is needed to achieve successful floorcovering performance.Keywords: admixtures; cracking; curing; curling; drying; mixture propor-tioning; moisture movement; moisture test; relative humidity; slab-on-ground; specifications; vapor retarder/barrier.CONTENTSChapter 1
10、Introduction and background,p. 302.2R-21.1Introduction1.2Flooring moisture issues1.3Concrete slabs that receive flooring materials1.4Changes in construction methods and materials thataffect floor systems1.5Floor flatness changes with time1.6Other considerationsChapter 2Concrete moisture basics, p. 3
11、02.2R-52.1Introduction2.2Moisture movement2.3Concrete drying profiles2.4Effects of moisture movement2.5Equilibrium moisture content2.6Drying and wetting of concrete2.7Moisture loss during dryingChapter 3Concrete moisture testing, p. 302.2R-123.1Introduction3.2Standard guides and test methods3.3Quali
12、tative and quantitative tests3.4Test parameters3.5Underlayment testing3.6Comments on moisture vapor emission rate testsRobert B. Anderson C. Rick Felder Kevin A. MacDonald William S. PhelanCharles M. Ault Edward B. Finkel Arthur W. McKinney Dennis PhillipsKenneth L. Beaudoin Jerome H. Ford Steven M.
13、 Metzger John W. Rohrer*Peter A. CraigBarry E. Foreman John P. Munday*Phillip A. SmithDouglas W. Deno Terry Fricks Joseph Neuber Bruce A. SuprenantAlphonse E. Engleman*Robert J. Gulyas Russell E. Neudeck Scott M. Tarr*Robert A. Epifano Jerry A. Holland*Scott E. Niemitalo Gregory R. TaylorAllen Face
14、John J. Lewis Mark E. Patton Eldon G. Tipping*Member, Moisture Task Group.Secretary, Moisture Task Group.Chair, Moisture Task Group, and principal author.Patrick J. Harrison*ChairDennis AhalSecretary302.2R-2 ACI COMMITTEE REPORTChapter 4Concrete pH testing, p. 302.2R-194.1Introduction4.2Test methods
15、4.3ASTM test differences4.4Factors affecting pH test resultsChapter 5Floor covering and adhesive manufacturers recommendations, p. 302.2R-215.1Introduction5.2Manufacturers recommendations5.3Dealing with multiple floor covering requirementsChapter 6Drying of concrete, p. 302.2R-236.1Introduction6.2Co
16、ncrete drying with no external source of moisture6.3Concrete drying: exposed to moisture from below6.4Concrete drying: exposed to moisture from above6.5Concrete drying from both sides6.6Effect of concrete-making materials6.7Effect of fresh and hardened concrete properties6.8Effect of thickness6.9Eff
17、ect of curing6.10Drying of mature concrete6.11Effect of drying environment6.12Drying at exposed edge6.13Drying of lightweight concreteChapter 7Vapor retarder/barrier, p. 302.2R-287.1Introduction7.2Vapor retarder/barrier location7.3Vapor transmission through retarder/barrierChapter 8Floor covering ma
18、terials, p. 302.2R-328.1Introduction8.2Communication between architect and engineer8.3Floor covering technical resources8.4Floor adhesives and coverings8.5Effect of moisture in flooring adhesives8.6Effect of concrete moisture on adhesive performanceChapter 9Design and construction recommendations, p
19、. 302.2R-359.1Introduction9.2Testing9.3Vapor retarder/barrier9.4Concrete materials9.5Concrete properties9.6Surface finish9.7Curing9.8Surface preparation9.9Repairs9.10Protection9.11Moisture mitigationChapter 10References, p. 302.2R-3910.1Referenced standards and reports10.2Cited referencesAppendixTwo
20、 case studies of moisture-related flooring problems, p. 302.2R-41A.1Value engineering results in flooring failureA.2Postconstruction trench drains results in flooringfailureCHAPTER 1INTRODUCTION AND BACKGROUND1.1IntroductionDelamination, blistering, staining, mold growth, and otherproblems related t
21、o the installation and performance ofmoisture-sensitive flooring materials on concrete slabs arecommon. The problems include claims for total failure of theflooring system, construction-schedule delays caused by slowconcrete drying, and lawsuits involving indoor air quality. It iscurrently up to arc
22、hitects, engineers, floor covering installers,flooring and adhesive manufacturers, concrete contractors,and concrete producers to solve these problems.The objective of this document is to reduce the potentialfor moisture-related problems in both slabs-on-ground andsuspended slabs. It provides basic
23、information on the concretedrying process, moisture behavior in concrete, testing for pHand moisture, and vapor retarders/barriers. Based on thisinformation, recommendations for the design and constructionof concrete slabs that will receive moisture-sensitive or pH-sensitive flooring materials or co
24、atings are presented.1.2Flooring moisture issuesFigures 1.1 to 1.4 show typical problems that can occur inconcrete slabs covered with flooring materials. Theseproblems include debonding, adhesive bleed, blistering,mold growth, and adhesive degradation.1.3Concrete slabs that receive flooring material
25、sThis document focuses on the behavior of moisture inconcrete slabs, and the effect of the concrete moisture conditionon the performance of applied flooring materials. Reachinga desired moisture state, however, should not be the onlyacceptance criterion for a concrete slab that will be coated orcove
26、red. Floor flatness, surface texture, cracking, curling,structural capacity, jointing requirements, and the potentialfor the slab to stay acceptably dry should also be considered.The goal is installation of a flooring systemsubgrade,subbase, vapor retarder/barrier, concrete slab (and possiblyreinfor
27、cement), coating or flooring adhesive, and floorcoveringthat satisfies performance requirements.ACI 360R and 302.1R provide recommendations fordesigning and building concrete slab-on-ground substratesthat are suitable for receiving flooring materials. This docu-ment supplements information contained
28、 in the ACI 360Rand 302.1R guides and also applies to suspended slabs.When designing and building suspended slabs, this guideshould be used in conjunction with ACI 318 and 302.1R.1.4Changes in construction methods and materials that affect floor systemsIn the last 10 to 15 years, there has been an i
29、ncrease in thenumber of reported flooring problemsfor example, blisters,debonding, staining, and mold growthcaused by moistureoriginating within or moving through concrete slabs. SomeCONCRETE SLABS THAT RECEIVE MOISTURE-SENSITIVE FLOORING MATERIALS 302.2R-3problems may be related to fast-track const
30、ruction methodsthat allow less time for concrete drying. Other problems mayresult from changes in the composition of floor coveringadhesives related to restrictions on the use of volatile organiccompounds (VOCs).1.5Floor flatness changes with timeConcrete shrinks when it loses moisture, and expandsw
31、hen it gains moisture. When the top of a slab loses moremoisture than the bottom, the differential shrinkage causesedges and corners of the slab to deflect upward. This is calledcurling or warping. Because of this, concrete slabs that arebuilt flat do not always stay flat.The foreword of ACI 302.1R
32、states that it is normal toexpect some amount of curling on every project. Control ofcurling will be a design challenge if floor specifications arewritten to meet both CSI Division 3 and Division 9 flatnesscriteria (Construction Specifications Institute 2000; Craig2004; Holland and Walker 1998; Supr
33、enant 2002b,c). Asshown in the examples by Suprenant (2003d), curling orwarping can cause floor flatness and levelness, as measuredby F-numbers, to decrease by 20 to 50% in a year.Time-dependent changes in floor profiles occur on everyproject, but the magnitude of the profile change can vary.ACI 117
34、-90 states: “Since neither deflection nor curling willsignificantly change a floors FFvalue, there is no time limiton the measurement of this characteristic.” Flatnessmeasurements on given floors at different ages, however,indicate that this statement is not true. Therefore, the designteam should co
35、nsider how changes in floor profiles with timemight affect:The floor covering installers ability to meet Division 9specification requirements; andLong-term floor performance after the floor coveringhas been installed.Figure 1.5 shows schematically how flatness of an unre-inforced floor can vary over
36、 time. The FF50 required by aDivision 3 specificationand produced by the contractordecreases after 12 months. Because of curling, unreinforcedjointed floors exhibit a similar flatness loss with time. Thiscreates the gap between Division 3 and 9 requirements.Design professionals can use one of severa
37、l approaches toprovide a floor that meets the flatness needs of the floorcovering installer.Figures 1.6 (a) through (c) show three possible approaches:Produce a higher initial FF. The engineer estimatesthe decrease in floor flatness with time, then specifiesan initial FFthat later drops to the value
38、 needed by thefloor covering installer. Making the estimate is difficultFig. 1.1Debonded sheet flooring due to moisture in theconcrete slab. (Courtesy of Peter Craig and Herman Protze III.)Fig. 1.2Blisters due to moisture in concrete. (Courtesy ofPeter Craig.)Fig. 1.3Mold growth in carpet due to moi
39、sture in concrete.(Courtesy of Floor Seal Technology, Inc.)Fig. 1.4Adhesive degradation leading to debondedsolid vinyl tile installed over asbestos tile. (Courtesy ofPeter Craig.)302.2R-4 ACI COMMITTEE REPORTbecause the amount of curling varies with the concreteproperties and service environment. In
40、 addition, a floorwith a high initial FFexperiences a greater percentageflatness loss for a given curling deflection;Use reinforcing steel. The engineer selects a ratio ofreinforcement area to gross concrete areatypicallyapproximately 0.5% for Grade 60 steelthat minimizescurling. Refer to ACI 360R f
41、or more information; orCorrect flatness problems by grinding and patching.The engineer designs a floor that is expected to curl, butrequires the contractor or floor covering installer toinclude an allowance in the bid for repairing the curl(Suprenant and Malisch 1999b). Section 5.2.9 discussesvariou
42、s repair options.1.6Other considerationsWide random cracks in slabs create problems when floormaterials are placed over them. Floor covering manufacturersall require some form of crack repair for wide cracks. Tominimize crack width and crack repair, steel reinforcementshould be considered for use in
43、 the slab (Fig. 1.7), as recom-mended by Holland and Walker (1998). Other methods forreducing the potential for excessive cracking include properconcrete mixture proportioning and joint spacing or othertypes of reinforcement such as post-tensioning.Contraction, construction, and column blockout join
44、ts arealmost always visible under thin flooring materials. Becauseof this problem, Holland and Walker (1998) recommendusing reinforcing bars to minimize crack widths, and elimi-nating contraction joints and the traditional diamond-shapedisolation joints at columns when floors will receive acovering.
45、 Instead of using diamond-shaped isolation joints,steel columns in a floor system should be wrapped for thefull floor depth with 1/4 to 3/8 in. (6.4 to 9.5 mm) thickcompressible isolation joint material (Fig. 1.8). Refer to ACI360R for more information.Carpeting and some other floor coverings can to
46、leratelarger crack widths in the concrete floor without noticeableprojection of the crack through the surface opening. Whenthese coverings are used, crack-control measures at columnsmay not be needed. The column-slab interfaces shouldsimply be wrapped to isolate them from the slab. Refer toACI 360R
47、for more detailed information on the design ofslabs-on-ground.Fig. 1.5When flatness of an unreinforced floor is measuredinitially, F-numbers may indicate a very flat floor. Whenflooring installers start their work, however, flatness mayhave changed, as indicated by the gap between Division 3 andDivi
48、sion 9 flatness (Suprenant 2003d).Fig. 1.6Approaches to providing a floor that meets theneeds of the floor covering installer: (a) produce a higherinitial FF; (b) use reinforcing steel to reduce curling; and(c) correct flatness problems by grinding and patching(Suprenant 2003d).CONCRETE SLABS THAT R
49、ECEIVE MOISTURE-SENSITIVE FLOORING MATERIALS 302.2R-5CHAPTER 2CONCRETE MOISTURE BASICS2.1IntroductionHardened concrete slabs contain water in either a liquid orvapor form. The amount and distribution of this water is ofprimary concern with regard to the installation and perfor-mance of floors and flooring materials. The amount of waterin fresh concrete is determined by the concrete mixtureproportions, the concrete batch weights, and any water addedafter batching. Initially, the distributi
