ACI 207 3R-1994 Practices for Evaluation of Concrete in Existing Massive Structures for Service Conditions《现有作业环境用块状结构的评估规范》.pdf

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1、ACI 207.3R-94 supersedes ACI 207.3R-79 (Revised 1985) and became effectiveJuly 1, 1994.Copyright 1994, 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 ormechanic

2、al device, printed, written, or oral, or 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.207.3R-1ACI Committee Reports, Guides, Standard Practices, andCommentaries are intended

3、 for guidance in planning,designing, executing, 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 co

4、ntains.The American Concrete Institute disclaims 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 theArchite

5、ct/Engineer to be a part of the contract documents, theyshall be restated in mandatory language for incorporation bythe Architect/Engineer.Practices for Evaluation of Concrete inExisting Massive Structures for Service ConditionsReported by ACI Committee 207ACI 207.3R-94(Reapproved 2008)Current metho

6、ds available for evaluating physical properties of concrete inexisting structures to determine its capability of performing satisfactorilyunder service conditions are identified and discussed. Although generalknowledge of the structural design criteria used for the principal structuresof a project i

7、s essential to determine satisfactory procedures and locationsfor evaluation of the concrete physical properties, analysis for the purposeof determining structural capability is not within the scope of this report.The report recommends project design, operation, and maintenancerecords and in-service

8、 inspection data to be reviewed. Existing methods ofmaking condition surveys and nondestructive tests are reviewed; destructivephenomena are identified; methods for evaluation of tests and survey dataare presented; and finally, preparation of the final report is discussed.Keywords: alkali-aggregate

9、reaction; alkali-carbonate reaction; cavitation;cements; chemical analysis; concrete cores; concrete dams; concretedurability; cracking (fracturing); elastic properties; erosion; evaluation;extensometers; impact tests; inspection; laboratories; maintenance; massconcrete; nondestructive tests; nuclea

10、r power plants; post-tensioning;pozzolans; resurfacing; sampling; seepage; serviceability; spalling; statictests; stresses; surveys; x-ray diffraction.CONTENTSChapter 1Introduction, p. 207.3R-21.1Scope1.2Objective1.3ReportChapter 2Pre-inspection and in-service inspection, p. 207.3R-22.1Preconstructi

11、on evaluation2.2Design criteria2.3Concrete laboratory records2.4Batch plant and field inspection records2.5Operation and maintenance records2.6In-service inspectionsChapter 3In-situ condition surveys and testing, p. 207.3R-43.1Surface damage surveys3.2Joint surveys3.3Vibration load testing3.4In-situ

12、 stress determinations3.5Supplemental instrumentation3.6Geophysical logging3.7Down-hole video camera3.8Seepage monitoring3.9Nondestructive testingFred A. Anderson Robert W. Cannon Michael I. Hammons Robert F. OuryHoward L. Boggs James L. Cope Kenneth D. Hansen Ernest K. SchraderDan A. Bonikowsky Lui

13、s H. Diaz Allen J. Hulshizer Stephen B. TatroRichard A. J. Bradshaw Timothy P. Dolen Meng K. Lee Terry W. WestEdward G. W. Bush James R. Graham Gary R. MassJohn M. ScanlonChairman207.3R-2 ACI COMMITTEE REPORTChapter 4Sampling and laboratory testing,p. 207.3R-104.1Core drilling and testing4.2Petrogra

14、phic analysis4.3Chemical analysis4.4Physical tests4.5ReportChapter 5Damage, p. 207.3R-125.1Origin of distress5.2Considerations for repair and rehabilitationChapter 6Report, p. 207.3R-136.1General6.2Contents of reportChapter 7References, p. 207.3R-147.1Recommended references7.2Cited referencesCHAPTER

15、 1INTRODUCTIONDeteriorating infrastructure continues to be a growingconcern. Accurate information on the condition of concretein a massive structure is critical to evaluating its safety andserviceability. This information is required by decisionmakers to determine if repair or replacement is necessa

16、ry andto select optimum repair techniques where conditions require.The guidelines for evaluating the serviceability of concretedescribed herein apply to massive concrete structures such asdams or other hydraulic structures, bridge foundations andpiers, building and reactor foundations, and other app

17、licationsthat qualify to be considered mass concrete. Mass concrete isdefined in ACI 116R as “any volume of concrete withdimensions large enough to require that measures be taken tocope with the generation of heat and attendant volumechange to minimize cracking.” The practices describedpertain to co

18、ncrete placed either by conventional means orby roller compaction.In addition to this report, other documents such as ACI201.1R, ACI 201.2R, ACI 224.1R, ACI 228.1R, ACI 437R,and ASTM C 823 provide good tools for those evaluatingconcrete in existing massive structures.1.1ScopeThis report focuses on p

19、ractices used to evaluate concrete inexisting massive structures. Design considerations, evaluationof existing operating records and past inspection reports,condition surveys, maintenance reports, determination ofin-situ conditions, instrumentation, identification of damage,and final evaluation of c

20、oncrete are principal subjects thatare covered.1.2ObjectiveThe objective of this report is twofold: (a) to presentcurrent methods available for evaluating the capability ofmass concrete to meet design criteria under service conditions;and (b) to present procedures to detect the change in physicalpro

21、perties of concrete that could affect the capability of theconcrete to meet performance requirements in the future.1.3ReportThe prepared report should identify and evaluate propertiesof the concrete as they relate to the design criteria of theproject structures, but should not preempt the structural

22、engineers responsibility for determining if the structures ofthe project are meeting design requirements. Photographicand graphic presentation of investigation data should be usedto a maximum practical extent. The report is an essential toolfor those charged with the final responsibility of determin

23、ingthe structural adequacy and safety of the project.CHAPTER 2PRE-INSPECTIONAND IN-SERVICE INSPECTIONArrangements prior to an inspection should be made toobtain or have access to all available records and datapertaining to the structure. Pertinent engineering data to bereviewed include design criter

24、ia and memoranda, constructionprogress reports, instrumentation records, operation andmaintenance records, and to the extent available, precon-struction data. Information on adjacent projects, additions, ormodifications that may affect a change in the original designconditions should also be reviewe

25、d.2.1Preconstruction evaluationEngineering data relating to design criteria, design siteconditions, purpose of project, and construction planningand procedure should be collected and arranged for ease ofinformation retrieval. Documents that are readily available canbe assembled first. Data that are

26、missing but deemed necessaryfor evaluation should be identified. A suggested list of datato be reviewed is as follows:2.1.1 Project description documents2.1.1.1 For a hydroelectric plant, the Federal EnergyRegulatory Commission (FERC) licensed application2.1.1.2 For a nuclear plant: the Preliminary

27、Safety AnalysisReport (PSAR)2.1.1.3 All formal and final completion reports2.1.2 Contract documents2.1.2.1 Contract documents: technical specifications anddrawings including modifications or addendums2.1.2.2 As-built drawings2.1.2.3 Original issue drawings2.1.3 Regional data2.1.3.1 Land use map show

28、ing location of structure andits relationship to surrounding localities2.1.3.2 Topographic map of site and drainage area2.1.3.3 Geologic plans and sections2.1.3.4 Seismic data2.1.3.5 Reservoir volume versus elevation curve2.1.4 Site subsurface data2.1.4.1 Logs of borings2.1.4.2 Geological maps, prof

29、iles, and cross sections2.1.4.3 Soils investigation, availability of test results2.1.4.4 Foundation treatment reports2.1.4.5 Water table elevation2.1.4.6 Geohydrologic data2.1.5 Site surface data2.1.5.1 Control elevationsCONCRETE IN EXISTING MASSIVE STRUCTURES 207.3R-32.1.5.1.a For buildings: finish

30、ed grade, basement,floors, roof, etc.2.1.5.1.b For dams and spillways: Crest, maximumand minimum reservoir surface, outlet works, maximum andminimum tailwater, etc.2.1.6 Drainage2.1.6.1 Detail of drains in structure and foundation2.1.7 Environmental2.1.7.1 Temperatures: Maximum, minimum, and meandai

31、ly2.1.7.2 Precipitation, maximum, and mean annual2.1.7.3 Average humidity and range2.1.7.4 Number of sunny days2.1.7.5 Exposure: To sulfates; to organic acids; todeleterious atmospheric gases2.2Design criteria2.2.1 Design memorandum or report2.2.2 Values of static and intermittent loadings, wind,tem

32、perature, impact, loads2.2.3 For hydraulic structures: hydrostatic and hydro-dynamic loads2.2.4 Type of analysis: static, dynamic2.3Concrete laboratory records2.3.1 Materials used2.3.1.1 Cement2.3.1.1.a Certified mill test records including finenessmoduli2.3.1.1.b Additional physical and chemical pr

33、opertiestests2.3.1.2 Pozzolan2.3.1.2.a Certified test records2.3.1.2.b Physical and chemical properties2.3.1.3 Aggregates2.3.1.3.a Type and source(s)2.3.1.3.b Gradation2.3.1.3.c Summary of physical and chemical propertiesas specified in ASTM C 332.3.1.3.d Results of tests for potential reactivity2.3

34、.1.3.e Report of petrographic examination2.3.1.4 Mixing water quality tests2.3.2 Concrete records2.3.2.1 Mix proportions2.3.2.2 Water-cement ratio2.3.2.3 Slump or, for roller-compacted concrete, Vebe time2.3.2.4 Unit weight or, for roller-compacted concrete,compacted density measurements2.3.2.5 Temp

35、erature records including complete thermalhistory, if available2.3.2.6 Records of strength tests2.3.2.7 Admixtures including air-entraining agents used,percent air entrained.2.4Batch plant and field inspection records2.4.1 Storage and processing of aggregates2.4.1.1 Stockpiles2.4.1.2 Rinsing and fin

36、ish screens for coarse aggregate2.4.1.3 Bins or silos2.4.2 Cement, pozzolan, and admixture storage andhandling2.4.3 Forms2.4.3.1 Type and bracing, tightness of joints2.4.3.2 Time interval for stripping2.4.3.3 Method of finish or cleanup of unformed surfaces2.4.4 Preparation and condition of construc

37、tion joints2.4.5 Mixing operation2.4.5.1 Type of batch plant2.4.5.2 Type of mixing equipment and mixing time2.4.5.3 Condition of equipment2.4.5.4 Monitoring and control practices2.4.5.5 Any unscheduled interruptions due to plantbreakdown or weather2.4.5.6 Any scheduled seasonal interruption2.4.6 Met

38、hod of transporting concrete: Pumps, chutes,conveyor belts, trucks, buckets, etc.2.4.7 Method of placing concrete2.4.7.1 Where vibrated: lift heights, vibrator types andnumber2.4.7.2 Where roller-compacted: layer thickness, roller type2.4.8 Concrete protection2.4.8.1 Curing methods: Water ponding or

39、 spray; curingcompounds; shading; starting time and duration2.4.8.2 Hot weather protection2.4.8.3 Cold weather protection2.5Operation and maintenance records2.5.1 Operation records2.5.1.1 Instrumentation data2.5.1.2 Seepage: amount with time, type and location ofmeasuring device2.5.1.3 Unusual loadi

40、ng conditions2.5.1.3.a Earthquake2.5.1.3.b Floods2.5.1.3.c Extreme temperatures (temporary andprolonged)2.5.1.3.d Operational failure2.5.1.4 Change in operating procedures2.5.1.5 Shutdown of all or parts of the system2.5.1.6 Increased loads or loadings2.5.2 Maintenance records2.5.2.1 Location and ex

41、tent2.5.2.2 Type of maintenance2.5.2.3 Dates of repair2.5.2.4 Repair materials2.5.2.5 Performance of repaired work2.6In-service inspections2.6.1 GeneralMost organizations monitor the performanceof completed structures to ensure that they function safelyand in accordance with the design. The monitori

42、ng may bepart of the owners operation and maintenance program ormay be required by law.1,2Service records are generallymore complete for recently constructed structures than forolder structures as the concern for public safety hasincreased in recent years. The scope of surveillance can vary207.3R-4

43、ACI COMMITTEE REPORTwidely between organizations and may depend to an evengreater extent on the size and nature of the project or structureand potential hazards it may present.To properly compare and evaluate the existing conditionof concrete in massive structures, it is essential to reviewthese in-

44、service records, which may also include routine andperiodic inspections.2.6.2 Routine inspectionsRoutine inspection by variousorganizations are generally made at a frequency of 6 monthsto 2 years. They commonly consist of a visual examinationof the condition of the exposed and accessible concrete in

45、various components of a structure or project. Submergedstructures or portions thereof may be visually examined by adiver or by a remotely-operated vehicle (ROV) with an on-board video camera. In some cases, visual examination maybe supplemented by nondestructive tests as described inChapter 3 to ind

46、icate certain properties and conditions of thein-situ concrete at that particular time, such as compressivestrength, modulus of elasticity, and presence of voids andcracking. Data from instrumentation embedded in theconcrete may also be available. A comparison of theconcrete properties, conditions,

47、and instrumentation at eachinspection interval are useful analysis tools and may revealabnormal changes.Immediately after placing the structure in service, frequentinspections are made so that performance can be assessedand, if necessary, modifications made to the design andoperating practices. Insp

48、ections made thereafter are directedat identifying any changes in condition of the concrete orconcrete properties that may affect the integrity of the structureand its future serviceability. Inspections may be performedby trained technicians or qualified engineers, depending onthe program establishe

49、d. A report describing the findings ofeach routine inspection generally notes any changed conditions,contains photographs of the conditions and recommendscorrective action. Further in-depth investigations may beinitiated if for any reason problems are suspected. Docu-mentation of the inspection and any action taken are generallyfiled with the owner.2.6.3 Periodic inspectionsPeriodic inspections aregenerally conducted at a frequency of 2 to 10 years and arethe same in nature or objective as routine inspections.However, periodic inspections e