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1、ACI 207.3R-94 supersedes ACI 207.3R-79 (Revised 1985) and became effective July 1, 1994. Copyright 1994, American Concrete Institute. All rights reserved including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by electronic or mec
2、hanical device, printed, written, or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. 207.3R-1 ACI Committee Reports, Guides, Standard Practices, and Commentaries ar
3、e intended for guidance in planning, designing, executing, and inspecting construction. This document is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who will accept responsibility for the application of the
4、 material it contains. The American Concrete Institute disclaims any and all responsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom. Reference to this document shall not be made in contract documents. If items found in this document are d
5、esired by the Architect/Engineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the Architect/Engineer. Practices for Evaluation of Concrete in Existing Massive Structures for Service Conditions Reported by ACI Committee 207 ACI 207.3R-94 (R
6、eapproved 2008) Current methods available for evaluating physical properties of concrete in existing structures to determine its capability of performing satisfactorily under service conditions are identified and discussed. Although general knowledge of the structural design criteria used for the pr
7、incipal structures of a project is essential to determine satisfactory procedures and locations for evaluation of the concrete physical properties, analysis for the purpose of determining structural capability is not within the scope of this report. The report recommends project design, operation, a
8、nd maintenance records and in-service inspection data to be reviewed. Existing methods of making condition surveys and nondestructive tests are reviewed; destructive phenomena are identified; methods for evaluation of tests and survey data are presented; and finally, preparation of the final report
9、is discussed. Keywords: alkali-aggregate reaction; alkali-carbonate reaction; cavitation; cements; chemical analysis; concrete cores; concrete dams; concrete durability; cracking (fracturing); elastic properties; erosion; evaluation; extensometers; impact tests; inspection; laboratories; maintenance
10、; mass concrete; nondestructive tests; nuclear power plants; post-tensioning; pozzolans; resurfacing; sampling; seepage; serviceability; spalling; static tests; stresses; surveys; x-ray diffraction. CONTENTS Chapter 1Introduction, p. 207.3R-2 1.1Scope 1.2Objective 1.3Report Chapter 2Pre-inspection a
11、nd in-service inspection, p. 207.3R-2 2.1Preconstruction evaluation 2.2Design criteria 2.3Concrete laboratory records 2.4Batch plant and field inspection records 2.5Operation and maintenance records 2.6In-service inspections Chapter 3In-situ condition surveys and testing, p. 207.3R-4 3.1Surface dama
12、ge surveys 3.2Joint surveys 3.3Vibration load testing 3.4In-situ stress determinations 3.5Supplemental instrumentation 3.6Geophysical logging 3.7Down-hole video camera 3.8Seepage monitoring 3.9Nondestructive testing Fred A. AndersonRobert W. CannonMichael I. HammonsRobert F. Oury Howard L. BoggsJame
13、s L. CopeKenneth D. HansenErnest K. Schrader Dan A. BonikowskyLuis H. DiazAllen J. HulshizerStephen B. Tatro Richard A. J. BradshawTimothy P. DolenMeng K. LeeTerry W. West Edward G. W. BushJames R. GrahamGary R. Mass John M. Scanlon Chairman 207.3R-2ACI COMMITTEE REPORT Chapter 4Sampling and laborat
14、ory testing, p. 207.3R-10 4.1Core drilling and testing 4.2Petrographic analysis 4.3Chemical analysis 4.4Physical tests 4.5Report Chapter 5Damage, p. 207.3R-12 5.1Origin of distress 5.2Considerations for repair and rehabilitation Chapter 6Report, p. 207.3R-13 6.1General 6.2Contents of report Chapter
15、7References, p. 207.3R-14 7.1Recommended references 7.2Cited references CHAPTER 1INTRODUCTION Deteriorating infrastructure continues to be a growing concern. Accurate information on the condition of concrete in a massive structure is critical to evaluating its safety and serviceability. This informa
16、tion is required by decision makers to determine if repair or replacement is necessary and to select optimum repair techniques where conditions require. The guidelines for evaluating the serviceability of concrete described herein apply to massive concrete structures such as dams or other hydraulic
17、structures, bridge foundations and piers, building and reactor foundations, and other applications that qualify to be considered mass concrete. Mass concrete is defined in ACI 116R as “any volume of concrete with dimensions large enough to require that measures be taken to cope with the generation o
18、f heat and attendant volume change to minimize cracking.” The practices described pertain to concrete placed either by conventional means or by roller compaction. In addition to this report, other documents such as ACI 201.1R, ACI 201.2R, ACI 224.1R, ACI 228.1R, ACI 437R, and ASTM C 823 provide good
19、 tools for those evaluating concrete in existing massive structures. 1.1Scope This report focuses on practices used to evaluate concrete in existing massive structures. Design considerations, evaluation of existing operating records and past inspection reports, condition surveys, maintenance reports
20、, determination of in-situ conditions, instrumentation, identification of damage, and final evaluation of concrete are principal subjects that are covered. 1.2Objective The objective of this report is twofold: (a) to present current methods available for evaluating the capability of mass concrete to
21、 meet design criteria under service conditions; and (b) to present procedures to detect the change in physical properties of concrete that could affect the capability of the concrete to meet performance requirements in the future. 1.3Report The prepared report should identify and evaluate properties
22、 of the concrete as they relate to the design criteria of the project structures, but should not preempt the structural engineers responsibility for determining if the structures of the project are meeting design requirements. Photographic and graphic presentation of investigation data should be use
23、d to a maximum practical extent. The report is an essential tool for those charged with the final responsibility of determining the structural adequacy and safety of the project. CHAPTER 2PRE-INSPECTION AND IN-SERVICE INSPECTION Arrangements prior to an inspection should be made to obtain or have ac
24、cess to all available records and data pertaining to the structure. Pertinent engineering data to be reviewed include design criteria and memoranda, construction progress reports, instrumentation records, operation and maintenance records, and to the extent available, precon- struction data. Informa
25、tion on adjacent projects, additions, or modifications that may affect a change in the original design conditions should also be reviewed. 2.1Preconstruction evaluation Engineering data relating to design criteria, design site conditions, purpose of project, and construction planning and procedure s
26、hould be collected and arranged for ease of information retrieval. Documents that are readily available can be assembled first. Data that are missing but deemed necessary for evaluation should be identified. A suggested list of data to be reviewed is as follows: 2.1.1 Project description documents 2
27、.1.1.1 For a hydroelectric plant, the Federal Energy Regulatory Commission (FERC) licensed application 2.1.1.2 For a nuclear plant: the Preliminary Safety Analysis Report (PSAR) 2.1.1.3 All formal and final completion reports 2.1.2 Contract documents 2.1.2.1 Contract documents: technical specificati
28、ons and drawings including modifications or addendums 2.1.2.2 As-built drawings 2.1.2.3 Original issue drawings 2.1.3 Regional data 2.1.3.1 Land use map showing location of structure and its relationship to surrounding localities 2.1.3.2 Topographic map of site and drainage area 2.1.3.3 Geologic pla
29、ns and sections 2.1.3.4 Seismic data 2.1.3.5 Reservoir volume versus elevation curve 2.1.4 Site subsurface data 2.1.4.1 Logs of borings 2.1.4.2 Geological maps, profiles, and cross sections 2.1.4.3 Soils investigation, availability of test results 2.1.4.4 Foundation treatment reports 2.1.4.5 Water t
30、able elevation 2.1.4.6 Geohydrologic data 2.1.5 Site surface data 2.1.5.1 Control elevations CONCRETE IN EXISTING MASSIVE STRUCTURES207.3R-3 2.1.5.1.a For buildings: finished grade, basement, floors, roof, etc. 2.1.5.1.b For dams and spillways: Crest, maximum and minimum reservoir surface, outlet wo
31、rks, maximum and minimum tailwater, etc. 2.1.6 Drainage 2.1.6.1 Detail of drains in structure and foundation 2.1.7 Environmental 2.1.7.1 Temperatures: Maximum, minimum, and mean daily 2.1.7.2 Precipitation, maximum, and mean annual 2.1.7.3 Average humidity and range 2.1.7.4 Number of sunny days 2.1.
32、7.5 Exposure: To sulfates; to organic acids; to deleterious atmospheric gases 2.2Design criteria 2.2.1 Design memorandum or report 2.2.2 Values of static and intermittent loadings, wind, temperature, impact, loads 2.2.3 For hydraulic structures: hydrostatic and hydro- dynamic loads 2.2.4 Type of ana
33、lysis: static, dynamic 2.3Concrete laboratory records 2.3.1 Materials used 2.3.1.1 Cement 2.3.1.1.a Certified mill test records including fineness moduli 2.3.1.1.b Additional physical and chemical properties tests 2.3.1.2 Pozzolan 2.3.1.2.a Certified test records 2.3.1.2.b Physical and chemical prop
34、erties 2.3.1.3 Aggregates 2.3.1.3.a Type and source(s) 2.3.1.3.b Gradation 2.3.1.3.c Summary of physical and chemical properties as specified in ASTM C 33 2.3.1.3.d Results of tests for potential reactivity 2.3.1.3.e Report of petrographic examination 2.3.1.4 Mixing water quality tests 2.3.2 Concret
35、e records 2.3.2.1 Mix proportions 2.3.2.2 Water-cement ratio 2.3.2.3 Slump or, for roller-compacted concrete, Vebe time 2.3.2.4 Unit weight or, for roller-compacted concrete, compacted density measurements 2.3.2.5 Temperature records including complete thermal history, if available 2.3.2.6 Records o
36、f strength tests 2.3.2.7 Admixtures including air-entraining agents used, percent air entrained. 2.4Batch plant and field inspection records 2.4.1 Storage and processing of aggregates 2.4.1.1 Stockpiles 2.4.1.2 Rinsing and finish screens for coarse aggregate 2.4.1.3 Bins or silos 2.4.2 Cement, pozzo
37、lan, and admixture storage and handling 2.4.3 Forms 2.4.3.1 Type and bracing, tightness of joints 2.4.3.2 Time interval for stripping 2.4.3.3 Method of finish or cleanup of unformed surfaces 2.4.4 Preparation and condition of construction joints 2.4.5 Mixing operation 2.4.5.1 Type of batch plant 2.4
38、.5.2 Type of mixing equipment and mixing time 2.4.5.3 Condition of equipment 2.4.5.4 Monitoring and control practices 2.4.5.5 Any unscheduled interruptions due to plant breakdown or weather 2.4.5.6 Any scheduled seasonal interruption 2.4.6 Method of transporting concrete: Pumps, chutes, conveyor bel
39、ts, trucks, buckets, etc. 2.4.7 Method of placing concrete 2.4.7.1 Where vibrated: lift heights, vibrator types and number 2.4.7.2 Where roller-compacted: layer thickness, roller type 2.4.8 Concrete protection 2.4.8.1 Curing methods: Water ponding or spray; curing compounds; shading; starting time a
40、nd duration 2.4.8.2 Hot weather protection 2.4.8.3 Cold weather protection 2.5Operation and maintenance records 2.5.1 Operation records 2.5.1.1 Instrumentation data 2.5.1.2 Seepage: amount with time, type and location of measuring device 2.5.1.3 Unusual loading conditions 2.5.1.3.a Earthquake 2.5.1.
41、3.b Floods 2.5.1.3.c Extreme temperatures (temporary and prolonged) 2.5.1.3.d Operational failure 2.5.1.4 Change in operating procedures 2.5.1.5 Shutdown of all or parts of the system 2.5.1.6 Increased loads or loadings 2.5.2 Maintenance records 2.5.2.1 Location and extent 2.5.2.2 Type of maintenanc
42、e 2.5.2.3 Dates of repair 2.5.2.4 Repair materials 2.5.2.5 Performance of repaired work 2.6In-service inspections 2.6.1 GeneralMost organizations monitor the performance of completed structures to ensure that they function safely and in accordance with the design. The monitoring may be part of the o
43、wners operation and maintenance program or may be required by law.1,2 Service records are generally more complete for recently constructed structures than for older structures as the concern for public safety has increased in recent years. The scope of surveillance can vary 207.3R-4ACI COMMITTEE REP
44、ORT widely between organizations and may depend to an even greater extent on the size and nature of the project or structure and potential hazards it may present. To properly compare and evaluate the existing condition of concrete in massive structures, it is essential to review these in-service rec
45、ords, which may also include routine and periodic inspections. 2.6.2 Routine inspectionsRoutine inspection by various organizations are generally made at a frequency of 6 months to 2 years. They commonly consist of a visual examination of the condition of the exposed and accessible concrete in vario
46、us components of a structure or project. Submerged structures or portions thereof may be visually examined by a diver or by a remotely-operated vehicle (ROV) with an on- board video camera. In some cases, visual examination may be supplemented by nondestructive tests as described in Chapter 3 to ind
47、icate certain properties and conditions of the in-situ concrete at that particular time, such as compressive strength, modulus of elasticity, and presence of voids and cracking. Data from instrumentation embedded in the concrete may also be available. A comparison of the concrete properties, conditi
48、ons, and instrumentation at each inspection interval are useful analysis tools and may reveal abnormal changes. Immediately after placing the structure in service, frequent inspections are made so that performance can be assessed and, if necessary, modifications made to the design and operating prac
49、tices. Inspections made thereafter are directed at identifying any changes in condition of the concrete or concrete properties that may affect the integrity of the structure and its future serviceability. Inspections may be performed by trained technicians or qualified engineers, depending on the program established. A report describing the findings of each routine inspection generally notes any changed conditions, contains photographs of the conditions and recommends corrective action. Further in-depth investigations may be initiated if for
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