1、Guide to Formwork for ConcreteReported by ACI Committee 347ACI 347R-14First PrintingJuly 2014ISBN: 978-0-87031-910-5Guide to Formwork for ConcreteCopyright by the American Concrete Institute, Farmington Hills, MI. All rights reserved. This material may not be reproduced or copied, in whole or part,
2、in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of ACI.The technical committees responsible for ACI committee reports and standards strive to avoid ambiguities, omissions, and errors in these documents. In spite of these efforts, the
3、 users of ACI documents occasionally find information or requirements that may be subject to more than one interpretation or may be incomplete or incorrect. Users who have suggestions for the improvement of ACI documents are requested to contact ACI via the errata website at http:/concrete.org/Publi
4、cations/DocumentErrata.aspx. Proper use of this document includes periodically checking for errata for the most up-to-date revisions.ACI committee documents are intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and w
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7、luding without limitation, lost revenues or lost profits, which may result from the use of this publication.It is the responsibility of the user of this document to establish health and safety practices appropriate to the specific circumstances involved with its use. ACI does not make any representa
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10、on: ACI documents are available in print, by download, on CD-ROM, through electronic subscription, or reprint and may be obtained by contacting ACI.Most ACI standards and committee reports are gathered together in the annually revised ACI Manual of Concrete Practice (MCP).American Concrete Institute
11、38800 Country Club DriveFarmington Hills, MI 48331Phone: +1.248.848.3700Fax: +1.248.848.3701www.concrete.orgObjectives of safety, quality, and economy are given priority in these guidelines for formwork. A section on contract documents explains the kind and amount of specification guidance the engin
12、eer/architect should provide for the contractor. The remainder of the guide advises the formwork engineer/contractor on the best ways to meet the specification requirements safely and economically. Separate chapters deal with design, construction, and materials for formwork. Considerations specific
13、to architectural concrete are also outlined in a separate chapter. Other sections are devoted to formwork for bridges, shells, mass concrete, and underground work. The concluding chapter on formwork for special methods of construction includes slipforming, preplaced-aggregate concrete, tremie concre
14、te, precast concrete, and prestressed concrete.Keywords: anchors; architectural concrete; coatings; construction; construction loads; contract documents; falsework; form ties; forms; form-work; foundations; quality control; reshoring; shoring; slipform construc-tion; specifications; tolerances.CONTE
15、NTSCHAPTER 1INTRODUCTION AND SCOPE, p. 21.1Introduction, p. 21.2Scope, p. 2CHAPTER 2NOTATION AND DEFINITIONS, p. 22.1Notation, p. 22.2Definitions, p. 2CHAPTER 3GENERAL CONSIDERATIONS, p. 33.1Achieving economy in formwork, p. 33.2Contract documents, p. 4CHAPTER 4DESIGN, p. 54.1General, p. 54.2Loads,
16、p. 64.3Member capacities, p. 94.4Safety factors for accessories, p. 94.5Shores, p. 104.6Bracing and lacing, p. 104.7Foundations for formwork, p. 104.8Settlement, p. 10CHAPTER 5CONSTRUCTION, p. 105.1Safety precautions, p. 105.2Construction practices and workmanship, p. 125.3Tolerances, p. 135.4Irregu
17、larities in formed surfaces, p. 145.5Shoring and centering, p. 145.6Inspection and adjustment of formwork, p. 145.7Removal of forms and supports, p. 155.8Shoring and reshoring of multistory structures, p. 17Kenneth L. Berndt, ChairACI 347R-14Guide to Formwork for ConcreteReported by ACI Committee 34
18、7Rodney D. AdamsMary Bordner-TanckGeorge CharitouEamonn F. ConnollyJames N. Cornell IIJack L. DavidAubrey L. DunhamJeffrey C. ErsonNoel J. GardnerBrian J. GolanowskiTimothy P. HayesGardner P. HorstJeffery C. JackDavid W. JohnstonRoger S. JohnstonRobert G. KentKevin R. KoogleJim E. KretzH. S. LewRobe
19、rt G. McCrackenEric S. PetersonSteffen PippigMatthew J. PoiselDouglas J. SchoonoverAviad ShapiraJohn M. SimpsonRolf A. SpahrPericles C. StivarosDaniel B. ToonRalph H. TulisConsulting MembersSamuel A. GreenbergR. Kirk GregoryACI Committee Reports, Guides, and Commentaries are intended for guidance in
20、 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 material it contains. The
21、 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 desired by the Architect/Eng
22、ineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the Architect/Engineer.ACI 347R-14 supesedes ACI 347-04 and was adopted and published July 2014.Copyright 2014, American Concrete Institute.All rights reserved including rights of reproduc
23、tion and use in any form or by any means, including the making of copies by any photo process, or by electronic or mechanical device, printed, written, or oral, or recording for sound or visual reproduc-tion or for use in any knowledge or retrieval system or device, unless permission in writing is o
24、btained from the copyright proprietors.1CHAPTER 6MATERIALS, p. 186.1General, p. 186.2Properties of materials, p. 196.3Accessories, p. 196.4Form coatings and release agents, p. 21CHAPTER 7ARCHITECTURAL CONCRETE, p. 217.1Introduction, p. 217.2Role of architect, p. 217.3Materials and accessories, p. 23
25、7.4Design, p. 237.5Construction, p. 247.6Form removal, p. 25CHAPTER 8SPECIAL STRUCTURES, p. 258.1Discussion, p. 258.2Bridges and viaducts, including high piers, p. 258.3Structures designed for composite action, p. 258.4Folded plates, thin shells, and long-span roof struc-tures, p. 268.5Mass concrete
26、 structures, p. 278.6Underground structures, p. 28CHAPTER 9SPECIAL METHODS OF CONSTRUCTION, p. 299.1Preplaced-aggregate concrete, p. 299.2Slipforms, p. 299.3Permanent forms, p. 319.4Forms for prestressed concrete construction, p. 329.5Forms for site precasting, p. 329.6Use of precast concrete for fo
27、rms, p. 339.7Forms for concrete placed under water, p. 33CHAPTER 10REFERENCES, p. 34Authored references, p. 35CHAPTER 1INTRODUCTION AND SCOPE1.1IntroductionMany individuals, firms, and companies are usually involved in the design of the facility to be built and in the design and construction of the
28、formwork. The facility team typically involves structural engineers and architects who determine the requirements for the concrete structure to be built. For simplicity, the facility design team will usually be referred to as the engineer/architect, although they may be referred to separately in som
29、e situations. The form-work team may include the general contractor, formwork specialty subcontractors, formwork engineers, form manu-facturers, and form suppliers. The participating companies and firms also have form designers and skilled workers executing many detailed tasks. For simplicity, the f
30、ormwork team will usually be referred to as the formwork engineer/contractor, although they may be referred to separately in some situations.This guide is based on the premise that layout, design, and construction of formwork should be the responsibility of the formwork engineer/contractor. This is
31、believed to be fundamental to the achievement of safety and economy of formwork and of the required formed surface quality of the concrete.The paired values stated in inch-pound and SI units are usually not exact equivalents. Therefore, each system is to be used independently of the other.1.2ScopeTh
32、is guide covers:a) A listing of information to be included in the contract documentsb) Design criteria for horizontal and vertical loads on formworkc) Design considerations, including safety factors for determining the capacities of formwork accessoriesd) Preparation of formwork drawingse) Construct
33、ion and use of formwork, including safety considerationsf) Materials for formworkg) Formwork for special structuresh) Formwork for special methods of constructionCHAPTER 2NOTATION AND DEFINITIONS2.1NotationCCP= concrete lateral pressure, lb/ft2(kPa)Cc= chemistry coefficientCw= unit weight coefficien
34、tc1= slipform vibration factor, lb/ft2(kPa)g = gravitational constant, 0.00981 kN/kgh = depth of fluid or plastic concrete from top of place-ment to point of consideration in form, ft (m)R = rate of placement, ft/h (m/h)T = temperature of concrete at time of placement, F (C)w = unit weight of concre
35、te, lb/ft3 = density of concrete, kg/m32.2DefinitionsThe 2014 ACI Concrete Terminology (http:/www.concrete.org/Tools/ConcreteTerminology.aspx) provides a comprehensive list of definitions. The definitions provided herein complement that source.backshoresshores left in place or shores placed snugly u
36、nder a concrete slab or structural member after the original formwork and shores have been removed from a small area, without allowing the entire slab or member to deflect or support its self-weight and construction loads.bracestructural member used to provide lateral support for another member, gen
37、erally for the purpose of ensuring stability or resisting lateral loads.centeringfalsework used in the construction of arches, shells, space structures, or any continuous structure where the entire falsework is lowered (struck or decentered) as a unit.climbing formform that is raised vertically for
38、succeeding lifts of concrete in a given structure.American Concrete Institute Copyrighted Material www.concrete.org2 GUIDE TO FORMWORK FOR CONCRETE (ACI 374R-14)drop-head shoreshore with a head that can be lowered to remove forming components without removing the shore or changing its support for th
39、e floor system.engineer/architectthe engineer, architect, engineering firm, architectural firm, or other agency issuing project plans and specifications for the permanent structure, administering the work under contract documents, or both.falseworktemporary structure erected to support work in the p
40、rocess of construction; composed of shoring or vertical posting and lateral bracing for formwork for beams and slabs.flying formslarge, prefabricated, mechanically handled sections of floor system formwork designed for multiple reuse; frequently including supporting truss, beam, or shoring assemblie
41、s completely unitized.formtemporary structure or mold for the support of concrete while it is setting and gaining sufficient strength to be self-supporting.formworktotal system of support for freshly placed concrete, including the mold or sheathing that contacts the concrete as well as supporting me
42、mbers, hardware, and necessary bracing.formwork engineer/contractorengineer of the form-work system or contractor in charge of designated aspects of formwork design and formwork operations.ganged formslarge mechanically hoisted assemblies with special lifting hardware used for forming vertical surfa
43、ces; also called “gang forms”.horizontal lacinghorizontal bracing members attached to shores to reduce their unsupported length, thereby increasing load capacity and stability.preshoresadded shores placed snugly under selected panels of a deck-forming system before any primary (orig-inal) shores are
44、 removed.reshoresshores placed snugly under a stripped concrete slab or other structural member after the original forms and shores have been removed from a full bay, requiring the new slab or structural member to deflect and support its own weight and existing construction loads to be applied befor
45、e installation of the reshores.scaffoldtemporary structure with an elevated platform for supporting workers, tools, and materials.shorevertical or inclined support member or braced frame designed to carry the weight of the formwork, concrete, and construction loads.slipforma form that is pulled or r
46、aised as concrete is placed.surface air voidssmall regular or irregular cavities, usually not exceeding 0.6 in. (15 mm) in diameter, resulting from entrapment of air bubbles in the surface of formed concrete during placement and consolidation.CHAPTER 3GENERAL CONSIDERATIONS3.1Achieving economy in fo
47、rmworkThe engineer/architect can improve the overall economy of the structure by planning so that formwork costs are mini-mized. The cost of formwork can be greater than half the total cost of the concrete structure. This investment requires careful thought and planning by the engineer/architect whe
48、n designing and specifying the structure and by the formwork engineer/contractor when designing and constructing the formwork. Formwork drawings, prepared by the formwork engineer/contractor, can identify potential problems and should give project site employees a clear picture of what is required a
49、nd how to achieve it.The following guidelines show how the engineer/architect can plan the structure so that formwork economy may best be achieved:a) To simplify and permit maximum reuse of formwork, the dimensions of footings, columns, and beams should be of standard material multiples, and the number of sizes should be minimized.b) When interior columns are the same width as or smaller than the girders they support, the column form becomes a simple rectangular or square box without boxouts, and the
