1、Report on Measuring Mechanical Properties of Hardened Fiber- Reinforced Concrete Reported by ACI Committee 544 ACI 544.9R-17First Printing January 2017 ISBN: 978-1-945487-49-1 Report on Measuring Mechanical Properties of Hardened Fiber-Reinforced Concrete Copyright by the American Concrete Institute
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11、reports are gathered together in the annually revised ACI Manual of Concrete Practice (MCP). American Concrete Institute 38800 Country Club Drive Farmington Hills, MI 48331 Phone: +1.248.848.3700 Fax: +1.248.848.3701 www.concrete.orgThis report provides a synopsis of the existing testing method- olo
12、gies for the determination of mechanical properties of hard- ened fiber-reinforced concrete (FRC). This report applies to the mechanical properties of conventionally mixed and placed FRC, including fiber-reinforced self-consolidating concrete (FRSCC), or fiber-reinforced shotcrete (FRS) using steel,
13、 glass, polymeric, and natural fibers. The objective is to enable manufacturers to characterize the mechanical properties of hardened FRC and encourage researchers and testing laboratories to adopt common and unified test methods to build a meaningful database of mechanical properties of hard- ened
14、FRC materials and products. Test results from the test proce- dures used in this report are not intended for the design of FRC structures, but to gain a better understanding of factors influencing the determination of their mechanical properties and of FRCs and FRC products. Keywords: compressive st
15、rength; fiber pullout; fiber-reinforced concrete; flexural fatigue resistance; flexural strength; impact resistance; multiaxial behavior; shear and torsion; tensile strength; toughness. CONTENTS CHAPTER 1INTRODUCTION AND SCOPE, p. 2 1.1Introduction, p. 2 1.2Scope, p. 2 CHAPTER 2NOTATION AND DEFINITI
16、ONS, p. 2 2.1Notation, p. 2 2.2Definitions, p. 3 Barzin Mobasher * , Chair Neven Krstulovic-Opara, Secretary Clifford N. MacDonald * , Membership Secretary ACI 544.9R-17 Report on Measuring Mechanical Properties of Hardened Fiber-Reinforced Concrete Reported by Committee 544 Corina-Maria Aldea Emman
17、uel K. Attiogbe Mehdi Bakhshi Nemkumar Banthia Joaquim Oliveira Barros * Amir Bonakdar * Amanda C. Bordelon Jean-Philippe Charron Xavier Destree * Ashish Dubey Mahmut Ekenel Liberato Ferrara Gregor D. Fischer Dean P. Forgeron * Emilio Garcia Taengua Rishi Gupta Heidi Helmink George C. Hoff Marco Inv
18、ernizzi John Jones David A. Lange Michael A. Mahoney Bruno Massicotte James Milligan Nicholas C. Mitchell Jr. Jeffrey L. Novak Giovanni A. Plizzari Klaus Alexander Rieder Pierre Rossi Steve Schaef Surendra P. Shah Flavio de Andrade Silva Luca Sorelli Thomas E. West Kay Wille Robert C. Zellers Consul
19、ting members P. N. Balaguru Hiram Price Ball Jr. Gordon B. Batson Arnon Bentur Andrzej M. Brandt James I. Daniel Sidney Freedman Christian Meyer Henry J. Molloy Antoine E. Naaman Venkataswamy Ramakrishnan *Members of subcommittee who contributed to this report. Chair of the subcommittee that develop
20、ed this report. Consulting members who contributed to this report. The committee would like to thank H. Aoude and F. V ossoughi for their contributions to this report. ACI Committee Reports, Guides, and Commentaries are intended for guidance in planning, designing, executing, and inspecting construc
21、tion. 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 American Concrete Institute disclaims any and all respo
22、nsibility 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/Engineer to be a part of the contract documents, they shal
23、l be restated in mandatory language for incorporation by the Architect/Engineer. ACI 544.9R-17 was adopted and published January 2017. Copyright 2017, American Concrete Institute. All rights reserved including rights of reproduction and use in any form or by any means, including the making of copies
24、 by any photo process, or by electronic or mechanical 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. 1CHAPTER 3SAMPLING AND SPECIMEN P
25、REPARATION, p. 4 3.1General, p. 4 3.2Test specimens, p. 4 3.3Sample size, p. 4 CHAPTER 4COMPRESSIVE STRENGTH, MODULUS OF ELASTICITY, AND POISSONS RATIO, p. 4 4.1General, p. 4 4.2Compressive stress-strain curve, p. 5 CHAPTER 5TENSILE BEHAVIOR, p. 6 5.1General, p. 6 5.2Direct tension tests, p. 6 5.3In
26、direct tension tests, p. 10 CHAPTER 6FLEXURAL BEHAVIOR: STRENGTH, TOUGHNESS, AND CLOSED-LOOP TESTS, p. 14 6.1General, p. 14 6.2Flexural strength, p. 15 6.3Flexural toughness and residual post-cracking strength, p. 15 CHAPTER 7INTERFACE, BOND SLIP, AND FIBER PULLOUT, p. 20 7.1General, p. 20 7.2Pullou
27、t tests, p. 21 CHAPTER 8HIGH STRAIN RATE TESTING, p. 24 8.1General, p. 24 8.2High-speed tension tests, p. 25 8.3Split Hopkinson (pressure) bar test, p. 26 CHAPTER 9IMPACT PERFORMANCE TESTING, p. 27 9.1General, p. 27 9.2Noninstrumented impact tests, p. 27 9.3Instrumented impact tests, p. 27 CHAPTER 1
28、0FATIGUE RESISTANCE, p. 35 10.1General, p. 35 10.2Uniaxial compression fatigue, p. 37 10.3Biaxial compression fatigue, p. 38 10.4Tensile fatigue, p. 38 10.5Flexural fatigue, p. 39 CHAPTER 11SHEAR AND TORSION, p. 40 CHAPTER 12BIAXIAL/MULTIAXIAL BEHAVIOR, p. 41 CHAPTER 13CONCLUSIONS, p. 41 CHAPTER 14R
29、EFERENCES, p. 42 Authored documents, p. 43 CHAPTER 1INTRODUCTION AND SCOPE 1.1Introduction The use of fiber-reinforced concrete (FRC) has evolved from small-scale applications to routine factory and field applications that involve the global use of tens of millions of cubic yards (meters) annually.
30、This growth of application, in conjunction with new fibers, admixtures, and mixture designs, has created an urgent need to review existing test methods and, where necessary, develop new methods for determining the fresh and hardened properties of FRC. 1.2Scope This report documents the determination
31、 of mechanical properties of hardened FRC. The objective is to charac- terize these mechanical properties and encourage common and unified test methods. This objective builds a meaningful database of mechanical properties of hardened FRC mate- rials and products. Further, the results should not be t
32、aken out of the context presented for illustrating the tests and not for comparing fibers out of context. The results from the tests and procedures used in this document are not intended to be used for the design of FRC structures. The purpose of this document is to gain a better understanding of th
33、e many factors influencing tests for the determination of mechanical properties of FRCs and FRC products. Although most of the test methods described in this report were developed initially for steel FRC (SFRC), they are applicable to concretes reinforced with glass, synthetic/poly- meric, and natur
34、al fibers, except when noted. In Fig. 1.2, an example of different types of fibers commonly employed in FRC is provided. This report applies to the mechanical properties of conven- tionally mixed and placed FRC or fiber-reinforced shotcrete (FRS) using steel, glass, synthetic/polymeric, and cellulos
35、e/ natural fibers. Some newer test methods and evaluation procedures under development are not included in this report. Examples of this are tensile creep and flexural creep of concrete where the section has cracked and the bridging fibers are carrying loads. This report does not discuss test method
36、s for thin glass FRC or mortar products produced by the spray-up process. The Prestressed Concrete Institute (PCI MNL 128) and the International Glassfibre Reinforced Cement Association (2016a,b) have prepared recommendations for test methods for these spray-up materials. CHAPTER 2NOTATION AND DEFIN
37、ITIONS 2.1Notation a, b = dimensions, in. (mm) b = width, in. (mm) d = depth, in. (mm) d f= fiber diameter, in. (mm) f 1= first cracking nominal stress (as from results of flex- ural tests according to ASTM C1609/C1609M), psi (MPa) American Concrete Institute Copyrighted Material www.concrete.org 2
38、REPORT ON MEASURING MECHANICAL PROPERTIES OF HARDENED FIBER-REINFORCED CONCRETE (ACI 544.9R-17)f 150= residual nominal bending strength corresponding to P 150 , psi (MPa) f 600= residual nominal bending strength corresponding to P 600 , psi (MPa) f eq= equivalent nominal flexural strength, calculate
39、d with reference to predefined crack opening range, from nominal flexural stress versus crack opening curves obtained from flexural tests, psi (MPa) f p= peak nominal stress (as from results of flexural tests according to ASTM C1609/C1609M); may coin- cide with or be higher than f 1 , psi (MPa) f R
40、, f Rj= residual nominal flexural strength, at a specified value of the crack mouth opening displacement, as from results of flexural tests on notched specimens as per EN 14651, psi (MPa) f R1= residual nominal flexural strength, at CMOD = 0.02 in. (0.5 mm), as from results of flexural tests on notc
41、hed specimens as per EN 14651, psi (MPa) f R1k= characteristic value of f R1 f R2= residual nominal flexural strength, at CMOD = 0.06 in. (1.5 mm), as from results of flexural tests on notched specimens as per EN 14651, psi (MPa) f R3= residual nominal flexural strength, at CMOD = 0.10 in. (2.5 mm),
42、 as from results of flexural tests on notched specimens as per EN 14651, psi (MPa) f R3k= characteristic value of f R3 f R4= residual nominal flexural strength, at CMOD = 0.14 in. (3.5 mm), as from results of flexural tests on notched specimens as per EN 14651, psi (MPa) h = specimen height, in. (mm
43、) L = length, span, in.-ft. (mm); also gauge length, in. (mm) l f= fiber length, in. (mm) P = load, lbf (N) P 1= first cracking load (as from results of flexural tests according to ASTM C1609/C1609M), lbf (N) P 150= residual load measured in flexural tests as per ASTM C1609/C1609M in correspondence
44、of a midspan net deflection equal to 1/150 of the spec- imen length, lbf (N) P 600= residual load measured in flexural tests as per ASTM C1609/C1609M in correspondence of a midspan net deflection equal to 1/600 of the spec- imen length, lbf (N) P p= peak load (as from results of flexural tests accor
45、ding to ASTM C1609/C1609M); may coincide with or be higher than P 1 , kip (kN) T 150= area under the load deflection curve obtained from flexural tests as per ASTM C1609/C1609M up to a value of the net deflection equal to 1/150 of the specimen length, in.-lb (J) V f= fiber volume fraction (generally
46、 expressed in percent) = deflection, in. (mm) = angle, deg 2.2Definitions ACI provides a comprehensive list of definitions through an online resource, “ACI Concrete Terminology”, http:/ Fig. 1.2Examples of different types of fibers used in FRC: (a) steel (with hooked ends, flattened ends, corrugated
47、/undu- lated); (b) through (c) synthetic/polymeric microfibers; (d) glass; (e) carbon; and (f) natural; dimension scale where provided is in mm. (Note: 1 in. = 25.4 mm.) American Concrete Institute Copyrighted Material www.concrete.orgREPORT ON MEASURING MECHANICAL PROPERTIES OF HARDENED FIBER-REINF
48、ORCED CONCRETE (ACI 544.9R-17) 3www.concrete.orgstoreproductdetails.aspx?ItemID=CT16. Definitions provided herein complement that resource. aspect ratioratio of the length to the diameter of one single fiber or fiber filament. The diameter may be the actual or equivalent diameter, defined below. cra
49、ckcomplete or incomplete separation of concrete in to two or more parts produced by breaking or fracturing. equivalent diameterfor fibers with noncircular cross section, diameter of the equivalent circular cross section having the same area as the fiber cross section. equivalent flexural residual strengthaverage flexural stress measured for an FRC beam based on the toughness, up to a specified deflection (or crack width). fiberslender and elongated solid material, generally with a length of at least 100 times it
