1、Designation: A1096/A1096M 15Standard Test Method forEvaluating Bond of Individual Steel Wire, Indented or Plain,for Concrete Reinforcement1This standard is issued under the fixed designation A1096/A1096M; the number immediately following the designation indicates theyear of original adoption or, in
2、the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes procedures for evaluatingbond of individual steel wire, i
3、ndented or plain, for concretereinforcement. The bond determined by this test method isstated as the tensile force needed to pull the wire through thecured mortar in a cylindrical steel casing.1.2 The result of the test is the maximum tensile forcemeasured on the loaded end of the wire recorded at a
4、 free-endslip less than or equal to 0.10 in. 2.5 mm.1.3 UnitsThe values stated in either inch-pound units orSI units are to be regarded separately as standard. Within thetext, the SI units are shown in brackets. The values stated ineach system may not be exact equivalents; therefore, eachsystem shal
5、l be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-
6、priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A421/A421M Specification for Stress-Relieved Steel Wirefor Prestressed ConcreteA881/A881M Specification for Steel Wire, Indented, Low-Relaxation for P
7、restressed ConcreteC109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C150/C150M Specification for Portland CementC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC511 Specification for Mixing Rooms, Moist C
8、abinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC778 Specification for Standard Sand3. Terminology3.1 Definitions:3.1.1 bond, nlongitudinal components of adhesion,friction, and mechanical interlock between wire and mortar orconcrete.3.1.2 bond breake
9、r, nproduct wrapped around wire toprevent wire-to-mortar bond over a certain length.3.1.2.1 DiscussionDuct tape is commonly used for thispurpose.3.1.3 mortar, nmixture of cement, fine aggregate, andwater.3.1.4 test specimen, nassembly consisting of one steelcasing, one sample of wire, and mortar.4.
10、Summary of Test Method4.1 Six samples of 0.2 0.3 in. 5 8 mm diameter (seeNote 1) steel wire are selected from a single continuous lengthfor testing. Each wire sample is cast into a steel casing with abonded length of 6 in. 150 mm.4.2 Amortar mixture, including the fine aggregate source, isprescribed
11、, but the cement source is not.4.3 Testing of the six specimens begins shortly after themortar-cube compressive strength reaches 4500 psi 31.0 MPaand ends before the strength reaches 5000 psi 34.5 MPa. Aspecified, force-controlled loading rate is applied at the bottomof the wire while the applied lo
12、ad and free-end slip at theopposite (top) end is continuously monitored and recorded.The maximum pullout force occurring at an end slip less thanor equal to 0.10 in. 2.5 mm is recorded as the “test result.”One complete test is comprised of the average of these sixspecimens.NOTE 1This test method was
13、 developed specifically to correlatepullout values with transfer lengths for 0.208 in. 5.28 mm diameter steelwire conforming to Specification A881/A881M for prestressed concrete1This test method is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the di
14、rect responsibility of SubcommitteeA01.05 on Steel Reinforcement.Current edition approved Dec. 1, 2015. Published January 2016. DOI: 10.1520/A1096_A1096M-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
15、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1railroad ties but may be modified or adapted to accommodate smaller orlarger wire sizes an
16、d in prestressing or other non-prestressed concretereinforcement applications.5. Significance and Use5.1 Steel wire for concrete reinforcement is used in variousapplications wherein the wire is expected to transfer passive orprestressing forces to the structural member via the bond of theexposed wir
17、e surfaces to the surrounding concrete.5.2 Wire manufacturing processes, subsequent handling,and storage conditions can influence the wire bond.5.3 Steel wire for concrete reinforcement is used in con-struction applications with a variety of concrete mixtures.Developing test methods and threshold va
18、lues for the perfor-mance of the wire in each of these unique mixtures isimpractical.6. Apparatus6.1 A position transducer having a minimum precision of0.001 in. 0.025 mm is used.6.2 A tensile testing machine is used with the followingfunctionality:6.2.1 Force-controlled loading rate;6.2.2 Gripping
19、Device without Torsional RestraintThismay be accomplished by providing a thrust bearing to allowrotation; other similar methods may be used (see Note 2).FIG. 1 Photo of Pullout Test Frame and Specimen as the Test is Being ConductedA1096/A1096M 1526.2.3 Rigid Testing FrameAn example of the frame used
20、for conducting the test is shown in Fig. 1. Other similar testframe setups may be used.NOTE 2This test method was developed without torsional restraint. Inthe case of some particular wire geometries (for instance, helical-deformed wire), wire behavior during test method development indicateda tenden
21、cy for the frame to rotate.7. Wire Sampling7.1 The wire shall conform to Specifications A421/A421Mor A881/A881M.7.2 Samples of wire approximately 20 in. 500 mm longshall be taken from the same coil or reelless pack of wire. Thewire shall be cut to have flat ends. A minimum of six wiresamples are req
22、uired.8. Mortar Requirements8.1 Materials:8.1.1 SandThe sand shall be silica sand from the Ottawa,Illinois region and shall be Graded Sand conforming toSpecification C778.8.1.2 CementThe cement shall conform to SpecificationC150/C150M requirements for Type III cement.8.1.3 WaterThe water shall be po
23、table.8.1.4 AdmixturesAdmixtures shall not be used.8.1.5 AggregatesNo aggregates other than sand as speci-fied in 8.1.1 shall be used.8.2 Mixing ProcedureThe mixing procedure shall con-form to Practice C192/C192M except no coarse aggregates oradmixtures are allowed.8.3 StrengthMortar strength shall
24、be evaluated accordingto Test Method C109/C109M using 2 in. 50 mm mortarcubes. Brass molds shall be used. Testing of the pulloutspecimens should begin as soon as practical after the 2 in. 50mm mortar cube compressive strength reaches 4500 psi 31.0MPa. This mortar strength is defined as the average c
25、ompres-sive strength of at least two individual 2 in. 50 mm mortarcubes. If the mortar strength exceeds 5000 psi 34.5 MPabefore the end of the test, then the test shall be consideredinvalid and shall be repeated.NOTE 3Practice C192/C192M is described as a standard practice to beused for concrete tes
26、t specimens. As outlined in 8.1, only fine aggregates(that is, sand) are included in the mixture along with cement and water.Because coarse aggregates are not included, this mixture is defined as“mortar” and not “concrete.” Aside from this difference and a few otherexceptions noted in Section 8, the
27、 practices documented in PracticeC192/C192M are to be applied when making the mortar used in this testmethod.8.4 Mixture Proportions:8.4.1 The mixture proportions and batch weights listed inTable 1 shall be used (Note 4).NOTE 4In Table 1, a mortar with a water-to-cement ratio (w/c) of0.425 and an ov
28、en-dry sand-to-cement (s/c) ratio of 2.0 is shown.9. Preparation of Test Specimens9.1 Materials:9.1.1 Wire SamplesRequirements as defined in Section 7.9.1.2 MortarRequirements as defined in Section 8.9.1.3 Bottom Bond BreakerA 1.0-in. 25-mm wide 60.125-in. 3.0-mm strip of woven cloth adhesive tape (
29、ducttape) shall be used as a bottom bond breaker. The length ofbond breaker should not be less than 5 in. 130 mm beforeapplication. Wrap the bond breaker around the wire snugly.9.1.4 Top Bond BreakerUse a 2.0-in. 50-mm wide 60.125-in. 3.0-mm strip of woven adhesive cloth (duct tape) asa top bond bre
30、aker. The length of bond breaker should not beless than 3.0 in. 75 mm before application. Wrap the bondbreaker around the wire snugly. The top bond breaker extendsbelow the top mortar surface approximately 1.0 in. 25 mm toensure the actual bond length desired in case of settlement. Thedistance betwe
31、en the top and bottom bond breaker (embedmentlength) is maintained at 6.0 6 0.0625 in. 150 6 1.6 mm.9.1.5 Steel CasingEach individual wire sample shall becast in a 4 in. 100 mm outer diameter steel tube, approxi-mately18 in. 3 mm wall thickness (11 gauge), and a totallength of 8 in. 200 mm. A 6.0 in
32、. 6.0 in. 316 in. 150 mm 150 mm 5 mm thick steel plate is tack welded to thebottom of the tube. The remaining contact surface between thetube and plate shall be caulked to prevent any leakage ofmortar during filling and curing. A schematic of the wirepullout specimen is shown in Fig. 2. The bottom p
33、late shallhave a center-drilled hole using the smallest standard132-in.0.8-mm drill bit to allow the wire to freely pass through thehole.9.2 Specimen AssemblyEach wire sample shall be castinto a steel casing in the vertical position. The wires shall beheld centered (concentrically 618 in. 63 mm) in
34、the steelcasing using an additional fixture and reinforcing bar tie wire.The fixture shall be able to prevent movement of the wireduring the consolidation process. The additional fixture shallbe removed after the mortar has cured and before testing. Anexample of a fixture used to secure the wire at
35、the center of thesteel casing is shown in Fig. 3.9.3 ConsolidationThe pullout specimens shall be filled intwo approximately equal lifts and consolidated using internalvibration (approximately five seconds total) between each lift.The first lift shall be approximately 50 % and the second liftapproxim
36、ately 40 %. The remaining 10 % of mortar shall beadded and smoothed using a hand trowel.9.4 CuringThe pullout test specimens shall be cured sothat the relative humidity of the exposed top surface is greaterthan or equal to 95 % for the duration of curing. The 2 in. 50mm mortar cubes shall be cured a
37、t a minimum of 95 %relative humidity. The specimens and cubes shall be cured in atemperature and humidity controlled room maintained at atemperature of 73.5 6 3.5F 23 6 1.9C (see Note 5). Thetest specimens shall be cured in an environment free ofvibrations.TABLE 1 Recommended Batch WeightMaterial Pr
38、oportional WeightC150/C150M Type III Cement 1.0C778 Ottawa Sand (Oven-Dry) 2.0Water 0.425A1096/A1096M 153NOTE 5These parameters may be met with the use of a moist room orcloset, as in Specification C511, or through other suitable means.10. Test Setup10.1 Test FrameThe specimens shall be tested in a
39、frameas described in Section 6. A photo of the test frame used isshown in Fig. 1. Other similar test frames may be used.10.2 Free-End Slip MeasurementA position transducer,generally a linear variable differential transformer (LVDT),shall be installed to measure the free-end slip of the wirerelative
40、to the hardened mortar surface. The position transducershall be centered on the wire. A picture of a typical test setupis shown in Fig. 4.NOTE 1The End Slip Measurementapparatus shown here is an example of one type of measurement set-up. Other configurations and devices maybe used.A SI equivalent: 5
41、1 mm 13 mmB SI equivalent: 102 mm3mm(OD)3mmmin(wallthickness)C SI equivalent: 152 mm 152 mm 4.8 mmD 0.25 in.SI equivalent: 51 mm 6.4 mmE 0.063 in.SI equivalent: 152.4 mm 1.6 mmF 0.036 in.SI equivalent: 25.4 mm 1.6 mmG + 10 in. / 0 in.SI equivalent: 508 mm + 254 mm / 0mmH SI equivalent: 203 mm 3.2 mm
42、FIG. 2 Schematic of Wire Pullout Test SpecimenA1096/A1096M 15410.3 Wire GrippingThe wire shall be gripped by a chuck-ing device. The free length between the bottom of the plate ofthe steel casing and the top of the chucking device shall be aminimum of 7.0 in. 180 mm. The test shall be free fromtorsi
43、onal restraint.11. Procedure11.1 Test StartThe test specimens shall be removed fromthe temperature and humidity controlled environment, andtesting may begin once the compressive strength of the mortarreaches 4500 psi 31.0 MPa as evaluated by the 2 in. 50 mmmortar cubes. This mortar strength is defin
44、ed as the averagecompressive strength of at least two individual 2 in. 50 mmmortar cubes.11.2 Mortar StrengthThe compressive strength of themortar shall be determined at the beginning of the test and theend of the test.11.3 Force RateLoad shall be applied to the wire bydisplacement of the chucking d
45、evice.Aforce-controlled rate of2000 6 100 lbf/min 8900 6 450 N/min shall be maintainedafter the chuck has been initially seated.11.4 Test ResultThe maximum pullout force occurring atan end slip less than or equal to 0.10 in. 2.5 mm shall berecorded. This force shall be rounded to the nearest 10 lbf
46、50N.11.5 Acceptance of Test ResultIf the mortar exhibitscracking visible to a person with normal or corrected vision inFIG. 3 Example of Fixture Used to Keep Wire Centered in Steel Casing During Mortar Placement and ConsolidationA1096/A1096M 155two or more of the six test specimens, the entire batch
47、 of sixspecimens shall be discarded and new specimens prepared. Ifthe mortar exhibits cracking visible to a person with normal orcorrected vision in one of the six test specimens, that shall bereported.12. Report12.1 The following items shall be reported:12.1.1 Specification the wire was produced to
48、.12.1.2 Identification of the wire tested (that is, coil number).12.1.3 Wire manufacturer.12.1.4 Date of original wire manufacture.12.1.5 Location of original wire manufacture.12.1.6 Dates of test.12.1.7 Wire diameter.12.1.8 Indentation type.12.1.9 Specified wire tensile strength.12.1.10 Six individ
49、ual test results.12.1.11 Average test results.12.1.12 Batch weights and origin of constituent materials.12.1.13 Date and Time of BatchingBatching time is re-ported as the time the mixing of the mortar is completed,rounded to the nearest 5 minutes.12.1.14 Mortar temperature at the time mixing of themortar is completed.FIG. 4 LVDT and Magnetic Base SetupA1096/A1096M 15612.1.15 Individual Mortar Cube Compressive Strengths an
