ASTM C1521-2008 Standard Practice for Evaluating Adhesion of Installed Weatherproofing Sealant Joints.pdf

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1、Designation: C 1521 08Standard Practice forEvaluating Adhesion of Installed Weatherproofing SealantJoints1This standard is issued under the fixed designation C 1521; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last

2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes field tests to determine theadhesive and cohesive characteristics of an installed sealantjoint, by

3、manually placing a strain on the sealant. The sealantto be tested shall be fully cured. The results of this method canbe used in conjunction with other information to determine theoverall performance of the sealant joint. The user of thispractice should define the other parameters to be evaluatedsuc

4、h as cleaning of the substrate, depth control of the sealant,sealant profile, etc. This method describes both nondestructiveand destructive procedures.1.2 The destructive procedure stresses the sealant in such away as to cause either cohesive or adhesive failure of thesealant or cohesive failure of

5、the substrate where deficientsubstrate conditions exist. The objective is to characterize theadhesive/cohesive performance of the sealant on the specificsubstrate by applying whatever strain is necessary to effectfailure of the sealant bead. It is possible that the strain appliedto the sealant bead

6、may result in the failure of a deficientsubstrate before effecting a failure in the sealant.NOTE 1The destructive procedure requires immediate repair of thesealant bead. Appropriate materials and equipment should be available forthis purpose.NOTE 2Sealant formulations may fail in cohesion or adhesio

7、n whenproperly installed, and tested by this method. The sealant manufacturershould be consulted to determine the appropriate guidelines for using thismethod.1.3 The nondestructive procedure places strain on the seal-ant and a stress on the adhesive bond. Though termed nonde-structive, this procedur

8、e may result in an adhesive failure of adeficient sealant bead, but should not cause a cohesive failurein the sealant. The results of this procedure should be eitheradhesive failure or no failure.NOTE 3The nondestructive procedure may require immediate repairof the sealant bead, if failure is experi

9、enced. Appropriate materials andequipment should be available for this purpose.1.4 The non-destructive procedure can be used for continu-ous inspection of 100 % of the joint(s) or for any areas wheredeficient conditions, which are inconsistent with the practicesof Guide C 1193, are suspected.1.5 The

10、 committee with jurisdiction over this practice is notaware of any comparable practices published by other organi-zations or committees.1.6 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 es

11、tablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 717 Terminology of Building Seals and SealantsC 1193 Guide for Use of Joint Sealants3. Terminology3.1 DefinitionsFor definitions of te

12、rms used in this rec-ommended procedure, see Terminology C 717.3.2 Definitions of Terms Specific to This Standard:3.2.1 flap, nthe term “flap” as used in this specificationrefers to a portion of an installed sealant bead that has beenpurposely cut along one substrate bond line and across the beadat

13、two locations resulting in a portion of bead adhered alongone substrate bond line.3.2.2 tail, nthe term “tail” as used in this specificationrefers to a portion of an installed sealant bead that has beenpurposely cut along both substrate bond lines and across thebead at one location resulting in a po

14、rtion of bead unadhered tothe substrates but adhered to the remainder of the sealant bead.4. Significance and Use4.1 Many parameters contribute to the overall performanceof a sealant application. Some of the most significant param-eters are sealant bead size and configuration, joint movement,1This p

15、ractice is under the jurisdiction of ASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.30 onAdhesion.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 2002. Last previous edition approved in 2002 as C 1521 02a.2For re

16、ferenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W

17、est Conshohocken, PA 19428-2959, United States.quality of workmanship, the quality of the adhesive bond, andthe quality of the sealant material.4.2 A sealant usually fails to perform as a weatherseal whenit experiences cohesive or adhesive failure.4.3 If a sealant bead fails, an evaluation of the to

18、tal jointmovement may be needed to determine if the joint sealant wasstrained beyond design or if the sealant failed within designparameters.4.4 If a sealant bead fails adhesively, there is no straight-forward procedure for determining the cause. The adhesivefailure may be due to workmanship, the sp

19、ecific surfacepreparation used, the specific sealant used, poor “installed”joint design, poor bond chemistry and other causes.4.5 Because of the complex nature of the performance of asealant bead, an understanding of the quality of the adhesivebond is instrumental in any evaluation of sealant perfor

20、mance.It is critical that the test procedures used truly evaluate thequality of the adhesive bond and do not simply take advantageof the tear resistance of the sealant.4.6 This method does not evaluate the performance of asealant joint as a weatherseal. It only evaluates the character-istics of the

21、adhesive bond relative to the cohesive strength ofthe sealant in a particular installation. Since any failures thatresult from use of this test method are intentionally induced,they do not necessarily mean that the sealant joint will notperform as a weatherseal.4.7 The method results are most useful

22、 in identifying sealantjoints with poor adhesion. The results of these methods can beused to assess the likely performance of the sealant joint and tocompare performance against other joints.5. Testing Equipment5.1 Field EquipmentThe following equipment is requiredto perform this practice: rule with

23、132 in. divisions (mm),probing tool, razor knife, knife or other cutting instrument witha pointed 2 in. (50 mm) minimum length blade, sealablesample bags, repair sealant compatible with existing sealant,tools for installing sealant, butyl tape, water.6. Summary of Methods6.1 Nondestructive MethodThi

24、s method makes use of ablunt dowel shaped tool to impart pressure against the surfaceof the sealant bead. Firm pressure is applied to the surface ofthe sealant in the center of the bead and near the bond line.6.2 Destructive MethodThis method is performed bycutting through the sealant bead to provid

25、e either a “tail” or a“flap” of sealant that can be pulled by hand, to stress the bondline of the sealant. The width and location of the sealant beadwill determine how and to what degree the hand pull methodcan be performed. This method uses described techniques tocause an adhesive failure from the

26、substrate.NOTE 4Narrow joints (less than516 in. or 8 mm wide) do not lendthemselves to destructive field adhesion tests. Usually, some kind of “tail”can be provided to perform an adhesion pull. However, these tests tend toevaluate the cohesive property of the sealant more than the adhesiveproperty.N

27、OTE 5Joints that are less than58 in. or 16 mm wide or that are morethan12 in. (13 mm) deep do not lend themselves to a “flap” style adhesionpull. The “tail” style adhesion pull should be performed on these joints.7. Procedures7.1 Nondestructive Procedure:7.1.1 Select a probing tool that is at least1

28、8 in. (3 mm)narrower than the width of the sealant joint to be evaluated.Fig. 1 provides example dimensions for a probing tool.NOTE 6The probing tool should be blunt without sharp edges andshaped in such a way that it will not puncture the sealant bead.7.1.2 Technique 1Using the probing tool, depres

29、s thecenter of the sealant bead to create an elongation strain on thesealant joint. Record the depth of the depression as a percent-age of the width of the bead. A common percentage used tocreate reasonable strain and reveal poor adhesion is 50 %. Theappropriate percentage varies with each sealant j

30、oint and isapproximately proportional to the expected joint movement.The percentage can be correlated with destructive proceduretest results.7.1.3 Technique 2Locating the probing tool adjacent tothe sealant/substrate bond line, depress the sealant bead to theextent that (visually) it appears the sea

31、lant is about to failcohesively. The sealant bead should be depressed in such a waythat the probing tool does not contact or scrape against thesubstrate, nor slide toward the center of the joint. Thistechnique will effect a peel-type strain on the sealant joint. Thistechnique will produce shear forc

32、es close to the bond line andtherefore the results should be prudently interpreted.7.2 Destructive Procedure:7.2.1 The “Tail” Procedure consists of cutting through thesealant, 6 in. (150 mm) along the bond line at both substrates.Cut across the sealant bead to release one end of the “tail” thatis fo

33、rmed (see Fig. 2). Insure that the sealant is cut at thesubstrate and that the sealant bead is free of nicks or jaggededges.7.2.2 Method A:7.2.2.1 Mark the cut portion of the sealant 1 in. (25 mm)from the adhesive bond.7.2.2.2 Grasp the sealant “tail” at the mark 1 in. (25 mm)from the adhesive bond.

34、7.2.2.3 Pull tail at an angle of 90 to the substrate toeffectively extend the 1-in. mark to two times the statedmovement capability of the sealant.7.2.2.4 Record the type of failure that occurred and thedistance of the mark from the adhesive bond when failureoccurred, or the distance recommended by

35、manufacturer with-out causing failure.FIG. 1 Probing ToolC15210827.2.3 Method B:7.2.3.1 Mark the cut portion of the sealant 1 in. (25 mm)from the adhesive bond.7.2.3.2 Grasp the sealant tail at the mark 1 in. (25 mm) fromthe adhesive bond.7.2.3.3 Various tests can be performed pulling the tailslowly

36、 at an angle of 30, 90 or 150 to the substrate, keepingthe tail in line with the sealant bead as nearly as possible.Monitor the extension to determine the elongation resulting infailure.NOTE 7Techniques using the “tail procedure” that allow evaluationsof sealant adhesion to one substrate at a time a

37、re acceptable.7.2.3.4 If the sealant begins to tear cohesively, stop pullingand readjust the grasp on the tail and begin pulling again. Pullon the tail in whatever direction or manner that best avoidscohesive tearing and encourages adhesive failure.7.2.3.5 Repeat procedure as necessary to evaluate a

38、dhesionto both substrates forming the joint.7.2.4 Flap Procedure:7.2.4.1 The “Flap” Procedure consists of cutting through thesealant, 3 in. (76 mm) along the bondline on the substrateopposite to the substrate to be evaluated. Make two cuts acrossthe sealant bead, one at each end of the 3 in. (76 mm)

39、 cut. Pryup the flap that is formed by the three cuts through the sealantbead (see Fig. 3).7.2.4.2 Grasp the flap near the edge opposite the bond lineto be evaluated.7.2.4.3 Pull the flap in the tensile mode until adhesive orcohesive failure.7.2.4.4 Stop pulling and grasp the flap near the other end

40、.7.2.4.5 Pull the flap in a shear mode until the onset ofadhesive or cohesive failure.7.2.4.6 Trim away the portions of the flap that have failed.7.2.4.7 Bend, twist and/or rotate the flap until adhesive orcohesive failure occurs.7.2.4.8 The Flap Procedure should be performed to evaluatethe bond at

41、each substrate, particularly if the substrates oneither side of the joint vary.7.3 Number of Tests:7.3.1 The frequency of the testing depends upon the reasonsfor performing the test procedures; for example, to evaluatenewly installed sealant as part of a Quality Control program, toevaluate aged seal

42、ant as part of a condition survey or toevaluate failing sealant as part of an investigation.7.3.2 Nondestructive ProcedureFor each area to be in-spected, perform procedure every 12 in. (300 mm) for first 10linear ft (3 m) of joint. If no test failure loss is observed in thefirst 10 linear ft (3 m) o

43、f joint tested, test every 24 in. (600 mm)thereafter.7.3.2.1 After any observation of test failure, increase thefrequency of the testing.7.3.3 Destructive ProcedureFor each area to be inspected,perform procedure every 100 linear ft in the first 1,000 linearft of joint. If no test failure is observed

44、 in the first 1,000 ft ofjoint, perform procedure every 1,000 linear ft thereafter orapproximately once per floor per elevation.7.3.3.1 After any observation of test failure, increase thefrequency of the testing. Correlate results with nondestructiveprocedure results.7.3.4 Frequency of tests may be

45、increased for either proce-dure for any reason or may be decreased if only spot-checkingis desired. Test each joint condition as deemed necessary.7.3.5 Testing at non-typical locations such as joint intersec-tions and complex joint configurations is recommended.7.4 Water Exposure:7.4.1 The addition

46、of exposure of the sealant bead to watercan be added to any of the above procedures.7.4.2 Water exposure can be achieved at installed weather-proofing sealant joints by creating a vessel attached to thesubstrate and sealant bead that can contain water. A prefabri-cated vessel, sized to expose the le

47、ngth of joint to be tested, canbe adhered to the substrate and sealant bead using sealant orsealant tape. Water exposure should only be performed afterthe cure time recommended by the sealant manufacturer. Thevessel top should be left open to allow placement of water.7.4.3 The vessel should be fille

48、d with distilled water causingthe face of the vessel to be completely filled with water. Sealthe top of the chamber after filling to prevent evaporation. Incold climates, consideration should be given to protecting thechamber from freezing.7.4.4 Remove the vessel and contents and perform theprocedur

49、es described in 7.1-7.3.FIG. 2 Tail ProcedureFIG. 3 Flap ProcedureC15210838. Reporting8.1 Record test conditions and results for each procedure onan appropriate form; (see Fig. 4, for example form).8.2 Each sealant joint is unique. This uniqueness requiresthat the procedures described in this method be subjectivelyapplied and/or modified for each test. Reproducibility willtherefore vary due to the subjectivity of the method.8.3 It is recommended that the owner retain the sealantsamples in a sealed plastic bag labeled with the location fromwhich the sample was