1、Designation: C 1521 02aStandard 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 (e) 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, b
3、y 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 evaluateds
4、uch 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 o
5、f 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 bea
6、d 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 adhes
7、ion 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 proced
8、ure 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 expe
9、rienced. Appropriate materials andequipment should be available for this purpose.1.4 The committee with jurisdiction over this practice is notaware of any comparable practices published by other organi-zations or committees.1.5 This standard does not purport to address all of thesafety concerns, if
10、any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 717 Terminology of Building Seals and Sealants2
11、3. Terminology3.1 DefinitionsFor definitions of terms 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 al
12、ong one substrate bond line and across the beadat 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 an
13、d across thebead at one location resulting in a portion 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 b
14、ead size and configuration, joint movement,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 total
15、jointmovement may be needed to determine if the joint sealant wasstrained beyond design or if the sealant failed within designparameters.1This practice is under the jurisdiction of ASTM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of Subcommittee C24.30 onAdhesion.Cur
16、rent edition approved May 10, 2002. Published July 2002. Originallypublished as C 1521 02. Last previous edition C 1521 02.2Annual Book of ASTM Standards, Vol 04.07.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 If a sealant bea
17、d fails adhesively, there is no straight-forward procedure for determining the cause. The adhesivefailure may be due to workmanship, the specific surfacepreparation used, the specific sealant used, poor “installed”joint design, poor bond chemistry and other causes.4.5 Because of the complex nature o
18、f the performance of asealant bead, an understanding of the quality of the adhesivebond is instrumental in any evaluation of sealant performance.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 s
19、ealant.4.6 This method does not evaluate the performance of asealant joint as a weatherseal. It only evaluates the character-istics of the adhesive bond relative to the cohesive strength ofthe sealant in a particular installation. Since any failures thatresult from use of this test method are intent
20、ionally induced,they do not necessarily mean that the sealant joint will notperform as a weatherseal.4.7 The method results are most useful in identifying sealantjoints with poor adhesion. The results of these methods can beused to assess the likely performance of the sealant joint and tocompare per
21、formance against other joints.5. Testing Equipment5.1 Field EquipmentThe following equipment is requiredto perform this practice: rule with132 in. divisions (mm),probing tool, razor knife, knife or other cutting instrument witha pointed 2 in. (50 mm) minimum length blade, sealablesample bags, repair
22、 sealant compatible with existing sealant,tools for installing sealant, butyl tape, water.6. Summary of Methods6.1 Nondestructive MethodThis 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 i
23、n the center of the bead and near the bond line.6.2 Destructive MethodThis method is performed bycutting through the sealant bead to provide 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 determi
24、ne how and to what degree the hand pull methodcan be performed. This method uses described techniques tocause an adhesive failure from the 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 provi
25、ded to perform an adhesion pull. However, these tests tend toevaluate the cohesive property of the sealant more than the adhesiveproperty.NOTE 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” styl
26、e adhesion pull should be performed on these joints.7. Procedures7.1 Nondestructive Procedure:7.1.1 Select a probing tool that is at least18 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 b
27、lunt without sharp edges andshaped in such a way that it will not puncture the sealant bead.7.1.2 Technique 1Using the probing tool, depress 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.
28、 A common percentage used tocreate reasonable strain and reveal poor adhesion is 50 %. Theappropriate percentage varies with each sealant joint and isapproximately proportional to the expected joint movement.The percentage can be correlated with destructive proceduretest results.7.1.3 Technique 2Loc
29、ating the probing tool adjacent tothe sealant/substrate bond line, depress the sealant bead to theextent that (visually) it appears the sealant 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 sli
30、de toward the center of the joint. Thistechnique will effect a peel-type strain on the sealant joint. Thistechnique will produce shear forces 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 throu
31、gh 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 formed (see Fig. 2). Insure that the sealant is cut at theFIG. 1 Probing ToolFIG. 2 Tail ProcedureC 1521 02a2substrate and that the sealant bead is free of nicks o
32、r 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.7.2.2.3 Pull tail at an angle of 90 to the substrate toeffectively extend the 1-in. mark to two times the stat
33、edmovement 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 manufacturer with-out causing failure.7.2.3 Method B:7.2.3.1 Mark the cut portion of the sealant 1 in. (25 mm)
34、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 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
35、 to determine the elongation resulting infailure.NOTE 7Techniques using the “tail procedure” that allow evaluationsof sealant adhesion to one substrate at a time are acceptable.7.2.3.4 If the sealant begins to tear cohesively, stop pullingand readjust the grasp on the tail and begin pulling again. P
36、ullon 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 adhesionto both substrates forming the joint.7.2.4 Flap Procedure:7.2.4.1 The “Flap” Procedure consists of cutting through thesealant, 3 i
37、n. (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) 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
38、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.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 hav
39、e 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 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 dep
40、ends upon the reasonsfor performing the test procedures; for example, to evaluatenewly installed sealant as part of a Quality Control program, toevaluate aged sealant as part of a condition survey or toevaluate failing sealant as part of an investigation.7.3.2 Nondestructive ProcedureFor each area t
41、o 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) of joint tested, test every 24 in. (600 mm)thereafter.7.3.2.1 After any observation of test failure, increase thefrequency of the testing.
42、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 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 A
43、fter any observation of test failure, increase thefrequency of the testing. Correlate results with nondestructiveprocedure results.7.3.4 Frequency of tests may be increased for either proce-dure for any reason or may be decreased if only spot-checkingis desired. Test each joint condition as deemed n
44、ecessary.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 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 wea
45、ther-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 length of joint to be tested, canbe adhered to the substrate and sealant bead using sealant orsealant tape. Water exposure should only be p
46、erformed 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 filled with distilled water causingthe face of the vessel to be completely filled with water. Sealthe top of the chamber after filling to prev
47、ent evaporation. Incold climates, consideration should be given to protecting thechamber from freezing.7.4.4 Remove the vessel and contents and perform theprocedures described in 7.1-7.3.8. Reporting8.1 Record test conditions and results for each procedure onan appropriate form; (see Fig. 4, for exa
48、mple form).FIG. 3 Flap ProcedureC 1521 02a3FIG. 4 Field Adhesion Report FormC 1521 02a48.2 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 subjectivi
49、ty 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 removed, date removed, results ofmethod and project identification. These samples should bestored in a secure identified location for the duration of thewarranty period.8.4 Photographs of test areas can be useful in studying andcomparing adhesion results.9. Repair9.1 Contact the sealant manufacturer for specific recom-mendations for the repair of sealant damaged during fieldadhesion testing procedures.10
