1、Designation: C1521 091C1521 13Standard Practice forEvaluating Adhesion of Installed Weatherproofing SealantJoints1This standard is issued under the fixed designation C1521; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTEEditorial changes were made in Section 7 in December 2009.1. Scope1.1 This practice describes destructive and nondestructi
3、ve procedures.1.2 The destructive procedure stresses the sealant in such a way as to cause either cohesive or adhesive failure of the sealantor cohesive failure of the substrate where deficient substrate conditions exist. The objective is to characterize the adhesive/cohesiveperformance of the seala
4、nt on the specific substrate by applying whatever strain is necessary to effect failure of the sealant bead.It is possible that the strain applied to the sealant bead may result in the failure of a deficient substrate before effecting a failurein the sealant.NOTE 1The destructive procedure requires
5、immediate repair of the sealant bead. Appropriate materials and equipment should be available for thispurpose.NOTE 2Sealant formulations may fail in cohesion or adhesion when properly installed, and tested by this method. The sealant manufacturer shouldbe consulted to determine the appropriate guide
6、lines for using this method.1.3 The nondestructive procedure places strain on the sealant and a stress on the adhesive bond. Though termed nondestructive,this procedure may result in an adhesive failure of a deficient sealant bead, but should not cause a cohesive failure in the sealant.The results o
7、f this procedure should be either adhesive failure or no failure.NOTE 3The nondestructive procedure may require immediate repair of the sealant bead, if failure is experienced. Appropriate materials andequipment should be available for this purpose.1.4 The non-destructive procedure can be used for c
8、ontinuous inspection of 100 % of the joint(s) or for any areas where deficientconditions, which are inconsistent with the practices of Guide C1193, are suspected.1.5 The committee with jurisdiction over this practice is not aware of any comparable practices published by other organizationsor committ
9、ees.1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.7 This standard does not purport to address all of the safety concerns, if an
10、y, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and SealantsC794 T
11、est Method for Adhesion-in-Peel of Elastomeric Joint SealantsC1193 Guide for Use of Joint Sealants3. Terminology3.1 DefinitionsFor definitions of terms used in this recommended procedure, see Terminology C717.3.2 Definitions of Terms Specific to This Standard:1 This practice is under the jurisdictio
12、n of ASTM Committee C24 on Building Seals and Sealants and is the direct responsibility of Subcommittee C24.30 on Adhesion.Current edition approved June 1, 2009May 1, 2013. Published July 2009May 2013. Originally approved in 2002. Last previous edition approved in 20082009 asC1521 08a.C1521 091. DOI
13、: 10.1520/C1521-09.10.1520/C1521-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an A
14、STM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In
15、all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 flap, nthe term “flap” as used in this specification refers to a po
16、rtion of an installed sealant bead that has been purposelycut along one substrate bond line and across the bead at two locations resulting in a portion of bead adhered along one substratebond line.3.2.2 tail, nthe term “tail” as used in this specification refers to a portion of an installed sealant
17、bead that has been purposelycut along both substrate bond lines and across the bead at one location resulting in a portion of bead unadhered to the substratesbut adhered to the remainder of the sealant bead.4. Significance and Use4.1 Many parameters contribute to the overall performance of a sealant
18、 application. Some of the most significant parametersare sealant bead size and configuration, joint movement, quality of workmanship, the quality of the adhesive bond, and the qualityof the sealant material.4.2 A sealant usually fails to perform as a weatherseal when it experiences cohesive or adhes
19、ive failure.4.3 If a sealant bead fails, an evaluation of the total joint movement may be needed to determine if the joint sealant was strainedbeyond design or if the sealant failed within design parameters.4.4 If a sealant bead fails adhesively, there is no straightforward procedure for determining
20、 the cause. The adhesive failure maybe due to workmanship, the specific surface preparation used, the specific sealant used, poor “installed” joint design, poor bondchemistry and other causes.4.5 Because of the complex nature of the performance of a sealant bead, an understanding of the quality of t
21、he adhesive bondis instrumental in any evaluation of sealant performance. It is critical that the test procedures used truly evaluate the quality of theadhesive bond and do not simply take advantage of the tear resistance of the sealant.4.6 This method does not evaluate the performance of a sealant
22、joint as a weatherseal. It only evaluates the characteristics ofthe adhesive bond relative to the cohesive strength of the sealant in a particular installation. Since any failures that result from useof this test method are intentionally induced, they do not necessarily mean that the sealant joint w
23、ill not perform as a weatherseal.4.7 The results of these methods are most useful in identifying sealant joints with poor adhesion. The continuous inspectionprocedure is also useful in the identification of places of poor joint configuration. Obvious cohesive failures are also identified. Theresults
24、 of these methods can be used to assess the likely performance of the sealant joint and to compare performance against othersealant joints.4.8 The nondestructive methods are most effective while the sealant is in a state of extension due to mild or low temperatures.They are least effective during hi
25、gh temperature when the sealant is in a compressed condition.5. Testing Equipment5.1 Field EquipmentThe following equipment is required to perform this practice: rule with 132 in. divisions (mm), probingtool, razor knife, knife or other cutting instrument with a pointed 2 in. (50 mm) minimum length
26、blade, sealable sample bags, repairsealant compatible with existing sealant, tools for installing sealant, butyl tape, water.5.2 Field Equipment, Nondestructive Continuous MethodAwheel roller such as a screen roller or a backer rod insertion rolleror a pressure controlled roller.5.3 Provide material
27、s for recording data. These may include masking tape, marking pen, note books, shop or architecturaldrawings, a camera or video recorder, or both.6. Summary of Methods6.1 Nondestructive Spot MethodThis method makes use of a blunt dowel shaped tool to impart pressure against the surfaceof the sealant
28、 bead. Firm pressure is applied to the surface of the sealant in the center of the bead and near the bond line. Thismethod evaluates a discrete area of the sealant bead and is repeated numerous times to provide an evaluation of a given length ofsealant joint.6.2 Nondestructive Continuous MethodThis
29、method makes use of a wheel to impart pressure against the surface of the sealantbead. The wheel is rolled continuously along the center of the sealant bead to provide 100 % inspection of a given length of sealantjoint.6.3 All MethodsData is collected continuously for all methods. Precise descriptio
30、n of location and type of all anomalies isrecorded by a method appropriate for the given evaluation. See Appendix X1.6.4 Destructive MethodThis method is performed by cutting through the sealant bead to provide either a “tail” or a “flap” ofsealant that can be pulled by hand, to stress the bond line
31、 of the sealant. The width and location of the sealant bead will determinehow and to what degree the hand pull method can be performed. This method uses described techniques to cause an adhesivefailure from the substrate.C1521 1326.4.1 Water ImmersionThis method makes use of a vessel filled with wat
32、er to expose a sealant bead to water beforeperforming the procedures described in 7.1-7.4. This method can also be performed in the event that project specific substrates arenot able to be evaluated in the laboratory for surface preparation recommendations based on testing in accordance with adhesio
33、nmethods such as Test Method C794. It is advisable to perform a field adhesion evaluation both dry and wet.NOTE 4Narrow joints (less than 516 in. or 8 mm wide) do not lend themselves to destructive field adhesion tests. Usually, some kind of “tail” canbe provided to perform an adhesion pull. However
34、, these tests tend to evaluate the cohesive property of the sealant more than the adhesive property.NOTE 5Joints that are less than 58 in. or 16 mm wide or that are more than 12 in. (13 mm) deep do not lend themselves to a “flap” style adhesionpull. The “tail” style adhesion pull should be performed
35、 on these joints.7. Procedures7.1 Nondestructive Procedure:7.1.1 Select a probing tool that is at least 18 in. (3 mm) narrower than the width of the sealant joint to be evaluated. Fig. 1provides example dimensions for a probing tool.NOTE 6The probing tool should be blunt without sharp edges and shap
36、ed in such a way that it will not puncture the sealant bead.7.1.2 Technique 1Using the probing tool, depress the center of the sealant bead to create an elongation strain on the sealantjoint. Record the depth of the depression as a percentage of the width of the bead.Acommon percentage used to creat
37、e reasonablestrain and reveal poor adhesion is 50 %. The appropriate percentage varies with each sealant joint and is approximatelyproportional to the expected joint movement. The percentage can be correlated with destructive procedure test results.7.1.3 Technique 2Locating the probing tool adjacent
38、 to the sealant/substrate bond line, depress the sealant bead to the extentthat (visually) it appears the sealant is about to fail cohesively. The sealant bead should be depressed in such a way that the probingtool does not contact or scrape against the substrate, nor slide toward the center of the
39、joint. This technique will effect a peel-typestrain on the sealant joint. This technique will produce shear forces close to the bond line and therefore the results should beprudently interpreted.7.2 Nondestructive Continuous Inspection Procedure:7.2.1 Place masking tape on the exposed surface of the
40、 substrate adjacent to the sealant to be inspected. Using a roller of suchthickness as to be equal to or less than half of the width of the joint, apply pressure to the sealant through the roller to developa depression in the sealant joint that represents approximately 50 % deflection of the sealant
41、.Advance the roller along the centerlineof the length of the joint, using uniform pressure. Observe the condition of the sealant for conditions, such as deflection of thesealant that is greater than or less than expected, adhesive failure, cohesive failure or mechanical damage to the sealant, and ma
42、rkthe location of these conditions on the masking tape. It is helpful to use characteristic marks such as “A” for adhesion loss, “H”where the sealant appears hard, “S” where the sealant appears soft, “C” where a cohesive failure exists, for example, when markingthe masking tape. Where extended lengt
43、h of adhesive failure occurs, the masking tape can be marked to indicate the ends of theadhesive failures. The tape can also contain markings that identify the location and side of the joint at which it is located. Uponcompletion of depressing the sealant with the roller, documentation of the locati
44、ons and types of conditions can be performed.7.2.2 Determining the Causes of the AnomaliesEach anomaly can be inspected for obvious causes. However, it is generallyhelpful to remove a portion of the sealant and backer material for inspection. Sometimes, a more thorough examination of theanomaly loca
45、tion will be required. The destructive procedure described in 7.3 can be used.7.3 Destructive Procedure:FIG. 1 Probing ToolC1521 1337.3.1 The “Tail” Procedure consists of cutting through the sealant, 6 in. (150 mm) along the bond line at both substrates. Cutacross the sealant bead to release one end
46、 of the “tail” that is formed (see Fig. 2). Insure that the sealant is cut at the substrate andthat the sealant bead is free of nicks or jagged edges.7.3.2 Method A:7.3.2.1 Mark the cut portion of the sealant 1 in. (25 mm) from the adhesive bond.7.3.2.2 Grasp the sealant “tail” at the mark 1 in. (25
47、 mm) from the adhesive bond.7.3.2.3 Pull tail at an angle of 90 to the substrate to effectively extend the 1-in. mark to two times the stated movementcapability of the sealant.7.3.2.4 Record the type of failure that occurred and the distance of the mark from the adhesive bond when failure occurred,
48、orthe distance recommended by manufacturer without causing failure.7.3.3 Method B:7.3.3.1 Mark the cut portion of the sealant 1 in. (25 mm) from the adhesive bond.7.3.3.2 Grasp the sealant tail at the mark 1 in. (25 mm) from the adhesive bond.7.3.3.3 Various tests can be performed pulling the tail s
49、lowly at an angle of 30, 90 or 150 to the substrate, keeping the tail inline with the sealant bead as nearly as possible. Monitor the extension to determine the elongation resulting in failure.NOTE 7Techniques using the “tail procedure” that allow evaluations of sealant adhesion to one substrate at a time are acceptable.7.3.3.4 If the sealant begins to tear cohesively, stop pulling and readjust the grasp on the tail and begin pulling again. Pull onthe tail in whatever direction or manner that best avoids cohesive tearing and encourages adhesive f
