1、Designation: D7992/D7992M 15Standard Practice forElevated Temperature and Moisture Conditioning ofPultruded Fiber Reinforced Polymer (FRP) Composites Usedin Structural Designs1This standard is issued under the fixed designation D7992/D7992M; the number immediately following the designation indicates
2、 theyear of original adoption or, in 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 In general, it is feasible that the mechanical
3、properties ofFRP composites will be affected by environmental conditionssuch as exposure to moisture at elevated temperatures. In orderto make reliable comparisons between different materials underelevated temperature and moisture environmental conditions, itis necessary to standardize the elevated
4、temperature andmoisture conditions to which specimens of these materials aresubjected prior to and during testing. This practice definesprocedures for elevated temperature and moisture conditioningof pultruded FRP composites intended for use in structuraldesign applications. The conditioning medium
5、representingelevated temperature and moisture exposure described in thisstandard practice is distilled water maintained at 37.8 6 1.5C(100 6 3F) for 1000 hours.1.2 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system
6、 may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in noncon-formance with the standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespo
7、nsibility 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:2D618 Practice for Conditioning Plastics for TestingD3918 Terminology Relating to Reinforced
8、Plastic Pul-truded ProductsD6641/D6641M Test Method for Compressive Properties ofPolymer Matrix Composite Materials Using a CombinedLoading Compression (CLC) Test FixtureD7290 Practice for Evaluating Material Property Character-istic Values for Polymeric Composites for Civil Engineer-ing Structural
9、ApplicationsD7745 Practice for Testing Pultruded Composites3. Terminology3.1 Definitions:3.1.1 standard laboratory temperature, na temperature of23 6 2C (73.4 6 3.6F)3.1.2 standard laboratory atmosphere, nan atmospherehaving a temperature of 23 6 2C (73.4 6 3.6F) and a rela-tive humidity of 50 6 10
10、%.3.1.3 elevated temperature and moisture resistance, ntheability of a thermoset pultruded composite to withstand el-evated temperature and moisture exposure at 37.8 6 1.5C(100 6 3F) for 1000 hours. This ability will be quantified interms of the % retention of the mechanical property of interestas c
11、ompared to samples held at standard laboratory atmo-sphere.3.2 Terminology relating to pultruded composites is foundin Terminology D3918.4. Significance and Use4.1 The elevated temperature and moisture conditioningprocedures prescribed in this practice are designed to providea standard procedure to
12、be used to evaluate and compare theeffect of elevated temperature and moisture conditioning undercontrolled laboratory conditions on pultruded FRP compositesto be used in structural design applications. The conditioningprocedures prescribed in this practice are designed to obtainreproducible results
13、 to compare and evaluate these materialsbut are not intended to produce equilibrium conditions oractual service conditions for these materials.5. Sampling5.1 Sampling shall be in accordance with the locations fromwhich test specimens shall be taken from the reinforcedpultruded composites as defined
14、in Practice D7745.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.18 on Reinforced Thermoset-ting Plastics.Current edition approved Sept. 1, 2015. Published October 2015. DOI: 10.1520/D7992_D7992M-15.2For referenced AS
15、TM 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoho
16、cken, PA 19428-2959. United States15.2 Sampling shall be in accordance with the ASTM testmethods for the specific mechanical properties to be deter-mined.36. Test Specimens6.1 The numbers and types of test specimens shall be inaccordance with the ASTM test methods for the specificmechanical properti
17、es to be determined. If Practice D7290 is tobe used to determine characteristic values for a particularmechanical property, at least ten samples are needed for thecontrol and ten samples are needed for the elevated tempera-ture and moisture conditioning for a total of at least 20samples.6.2 Test spe
18、cimens shall be machined or otherwise fabri-cated to the test coupon geometry specified by the ASTM testmethod for the property to be determined prior to theirexposure to the environmental conditioning.6.3 The thickness of the test specimens shall be the originalproduct thickness without any machini
19、ng of the surface. Thespecimen thickness needs to be compatible with the thicknessrequirements of the mechanical property test method that willbe used to evaluate the samples.6.4 All test specimens shall be conditioned in the standardlaboratory atmosphere in accordance with Practice D618,Procedure A
20、 prior to initiating the elevated temperature andmoisture conditioning procedures described here.7. Apparatus7.1 Conditioning ChamberAtemperature controlled waterbath is to be used for immersion purposes. This bath is to becapable of maintaining a constant water temperature of37.8 6 1.5C (100 6 3F)
21、and is to be equipped with a deviceor mechanism for separating test specimens from each othersuch that the faces of the gage sections of the specimens do notrest against one another. If necessary due to space available inthe conditioning chamber, it is acceptable to stack samples ina lattice type ar
22、rangement such that the samples lie on eachother at the grip area. The chamber dimensions need to be suchthat the depth of the water necessary to immerse the samples isno more than 0.5 m (19.7 in.). The temperature of the waterbath is to be monitored at least daily, and the water bath mustpossess a
23、cover in order to minimize loss of water to the airthrough evaporation.7.2 Water PumpIn order to reduce or minimize deadzones in the water bath of the conditioning chamber, a smallwater pump (or similar device) shall be placed in the waterbath. It is acceptable to utilize and air pump for this purpo
24、se;if such an air pump is used, the information shall be reported.8. Procedure8.1 Distilled water shall be used for all conditioning. Dis-tilled water is to be used to serve as a standard medium for theconditioning procedure; however, distilled water is not in-tended to mimic field conditions.8.2 Th
25、e presence of any residue in the water bath during theexposure time shall be noted in the report as the presence ofresidue indicates a material loss of the test specimens.8.3 Samples shall be immersed in distilled water in theconditioning chamber for 1000 6 8 hours, with the 68 hourtime period to be
26、 utilized for the mechanical property testing ofthe samples.8.3.1 The conditioning chamber is required to be thoroughlycleaned with distilled water and wiped clean of debris prior touse. The temperature sensor must be placed in such a way thatits sensor does not come in contact with the walls of the
27、conditioning chamber.8.3.2 Prepare the conditioning chamber by filling it withdistilled water and control its temperature until it is steady atthe temperature required for conditioning the samples. Allowthe conditioning chamber to stabilize at 37.8 6 1.5C prior tothe immersion of the samples.8.3.3 D
28、aily monitoring of the temperature of the condition-ing chamber and water level is recommended until 1000 6 8hours of immersion conditioning are reached.8.4 Perform tests for desired mechanical properties on theunconditioned samples held at standard laboratory atmosphereto establish the baseline pro
29、perties of the material prior to theelevated temperature and moisture conditioning testing.8.5 Perform tests for the desired mechanical properties onthe elevated temperature and moisture conditioning specimensafter 1000 6 8 hours of conditioning according to the appli-cable ASTM mechanical property
30、test method.8.5.1 When conducting mechanical property tests on speci-mens removed from the water immersion, wipe the specimenswith a dry cloth and test them at standard laboratory tempera-ture.8.5.2 Do not remove specimens from the water until themechanical property tests are ready to be conducted.8
31、.5.3 Record the testing time period in the report.9. Precision and Bias9.1 No statements of precision and bias are applicable tothis practice; these are dependent upon the ASTM test methodsfor the specific properties to be determined.10. Report10.1 The report of any test referencing this practice sh
32、allstate:10.1.1 The specific identification of the pultruded compos-ite.10.1.2 The location on the pultruded composite from whichthe specimens were machined.10.1.3 The geometry of the test specimens used and themechanical testing procedure for which they were prepared.10.1.4 Any deviation from the s
33、pecified conditioning pro-cedures.3To evaluate the effect of elevated temperature and moisture conditioning on thematrix and fiber/matrix interface of a pultruded composite material, the use of TestMethod D6641/D6641M for mechanical property determination is suggested. Toevaluate the effect of freez
34、e/thaw cycling on the matrix and fiber/matrix interface ofa pultruded composite material, the use of Test Method D6641/D6641M formechanical property determination is suggested. If other property effects are to beexamined, appropriate test methods for the desired property should be selected.D7992/D79
35、92M 15210.1.5 The time period of testing of each specimen.10.1.6 Any visual observations made during the condition-ing or subsequent testing.10.1.7 The % retention of the mechanical property ofinterest after elevated temperature and moisture conditionedsamples as compared to the same mechanical prop
36、erty forsamples exposed to standard laboratory atmosphere.11. Keywords11.1 elevated temperature; moisture immersion; pultrusionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are
37、expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not re
38、vised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you
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