1、Designation: C 217 94 (Reapproved 2004)Standard Test Method forWeather Resistance of Slate1This standard is issued under the fixed designation C 217; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers two procedures for weatherresista
3、nce of slate in all outdoor installations by determiningthe depth of softening by an abraser or by hand scraping.NOTE 1The test is based on the fact that slates containing pyrite,calcite, and carbon undergo a chemical weathering which results in theconversion of the calcite particles to gypsum. The
4、swelling action thatresults causes disintegration of the slate. The extent of this action onvarious slates in the test has been found to correlate with the durability ofthe materials in actual weathering.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with
5、 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:2C 119 Terminology Relating to Dimension Stone3. Terminology3.1 Defin
6、itionsAll definitions are in accordance with Ter-minology C 119.4. Significance and Use4.1 This test method is useful in indicating the differences inweather resistance between various slates. This test methodalso provides one element in the comparison of slates.5. Apparatus5.1 Either one of the fol
7、lowing shall be used:5.1.1 Shear/Scratch Tester, Taber Model 203 or 502,3withthe shear hardness tool, Model S-20, or its equivalent.5.1.2 Hand Scraping ToolThe scraping tool shall be madeby grinding down the blade of a putty knife to a length of 3 in.(76.2 mm) and a width of34 in. (19.05 mm). The en
8、d of theblade shall be ground to a plane surface perpendicular to thelength of the tool to form a sharp edge with either side of theblade. These sharp edges will be referred to as the “cuttingedges.”6. Sampling6.1 The samples shall be selected by the purchaser or hisauthorized representative so as t
9、o be truly representative of theconsignment under consideration. Six shingles of roofing fromeach carload or fraction thereof or similar quantities from otherkinds of slate shall constitute a sample.NOTE 2Six shingles 10 in. (254 mm) or more in length and of anystandard width are sufficient for this
10、 test and also for modulus of ruptureand absorption tests.7. Test Specimens7.1 Prepare at least three specimens, each 2 by 4 in. (50.8 by101.6 mm) measured along the cleavage faces, for determiningthe depth of softening in a 1 % solution of sulfuric acid. The 2by 4-in. faces shall be ground smooth a
11、nd finished with No. 80abrasive. Specimens cut from sheared or punched slate shallhave no saw cut nearer than 1 in. (25.4 mm) from the edges ornail holes.8. Procedure with Shear/Scratch Tester8.1 In this procedure determine the depth of softening inacid with the shear/scratch tester (described in 5.
12、1.1). The testinvolves measuring the depth of a groove made by the shearingtool in fresh specimens and also in the same specimens aftersoaking 7 days in 1 % sulfuric acid.8.2 Draw with a pencil compass, on at least three of the 2 by4-in. (50.8 by 101.6-mm) specimens, an arc of a circle of thesame ra
13、dius as that made by the shearing tool. Mark each arc1This test method is under the jurisdiction of ASTM Committee C18 onDimension Stone and is the direct responsibility of Subcommittee C18.01 on TestMethods.Current edition approved Oct. 1, 2004. Published November 2004. Originallypublished in 1948
14、as C 217 48 T. Last previous edition approved in 1999 asC 217 94 (1999).2For referenced 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 AS
15、TM website.3Described in the 1962 Bulletin 62203502 of the Taber Instrument Co., NorthTonawanda, NY.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.at four points for thickness measurements, as indicated in Fig.1. Measure the thickne
16、ss at each point to the nearest 0.0001 in.(0.0025 mm). With a 2.2-lbf (9.8-N) load on the shearing tool,groove each specimen along the penciled arc by rotating theturntable slowly and steadily by hand in a counter clockwisedirection. Then repeat the thickness measurements at the samefour points to d
17、etermine the depth of groove made by theshearing tool in fresh specimens.8.3 Then put the specimens in a glass vessel and completelycover with 1 % sulfuric acid solution. Space the specimens inthe container so that the acid has free access to the 2 by 4-in.(50.8 by 101.6-mm) faces. Pour off the acid
18、 solution each dayand replace with fresh solution. At the end of 7 days removethe specimens from the acid, thoroughly wash with water, anddry for 24 h at 105 6 2C.NOTE 3 ExampleA convenient means of determining the amount ofH2SO4required for the test is as follows: Suppose one has 96 % H2SO4(sp gr 1
19、.84) and the volume of diluted acid necessary for the test is 2000mL. Let X equal the weight of 96 % H2SO4required. Then:0.96X/X 1 2000! 5 0.01 (1)From this equation, X is determined as 21.05 g. The volume of this weightof 96 % H2SO4is 21.05/1.84 = 11.4 mL. (The error due to assuming theweight of 1
20、mL of water as1gisnotappreciable.)8.4 When the specimens have cooled, repeat the sameprocedure as outlined in 8.2 on the faces opposite to thosescored before the treatment.8.5 Record the depth of softening for the specimen as theaverage depth of groove for each specimen after the acidtreatment minus
21、 that for the specimen before the treatment.9. Procedure by Hand Scraping9.1 In this procedure the depth of softening in acid isdetermined by hand scraping. The scraping shall be done withthe “cutting edges” of the tool.9.2 Apply approximately a 3-lbf (13-N) pressure on the“cutting edge” (Note 4). H
22、old the blade on the top surface of thespecimen at an angle of approximately 30. Move the cuttingedge forward about 112 in. (38.1 mm) for each stroke, and leteach stroke follow the same path. Make eight strokes with onecutting edge and eight with the other. Before each specimen isscraped, sharpen th
23、e cutting edge.NOTE 4In this test the pressure on the blade is estimated but notdefinitely controlled. The following guide in applying the proper pressureis suggested: Grasp the handle of the tool in the same way as in scrapinga specimen. Press a “cutting edge” on the weighing table of a smallplatfo
24、rm scale when the weighing beam is loaded for 3 lbf (13 N). Thepressure on the tool and also the amount of bending of the blade requiredto raise the beam are used as criteria in judging the pressure to apply in thetest. This seemingly crude test gives reasonably concordant results for thereason that
25、 the softened layer of slate is easily scraped off but the soundslate underneath is removed very slowly. Since the specified number ofstrokes is considerably more than necessary to remove the softened layer,it is more important to apply a constant pressure than one of a definiteamount.9.3 Scrape thr
26、ee or more specimens of each sample (asdescribed in Section 6) in the original condition at the center ofone 2 by 4-in. (50.8 by 101.6-mm) face. Locate the center bydrawing the diagonals of the rectangle, and do the thicknessmeasurements before and after scraping to the nearest 0.0001in. (0.0025 mm)
27、. After soaking the specimens for 7 days in acid(as described in 8.3), measure the thickness before scraping,then scrape the other faces of the specimens to determine thedepth of softening. Reduce the second depth of scraping by thedepth scraped off before the acid treatment. Record the averageof al
28、l specimens of each sample as the depth of softening of thesample.9.4 The depth of softening is the depth of scraping after theacid treatment minus the depth of scraping before the acidtreatment. Record the average of all specimens of each sampleas the depth of softening of the sample.NOTE 5Thicknes
29、s measurements are required before scraping in theacid soak condition because in some cases, there is swelling of thespecimen that could result in an erroneous depth of softening.FIG. 1 Diagram of Slate Specimen Prepared for Test with Taber Shear/Scratch TesterC 217 94 (2004)210. Report10.1 The repo
30、rt shall include the following:10.1.1 The procedure used,10.1.2 The average depth of softening of all individualspecimens of each sample reported as the depth of softening ofthat sample,10.1.3 Identification of each sample, including name andlocation of the quarry, name and position of the ledge, da
31、tewhen sample was taken, and trade name or grade of the slate,10.1.4 Size and shape of the test specimens, and10.1.5 Description of the way in which the specimens wereprepared.11. Precision and Bias11.1 Individual variations in a natural product may result indeviation from accepted values. A precisi
32、on section will beadded when sufficient data are available to indicate acceptabletolerances in repeatability and reproducibility.12. Keywords12.1 dimension stone; slate; stone; weather resistanceASTM International takes no position respecting the validity of any patent rights asserted in connection
33、with any item mentionedin this standard. Users of this standard are 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 te
34、chnical committee and must be reviewed every five years andif not revised, 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 consider
35、ation at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr
36、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 217 94 (2004)3
