1、Designation: C 1082 98 (Reapproved 2008)Standard Specification forAsbestos-Cement Flat Sheet for Cooling Tower Fill1This standard is issued under the fixed designation C 1082; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of 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. Scope1.1 This specification covers three classes of flat asbestos-cement sheets for use as cooling tower fill.1.2 Specific
3、ally excluded from this specification areasbestos-cement products intended for use as tower partition-ing and casing materials, splash bars, water distribution con-duits, and demisters. Also excluded are corrugated sheets andsplash bars used as cooling tower fill (heat exchange surfaces)that are cov
4、ered in Specification C 1081.1.3 The values stated in the SI system are to be regarded asthe standard. The inch-pound units in parentheses are providedfor information only.1.4 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and
5、 for those with whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the safe use of chrysotile asbestos, refer to “Safe Use ofChrysotile: A Manual on Preventive and Control Measures.”21.5 This s
6、tandard 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.
7、1 ASTM Standards:3C 150 Specification for Portland CementC 458 Test Method for Organic Fiber Content of Asbestos-Cement ProductsC 459 Test Methods for Asbestos-Cement Flat ProductsC 500 Test Methods for Asbestos-Cement PipeC 1081 Specification for Asbestos-Cement Corrugated FillFor Use in Cooling To
8、wersD 2946 Terminology for Asbestos and AsbestosCementProducts3. Terminology3.1 Definitions:3.1.1 autoclaved product, nin asbestos cement, producttreated in a saturated steam atmosphere at between 689 to 1517kPa (110 to 220 psi) for at least 8 h, and that contain portlandcement as defined in Specifi
9、cation C 150 together with silica inthe ratio of 3:2 that can react to form calcium silicate reactionproducts.3.1.2 pressed product, nproduct pressed singly or instacks interlayered with templates, at a minimum pressure of12 MPa (1740 psi).3.1.3 textured product, nproduct with bas-relief motifsthat
10、extend the external surface of a sheet sufficiently toincrease its heat transfer capacity by at least 10 % underconditions of turbulent gravity flow.3.1.4 For additional definitions, refer to TerminologyD 2946.4. Classification4.1 Type IFill consisting of autoclaved pressed sheetswithout textured su
11、rfaces that meet the requirements set forthin Table 1.4.2 Type IIFill consisting of non-autoclaved pressedsheets without textured surfaces that meet requirements pre-sented in Table 1.4.3 Type IIIFill consisting of non-autoclaved, non-pressedsheets with textured surfaces, conforming to requirementss
12、tated in Table 1.1This specification is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cement Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos - Cement Sheet Products and Accessories.Current edition approved May 1, 2008. Published July 2008. Originally app
13、rovedin 1990. Last previous edition approved in 2003 as C 1082 98(2003)1.2Available from The Asbestos Institute, http:/ 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 t
14、he standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Test Methods5.1 Apparent Density:5.1.1 This is determined by dividing the mass of a specimenafter drying to constant weight at 1
15、10C 6 10F, by the volumeof the specimen.5.2 Water AbsorptionIn accordance with Test MethodsC 459.5.3 Flexural StrengthIn accordance with Test MethodsC 459.5.4 Freeze-Thaw Resistance:5.4.1 The number of freeze-thaw cycles specified must notcause any apparent deterioration. Check for signs of delami-n
16、ation by means of a magnifying glass. Inspect the specimensfor the presence of invisible cracks by spraying isopropylalcohol from a hand spray bottle onto the specimen (hairlinecracks are revealed when the alcohol evaporates from thesurface).5.4.2 Each cycle shall consist of saturating the specimen
17、bysubmerging in water at 30 6 2C (36 6 3F) during 2 hfollowed by rapid drainage and freezing to 20 6 2C (4 63F) during 106 0.2 h. The twice-daily cycle then repeatsstarting with the 2 h period of thawing and saturation in waterat 30C.5.5 Harkort Test:5.5.1 The specimen is dried in an oven at 100 6 2
18、C (2126 3F) for 2 6 0.2 h before rapidly dunking it in 10 6 0.1 kg(20 6 0.2 lb) of water at 20 6 2C (68 6 3F) for 10 6 0.2min. Then the specimen is examined for signs of deterioration.Check and inspect as in 5.4.1. If the specimen does not appeardeteriorated, return it to the oven for drying during
19、24 6 0.2 hat 110 6 2C (230 6 3F) before dunking again in the sameway.5.5.2 Subsequent drying cycles are all of 23 h 45 6 12 min.duration at the following temperatures:3rd drying 1206 2C (258 6 3F)4th drying 130 6 2C (266 6 3F)5th drying 140 6 2C (284 6 3F)6th drying 150 6 2C (302 6 3F)7th drying 160
20、 6 2C (320 6 3F)5.5.3 Report the number of cycles sustained without dete-rioration.6. Inspection6.1 Inspection of the material shall be agreed upon by thepurchaser and the supplier as part of the purchase contract.7. Rejection and Rehearing7.1 Material that fails to conform to the requirements ofthe
21、se specifications may be rejected. Rejection shall be re-ported to the producer or supplier promptly and in writing. Incase of dissatisfaction with the results of the tests, the produceror supplier may make claim for a rehearing.8. Certification8.1 When specified in the purchase order or contract, a
22、producers or supplier certification shall be furnished to thepurchaser that the material was manufactured, sampled, tested,and inspected in accordance with this specification and hasbeen found to meet the requirements. When specified in thepurchase order or contract, a report of the test results sha
23、ll befurnished.8.2 Upon request of the purchaser in the contract or orderthe certification of an independent third party indicatingconformance to the requirements of this specification may beaccepted instead of the manufacturers certification9. Product Marking9.1 For Types I and II, print or stencil
24、 on each piece, inalkali-resistant ink or paint, the identification either “Type I” or“Type 2.”TABLE 1 Manufacturing Composition and Performance RequirementsType No. I II IIIManufacturing Requirements:Autoclaved yes no noPressed yes yes noTextured no no yesThickness,mm 4.26 0.1 4.2 6 0.1 4.2 6 0.1(i
25、n.) (0.165 6 0.005) (0.165 6 0.005) (0.165 6 0.005)Composition Requirements:Silica passing through a 149 m sieve (No. 100) yes no noRatio, cement:silica 3:2 . Mineral diluents no no noCellulose no no noMaximum organic content per Test Method C 458, % 0.01 0.01 0.01Cement type; per Specification C 15
26、0 1 IorV I,IIorVor ISO type 10 10 or 50 10, 20 or 50Performance Requirements:Minimum apparent density g/cm3(lb/ft3) 1.6 (100) 1.6 (100) 1.4 (100)Maximum water absorption, % 25 25 30Average of lengthwise and crosswise orientations:Minimum flexural modulus of rupture:MPa (psi) 24.8 (3600) 24.8 (3600)
27、20.7 (3000)Minimum deflection (per Test Methods C 459):mm 332(in.) (0.13) (0.13) (0.09)Minimum freeze-thaw, cycles 200 100 50Minimum Harkort test, cycles 7 5 3Maximum free lime, per Test Methods C 500,% 1 6 7C 1082 98 (2008)210. Keywords10.1 asbestos; asbestos-cement; cooling tower fill; flat sheetA
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29、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 revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standard
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31、e on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr 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 1082 98 (2008)3
