ASTM_C_220_-_91_2015.pdf

Designation:C22091(Reapproved 2015)Standard Specification forFlat Asbestos-Cement Sheets1This standard is issued under the fixed designation C220;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year 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 asbestos-cement sheets in flatform designed for industrial,commercial,and general buildingpurposes,of the following types:1.1.1 Flat Sheets,Type F(Flexible)An asbestos-cementflat sheet suitable for exterior and interior use,where a boardhaving higher strength and density,smoother surface,greaterflexibility,and lower moisture absorption is desired.1.1.2 Flat Sheets,Type U(Utility)An asbestos-cement flatsheet suitable for exterior and interior use,having sufficientstrength for general utility and construction purposes,andwhere a board having maximum flexibility,highest density,smoother surface,and lower moisture absorption is not essen-tial.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and 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.”21.4 This standard 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 Documents2.1 ASTM Standards:3C458 Test Method for Organic Fiber Content of Asbestos-Cement ProductsC459 Test Methods for Asbestos-Cement Flat Products2.2 Federal Standard:Fed.Std.No.123 Marking for Shipment(Civil Agencies)42.3 Military Standard:MIL-STD-129 Marking for Shipment and Storage43.Materials and Manufacture3.1 Flat asbestos-cement sheets shall be composed of acombination of asbestos fiber and portland cement or portlandblast-furnace slag cement,with or without the addition ofcuring agents,water-repellent substances,mineral fillers,coatings,pigments,or mineral granules,formed under pressureand cured to meet the physical requirements of this specifica-tion.Sheets shall not contain more than 1 mass%organic fiber,as determined in accordance with Test Method C458.Table 1and Table 2.4.Dimensions4.1 Flat asbestos-cement sheets are normally supplied in thecommercial dimensions given in Table 3.5.Permissible Variations in Dimensions5.1 ThicknessThe average thickness of all flat sheetssupplied under this specification shall be as prescribed in Table4.The average thickness of any one sheet shall not differ fromthe average of all sheets by more than 10%.5.2 Width and LengthThe permissible variation from thenominal width shall be 6116in.(61.6 mm),and,from the1This 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 July 1,2015.Published July 2015.Originally approvedin 1949.Last previous edition approved in 2009 as C220 91(2009).DOI:10.1520/C0220-91R15.2Available 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 the standards Document Summary page onthe ASTM website.4Available from Standardization Documents Order Desk,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 nominal length,618in.(63.2 mm),as measured after 48 h at73F(25C)and 50%relative humidity.5.3 SquarenessThe length of the diagonals shall not varyby more than164in./ft(1.3 mm/m)of length of the sheet.Opposite sides of the sheet shall not vary in length by morethan164in./ft.5.4 Edge StraightnessThe sheet edges shall be straightwithin164in./ft(1.3 mm/m)of length or width.Straightnessshall be determined by stretching a string or wire along theedge to be measured from one corner to the adjacent corner andmeasuring the greatest distance between the string or wire andthe sheet edge.6.Physical Requirements6.1 Flexural StrengthThe average breaking load in new-tons(or pounds-force)of dried specimens loaded as simplebeams on a span of 10 in.(254 mm)with the load appliedequally and simultaneously at b