1、Designation: D3880/D3880M 90 (Reapproved 2009)1Standard Test Method forAsbestos Strength Units1This standard is issued under the fixed designation D3880/D3880M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits information was corrected and warning notes in 6.7.2, 7.5, and 9.2.2 were moved into the standard text inMarch 2010.1. Scope1.1 T
3、his test method gives a procedure for the evaluation ofthe strength-giving properties of asbestos fibers used to rein-force asbestos-cement products.1.2 The purpose of this test method is to determine thenumber of strength units that may be assigned to the sampletested.1.3 Asbestos fiber possesses t
4、he ability to impart strength toan asbestos-cement product. Every fiber grade may be regardedas possessing a certain quantity of strength-giving units. Thequantity of fiber required in an asbestos-cement compositionvaries inversely with the number of strength units it possesses.For example, if an am
5、ount, designated by X, of a fiberpossessing 100 strength units produces a product of a givenstrength, 2X would be required to produce a product ofequivalent strength from fiber possessing only 50 strengthunits.1.4 The following definition is the basis for the strength unittest: An asbestos fiber tha
6、t gives the standard strength at thestandard density when used as 10 % of the furnish is defined ashaving 100 strength units. Therefore, by knowing the percentfiber required in the mix to give standard strength at thestandard density, it is possible to calculate the strength units ofa sample of asbe
7、stos.1.5 This procedure is intended primarily for chrysotileasbestos; it has not been verified whether or not it is applicableto other types.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equival
8、ents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.7 WarningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and for those with wh
9、om 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 chrysoltile asbestos, refer to “Safe Useof Chrysotile Asbestos: A Manual on Preventive and ControlMeasures.”21.8 This standard d
10、oes 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. For specificprecautionary stateme
11、nts see 6.7.2, 7.5, 9.2.2, and 1.7.2. Referenced Documents2.1 ASTM Standards:3C150 Specification for Portland CementC184 Test Method for Fineness of Hydraulic Cement by the150-m (No. 100) and 75-m (No. 200) Sieves4C204 Test Methods for Fineness of Hydraulic Cement byAir-Permeability ApparatusC430 Te
12、st Method for Fineness of Hydraulic Cement by the45-m (No. 325) SieveC1120 Test Method for Wash Test of AsbestosC1121 Test Method for Turner and Newall (T and N)Wet-Length Classification of AsbestosC1162 Test Method for Loose Density of AsbestosD1193 Specification for Reagent WaterD1655 Specificatio
13、n for Aviation Turbine FuelsD2590 Test Method for Sampling Chrysotile AsbestosD2946 Terminology for Asbestos and AsbestosCementProductsD2589 Test Method for McNett Wet Classification of DualAsbestos Fiber1This test method is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cement Prod
14、ucts and is the direct responsibility of C17.03 onAsbestos - Cement Sheet Products and Accessories.Current edition approved Nov. 1, 2009. Published March 2010. Originallyapproved in 1980. Last previous edition approved in 2004 as D3880 90(2004)1.DOI: 10.1520/D3880_D3880M-90R09E01.2Available from The
15、 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.4Withdrawn. The last approved version
16、of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D3639 Test Method for Classification of Asbestos by Que-bec Standard TestD3752 Test Method for Strength Imparted by Asbestos to
17、aCementitious MatrixE11 Specification for Woven Wire Test Sieve Cloth and TestSieves2.2 Other Standards:Quebec Asbestos Mining Association (QAMA) Standard,Designation for Chrysotile Asbestos Grades53. Terminology3.1 Definitions:3.1.1 point value, n in asbestos, an index of commercialvalue of asbesto
18、s fiber used in asbestos-cement products. Pointvalue = (SU-10)/1.39 where SU stands for strength units.3.1.2 strength unit, n in asbestos, unit of reinforcingpotential of asbestos fiber in asbestos-cement products. Anasbestos fiber that yields a flexural modulus of rupture of 27MPa at a product dens
19、ity of 1.6 g/cm3when used as 10 % ofthe furnish (dry ingredients) is defined as having 100 strengthunits. Therefore, the number of strength units of a givenasbestos is equal to 1000/(% fiber required in the dry mix toyield 27 MPa at 1.6 g/cm3).3.1.3 Refer to Terminology D2946 for other terms relatin
20、gto asbestos.4. Summary of Test Method4.1 This test method covers the fabrication and flexuraltesting of asbestos-cement test specimens that contain asbestosfiber from the sample being evaluated. The calculation ofstrength units of the asbestos, based upon the flexural strength,density and compositi
21、on of the test specimens, is also de-scribed.4.2 The specimen fabrication process includes the followingsteps:4.2.1 Asbestos fiber preparation, including ball milling,fiberizing, and blending.4.2.2 Compounding, including dry mixing, the preparationof saturated water, and wet mixing.4.2.3 Test specim
22、en formation, including the pressing ofasbestos-cement cakes in a semi-automatic press.4.2.4 Specimen curing, including a stage in a humiditycabinet, autoclaving, air cooling, and saturating in a water bath.4.3 Specimen testing, including the determination of im-mersed mass, saturated mass, flexural
23、 strength, specimenthickness and width, and dry mass.4.4 Calculations, involving the determination of specimenvolume, modulus of rupture, density, modulus of ruptureadjusted for density, asbestos fiber content required to attainstandard strength, fiber ratio required, point value, and strengthunits.
24、5. Significance and Use5.1 This test method facilitates the comparison of differenttypes and grades of chrysotile asbestos by the property mostpertinent to its use in asbestos-cement, namely, the strength orreinforcing value it imparts to the product.5.2 While similar comparative results could be ob
25、tained onany given production equipment, this method allows the testingof small samples, avoids costly interruptions in production fornumerous trial runs, and allows test values to be obtained by asingle standard method so that results can be compared amongdifferent locations.5.3 Strength Unit (SU)
26、value of a fiber blend used inasbestos-cement products may be estimated by taking theproportionate SU value of each component of the fiber blend.5.4 If the fiber blend is formulated with the aim to optimizeanother fiber property such as filterability, the SU calculationwill assure that the blend wil
27、l not fall below an acceptablestrength level.5.5 This test method is restricted to grades of asbestos usedin asbestos-cement products. Very long (Group 3) fibers aredifficult to evaluate by this method because the test specimensproduced may not be sufficiently homogeneous. Similarly, veryshort (Grou
28、p 7) grades may not be retained satisfactorily in themold during the pressing of test specimens or may not providesufficient strength to meet the test requirements.NOTE 1The term Group 3 or 7 refers to the standard designation forchrysotile asbestos grades established by the Quebec Asbestos MiningAs
29、sociation, See 2.2.5.6 Because of certain differences between this method andthe many variations in plant production procedure commonlyused in asbestos-cement manufacture, it is emphasized that thestrength values obtained by this standardized procedure willnot necessarily give exactly the same stren
30、gth values asobtained at any one specific manufacturing plant.6. Apparatus6.1 Ball Milling:6.1.1 Porcelain Ball Mill Jars,6meeting the followingspecifications:Capacity 11 000 cm3671 in.3External diameter 280 mm 11.02 in.Internal diameter 230 mm 9.06 in.Internal height 210 mm 8.27 in.6.1.2 Porcelain
31、Balls,7machine made, meeting the follow-ing specifications:Diameter 40 mm 1.575 in.Mass (each) 74 to 75 g 0.163 to 0.165 lbSpecific activity 2.3 6 0.1 (The manufacturer specifies a nominalspecific gravity of 2.22.)5Available from Asbestos Institute, 1130 Sherbrooke St. West, Montreal, Q.C.,H3A2 M8.6
32、The sole source of supply of the apparatus (Type KU5a ball mill jars, andmachine-made balls, manufactured by Staatliche Porzellan Manufaktur, Berlin WerkSeld, Selb/afr. Hartmannstrasse 13, German Federal Republic (West Germany)known to the committee at this time is Fish-Schurman, 70 Portman Road, Ne
33、wRochelle, NY. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.7The sole source of supply of the apparatus known to t
34、he committee at this timeis Ateliers de Lessines S.A., Division BOP, 55 rue de Wauthier 1020, Bruxelles,Belgium. If you are aware of alternative suppliers, please provide this informationto ASTM International Headquarters. Your comments will receive careful consid-eration at a meeting of the respons
35、ible technical committee,1which you may attend.D3880/D3880M 90 (2009)12Alternatively, handmade balls approaching these specifica-tions may be used.6.1.2.1 Discard balls when their diameter is 35 mm 1.38in. or less.6.1.3 Roll Table, to rotate the ball mill jars at 6.81 6 0.21rad/s 65 6 2 r/min. See N
36、ote 2.6.2 Fiberizing:6.2.1 Disintegrator,8B.O.P. (Ball, Opener, Penmen) TypeO, driven at 565 6 21 rad/s 5400 6 200 r/min by asquirrel-cage induction motor rated at no less than 1.492 kW 2hp.6.2.2 Perforated Steel Discharge Plates, for the fiberizer.One each of the following opening diameters: 3, 5,
37、7 and 10mm, 6 3 %. Holes must be on an equilateral triangular pitchwith wire edges pointing outward.6.2.3 Cardboard Drum, approximately 410 mm 16 in. indiameter by 400 mm 15 in. in height with removable ringclamp on top, and canvas dust cover (transition piece) to serveas a receiver for the fiberize
38、r discharge. Other arrangements forreceiving the fiberizer discharge that are satisfactory withrespect to relief of static pressure generated by the fiberizerrotor and with respect to the prevention of sample losses andcontamination are acceptable. The free area of cloth while inoperating position m
39、ust be within the limits from 1300 to 4500cm2, and the cloth must be square weave, unbleached cottonduck weighing 0.41 6 0.02 kg/m212 oz/yd2, or a cloth ofequivalent permeability.6.3 Blending:6.3.1 Polyethylene Jar with Cover,9meeting the followingspecifications:Inside diameter 311 mm 12.25 in.Outsi
40、de diameter 327 mm 12.875 in. (wall thickness 8 mm 0.3 in.)Inside height 311 mm 12.25 in.Other containers, such as stainless steel blenders, withsimilar internal dimensions may be used.6.3.1.1 The jar may be fitted with a circumferential rubbertension band 100 mm 3.94 in. wide by 3 mm 0.125 in. thic
41、kto retain the cover. This band may be rolled down, turtleneckfashion, when the cover must be opened. Alternatively, thecover may be retained by mechanical clamps. In that case, theuse of a gasket to seal the cover may be necessary.6.3.1.2 The jar must be fitted with tires around the outerdiameter t
42、o allow it to roll on a roll table in a horizontal attitudeand to allow any clamps or projections to clear the rolls.6.3.2 Roll-Table, to rotate the blending jar at a speed of 5.876 0.21 rad/s 56 6 2 r/min. See Note 2.6.3.3 Rolling Sheet,1m21 yd2 or larger, made of rubber,plastic, or some other flex
43、ible elastomer.6.4 Dry Mixing:6.4.1 Polyethylene Jar with Cover,9meeting the followingspecifications:Inside diameter 248 mm 9.75 in.Outside diameter 257 mm 10.125 in.Inside height 273 mm 10.75 in.Capacity 13 200 cm3Other containers, such as stainless steel mixers, with similarinternal dimensions may
44、 be used.8The sole source of supply of the apparatus known to the committee at this timeis Canadian Laboratory Supplied Limited, Box 2090 Stn. St. Laurent, Montreal 307,P. Q., Canada. Specify dimensions required, request a design similar to Catalog No.J3028, and refer to Canlab Quotation No. 2713 (1
45、969). If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.9The sole source of supply of the apparatus known to the commit
46、tee at this timeis Canadian Laboratory Supplies Limited, Box 2090, Stn. St. Laurent, Montreal 307,P. Q., Canada, (Catalog No. J3028-14). These must be fitted with suitable vanes. Ifyou are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comment
47、s will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.FIG. 1 Wet-Mixer AssemblyD3880/D3880M 90 (2009)136.4.1.1 The jar must be fitted with a rubber band asdescribed in 6.3.1.1.6.4.1.2 The exterior of the jar must be fitted with tires asdescribe
48、d in 6.3.1.2.6.4.1.3 The interior of the jar must be fitted with threemixing vanes located 2.09 rad 120 apart, along the fulllength of the jar and projecting 38.1 mm 1.5 in. from theinside wall. The vanes may be fastened to the wall by smoothhead rivets or an adhesive. The corners of the vanes at th
49、e jaropening should be rounded to a radius of 12.7 mm 0.5 in.The vanes may be fabricated from aluminum or any othercorrosion-resistant sheet metal 1 mm 0.04 in. thick.6.4.2 Roll-Table, to rotate the blending jar at a speed of 8.176 0.21 rad/s 78 6 2 r/min.NOTE 2If a judicious choice of drive roll diameter and speed ischosen for the roll table, together with suitable tire dimensions forcontainers mentioned in 6.1.1, 6.3.1 and 6.4.1, it is possible to use thesame
