1、Designation:G13/G13M13Standard Test Method forImpact Resistance of Pipeline Coatings(Limestone Drop Test)1This standard is issued under the fixed designation G13/G13M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last r
2、evision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the relativeresistance of pipeline coatings to impact by observing theeffects of fa
3、lling stones on coated pipe specimens.1.2 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 equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems
4、may result in non-conformancewith the standard.1.3 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 regulat
5、ory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2G12 Test Method for Nondestructive Measurement of FilmThickness of Pipeline Coatings on Steel(Withdrawn2013)3G62 Test Methods for Holiday Detection in Pipeline Coat-ings2.2 AASHTO Standard:4M8051(No.67)Specification for Coarse Ag
6、gregate forPortland Cement Concrete3.Summary of Test Method3.1 The impact resistance of pipeline coatings is determinedby dropping weighed amounts of a specified type of limestonethrough a chute onto a coated pipe specimen.Results arereported as the number of drops required to pierce through thecoat
7、ing to bare metal,as determined visually or electrically.4.Significance and Use4.1 This test method is intended to simulate the effects ofbackfilling after pipe has been placed in the trench.The backfillis often rocky soil and,if it is unscreened and the coated pipeis unshielded by sand or other pro
8、tective padding,the fallingrocks may seriously damage the coating.5.Apparatus5.1 The impact apparatus shall be essentially as shown inFig.1 and shall include the following:5.1.1 Box with Chute,providing a means of dropping stonesfrom a height of 1830 mm 6.0 ft measured to the top of apiece of coated
9、 pipe under test.Construction details are shownin Fig.2.NOTE1The box and chute described in Fig.2 are designed for testingcoatings on 100-mm 4-in.and 150-mm 6-in.pipe specimens.Smallerdiameter pipe may be used by inserting wood V-blocks in the trough in thebox below the chute.5.1.2 Stones,hard,coars
10、e,limestone aggregate,conformingto AASHTO Designation:M80-51(No.67)which is takenfrom America Association of State Highway and Transporta-tion Officials“Standard Specifications for Coarse Aggregatefor Portland Cement Concrete.”NOTE2These specifications cover the quality and size of coarseaggregate.N
11、o.67 designates a 19-mm 34-in.to No.4 size stone with thefollowing sieve analysis:Square Opening,mm in.Weight%Passing25 110019 1495 to 10010 1820 to 55No.40 to 105.1.3 BucketAny suitable bucket that will hold 16 kg 35lb of stones.5.1.4 Holiday DetectorsTwo types are needed as de-scribed in Test Meth
12、ods G62.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.48 on Durability of Pipeline Coating and Linings.Current edition approved Nov.1,2013.Published November 2013.Originall
13、yapproved in 1989.Last previous edition approved in 1996 as G13 89(1996)1which was withdrawn December 2003 and reinstated in November 2013.DOI:10.1520G0013_G0013M-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book
14、of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American Association of State Highway and TransportationOfficials(AASHTO),444 N.Capitol St.,NW,Suite
15、 249,Washington,DC 20001,http:/www.transportation.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE3A holiday is defined as small faults or pinholes that permitcurrent drainage through protective coatings on steel pipe.5.1.5 Thickn
16、ess GaugesAny instruments suitable for usewith Test Method G12.6.Test Specimens6.1 Test specimens shall be 600 mm 24 in.long and shallbe cut from a representative piece of coated pipe.Onlyholiday-free specimens shall be used in the test.7.Procedure7.1 Perform the test at a room temperature of 21 to 25C 70to 77F.7.2 The procedure consists of dropping up to 10 buckets ofstones on coated specimens.The number of buckets of stonesrequired represents the resistance of the coating to this type ofimpact
