1、Designation: F 1702 96 (Reapproved 2002)e1An American National StandardStandard Test Method forMeasuring Shock-Attenuation Characteristics of NaturalPlaying Surface Systems Using Lightweight PortableApparatus1This standard is issued under the fixed designation F 1702; the number immediately followin
2、g 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 (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe reference in 9.3 was
3、corrected editorially in August 2002.1. Scope1.1 This test method covers the determination of shock-attenuation characteristics of natural turfgrass and soil playingsurface systems using lightweight portable apparatus. This testmethod is applicable for comparing natural surfaces and forassessing the
4、 effects of management practices on shock attenu-ation. This test method also can be used to assess thecompactibility of natural surfaces by recording Gmaxvalues orpenetration of successive impacts, or both.1.2 This test method provides a procedure for assessingimpact characteristics in the field, o
5、n actual playing surfacesand on research plots. Numerical data will not be comparableto data obtained using a different missile mass or geometry,using a different drop height, or using a different standardmethod, for example, Test Method F 355.1.3 The values stated in SI units are to be regarded as
6、thestandard. The values given in parentheses are for informationonly.1.4 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
7、applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 5874 Test Method for Determination of the Impact Value(IV) of a SoilE 105 Practice for Probability Sampling of MaterialsE 122 Practice for Choice of Sample Size to Estimate aMeasure of Quality for a Lo
8、t or ProcessE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF 355 Test Method for Shock-Absorbing Properties of Play-ing Surface Systems and Materials3. Terminology3.1 Definitio
9、ns of Terms Specific to This Standard:3.1.1 acceleration, nthe instantaneous time rate of changeof velocity, which may be positive or negative.3.1.2 G, nthe dimensionless ratio of the acceleration (a)of the missile during impact to the acceleration due to gravity(g): G = a/g.3.1.3 Gmax, nthe maximum
10、 value of G encountered dur-ing impact.3.1.4 playing surface, nthe surface of contact with aplayer, ball, or any other object or animal utilizing the surface.A natural playing surface may be turfgrass or other vegetation,soil, sand, other natural organic and inorganic materials, orcombinations of th
11、ese types of surfaces.3.1.5 playing surface system, na composite that includesthe contact surface, energy-absorbing materials, if any, and thesubstrates.3.1.6 turf, na covering of mowed vegetation, usually aturfgrass, growing in association with an upper soil stratum ofintermingled roots and stems.3
12、.1.7 turfgrass, na species or cultivar of grass, usually ofspreading habit, which is maintained as a mowed turf.4. Summary of Test Method4.1 A 2.25-kg missile is dropped from a specific height ontoa playing surface. A linear accelerometer mounted on themissile monitors the acceleration and the time
13、history ofimpact. The Gmaxis detected, and with suitable instrumenta-tion, the time history may be recorded optionally. Depth of1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.64 onNatural Playin
14、g Surfaces.Current edition approved May 10, 1996. Published July 1996.2For 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 ASTM
15、 website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.penetration from successive drops may be recorded optionallyas an indication of soil compactibility.NOTE 1This test method is based on an impact tester developed byClegg (1,2).
16、3See Test Method D 5874. Such impact testers are commer-cially available. Commercially available Clegg Impact Soil Testers displayresults in impact value units, where one impact value equals ten Gmaxunits, and typically do not display tenths of an impact value unit. For usein this standard, the disp
17、lay should be altered by the manufacturer orauthorized personnel to indicate tenths of an impact value or one Gmaxunit. Also, other suitable recording equipment can be used to obtainresolution to one Gmax. A 4.5-kg missile has been used to evaluate roadbase surfaces (1,2).A0.5-kg poly(vinyl chloride
18、) missile has been utilizedto relate field surfaces to ball bounce (3-6), player response (77), andperformance including injury potential (8).5. Significance and Use5.1 The Gmaxvalues obtained by these procedures areindicative of the cushioning properties of playing surfaces.Optional time history da
19、ta can be used to describe further theseproperties.6. Apparatus6.1 MissileConstruct the 2.250 6 0.05-kg missile from asolid steel rod with a 5.0 6 0.02-cm diameter and a flatimpacting surface having a roundness or bevel of 0.5 to 1.0 mmon the edge. Include a T-shaped handle or other appropriatemeans
20、 for lifting the missile prior to dropping. The handle andaccelerometer (rated at 5000 g) constitute a portion of themissile mass. The missile should be marked around thecircumference to obtain a reference point to the guide tube top,which will indicate drop height.6.2 Guide TubeConstruct the vented
21、 guide tube, throughwhich the missile is dropped, of pipe having a smooth insidesurface and a nominal inside diameter of 5.08 cm (2.0 in.), suchas not to restrict a free fall of the missile, and a length ofapproximately 61 cm (24 in.). A bulls eye level may beattached to the guide tube to ensure tha
22、t the tube is held in avertical position during measurements.Acircular end flange onthe base of the tube helps to stabilize the tube. The bottom ofthe flange shall be milled so that it rests only on its perimeterand vented to allow for the escape of compressed air. Ventsmay also be utilized instead
23、in the side of the tube just abovethe flange.6.3 Recording EquipmentFollow the criteria below whenusing recording equipment:6.3.1 GmaxEnsure that the recording system is capable ofmeasuring shocks of up to a Gmaxof 1000, as produced by anaccelerometer mounted on the missile.6.3.2 Acceleration-TimeTh
24、e acceleration-time historymay be recorded optionally by suitable oscilloscope or com-puter instrumentation.6.3.3 The band width of the acceleration measuring instru-mentation must be sufficiently large to give good resolution ofthe peak acceleration (Gmax). Commercially available deviceshave a band
25、 width of 7 kHz.7. Test Unit7.1 The test unit will be either:7.1.1 An area of a playing surface that has had similar useand that has similar surface-system characteristics (for ex-ample, age, vegetation density, wear, soil moisture content)within its limits, or7.1.2 An experimental area (plot) subje
26、cted to uniformtreatment(s) that may or may not affect impact characteristics.7.2 A test unit on a playing surface should not exceedapproximately 1 m2.8. Number of Test Units8.1 Similar areas of use, wear, etc., may be used to replicatetest units on playing surfaces.8.2 To characterize adequately th
27、e surface variability on anatural surface of a sports field, areas having different levels ofuse, wear, soil compaction, vegetative cover, etc., should beevaluated. If possible, replicate each type of use area.8.3 Use a minimum of three test units (replications) inresearch experiments.8.4 Due to the
28、 variable nature of natural surfaces, measureand average at least four locations within a test unit to obtaina test result. To obtain a specific quality assurance level, followthe sampling procedures of Practices E 105 and E 122.9. Procedure9.1 Operate and calibrate all recording equipment as recom-
29、mended by the manufacturer. Periodically, at least prior to andafter each series of impact tests, check the instrumentationoutput by dropping the missile on a standard surface, forexample, a stable synthetic material placed on a rigid concreteor metal surface.9.2 Place the guide tube on the playing
30、surface and maintainin a vertical position during the drop.9.3 Lift the missile to obtain a drop height of 45.76 0.3 cm(18.0 6 0.1 in.), and an approximate impact velocity of 2.85m/s (9). A mechanical stop may be attached to the top of theguide tube to aid in achieving the exact drop height.9.4 Rele
31、ase the missile and record the Gmaxvalue. Liftingthe missile to an exact height and then releasing it freely ispossible with trained and experienced operators; however, amechanical holding/releasing mechanism is recommended toinsure proper height and release with less-experienced opera-tors. Such a
32、mechanism should not influence the impactvelocity to a greater extent than manual operation.9.5 Make one drop on each location and record the Gmaxvalue. Soil compaction due to impacting alters natural surfaceconditions. Successive drops, therefore, will not give resultsthat are indicative of the ini
33、tial impact characteristics of the testunit. Surface deformation due to successive impacts may beused to give an indication of surface compactibility. RecordGmaxvalues or depth of penetration, or both, for each drop. Ascale, graduated in units of 2.5 mm (0.1 in.) may be placed onthe missile handle t
34、o determine residual surface penetration.The scale should have at least 20 units, and readings should betaken before and after each drop.9.6 Record environmental conditions at time of the test,including the soil water content.3Numbers in parentheses refer to the list of references at the end of this
35、 testmethod.F 1702 96 (2002)e1210. Calculation10.1 GmaxDetermine Gmaxto the nearest whole unit bydirect readout (a truncated value is acceptable with digitalreadout equipment) or from the acceleration-time history.10.2 Additional impact related parameters such as time toGmax, impact duration, and pe
36、netration depth may be obtainedby using appropriate recording equipment.11. Report11.1 Include the following information in the report:11.1.1 Identification of the surface tested, including locationand type of surface (turfgrass or soil). Vegetation should bedescribed as to the type(s) and density,
37、and depth of thatch, ifpresent, should be indicated. Soil texture should be given. Ifthe surface is a research plot, treatment(s) should be listed.11.1.2 Conditions of test, including temperatures, humidity,soil water content, and any other pertinent data.11.1.3 Date of test.11.1.4 Record type and m
38、odel of instrumentation used todetect Gmax/time history.11.1.5 Record total missile mass (including handle, accel-erometer, etc.).11.1.6 Average Gmaxvalues from initial impacts on eachsimilar test unit.11.1.7 Average values from initial impacts on similar testunits (replication) for optional results
39、.11.1.8 If successive impacts are used to characterize com-pactibility, record Gmaxand penetration depth to nearest 2.5mm (0.10 in.). Report average values and changes in valueswith successive impacts for each test unit.11.1.9 Note on report “Numerical data with this test methodwill not be comparabl
40、e to data obtained using a differentmissile mass or geometry, a different drop height, or using adifferent standard method, for example, Test Method F 355.”12. Precision and Bias412.1 Interlaboratory Test ProgramDue to the nature ofsoil and turfgrass surfaces tested by this test method, it is either
41、not feasible or too costly at this time to produce multiplespecimens that have uniform mechanical properties. Anyvariation observed in the data is just as likely to result fromspecimen variation as from operator or laboratory testingvariation. In lieu of natural turf surfaces, six synthetic rubber-c
42、omposition flooring specimens, giving a range of Gmaxvaluesthat are representative of values obtained on natural surfaces ofathletic fields, were selected for testing by seven laboratories,using procedures of Practice E 691. Six impacting points weremarked on each specimen, and average Gmaxvalues fo
43、r aspecimen were calculated from the six impacts. After adesignated waiting period, specimens were retested to obtain asecond replication.12.2 Test ResultThe precision information given below inthe units of measurement (Gmax) is for two test results, each ofwhich is the average of six test determina
44、tions.12.3 PrecisionPrecision statistics are shown in Table 1.The terms x (average), sr(repeatability standard deviation),sR(reproducibility standard deviation), r (95 % repeatabilitylimit, within a laboratory), and R (95 % reproducibility limitbetween laboratories) are used as specified in Practice
45、 E 177.The temperature of samples influences shock attenuation withlower Gmaxvalues occurring as temperature increases. Roomtemperatures among the laboratories ranged from 20 to 23Cand no doubt contributed to the magnitude of the reproducibil-ity limit. Differences in Gmaxat 20C, however, ranged fro
46、m 9to 14 (avg = 11) and at 21C ranged from 8 to 14 (avg = 11)when all six surfaces are considered. Most of the variabilityamong laboratories, therefore, was due to the operator and testequipment.12.4 BiasThe bias for these measurements is undeter-mined because there is no reference value available f
47、or thematerials used.13. Keywords13.1 Clegg tester; Gmax; impact soil tester; impact testhammer; impact value; natural turf; playing surface; shockattenuation; soil; turfgrass4Research report available from ASTM Headquarters. Request RR:F08-1003.TABLE 1 Gmaxon Test SurfacesPrecision StatisticsMateri
48、al xsrsRrRA 50.8 1.134 4.042 3.2 11.3B 53.8 0.666 4.502 1.9 12.6C 76.2 1.128 4.911 3.2 13.8D 88.3 2.390 6.821 6.7 19.1E 110.6 0.695 5.474 1.9 15.3F 281.5 3.379 9.010 9.5 25.2F 1702 96 (2002)e13APPENDIX(Nonmandatory Information)X1. DIAGRAM OF TEST EQUIPMENTREFERENCES(1) Clegg, B., “An Impact Testing
49、Device for In Situ Base CourseEvaluation,” Australia Road Research Bureau Proceedings, Vol 8,1976, pp. 15.(2) Clegg, B., “An Impact Soil Test for Low Cost Roads,” Proceedings,Second Conference of Road Engineers Association of Asia andAustralia, Manilla, The Philippines, 1978, pp. 5865.(3) Lush, W. M., “Objective Assessment of Turf Cricket Pitches Using anImpact Hammer,” Journal of the Sports Turf Research Institute,Vol61, 1985, pp. 7179.(4) Holmes, G., and Bell, M. J., “Technical Note: Playing SurfaceHardness and Tennis Ball Rebound Resilience,” Journal o
