1、Designation: F1702 10 An American National StandardStandard Test Method forMeasuring Impact-Attenuation Characteristics of NaturalPlaying Surface Systems Using a Lightweight PortableApparatus1This standard is issued under the fixed designation F1702; the number immediately following the designation
2、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 test method is used to determine
3、the impact-attenuation characteristics of natural turfgrass and soil playingsurface systems with a lightweight portable apparatus. This testmethod can be used to compare the impact attenuation char-acteristics of natural playing surface systems, as well asassessing the effects of management practice
4、s on the impactattenuation characteristics. This test method also can be used toassess the compactibility of natural playing surfaces by record-ing g-max values or penetration of successive impacts, or both.1.2 This test method provides a procedure for assessingimpact attenuation characteristics in
5、the field, on both actualplaying surfaces and research plots. Numerical data will not becomparable to data obtained using a different missile mass orgeometry, different drop height, or different standard method,for example, Test Method F1936.1.3 The values stated in SI units are to be regarded as th
6、estandard. 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 ap
7、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D5874 Test Method for Determination of the Impact Value(IV) of a SoilE105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the A
8、verage for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF355 Test Method for ImpactAttenuation of Playing SurfaceSystems and MaterialsF1936 S
9、pecification for Impact Attenuation of Turf PlayingSystems as Measured in the FieldF2650 Terminology Relating to Impact Testing of SportsSurfaces and EquipmentF2651 Terminology Relating to Soil and Turfgrass Charac-teristics of Natural Playing Surfaces3. Terminology3.1 DefinitionsExcept as noted, de
10、finitions in this stan-dard are in accordance with Terminologies F2650 and F2651.4. Summary of Test Method4.1 A 2.25-kg missile is dropped from a specific height,through a guide tube, onto a playing surface. A linear acceler-ometer mounted on the missile monitors the acceleration andtime history of
11、the impact. The maximum acceleration duringthe impact (relative to gravity) is recorded and reported asg-max. Reporting the time history of the impact is optional.Depth of penetration from successive drops may also berecorded optionally as an indication of soil compactibility.NOTE 1This test method
12、is based on an impact tester developed byClegg (1,2).3See Test Method D5874. Such impact testers are commer-cially available. Commercially available Clegg Impact Soil Testers displayresults in impact value units, where one impact value equals 10 g-maxunits (Test Method D5874), and typically do not d
13、isplay tenths of animpact value unit. For use in this standard, the display should be alteredby the manufacturer or authorized personnel to indicate tenths of animpact value or 1 g-max unit. Also, other suitable recording equipmentcan be used to obtain resolution to 1 g-max. A 4.5-kg missile has bee
14、nused to evaluate road base surfaces (1,2). A 0.5-kg poly(vinyl chloride)1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility ofSubcommittee F08.64 on Natural Playing Surfaces.Current edition approved
15、July 1, 2010. Published August 2010. Originallyapproved in 1996. Last previous edition approved in 2002 as F1702 96 (2002)1.DOI: 10.1520/F1702-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
16、 volume information, refer to the standards Document Summary page onthe ASTM website.3Numbers in parentheses refer to the list of references at the end of this testmethod.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1missile has bee
17、n utilized to relate field surfaces to ball bounce (3-6),player response (7), and performance including injury potential (8).5. Significance and Use5.1 The g-max values obtained by these procedures areindicative of the impact attenuation characteristics of playingsurfaces used for sports such as Ame
18、rican football, soccer,baseball, lacrosse, rugby, etc. Optional time history data can beused to further describe these properties.6. Apparatus6.1 MissileConstruct the 2.25 6 0.05-kg missile frommetal with a hardened steel impacting surface that is flat andround with a 5.0 6 0.1-cm diameter and a rou
19、nded or bevelededge of 0.5 to 1.0 mm. Include a T-shaped handle or otherappropriate means for lifting the missile prior to dropping. Thehandle and accelerometer (rated at not less than 5000 g)constitute a portion of the missile mass. The missile should bemarked around the circumference to obtain a r
20、eference point tothe guide tube top, which will indicate drop height.6.2 Guide TubeConstruct the vented guide tube from pipehaving a smooth inside surface and a nominal inside diameterof 5.4 cm (2.125 in.), such as not to restrict a free fall of themissile. The length of the pipe typically is approx
21、imately 61cm (24 in.). A bulls eye level shall be attached to the guidetube to ensure that the tube is held in a vertical position duringmeasurement. Constructing a circular end flange on the base ofthe tube helps to improve stability during measurement. Thebottom flange shall be milled so that it r
22、ests only on itsperimeter and vented either with a hole or holes locatedthrough the flange top surface or by means of a hole or holeson the side of the guide tube just above the flange, or both, toallow for the escape of air under the compression of the fallingmissile.6.3 Recording EquipmentFollow t
23、he criteria below whenusing recording equipment:6.3.1 g-maxEnsure that the recording system is capable ofmeasuring impacts of up to a g-max of 1000, as measured byan accelerometer mounted on the missile.6.3.2 Acceleration-TimeThe acceleration-time historymay be recorded optionally using a suitable o
24、scilloscope orcomputer instrumentation.6.3.3 The band width of the acceleration measuring instru-mentation must be sufficiently large to give good resolution ofthe peak acceleration (g-max). Commercially available deviceshave a band width of 7 kHz.7. Test Unit7.1 The test unit will be either:7.1.1 A
25、n area of a playing surface system that has hadsimilar use and that has similar surface-system characteristics(for example, age, vegetation density, wear, soil moisturecontent) within its limits, or7.1.2 An experimental area (plot) subjected to uniformtreatment(s) that may or may not affect impact c
26、haracteristics.7.2 A test unit on a playing surface system should notexceed approximately 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 the surface variability on anatural surface of a sports fi
27、eld, 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 variable nature of natural surfaces, measureand average
28、 at least four locations within a test unit to obtaina test result. To obtain a specific quality assurance level, followthe sampling procedures of Practices E105 and E122.9. Procedure9.1 Operate and calibrate all recording equipment as recom-mended by the manufacturer. Periodically, at least prior t
29、o 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 surface and maintainin a vertical position during the drop
30、.9.3 Lift the missile to obtain a drop height of 45.7 6 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 Release the missile and record the g-max value. Liftingthe mis
31、sile 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 mechanism should not influence the impactvelocity to a g
32、reater extent than manual operation.9.5 Make one drop on each location and record the g-maxvalue. Soil compaction due to impacting alters natural surfaceconditions. Successive drops, therefore, will not give resultsthat are indicative of the initial impact characteristics of the testunit. Surface de
33、formation due to successive impacts may beused to give an indication of surface compactibility. Recordg-max for each drop.Ascale, graduated in units of 2.5 mm (0.1in.) may be placed on the missile handle to determine residualsurface penetration. The scale should have at least 20 units, andif deforma
34、tion (depth of penetration) readings are recordedthey shall be taken before and after each drop.9.6 Record environmental conditions at time of the test,including the soil moisture content.10. Calculation10.1 g-maxDetermine g-max to the nearest whole unit bydirect readout (a truncated value is accept
35、able with digitalreadout equipment) or from the acceleration-time history.10.2 Additional impact related parameters such as time tog-max, impact duration, and penetration depth may be obtainedby using appropriate recording equipment.F1702 10211. Report11.1 Include the following information in the re
36、port: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, and depth of thatch, ifpresent, should be indicated. Soil texture should be given. Ifthe surface is a research plot, treatment(s)
37、should be listed.11.1.2 Conditions of test, including temperatures, humidity,soil moisture content, and any other pertinent data.11.1.3 Date of test.11.1.4 Record type and model of instrumentation used todetect g-max/time history.11.1.5 Record total missile mass (including handle,accelerometer, etc.
38、).11.1.6 Average g-max values from initial impacts on eachsimilar test unit.11.1.7 Average values from initial impacts on similar testunits (replication) for optional results.11.1.8 If successive impacts are used to characterizecompactibility, record successive impact results. If penetrationdepth me
39、asurements are made, record each measurement takenprior to each impact and after the final impact to the nearest 2.5mm (0.10 in.). Report changes in values with successiveimpacts for each test unit.11.1.9 Notate the report to state, “Numerical data with thistest method will not be comparable to data
40、 obtained using adifferent missile mass, geometry, drop height, or standardmethod, for example, Test Method F1936.”NOTE 2Numerical data collected using this standard method is notdirectly comparable to data obtained using a different missile mass orgeometry, different drop height, or different stand
41、ard method, for example,Test Method F1936. Research suggests that impact results greater than100 g, measured using the apparatus described herein, may pose a safetyhazard (10,11). In such instances, corrective management actions may bepracticed to reduce impact results. Furthermore, should results e
42、xceed100 g using the apparatus described herein, a more accurate evaluation(Test Method F1936) will be required to more precisely assess potentialsafety hazards.12. Precision and Bias412.1 Interlaboratory Test ProgramDue to the nature ofsoil and turfgrass surfaces tested by this test method, it is e
43、ithernot 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 rub
44、ber-composition flooring specimens, giving a range of g-maxvalues that are representative of values obtained on naturalsurfaces of athletic fields, were selected for testing by sevenlaboratories, using procedures of Practice E691. Six impactingpoints were marked on each specimen, and average g-maxva
45、lues for a specimen were calculated from the six impacts.After a designated waiting period, specimens were retested toobtain a second replication.12.2 Test ResultThe precision information given below inthe units of measurement (g-max) is for two test results, eachof which is the average of six test
46、determinations.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 i
47、n Practice E177.The temperature of samples influences shock attenuation withlower g-max values 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 g-max at 20C, howeve
48、r, ranged from9 to 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 valu
49、e available for thematerials used.13. Keywords13.1 Clegg tester; g-max; impact attenuation; impact soiltester; impact test hammer; impact value; natural turf; playingsurface system; soil; turfgrass4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F08-1003.TABLE 1 Gmaxon Test SurfacesPrecision StatisticsMaterial 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 25.2F1702 103APP
