1、Designation: F2270 12 (Reapproved 2018) An American National StandardStandard Guide forConstruction and Maintenance of Warning Track Areas onAthletic Fields1This standard is issued under the fixed designation F2270; the number immediately following the designation indicates the year oforiginal adopt
2、ion 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 guide covers techniques that are appropriate for theconstruction and
3、 maintenance of warning track areas on sportsfields. This guide provides guidance for the selection ofmaterials, such as soil and sand for use in constructing orreconditioning warning track areas and for selection of man-agement practices that will maintain a safe and functioningwarning track. Altho
4、ugh this guide has applications to allsports where a warning track surface may be required ordesired, it has specific applications to baseball/softball.1.2 This guide does not address synthetic warning trackssuch as rubberized surfaces, artificial turf, or paved surfaces.1.3 Decisions in selecting c
5、onstruction and maintenancetechniques are influenced by local soil types, climatic factors,level of play, budget, and training/ability of managementpersonnel.1.4 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.5 This standard may
6、involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety, health, and environmental prac-tices and determine the app
7、licability of regulatory limitationsprior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by
8、the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2F1815 Test Methods for Saturated Hydraulic Conductivity,Water Retention, Porosity, and Bulk Density of AthleticField RootzonesF2651 Terminology Relating to Soil and Turfgrass Charac-ter
9、istics of Natural Playing Surfaces3. Terminology3.1 DefinitionsExcept as noted, soil- and turfgrass-relateddefinitions are in accordance with Terminology F2651.3.2 Definitions of Terms Specific to This Standard:3.2.1 aggregate materiala soil-like or earthy materialwithout appreciable soil structural
10、 properties such that anaggregate material is essentially granular or single-grained innature.3.2.2 warning tracka section of a sports field area typi-cally devoid of vegetation, that provides a change in surfacetexture such that an athlete can sense without looking theproximity to a hazard such as
11、a fence, post, or wall.4. Significance and Use4.1 Warning tracks are playing surfaces located on themargins of the playing area for the purpose of providing awarning to the player that he or she is approaching a hazard(commonly a fence) or out-of-bounds area. In order to providefor an effective warn
12、ing track surface, the warning track mustbe constructed and maintained in such a manner so that theplayer can sense the change in texture from the regular playingsurface and the warning track without having to look. Thisfeature is very important in that the player is often visuallyfocused on the bal
13、l during play and would not be looking at theground as he/she is running toward the warning track. Thewarning track must also be constructed and maintained in such1This guide is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct respon
14、sibility ofSubcommittee F08.64 on Natural Playing Surfaces.Current edition approved April 1, 2018. Published May 2018. Originallyapproved in 2004. Last previous edition approved in 2012 as F2270 12. DOI:10.1520/F2270-12R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orconta
15、ct ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standa
16、rd was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1a manne
17、r that the warning track itself, or the surface transition,does not pose a hazard to the players.4.2 The warning track areas of sports fields should providea uniform surface with good footing. The change in surfacetexture of the warning track from the surrounding playingsurface must be of enough con
18、trast such that the player cansense the change without looking. Most often, warning tracksurfaces are devoid of turf or other vegetation. However, turfedwarning track areas may be used in instances where suchpurpose is to “warn” the player of an impending hazard wherethe primary playing surface is a
19、 skinned area. This may be thecase in softball where the entire infield playing surface is askinned area and a turfed warning track is used along the firstbase and third base fencelines. Undulations, rough surface,hard or soft surface, weeds, stones, debris, wets spots, etc.detract from a good, safe
20、 warning track. The safety andeffectiveness of the warning track is largely affected byconstruction and maintenance procedures and this guide ad-dresses those procedures.4.2.1 During construction, consideration should be given tofactors such as the physical and chemical properties of mate-rials used
21、 in the area, freedom from stones, sticks, and otherdebris, and surface drainage and internal drainage. Consider-ation should also be given to the surface elevation such that adrastic change is not produced by the transition from theplaying surface to the warning track area which may create atrippin
22、g or falling hazard.4.2.2 Maintenance practices that influence the playability ofthe surface include edging, dragging, rolling, watering, vegeta-tion control, and removal of stones and debris that mayadversely affect play and safety.4.3 Those responsible for the design, construction, ormaintenance,
23、or a combination thereof, of baseball and softballfields, or play areas where the need for a warning track area hasbeen identified, will benefit from this guide.5. Design5.1 CompositionMost warning track constructions will bean area devoid of vegetation as a transition from a turfed(natural or artif
24、icial) playing surface. While areas devoid ofvegetation are technically “skinned” areas, for the purpose ofthis guide the term “warning track” is utilized to differentiatethe areas of the playing surface that are not part of the skinnedinfield area.5.1.1 Warning tracks can be constructed of various
25、materialsand still meet the objectives of an effective warning tracksurface. Various soil components and amendments may bespecified. The concept of a warning track surface with firmfooting is that the particle sizes of the materials used or blendedfor the construction are of a wide enough range so a
26、s to providea substrate that binds together or has good interlock of thecomponents. Clay soil materials may be used in such construc-tions in that they will bind together. However the plastic natureof clay materials when wet could preclude high-clay warningtracks in that they would not provide safe
27、and effective footingunder conditions of high moisture.5.1.2 The most effective warning tracks should be com-posed largely of granular or aggregate materials (fine graveland sand) of a wide enough particle size range such that theparticles interlock. Angular grains of aggregate (as opposed torounded
28、 grains) provide more interlock due to the increasedinternal friction they provide within the soil profile. Smalladditions of clay or clayey material may be appropriate toprovide some characteristics of cohesiveness and color. It isoften desired for the color of the warning track to match asclosely
29、as possible the color of the skinned areas of the field. Inthese instances, the clay material used in the skinned infieldconstructions may be included in smaller proportions in thematerial mixed for the warning track areas.5.2 DimensionsTypically, warning track dimensions arenot included in rule boo
30、ks and the recommended widths aretypically based upon such factors as the age, size, and ability ofthe players. For warning track areas adjacent to the backstopfence and extensions, the distance used for a warning track istypically13 of the distance from home plate to the back stop.For example, wher
31、e the rule book specifies a home plate toback stop distance of 7.6 m (25 ft), the appropriate dimensionfor the warning track in this instance would be 2.5 m (8.2 ft).The warning track dimension therefore would tell the catcherand infielders that they have covered two thirds of the distanceto the bac
32、kstop/fence. Other criteria for warning track dimen-sions include the rule of thumb for a distance equivalent tothree full strides of a running player. The concept here is thatthe player has a distance equivalent to three strides in order toadjust his position/speed to protect himself from the impen
33、dingobstruction. A distance of three full strides of a running playercan vary from about 2.5 m (8 ft) for youth players up to 5.5 m(18 ft) for collegiate or professional-level athletes. It should benoted that warning track dimensions that are too great may losetheir effectiveness in that a dimension
34、 that is too vast (too muchplaying area contained within the warning track area) will failto provide effective “warning” of the impending obstruction.5.2.1 A warning track construction should be designed toallow for surface drainage. A surface slope between 1 and1.75 % should be incorporated as a de
35、sign element in thewarning track.5.3 PerformanceA warning track could be constructed byblending an aggregate amendment into the on-site or existingsoil or could be constructed of entirely imported materials.5.3.1 AggregateThe aggregate material used for a warn-ing track blended material (whether ble
36、nded with on-sitematerials or imported materials) should meet the followingcriteria:5.3.1.1 Particle Size Criteria for Aggregate Component ofWarning Track Material:(1) Less than 5 % material greater than 6.35 mm (0.25 in.).(2) Relatively uniform or homogeneous in size fractionsbetween 6.35 and 0.3 m
37、m. Sieve sizes used for characterizingthe aggregate material shall include: 6.35 mm, 4.75 mm, 2.36mm, 1.18 mm, 0.6 mm, 0.3 mm, and 0.05 mm.(3) Less than 20 % of the particles in the 30 %clay size particles).5.3.2.2 Soil material shall have 5 cm-h-1(2 in.-h-1) when compacted to a bulkdensity of 1.7 k
38、g-m-3and using hydraulic conductivity testingprocedures as described in Test Method F1815.5.3.3.2 A material that can easily be packed or compactedby hand or with the use of a lightweight missile to a bulkdensity of 1.7 kg-m-3or higher in the laboratory.5.3.3.3 Total porosity 85 % com-paction) to av
39、oid differential settling of the subgrade materials.Once compacted, the slope of the subgrade should be re-checked and any irregularities or depressional areas should becorrected before proceeding. Once the subgrade is sufficientlyprepared, the warning track material may be installed andleveled. Onc
40、e the material is leveled, the area should be rolledand the final grade established so as to provide an even gradetransition from the play area to the warning track. The smoothtransition is imperative to lower the potential for tripping orstumbling. Tripping or stumbling could lead a player head-oni
41、nto a fence or hazard.6.3 A physical barrier (boards, landscape edging, etc.)placed in the soil to prevent encroachment of turfgrass into thewarning track or to minimize mixing of materials in warningtracks and adjacent areas may minimize the need for edging tocreate a sharp boundary line; however,
42、such barriers are notmaintenance-free and may be safety hazards.7. Maintenance7.1 Routine warning track maintenance is primarily com-posed of five processes: edging, dragging, watering, rolling,and topdressing. Warning tracks may also require periodicrenovation to restore the performance or appearan
43、ce, or both.With some installations, periodic weed control may also berequired. Weed control can be accomplished by hand (me-chanical) or through the use of herbicides (either post emergentor pre-emergent). Care should be taken to reduce the effects ofan excessive edge, lip, or uneven transition.7.2
44、 EdgingEdging prevents the encroachment of turfgrassinto the warning track area. Edging also creates a neat andprofessional appearance. Edging also prevents the formation ofa lip caused by warning track materials migrating into theadjoining turf area. Tools that are typically utilized for edgingincl
45、ude powered sidewalk edgers, string trimmers, handedgers, or flat-nosed shovels.7.3 DraggingDragging helps to condition the warningtrack leading to a neat professional appearance. Periodicdragging also fills and levels depressions and undulations thatmay begin to form in the warning track. Dragging
46、operationsshould consist of a nail drag procedure followed by a mat drag.It is recommended that dragging operations be performed atleast once per month during the playing season. Mat draggingmay be performed prior to each game for appearance. Careshould be exercised in the dragging operation so as n
47、ot topromote the formation of a lip at the transition with the grassplaying surface caused by dragging loose warning trackmaterial into the turf. Material forming a lip can create apotentially hazardous condition for tripping or stumbling.7.4 WateringWatering is used to keep dust down duringperiods
48、of play or maintenance, or both. Watering is also anessential practice to control moisture to achieve desired resultsfrom other maintenance practices. The moisture status of thewarning track materials in preparation for other maintenancepractices is primarily a matter of personal preference of thema
49、intenance manager. Considerations for supply of water tothe warning track should be considered during the field designor renovation planning stages. Water can be supplied by anirrigation design specific for the warning track area or bydesigning strategically placed quick disconnect outlets that willallow for the attachment of irrigation heads or hoses for handwatering.7.5 RollingRolling is required to continuously produce asurface that will provide firm footing. Rolling should beperformed periodically throughout the season upon a moist-ened warning track profile. It is imp
