1、Designation: F2270 12An 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 adoption or, in the case
2、 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 maintenance of war
3、ning 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. Although this guide has
4、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 construction and mai
5、ntenancetechniques 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 involve hazardous m
6、aterials, opera-tions, 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 and health practices and deter-mine the applicability of regulatory requirem
7、ents prior to use.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-teristics of Natural Playing Surfaces3. Terminology3.1 De
8、finitionsExcept 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 properties such that anaggregate material is essentia
9、lly 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 a fence, post, or wall.4. Significance and Use4.1 Warn
10、ing 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 warning track surface, the warning track mustbe constructe
11、d 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 ball during play and would not be looking at theground as
12、 he/she is running toward the warning track. Thewarning track must also be constructed and maintained in sucha manner 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
13、footing. The change in surfacetexture of the warning track from the surrounding playingsurface must be of enough contrast 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
14、 in instances where suchpurpose is to “warn” the player of an impending hazard wherethe primary playing surface is a 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 fenceline
15、s. Undulations, rough surface,hard or soft surface, weeds, stones, debris, wets spots, etc.detract from a good, safe warning track. The safety and1This guide is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.64 onNa
16、tural Playing Surfaces.Current edition approved July 15, 2012. Published August 2012. Originallyapproved in 2004. Last previous edition approved in 2004 as F2270 04. DOI:10.1520/F2270-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea
17、stm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.effectiveness of the warning track is largely affected byco
18、nstruction 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 in the area, freedom from stones, sticks, and otherdebris, and surface drainage and inte
19、rnal 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 atripping or falling hazard.4.2.2 Maintenance practices that influence the playability ofthe surf
20、ace 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, or main-tenance, or a combination thereof, of baseball and softballfields, or play areas where the need
21、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 artificial) playing surface. While areas devoid ofvegetation are technically “skinned” areas
22、, 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 materialsand still meet the objectives of an effective warning tracksurface. Various so
23、il 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 as to providea substrate that binds together or has good interlock of thecomponents. Cla
24、y 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 and effective footingunder conditions of high moisture.5.1.2 The most effective warning
25、 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 grains) provide more interlock due to the increasedinternal friction they provide with
26、in 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 as possible the color of the skinned areas of the field. Inthese instances, the clay ma
27、terial 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 books and the recommended widths aretypically based upon such factors as the age, size, an
28、d 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, where the rule book specifies a home plate toback stop distance of 7.6 m (25 ft), the appro
29、priate 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 backstop/fence. Other criteria for warning track dimen-sions include the rule of thumb for
30、 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 impendingobstruction. A distance of three full strides of a running playercan vary from abou
31、t 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 that is too vast (too muchplaying area contained within the warning track area) will f
32、ailto 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 design element in thewarning track.5.3 PerformanceA warning track could be constructed by
33、blending 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 blended with on-sitematerials or imported materials) should meet the followingcriteria:5.3
34、.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 mm. Sieve sizes used for characterizingthe aggregate material shall include: 6.35 mm, 4.
35、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 kg-m-3and using hydraulic conductivity testingprocedures as described in Test Method F18
36、15.5.3.3.2 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 avoid differential settling of the subgrade materials.Once compacted, the slope of the su
37、bgrade 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. Once the material is leveled, the area should be rolledand the final grade established so
38、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-oninto a fence or hazard.6.3 A physical barrier (boards, landscape edging, etc.)placed in
39、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, such barriers are notmaintenance-free and may be safety hazards.7. Maintenance7.1 Routi
40、ne 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 appearance, or both.With some installations, periodic weed control may also berequired. Weed co
41、ntrol 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 EdgingEdging prevents the encroachment of turfgrassinto the warning track area. Edging
42、 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 edginginclude powered sidewalk edgers, string trimmers, hand edg-ers, or flat-nosed shovels.7.3 D
43、raggingDragging 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 operationsshould consist of a nail drag procedure followed by a mat drag.It is recomm
44、ended 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 not topromote the formation of a lip at the transition with the grassplaying surface c
45、aused 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 of play or maintenance, or both. Watering is also anessential practice to control moi
46、sture 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 themaintenance manager. Considerations for supply of water tothe warning track should be c
47、onsidered 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 RollingRol
48、ling 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 imperative that rolling followany tillage operations that may be used to loosen up thewarning track profile.
49、Rolling should also follow any proce-dures where moderate to heavy topdressing applications havebeen applied. Mat dragging may follow rolling to eliminate anylines or marks left by the edge of the roller.7.6 TopdressingTopdressing material should meet thesame characteristics as the warning track profile construction.Topdressing should be performed periodically to replace ma-terial that may have been lost due to erosion or to relevel thesurface due to settlement. Topdressing can be broadcast overthe entire surface and then leveled by dragging or topdressingmay be applied t
