1、Designation: D 6270 98 (Reapproved 2004)Standard Practice forUse of Scrap Tires in Civil Engineering Applications1This standard is issued under the fixed designation D 6270; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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.1. Scope1.1 This practice provides guidance for testing the physicalproperties and gives data for assessment of the leachatege
3、neration potential of processed or whole scrap tires in lieu ofconventional civil engineering materials, such as stone, gravel,soil, sand, or other fill materials. In addition, typical construc-tion practices are outlined.2. Referenced Documents2.1 ASTM Standards:2C 127 Test Method for Specific Grav
4、ity and Absorption ofCoarse AggregateD 422 Test Method for Particle-Size Analysis of SoilsD 698 Test Method for Laboratory Compaction Character-istics of Soil Using Standard Effort (12,400 ft-lbf/ft3(600kN-m/m3)D 1557 Test Method for Laboratory Compaction Character-istics of Soil Using Modified Effo
5、rt (56,000 ft-lbf/ft3(2,700 kN-m/m3)D 2434 Test Method for Permeability of Granular Soils(Constant Head)D 3080 Test Method for Direct Shear Test of Soils UnderConsolidated Drained ConditionsD 4253 Test Methods for Maximum Index Density and UnitWeight of Soils Using a Vibratory Table2.2 AASHTO Standa
6、rd:T 274 Standard Method of Test for Resilient Modulus ofSubgrade Soils32.3 USEPA Standard:Method 1311 Toxicity Characteristics Leaching Procedure43. Terminology3.1 Definitions:3.1.1 baling, na method of volume reduction wherebytires are compressed into bales.3.1.2 bead, nthe anchoring part of the t
7、ire which is shapedto fit the rim and is constructed of bead wire wrapped by theplies.3.1.3 bead wire, na high tensile steel wire surrounded byrubber, which forms the bead of a tire that provides a firmcontact to the rim.3.1.4 belt wire, na brass plated high tensile steel wire cordused in steel belt
8、s.3.1.5 buffng rubber, nvulcanized rubber usually obtainedfrom a worn or used tire in the process of removing the oldtread in preparation for retreading.3.1.6 carcass, nsee casing.3.1.7 casing, nthe basic tire structure excluding the tread(Syn. carcass).3.1.8 granulated rubber, nparticulate rubber c
9、omposed ofmainly nonspherical particles that span a broad range ofmaximum particle dimension, from below 425 m (40 mesh) to12 mm (also refer to particulate rubber).53.1.9 ground rubber, nparticulate rubber composed ofmainly nonspherical particles that span a range of maximumparticle dimensions, from
10、 below 425 m (40 mesh) to 2 mm(also refer to particulate rubber).53.1.10 nominal size, nthe average size product (chip) thatcomprises 50 % or more of the through put in a scrap tireprocessing operation; scrap tire processing operations generateproducts (chips) above and below the nominal size.3.1.11
11、 particulate rubber, nraw, uncured, compounded orvulcanized rubber that has been transformed by means of amechanical size reduction process into a collection of particles,with or without a coating of a partitioning agent to preventagglomeration during production, transportation, or storage(also see
12、definition of buffing rubber, granulated rubber,ground rubber, and powdered rubber).53.1.12 passenger car tire, na tire with less than a 457-mmrim diameter for use on cars only.1This practice is under the jurisdiction of ASTM Committee D34 on Biotech-nology and is the direct responsibility of Subcom
13、mittee D34.03.03 on IndustrialRecovery and Reuse.Current edition approved June 10, 1998. Published August 1998.2For 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 s
14、tandards Document Summary page onthe ASTM website.3Standard Specifications for Transportation Materials and Methods of Samplingand Testing, Part II: Methods of Sampling and Testing, American Association ofState Highway and Transportation Officials, Washington, D.C.4Test Methods for Evaluating Solid
15、Waste: Physical/Chemical Methods, 3rded.,Report No. EPA 530/SW-846, U.S. Environmental Protection Agency, Washington,D.C.5The defined term is the responsibility of Committee D11 on Rubber.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Stat
16、es.3.1.13 powdered rubber, nparticulate rubber composed ofmainly nonspherical particles that have a maximum particledimension equal to or below 425 m (40 mesh) (also refer toparticulate rubber).53.1.14 rough shred, na piece of a shredded tire that islarger than 50 mm by 50 mm by 50 mm, but smaller t
17、han 762mm by 50 mm by 100 mm.3.1.15 rubber fines, nsmall particles of ground rubber thatresult as a by-product of producing shredded rubber.3.1.16 scrap tire, na tire, which can no longer be used forits original purpose due to wear or damage.3.1.17 shred sizing, na term which generally refers to the
18、process of particles passing through a rated screen openingrather than those which are retained on the screen.3.1.18 shredded tire, na size reduced scrap tire where thereduction in size was accomplished by a mechanical processingdevice, commonly referred to as a shredder.3.1.19 shredded rubber, npie
19、ces of scrap tires resultingfrom mechanical processing.3.1.20 sidewall, nthe side of a tire between the treadshoulder and the rim bead.3.1.21 single pass shred, na shredded tire that has beenprocessed by one pass through a shear type shredder and theresulting pieces have not been classified by size.
20、3.1.22 steel belt, nrubber coated steel cords that rundiagonally under the tread of steel radial tires and extend acrossthe tire approximately the width of the tread.3.1.23 tire chips, nPieces of scrap tires that have a basicgeometrical shape and are generally between 12 mm and 50mm in size and have
21、 most of the wire removed (Syn. chippedtire).3.1.24 tire shreds, nPieces of scrap tires that have a basicgeometrical shape and are generally between 50 mm and 305mm in size.3.1.25 tread, nthat portion of the tire which contacts theroad.3.1.26 truck tire, na tire with a rim diameter of 500 mmor large
22、r.3.1.27 waste tire, na tire which is no longer capable ofbeing used for its original purpose but which has been disposedof in such a manner that it cannot be used for any otherpurpose.3.1.28 whole tire, na scrap tire that has been removedfrom a rim but which has not been processed.3.1.29 x-mm minus
23、, npieces of classified, size reducedscrap tires where the maximum size of 95 % of the pieces isless than x-mm in any dimension (that is, 25-mm minus;50-mm minus; 75-mm minus, etc).4. Significance and Use4.1 This practice is intended for use of scrap tires includingtire chips or tire shreds comprise
24、d of pieces of scrap tires, tirechip/soil mixtures, tire sidewalls, and whole scarp tires in civilengineering applications. This practice includes the use of tirechips, tire shreds, and tire chip/soil mixtures as lightweightembankment fill, lightweight retaining wall backfill, drainagelayers, therma
25、l insulation to limit frost penetration beneathroads, insulating backfill to limit heat loss from buildings, andreplacement for soil or rock in other fill applications. Use ofwhole scrap tires and tire sidewalls includes construction ofretaining walls and drainage culverts, as well as use as fillwhe
26、n whole tires have been compressed into bales. It is theresponsibility of the design engineer to determine the appro-priateness of using scrap tires in a particular application and toselect applicable tests and specifications to facilitate construc-tion and environmental protection. This practice is
27、 intended toencourage wider utilization of scrap tires in civil engineeringapplications.4.2 Three tire shred fills with thicknesses in excess of 7 mhave experienced a serious heating reaction; however, morethan 70 fills with a thickness less than 3 m have beenconstructed with no evidence of a delete
28、rious heating reaction(1)6. Guidelines have been developed to minimize internalheating of tire shred fills (2) as discussed in 6.10. Theguidelines are applicable to fills less than 3 m thick; thus, thispractice should be applied only to tire shred fills less than 3 mthick.5. Material Characterizatio
29、n5.1 The specific gravity and water absorption capacity oftire shreds should be determined in accordance with TestMethod C 127; however, the specific gravity of tire shreds isless than half the value obtained for common earthen coarseaggregate, so it is permissible to use a minimum weight of testsam
30、ple that is half of the specified value. The particle densityor density of solids of tire shreds (rs) may be determined fromthe apparent specific gravity using the following equation:rs5 Sarw! (1)where:Sa= apparent specific gravity, andrw= density of water.5.2 The gradation of tires shreds should be
31、 determined inaccordance with Test Method D 422; however, the specificgravity of tire shreds is less than half the values obtained forcommon earthen materials so it is permissible to use aminimum weight of test sample that is half of the specifiedvalue.5.3 The laboratory compacted dry density, or bu
32、lk density,of tire chips and tire chip/soil mixtures with less than 30 %retained on the 19.0-mm sieve can be determined in accor-dance with Test Method D 698 or D 1557. Tire Shred and tireshred/soil mixtures used for civil engineering applications,however, almost always have more than 30 % retained
33、on the19.0-mm sieve, so these methods generally are not applicable.A larger compaction mold should be used to accommodate thelarger size of the tire shreds. The sizes of typical compactionmolds are summarized in Table 1. The larger mold requires thatthe number of layers, or the number of blows of th
34、e rammer/layer, or both, be increased to produce the desired compactiveenergy/unit volume. Compactive energies ranging from 60 %of Test Method D 698 (60 % 3 600 kN-m/m3= 360 kN-m/m3)to 100 % of Test Method D 1557 (2,700 kN-m/m3) have beenused. Compaction energy only has a small effect on the6The bol
35、dface numbers in parentheses refer to the list of references at the end ofthis standard.D 6270 98 (2004)2resulting dry density (3); thus, for most applications it ispermissible to use a compactive energy equivalent to 60 % ofTest Method D 698. To achieve this energy with a mold volumeof 0.0125 m3wou
36、ld require that the sample be compacted infive layers with 44 blows/layer with a 44.5 N rammer falling457 mm. The water content of the sample only has a smalleffect on the compacted dry density (3) so it is permissible toperform compaction tests on air or oven-dried samples.5.3.1 The dry densities f
37、or tire shreds loosely dumped intoa compaction mold and tire shreds compacted by vibratorymethods (similar to Test Method D 4253) are about the same(4, 5, 6); thus, vibratory compaction of tire shreds in thelaboratory (see Test Method D 4253) should not be used.5.3.2 When estimating an in-place dens
38、ity for use in design,the compression of a tire shred layer under its own self-weightand under the weight of any overlying material must beconsidered. The dry density determined as discussed in 5.3 areuncompressed values. In addition, short-term time dependentsettlement of tire shreds should be acco
39、unted for when esti-mating the final in-place density (7).5.4 The compressibility of tire shreds and tire shred/soilmixtures can be measured by placing tire shreds in a rigidcylinder with a diameter several times greater than the largestparticle size and then measuring the vertical strain caused by
40、anincreasing vertical stress. If it is desired to calculate thecoefficient of lateral earth pressure at rest KO, the cylinder canbe instrumented to measure the horizontal stress of the tireshreds acting on the wall of the cylinder.5.4.1 The high compressibility of tire shreds necessitates theuse of
41、a relatively thick sample. In general, the ratio of theinitial specimen thickness to sample diameter should be greaterthan one. This leads to concerns that a significant portion of theapplied vertical stress could be transferred to the walls of thecylinder by friction. If the stress transferred to t
42、he walls of thecylinder is not accounted for, the compressibility of the tireshreds will be underestimated. For all compressibility tests, theinside of the container should be lubricated to reduce theportion of the applied load that is transmitted by side frictionfrom the sample to the walls of the
43、cylinder. For testing wherea high level of accuracy is desired, the vertical stress at the topand the bottom of the sample should be measured so that theaverage vertical stress in the sample can be computed. A testapparatus designed for this purpose is illustrated in Fig. 1 (8).5.5 The resilient mod
44、ulus (MR) of subgrade soils can beexpressed as:MR5 AQB(2)where:Q = first invariant of stress (sum of the three principalstresses),A = experimentally determined parameter, andB = experimentally determined parameter.TABLE 1 Size of Compaction Molds Used to Determine DryDensity of Tire ShredsMaximum Pa
45、rticleSize (mm)Mold Diameter(mm)Mold Volume(m3)Reference75 254 0.0125 (3)75 305 0.0146 (4)51 203 and 305 N.R.A(5)AN.R. = not reported.FIG. 1 Compressibility Apparatus for Tire Shreds Designed to Measured Lateral Stress and the Portion of the Vertical Load Transferredby Friction from Tire Shreds to C
46、ontainer (8)D 6270 98 (2004)3Tests for the parametersAand B can be conducted accordingto AASHTO T 274. The maximum particle size typically islimited to 19 mm by the testing apparatus, which precludes thegeneral applicability of this procedure to the larger size tirechips and shreds typically used fo
47、r civil engineering applica-tions.5.6 The coefficient of lateral earth pressure at rest KOandPoissons ratio can be determined from the results ofconfined compression tests where the horizontal stresses weremeasured. A test apparatus designed for this purpose is shownin Fig. 1 KOand are calculated fr
48、om:KO5sh/ sv(3) 5 KO/ 1 1 KO! (4)where:sh= measured horizontal stress, andsv= measured vertical stress.5.7 The shear strength of tire shreds may be determined ina direct shear apparatus in accordance with Test MethodD 3080 or using a triaxial shear apparatus. The large size of tireshreds typically u
49、sed for civil engineering applications requiresthat specimen sizes be several times greater than used forcommon soils. Because of the limited availability of largetriaxial shear apparatus, this method is generally restricted totire chips 25 mm in size and smaller. Extrapolation of resultson small size pieces to the 75-mm and larger size shreds usedfor civil engineering applications is uncertain since smallpieces are nearly equidimensional while larger tire chips andshreds tend to be long and flat. Furthermore, the triaxial shearapparatus gen
