1、Designation: D6662 17Standard Specification forPolyolefin-Based Plastic Lumber Decking Boards1This standard is issued under the fixed designation D6662; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers polyolefin-based plastic lum-ber products for use as exterior residential decking boards.1.2 Plastic lumber p
3、roducts are currently made predomi-nantly with recycled polyolefin plastics (in particular high-density polyethylene) where the products are more or lessnon-homogenous in the cross-section. However, this specifica-tion is also potentially applicable to similar manufacturedplastic products made from
4、other plastic and plastic compositematerials that have non-homogenous cross-sections.1.3 This specification details a procedure to calculate rec-ommended span lengths for spacing of support joists. Thisprocedure was developed using experimental data from atypical unreinforced plastic lumber made pre
5、dominantly fromrecycled high-density polyethylene. The methodology to de-velop span lengths for other types and compositions of plasticlumber is detailed in Appendix X1 of this standard.1.4 The values are stated in inch-pound units, as these arecurrently the most common units used by the constructio
6、nindustry. Equivalent SI units are indicated in parentheses.However, the units stated for irradiance exposure in theweatherability section (6.3) are in SI units as these are the unitscommonly used for testing of this type.1.5 This standard does not purport to address all of thesafety concerns, if an
7、y, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no similar or equivalent ISO Standard.2. Referenced Documents2.1 The following
8、 documents of the issue in effect on thedate of material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2D883 Terminology Relating to PlasticsD2565 Practice for Xenon-Arc Exposure of Plastics In-tended for Outdoor ApplicationsD2915 Practice for Sampling
9、and Data-Analysis for Struc-tural Wood and Wood-Based ProductsD4329 Practice for Fluorescent Ultraviolet (UV) Lamp Ap-paratus Exposure of PlasticsD5033 Guide for Development ofASTM Standards Relatingto Recycling and Use of Recycled Plastics (Withdrawn2007)3D6109 Test Methods for Flexural Properties
10、of Unreinforcedand Reinforced Plastic Lumber and Related ProductsD6112 Test Methods for Compressive and Flexural Creepand Creep-Rupture of Plastic Lumber and ShapesD6341 Test Method for Determination of the Linear Coef-ficient of Thermal Expansion of Plastic Lumber andPlastic Lumber Shapes Between 3
11、0 and 140F (34.4and 60C)E84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE108 Test Methods for Fire Tests of Roof CoveringsG151 Practice for Exposing Nonmetallic Materials inAccel-erated Test Devices that Use Laboratory Light SourcesG154 Practice for Operating Fluorescent Ultr
12、aviolet (UV)Lamp Apparatus for Exposure of Nonmetallic MaterialsG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic Materials3. Terminology3.1 Definitions:3.1.1 plastic lumber, na manufactured product made pri-marily from plastic materials (filled or unfilled), typicall
13、y usedas a building material for purposes similar to those of tradi-tional lumber, which is usually rectangular in cross-section.(Terminology D883)3.1.1.1 DiscussionPlastic lumber is typically supplied insizes similar to those of traditional lumber board, timber and1This specification is under the j
14、urisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber.Current edition approved March 1, 2017. Published March 2017. Originallyapproved in 2001. Last previous edition approved in 2013 as D6662 - 13. DOI:10.1520/D6662-17.2For referenced
15、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 website.3The last approved version of this historical standard is referenced onwww.as
16、tm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardizati
17、on 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.1dimension lumber; however the tolerances for plastic lumberand for traditional lumber are not nec
18、essarily the same.(Terminology D883)3.1.2 resin, na solid or pseudo solid organic material oftenof high molecular weight, which exhibits a tendency to flowwhen subjected to stress, usually has a softening or meltingrange, and usually fractures conchoidally. (Terminology D883)3.1.2.1 DiscussionIn a b
19、road sense, the term is used todesignate any polymer that is a basic material for plastics.(1982)3.2 Definitions of Terms Specific to This Standard:3.2.1 bulgeconvex distortion (away from the center of thecross-section) of the face of the board from a straight linedrawn from edge to edge across the
20、width of the board.3.2.2 crookdistortion of the board in which there is adeviation in a direction perpendicular to the edge from astraight line from end to end of the board.3.2.3 cupconcave distortion (towards the center of thecross-section) of the face of the board from a straight linedrawn from ed
21、ge to edge across the width of the board.3.2.4 edgethe side of a rectangular-shaped board corre-sponding to the thickness of the board.3.2.5 facethe side of a rectangular-shaped board corre-sponding to the width of the board.3.2.6 thicknessthe lesser dimension of the cross-sectionalprofile of a rect
22、angular-shaped board.3.2.7 widththe greater dimension of the cross-sectionalprofile of a rectangular-shaped board.3.3 Additional definition of terms applying to this specifi-cation appear in Terminology D883 and D5033.4. Ordering Information4.1 The information contained in this specification is in-t
23、ended to be helpful to producers, distributors, regulatoryagencies and users. The information can also promote under-standing between purchasers and sellers. The purchaser shallstate whether this specification is to be used, select thepreferred options permitted herein, and include the allowabledesi
24、gn information in the invitation to bid and purchase orderfrom the following:4.1.1 Title, number and date of this specification,4.1.2 Minimum allowable bending strength and allowablebending stiffness,4.1.3 Percent recycled content (if requested),4.1.4 Flame spread index,4.1.5 Color,4.1.6 Quantity in
25、 lineal feet,4.1.7 Cut length,4.1.8 Cross-sectional dimensions,4.1.9 Packing requirements,4.1.10 Palletization, if required,4.1.11 Marking, if other than specified.4.2 If specific mechanical property values are not requiredby the purchaser (for example, when purchasing materials forgeneral retail sa
26、les distribution and not for a specific project),the manufacturer shall provide minimum allowable designinformation, as would be determined under this specification,to aid in the application of the decking board material by theend user.5. Dimensions and Permissible VariationsIt is permissible to pro
27、duce decking boards either in sizesthat are similar to the standard dimensions of the woodindustry, or to proprietary dimensions designed by manufac-turers. This specification does not limit the dimensionalrange of production. For reference, the standards of thewood industry are as follows:5.1 Thick
28、nessUnless otherwise specified in 4.1.8, boardsshall be:Nominal (in.) Actual (in.) Tolerance (in.)134 11654 111621-12 116Tolerance on thickness of boards thicker than 2 inches(nominal) shall be 6116 inch.5.2 Width of BoardsUnless otherwise specified in para-graph 4.1.8, board widths shall be:Nominal
29、 (in.) Actual (in.) Tolerance (in.)32-12 1164312 1166512 11687-14 11610 9-14 11612 11-14 116Tolerance on width of boards wider than 12 inches (nominal)shall be 6116 inch.5.3 Length of Boardsunless otherwise specified in 4.1.7,boards up to 20 feet shall have tolerances of +12 inch or -116inch. Over 2
30、0 feet, the tolerances will be +12-inch or -116 inchper 20-ft of length or fraction thereof. Measurement of lengthsto be made at 73 6 2 F and relative humidity of 50 6 5%.5.4 Flatness ToleranceBoard shall be flat with maximumcup or bulge in the board face limited to the tolerances in Table1. Linear
31、interpolation of the values is acceptable for dimen-sions other than listed.5.5 SquarenessUnless a specially shaped member isspecified, the cross-section of all boards shall be visuallyrectangular (that is, the face and edge of the board areperpendicular to each other) and suited for the intendedpur
32、pose.5.6 CrookCrook shall conform to the tolerances in Table2. Linear interpolation of the values is acceptable for dimen-sions other than listed.5.7 Tongue and GrooveBoards shall be without tongueand groove unless otherwise specified in 4.1.8. Because of loadtransfer between adjacent boards, the me
33、thodology and equa-tions presented in section 6.1.4 for determining recommendedTABLE 1 Cup or Bulge Tolerances Relative to Nominal Width ofthe Board FaceFace Width, in. #4 in. 6 in. 8 in. 10 in. 12 in.Tolerance132 in.116 in.18 in.316 in.14 in.D6662 172maximum span lengths are not applicable to tongu
34、e and grooveboards. Manufacturers of tongue and groove decking boardsshall provide recommended span lengths based on soundengineering practice, taking into account some of the issuesdescribed in 6.1.4 below, as well as previous, in-serviceperformance history.6. Performance Requirements6.1 Flexural P
35、roperties:6.1.1 Test ProcedureD6109.6.1.2 Specimens TestedA minimum of 15 specimens shallbe tested.6.1.3 Criteria(1) The mean value of the secant flexuralmodulus at 1 % outer fiber strain estimated statistically towithin 5 % with 75 % confidence shall equal or exceed 50 000psi. Table 3 shows the num
36、ber of specimens required toestablish the mean value at 75 % confidence interval with 65 % error using Practice D2915.(2) The 5 % lower tolerancelimit at 75 % confidence flexural stress at 3 % outer fiber strainshall equal or exceed 1000 psi. If any specimen fails prior toreaching 3 % strain, then t
37、he flexural strength at failure for thatspecimen shall equal or exceed 1000 psi. The 5 % lowertolerance limit at 75 % confidence is computed by subtractingK-times the standard deviation from the mean value, where Kis tabulated in statistics handbooks (and in Table 3 of PracticeD2915) as a factor for
38、 a one-sided tolerance limit for thedistribution. Table 4 shows the value of K for several samplesizes.NOTE 2Many standards require a minimum sample size of approxi-mately 30 to balance testing costs against the large reductions in theallowable values for very small sample sizes.NOTE 3A16 in. on cen
39、ter joist spacing is considered typical standardspacing for residential deck construction. While 50 000 psi is given as aminimum flexural modulus, a modulus greater than 50 000 psi ispotentially required for some decking board sizes in order to meet thisspacing when determining span lengths per the
40、guidance presented in6.1.4 below. Alternatively, use span lengths less than 16 in. on center asneeded.NOTE 4Concurrent to the development of this specification for PlasticLumber Decking, a Standard Guide for the Design and Construction ofPlastic Lumber Decking is being developed by Section D20.20.01
41、 (underthe Subcommittee D20.20 on Plastic Products). This Standard Guide isexpected to be available sometime after this Specification has beenapproved and in use.6.1.4 Span LengthsRecommended maximum span lengthsshall be determined using the following equations:For concentrated loads on boards which
42、 are continuous overa minimum of two spans (such as decking boards) as shown inFig. 1, the maximum recommended span shall be limited byeither the stress or the deflection formula as follow, whicheverprovides the lesser span:Stress Formula:L 5 64SFb!/13P! (1)Deflection Formula:L 5 67EI!/Pk!#12 (2)For
43、 distributed (or uniform) loads on boards which arecontinuous over a minimum of two spans (such as deckingboards) as shown in Fig. 2, the maximum span shall be limitedby either the stress or the deflection formula as follow,whichever provides the lesser span:Stress Formula:L 5 8SFb!144!/qb!#12 (3)De
44、flection Formula:L 5 185EI!144!/qb k!#13 (4)where:L = computed span length, in.,S = section modulus, in.3,Fb = allowable flexural stress as computed in 6.1.4.1, psi,P = concentrated load, lb,E = effective modulus of elasticity as computed in 6.1.4.2,psi,I = moment of inertia, in.4,k = factor used to
45、 limit deflection to L/k (for exampleL/360 with k = 360; or L/120 with k = 120),q = uniformly distributed load, lb/sq-ft,b = actual board width, in., and = Creep Adjustment Factor = 1.5.NOTE 5The attached commentary in Appendix X1 provides arationale for the Creep Adjustment Factor, .6.1.4.1 Allowab
46、le Flexural StressThe allowable flexuralstress, Fb, of the decking board is given as follows:Fb 5 Fb/FS!CDCT(5)TABLE 2 Crook Tolerances Relative to Nominal Length and Widthof the BoardLength in Feet #4in.Width6in.Width8 in. Width 10 in.Width12 in.Width4638 in.14 in.316 in.18 in.18 in.812 in.12 in.38
47、 in.14 in.316 in.1034 in.58 in.12 in.716 in.38 in.12 1 in.78 in.1316 in.34 in.916 in.14 114 in. 118 in. 1 in.78 in.34 in.16 112 in. 138 in. 118 in. 1 in.78 in.TABLE 3 Number of Specimens Required to Establish the MeanValue with an Error of 5 % with 75 % Confidence for VariousCoefficients of Variatio
48、n (COV) in the Data SetCOV Range, % 1015 1520 2025 25No. of Specimens, N 15 23 34 60TABLE 4 Value of K for Establishing the Lower 5 % LowerTolerance Limit with 75 % Confidence for Various Sample SizesNo. of Specimens, N 15 30 InfiniteValue of K 1.991 1.869 1.645FIG. 1 Schematic of Concentrated Load
49、on Boards that are Con-tinuous Over Two SpansD6662 173where:Fb= the base flexural stress value for plastic lumber madeof HDPE-type polyolefins for normal duration loading(10 yr. duration), psi,FS = Factor of Safety = 1.5,CD= Load Duration Factor for flexural stress, presented inFig. 3 and Table 5, depends on the shortest-durationload in combination, applied either cumulatively orcontinuously, andCT= Temperature Factor, Table 6.Fb, the
