1、Designation: D6662 13Standard 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. Scope1.1 This specification covers polyolefin-based plastic lum-ber products for use as exterior residential decking boards.1.2 Plastic lumber pr
3、oducts 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 o
4、ther 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 pred
5、ominantly 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 construction
6、industry. 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 any
7、, 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 a
9、nd Data-Analysis for Struc-tural Wood and Wood-Based ProductsD4329 Practice for Fluorescent UV Exposure of PlasticsD5033 Guide for Development ofASTM Standards Relatingto Recycling and Use of Recycled Plastics (Withdrawn2007)3D6109 Test Methods for Flexural Properties of Unreinforcedand Reinforced P
10、lastic 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 30 and 140F (34.4and 60C)E84 Tes
11、t 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 Ultraviolet (UV)Lamp Apparatus for
12、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), typically usedas a building material fo
13、r 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 jurisdiction of ASTM Committee D
14、20 onPlastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber.Current edition approved June 1, 2013. Published June 2013. Originallyapproved in 2001. Last previous edition approved in 2009 as D6662 - 09. DOI:10.1520/D6662-13.2For referenced ASTM standards, visit the ASTM we
15、bsite, 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.astm.org.Copyright ASTM Internation
16、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1dimension lumber; however the tolerances for plastic lumberand for traditional lumber are not necessarily the same.(Terminology D883)3.1.2 resin, na solid or pseudo solid organic material oftenof high molecular w
17、eight, 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 broad sense, the term is used todesignate any polymer that is a basic material for plastics.(1982)3.2 Definitions of
18、 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 width of the board.3.2.2 crookdistortion of the board in which there is adeviation in a direction perpendicular to
19、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 edge to edge across the width of the board.3.2.4 edgethe side of a rectangular-shaped board corre-sponding to the thi
20、ckness 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 rectangular-shaped board.3.2.7 widththe greater dimension of the cross-sectionalprofile of a rectangular-shaped board.3
21、.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-tended to be helpful to producers, distributors, regulatoryagencies and users. The information can also promote unde
22、r-standing between purchasers and sellers. The purchaser shallstate whether this specification is to be used, select thepreferred options permitted herein, and include the allowabledesign information in the invitation to bid and purchase orderfrom the following:4.1.1 Title, number and date of this s
23、pecification,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 lineal feet,4.1.7 Cut length,4.1.8 Cross-sectional dimensions,4.1.9 Packing requirements,4.1.10 Palletization, if
24、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 sales distribution and not for a specific project),the manufacturer shall provide minimum allowable designinformation
25、, 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 produce decking boards either in sizesthat are similar to the standard dimensions of the woodindustry, or to proprieta
26、ry 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 ThicknessUnless otherwise specified in 4.1.8, boardsshall be:Nominal (in.) Actual (in.) Tolerance (in.)134 11654 111621-
27、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 (in.) Actual (in.) Tolerance (in.)32-12 1164312 1166512 11687-14 11610 9-14 11612 11-14 116Tolerance on width of b
28、oards 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 20 feet, the tolerances will be +12-inch or -116 inchper 20-ft of length or fraction thereof. Measurement of lengths
29、to 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 interpolation of the values is acceptable for dimen-sions other than listed.5.5 SquarenessUnless a specially shaped
30、 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 intendedpurpose.5.6 CrookCrook shall conform to the tolerances in Table2. Linear interpolation of the values is acceptable for
31、 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 methodology and equa-tions presented in section 6.1.4 for determining recommendedTABLE 1 Cup or Bulge Tolerances Rela
32、tive 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 132maximum span lengths are not applicable to tongue and grooveboards. Manufacturers of tongue and groove decking boardsshall provide recommended span lengths based o
33、n 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 Properties:6.1.1 Test ProcedureD6109.6.1.2 Specimens TestedA minimum of 15 specimens shallbe tested.6.1.3 Criteria(1
34、) 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 number of specimens required toestablish the mean value at 75 % confidence interval with 65 % error using Practice D29
35、15.(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 the flexural strength at failure for thatspecimen shall equal or exceed 1000 psi. The 5 % lowertolerance limit at 75
36、 % 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 a one-sided tolerance limit for thedistribution. Table 4 shows the value of K for several samplesizes.NOTE 2Many s
37、tandards 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 center joist spacing is considered typical standardspacing for residential deck construction. While 50 000 psi is give
38、n 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 guidance presented in6.1.4 below. Alternatively, use span lengths less than 16 in. on center asneeded.NOTE 4Concurr
39、ent 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 (underthe Subcommittee D20.20 on Plastic Products). This Standard Guide isexpected to be available sometime after
40、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 are continuous overa minimum of two spans (such as decking boards) as shown inFig. 1, the maximum recommended span
41、 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 distributed (or uniform) loads on boards which arecontinuous over a minimum of two spans (such as deckingboards) a
42、s 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)Deflection Formula:L 5 185EI!144!/qb k!#13 (4)where:L = computed span length, in.,S = section modulus, in.3,Fb = allo
43、wable 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 limit deflection to L/k (for exampleL/360 with k = 360; or L/120 with k = 120),q = uniformly distributed load, lb/
44、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 Allowable Flexural StressThe allowable flexuralstress, Fb, of the decking board is given as follows:Fb 5 Fb/FS!CDCT(5)TABL
45、E 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 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.
46、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 Variation (COV) in the Data SetCOV Range, % 1015 1520 2025 25No. of Specimens, N 15 23 34 60TABLE 4 Value of K for Establis
47、hing 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 on Boards that are Con-tinuous Over Two SpansD6662 133where:Fb= the base flexural stress value for plastic lumber m
48、adeof 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
49、Factor, Table 6.Fb, the base flexural stress value for plastic lumber made ofHDPE type polyolefins, is determined as follows:Fb5 Fbt0.3 (6)where:Fbt= the 5 % lower tolerance limit at 75 % confidence of theflexural stress at 3 % outer fiber strain determined fromflexure tests conducted in accordance with TestMethod D6109, and0.3 = factor to convert the 3 minute test value to a ten yearnormal duration value (that is, a flexural stress equal to30%ofFbtwi
