1、Designation: D6109 10Standard Test Methods forFlexural Properties of Unreinforced and Reinforced PlasticLumber and Related Products1This standard is issued under the fixed designation D6109; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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 These test methods are suitable for determining theflexural properties for any solid or hollow man
3、ufactured plasticlumber product of square, rectangular, round, or other geomet-ric cross section that shows viscoelastic behavior. The testspecimens are whole “as manufactured” pieces without anyaltering or machining of surfaces beyond cutting to length. Assuch, this is a test method for evaluating
4、the properties ofplastic lumber as a product and not a material property testmethod. Flexural strength cannot be determined for thoseproducts that do not break or that do not fail in the extremeouter fiber.1.2 Test Method Adesigned principally for products in theflat or “plank” position.1.3 Test Met
5、hod Bdesigned principally for those productsin the edgewise or “joist” position.1.4 Plastic lumber currently is produced using several dif-ferent plastic manufacturing processes. These processes utilizea number of diverse plastic resin material systems that includefillers, fiber reinforcements, and
6、other chemical additives. Thetest methods are applicable to plastic lumber products wherethe plastic resin is the continuous phase, regardless of itsmanufacturing process, type or weight percentage of plasticresin utilized, type or weight percentage of fillers utilized, typeor weight percentage of r
7、einforcements utilized, and type orweight percentage of other chemical additives.1.4.1 Alternative to a single resin material system, diverseand multiple combinations of both virgin and recycled thermo-plastic material systems are permitted in the manufacture ofplastic lumber products.1.4.2 Diverse
8、types and combinations of inorganic andorganic filler systems are permitted in the manufacturing ofplastic lumber products. Inorganic fillers include such materi-als as talc, mica, silica, wollastonite, calcium carbonate, and soforth. Organic fillers include lignocellulosic materials made orderived
9、from wood, wood flour, flax shive, rice hulls, wheatstraw, and combinations thereof.1.4.3 Fiber reinforcements used in plastic lumber includemanufactured materials such as fiberglass (chopped or continu-ous), carbon, aramid and other polymerics; or lignocellulosic-based fibers such as flax, jute, ke
10、naf, and hemp.1.4.4 A wide variety of chemical additives are added toplastic lumber formulations to serve numerous different pur-poses. Examples include colorants, chemical foaming agents,ultraviolet stabilizers, flame retardants, lubricants, anti-staticproducts, biocides, heat stabilizers, and coup
11、ling agents1.5 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns, i
12、f any, 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 regulator limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM St
13、andards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD2915 Practice for Evaluating Allowable Properties forGrades of Structural LumberD5033 Guide for Development of ASTM Standards Relat-ing to Recycling and Use of Recycled Plastics3D5947 Test Methods for P
14、hysical Dimensions of SolidPlastics SpecimensE4 Practices for Force Verification of Testing MachinesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions: Definitions of terms applying to these testmethods appear in Terminology
15、D883 and Guide D5033.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.20 on Plastic Lumber(Section D20.20.01).Current edition approved Aug. 1, 2010. Published August 2010. Originallyapproved in 1997. Last previous e
16、dition approved in 2005 as D6109 - 05. DOI:10.1520/D6109-10.2For 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 standards Document Summary page onthe ASTM website.3
17、Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1 plastic lumber, na manufactured product composedof more than 50 weight percent resin,
18、 and in which the productgenerally is rectangular in cross-section and typically suppliedin sizes that correspond to traditional dimensional lumbersizes, may be filled or unfilled, and may be composed of singleor multiple resin blends.3.1.2 plastic lumber shape, nplastic lumber, which gen-erally is
19、not rectangular in cross section3.1.3 resin, nsolid or pseudosolid organic material oftenof high molecular weight, that exhibits a tendency to flowwhen subjected to stress, usually has a softening or meltingrange, and usually fractures conchoidally. (See TerminologyD883.)3.1.3.1 DiscussionIn a broad
20、 sense, the term is used todesignate any polymer that is a basic material for plastics.4. Summary of Test Method4.1 A specimen of rectangular cross section is tested inflexure as a beam either in a flat, or “plank,” mode (MethodA)or edgewise, or “joist,” mode (Method B) as follows:4.1.1 The beam res
21、ts on two supports and is loaded at twopoints (by means of two loading noses), each an equal distancefrom the adjacent support point. The distance between theloading noses (that is, the load span) is one-third of the supportspan (see Fig. 1; use of other distances for the load spans areaddressed in
22、Appendix X1).4.1.2 The specimen is deflected until rupture occurs in theouter fibers or until a maximum outer fiber strain of 3 % isreached, whichever occurs first.5. Significance and Use5.1 Flexural properties determined by these test methods areespecially useful for research and development, quali
23、ty control,acceptance or rejection under specifications, and special pur-poses.5.2 Specimen depth, temperature, atmospheric conditions,and the difference in rate of straining specified in Test MethodsA and B are capable of influencing flexural property results.6. Apparatus6.1 Testing MachineA proper
24、ly calibrated testing ma-chine that is capable of operation at a constant rate of motionof the movable head and has the accuracy of 61% ofmaximum load expected to be measured. It shall be equippedwith a deflection measuring device. The stiffness of the testingmachine shall be such that the total ela
25、stic deformation of thesystem does not exceed 1 % of the total deflection of the testspecimen during testing, or appropriate corrections shall bemade. The load indication mechanism shall be essentially freefrom inertial lag at the crosshead rate used. The accuracy of thetesting machine shall be veri
26、fied in accordance with PracticeE4.6.2 Loading Noses and SupportsThe loading noses andsupports shall have cylindrical surfaces. In order to avoidexcessive indentation, of the failure due to stress concentrationdirectly under the loading noses, the radius or noses andsupports shall be at least 0.5 in
27、. (12.7 mm) for all specimens.If significant indentation or compressive failure occurs or isobserved at the point where the loading noses contact thespecimen, then the radius of the loading noses shall beincreased up to 1.5 times the specimen depth (see Fig. 2).NOTE 2Test data have shown that the lo
28、ading noses and supportdimensions are capable of influencing the flexural modulus values.Dimensions of loading noses and supports must be specified in the testreport.7. Test Specimens7.1 The specimens shall be full size as manufactured, thencut to length for testing. The original outside surfaces sh
29、all beunaltered. The support span to depth ratio shall be nominally16:1.7.2 For Test Method A, flatwise or “plank” tests, the depthof the specimen shall be the thickness, or smaller dimension, ofthe product. For Test Method B, edgewise or “joist” tests thewidth becomes the smaller dimension and dept
30、h the larger. Forall tests, the support span shall be 16 (tolerance +4 and 2)times the depth of the beam. The specimen shall be longenough to allow for overhanging on each end of at least 10 %of the support span. Overhang shall be sufficient to prevent thespecimen from slipping through the supports.
31、8. Number of Test Specimens8.1 Five specimens shall be tested for each sample.FIG. 1 Loading DiagramNOTE 1(A) = minimum radius = 12.7 mm; (B) = maximum radius =1.5 times the specimen depth.FIG. 2 Four Point Loading and Support Noses at Minimum andMaximum RadiusD6109 1029. Conditioning9.1 Specimen Co
32、nditioningCondition the test specimensat 73.4 6 3.6F (23 6 2C) and 50 6 5 % relative humidity fornot less than 40 h prior to testing in accordance with ProcedureA of Practice D618 for those tests where conditioning isrequired. In cases of disagreement, the tolerances shall be61.8F (61C) and 62 % rel
33、ative humidity.9.2 Test ConditionsConduct the tests in the StandardLaboratory Atmosphere of 73.4 6 3.6F (23 6 2C) and 50 65 % relative humidity, unless otherwise specified in the refer-enced test methods or in these test methods. In cases ofdisagreement, the tolerances shall be 61.8F (61C) and62 % r
34、elative humidity.10. Procedure10.1 Test Method A:10.1.1 Flatwise or “plank” Testing:10.1.2 Use an untested specimen for each measurement.Measure the width of the specimen to a precision of 1 % of themeasured dimensions at several points along the productslength and record the average value. Measure
35、the depth of thespecimen at several points and record the average value (seeTest Methods D5947 for additional information).10.1.3 Determine the support span to be used as described inSection 7 and set the support span to within 1 % of thedetermined value.10.1.4 Calculate the rate of crosshead motion
36、 as follows,and set the machine as near as possible to that calculated ratefor a load span of one-third of the support span:R 5 0.185ZL2/d (1)where:R = rate of crosshead motion, in./min (mm/min),L = support span, in. (mm),d = depth of the beam, in. (mm), andZ = rate of straining of the outer fibers,
37、 in./in./min (mm/mm/min). Z shall be equal to 0.01.In no case shall the actual crosshead rate differ from thatcalculated from Eq 1, by more than 610 %.10.1.5 Align the loading noses and supports so that the axesof the cylindrical surfaces are parallel and the load span isone-third of the support spa
38、n. Check parallelism by means of aplate containing parallel grooves into which the loading nosesand supports will fit when properly aligned. Center the speci-men on the supports, with the long axis of the specimenperpendicular to the loading noses and supports. The loadingnose assembly shall be of t
39、he type which will not rotate.10.1.6 Apply the load to the specimen at the specifiedcrosshead rate, and take simultaneous load-deflection data.Measure deflection at the common center of the spans. Performthe necessary toe compensation (see Annex A1) to correct forseating and indentation of the speci
40、men and deflections in themachine. Stress-strain curves shall be plotted to determine theflexural yield strength, modulus of elasticity and secant modu-lus at 1 % strain.10.1.7 If no break has occurred in a specimen by the timethe maximum strain in the outer fibers has reached 0.03 in./in.(mm/mm), d
41、iscontinue the test (see Note 3 and Note 4). Thedeflection at which this strain occurs shall be calculated byletting r equal 0.03 in./in. (mm/mm) as follows for a load spanof one-third of the support span:D 5 0.21 rL2/d (2)where:D = midspan deflection, in. (mm),r = strain, in./in. (mm/mm), andd = de
42、pth of the beam, in. (mm).NOTE 3For some products the increase in strain rate provided underTest Method B is capable of inducing the specimen to yield or rupture, orboth, within the required 3 % strain limit.NOTE 4If the product does not fracture at a maximum of 3 % strain,these test methods do not
43、reveal true flexural strength.10.2 Test Method B:10.2.1 Edgewise or “Joist” Testing:10.2.2 Follow procedures of Test Method A, except that Z,the rate of strain of the outer fibers, shall nominally be in therange of 0.002 and 0.003 in./in./min (mm/mm/min).10.2.3 Lateral SupportsSpecimens tested in th
44、e edgewiseor “joist” position having a depth-to-width ratio greater thantwo are subject to lateral instability during loading, especiallyif the specimen breaks. For stability and safety during the test,lateral supports are needed while testing such specimens.Lateral support apparatus shall be provid
45、ed at least at pointslocated about half-way between the reaction and the load point.Additional supports shall be used as required to providenecessary stability and safety during the test. Each supportshall allow vertical movement without frictional restraint butshall restrict lateral deflection (See
46、 Fig. 3).11. Calculation11.1 Maximum Fiber StressWhen a beam is loaded inflexure at two central points and supported at two outer points,the maximum stress in the outer fibers occurs between the twocentral loading points that define the load span (See Fig. 1). Forrectangular cross-sections, this str
47、ess is calculated for any pointon the load-deflection curve for relatively small deflections bythe following equation for a load span of one-third of thesupport span:S 5 PL/bd2(3)where:S = stress in outer fiber throughout load span, psi (MPa),P = total load on beam at any given point on the load-def
48、lection curve, lb (N),L = support span, in. (mm),b = width of beam, in. (mm), andd = depth of beam, in. (mm).NOTE 5Eq 3 applies strictly to products for which the stress is linearlyproportional to the strain up to the point of rupture and for which thestrains are small. Since this is not always the
49、case, a slight error will beintroduced in the use of this equation.The equation will, however, be validfor comparison data and specification values up to the maximum fiberstrain of 3 % for specimens tested by the procedure herein described.11.2 Flexural Strength (Modulus of Rupture)The flexuralstrength is equal to the maximum stress in the outer fibers at themaximum load, load at rupture, or when the strain reaches 3 %,whichever occurs first. It is calculated in accordance with Eq 3D6109 103by letting P equal the maximum load, the load at rupture, or the
