1、Designation: D8058 171Standard Test Method forDetermining the Flexural Strength of a GeosyntheticCementitious Composite Mat (GCCM) Using the Three-PointBending Test1This standard is issued under the fixed designation D8058; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case 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.1NOTESubsection 3.2.7 was corrected editorially in August 2017.1. Scope1.1 Th
3、is test method provides guidelines for testing theflexural strength of cured geosynthetic cementitious compositemat (GCCM) products in a three (3)-point bend apparatus.1.2 The values in SI units are to be regarded as the standard.Values in inch-pound units are in parentheses for information.1.3 This
4、 standard may involve hazardous operations,equipment, and climates. 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 applic
5、ability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by th
6、e World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D76/D76M Specification for Tensile Testing Machines forTextilesD4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products (RECPs) for TestingD4439 Terminology for Geo
7、syntheticsD8030/D8030M Practice for Sample Preparation for GCCM3. Terminology3.1 For definitions of common technical terms used in thisstandard, refer to Terminology D4439.3.2 Definitions:3.2.1 cured, adja description of the state of a GCCM afterhydration for a specified period of time and quantity
8、of waterwhen known under specified conditions, followed by a periodof time where the GCCM is kept under a specified environ-mental condition during which the cementitious material con-tinues to cure and develop compressive strength.3.2.2 curing time, nthe time subsequent to initial hydra-tion of the
9、 GCCM and immediately prior to the testing of thematerial, during which the cementitious material is allowed toharden and form its final strength using the specific process forcuring as specified in 8.3.3.2.3 dry, adja description of the state of a GCCM beforeit has been exposed to a hydration sourc
10、e and typicallydescribes the “as-received” dry product after conditioning in aprescribed manner.3.2.4 final breaking load, nthe maximum load achievedprior to rupture of materials.3.2.5 final deflectionthe deflection of the specimen fromits initial position (before testing begins) measured at mid spa
11、nat the final breaking load.3.2.6 final flexural strength, nthe final flexural strength,expressed in megapascals (pound-force per square inch), iscalculated from the final breaking load of a hydrated and curedGCCM specimen, oriented in either the machine or cross-machine direction, loaded as simple
12、beams, when breaks occurperpendicular to the specimen length, with the load applied atthe center, in a three-point loading fixture.3.2.7 geosynthetic cementitious composite mat (GCCM),na factory-assembled geosynthetic composite consisting of acementitious material contained within a layer or layers
13、ofgeosynthetic materials that becomes hardened when hydrated.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.05 on Geosyn-thetic Erosion Control.Current edition approved July 1, 2017. Published July 2017. Original
14、ly approvedin 2017. Last previous edition approved in 2017 as D8058 17. DOI: 10.1520/D8058-17E01.2For 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 Docum
15、ent Summary page onthe ASTM website.Copyright 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 standardization established in the Decision on Pr
16、inciples for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.8 hydration, nexposure of the GCCM, in this case, towater in prescribed conditions for a prescribed time and waterquantity when k
17、nown.3.2.9 initial breaking load, nthe maximum load at whichthe first crack in the cementitious matrix of the GCCM forms.3.2.10 initial deflection, nthe deflection of the specimenfrom its initial position (before testing begins) measured at midspan at the initial breaking load.3.2.11 initial flexura
18、l strength, nthe initial flexuralstrength, expressed in megapascals (pound-force per squareinch), is calculated from the initial breaking load (maximumload at first crack) of a hydrated and cured GCCM specimen,oriented in either the machine or cross-machine direction,loaded as simple beams, with the
19、 load applied at the center, ina three-point loading fixture.3.2.12 initial modulus of elasticity, na measure of aspecimens resistance to elastic deformation, measured in theregion of linear response, before the initial breaking load.3.2.13 mean final flexural strength, nthe mean final flex-ural str
20、ength is the average result of ten or more final flexuralstrength values expressed in megapascals (pound-force persquare inch).3.2.14 mean initial flexural strength, nthe mean initialflexural strength is the arithmetic mean of ten or more initialflexural strength values when breaks occur perpendicul
21、ar to thespecimen length. Breaks expressed in megapascals (pound-force per square inch).3.2.15 topside, nthe side of the material that would faceupwards in a normal installation.4. Summary of Test Method4.1 A hydrated and cured GCCM specimen is loaded as asimple beam in a three-point loading fixture
22、, with the loadapplied at the center. The load level is recorded simultaneouslywith the deflection to characterize the initial and final flexuralstrength, the deflection of the specimen at those loads, and theinitial modulus of the specimen.5. Significance and Use5.1 This test method is applicable f
23、or testing geosyntheticcementitious composite mats in a cured state. It is used with aconstant rate of extension-type tension apparatus.5.2 This test is an index test that may be used for manufac-turing quality control (MQC). This test is appropriate forcharacterizing the flexural properties of a GC
24、CM.6. Apparatus6.1 Flexural Testing MachineA constant rate of extension(CRE)-type of testing machine described in SpecificationD76/D76M shall be used. When using the CRE-type tensiletester, the recorder must have adequate pen response toproperly record the force-elongation curve as specified inSpeci
25、fication D76/D76M.6.2 Three-Point Flexural FixtureA fixture designed foruse with the flexural testing machine with two bottom supportsand a third edge which is used to load the specimen from thetop at mid span. The fixture is designed so that the specimen isloaded and can be analyzed as a simple bea
26、m. The supports arecylindrical on the specimen contact surface with a 3.2-mm(18-in.) minimum radius and a 12.7-mm (12-in.) maximumradius. These support points must be designed so that theycannot exert longitudinal or vertical constraints (rocker-typebearing edges, rollers, etc.). The loading surface
27、 must have asimilar edge bearing. The test span shall be 100 6 1.6 mm (46116 in.) and the load line and support shall be parallel. Mounta dial micrometer reading to 0.25 mm (0.01 in.), or an equallysensitive apparatus, to bear on the loading member or on thespecimen at mid span to determine the defl
28、ection of thespecimen at the center of the test span as the load is measured.6.3 Sample ContainersSuitable containers which are re-sistant to corrosion and change in mass upon repeated exposureto moisture, materials of varying pH, and cleaning.6.4 DieA sample-cutting device of dimensions consistentw
29、ith 8.2.6.5 Rotary Tile Saw, with diamond-tipped blades capable ofdry cutting samples, used for cutting cured samples to prede-termined dimensions using pattern marked on cured specimenwith template and markers.6.6 Miscellaneous Knives, Templates, Markers, Rulers,Saw, as required for marking, measur
30、ing, and cutting speci-mens to fixed dimensions before measurement of weight. Aknife with a “snap off” type blade is recommended for cuttingGCCMs, which can dull blade tips rapidly.6.7 Thickness GageA measurement device for character-izing the thickness of the specimens in the vicinity of thebreaks
31、which occur during the flexural test. The thickness gageshall have flat parallel anvils of between 10-mm (0.4-in.) and15-mm (0.6-in.) diameter with an accuracy of 60.05 mm(60.002 in.).6.8 MicrometerA calibrated measurement device used forprecise measurement of components with a required accuracyof 6
32、0.25 mm (60.01 in.), or an equally sensitive apparatus.7. Sampling, Test Specimens, and Test Units7.1 Lot SampleFor the lot sample, refer to Practice D4354for discussion of recommended practice for breaking upshipments of GCCMs into lots for testing.7.2 Laboratory SamplesFor the laboratory sample, t
33、ake afull-width sample approximately 1 m (40 in.) long in themachine direction from each roll in the lot sample. The exactlength must be chosen to ensure enough sample is cured to cutthe required number of specimens for both the machine andcross-machine directions. The sample may be taken from theen
34、d portion of a roll, provided there is no evidence it isdistorted or different from other portions of the roll. In cases ofdispute, take a sample that will exclude material from the outerwrap of the roll or the inner wrap around the core, of at least30 in. from the interior end of the roll (wrapped
35、around thecore) or exterior end of the material roll, measured from theedge of the cementitious portion of the material.7.3 Test SpecimensFor tests in the machine direction andthe cross-machine direction, respectively, take from eachD8058 1712sample in the laboratory sample the number of specimensdi
36、rected in Section 8. Take specimens at random from thelaboratory sample, with those for the measurement of themachine direction tensile properties from different positionsacross the sample width, and the specimens for the measure-ment of the cross-machine direction tensile properties fromdifferent p
37、ositions along the length of the sample. Specimensmust not be taken near the edge of the material. Specimensmust be taken a minimum of 4 in. from the edge of thematerial, measured from the edge of the cementitious portionof the material. Specimens shall be collected for testing in boththe topside an
38、d bottom-side direction facing up.8. Test Specimen Preparation8.1 Number of Specimens:8.1.1 Unless otherwise agreed upon, the fixed number of ten(10) specimens for each the machine direction and the cross-machine direction tests should be used.8.2 Test Specimen Size:8.2.1 Prepare each finished speci
39、men a minimum of 40 61.6 mm (1.6 6116 in.) wide by at least 160 6 1.6 mm (6.3 6116 in.) long with the length dimension being designated andaccurately parallel to the direction for which the flexuralstrength is being measured. Specimens may be prepared usinga die, saw, or knives.8.2.2 The orientation
40、 of the specimen in the flexural test willaffect which face of the GCCM is under tensile load. Thespecimens should have a mark applied on the topside facewhich is to be up when loaded into the three-point flexuralfixture.8.3 Specimen Preparation:8.3.1 The specimens cut from the sample should be insa
41、tisfactory condition and representative of the bulk of theproduct delivered to the facility. For example, exclude innerand outer wraps of the roll, any material containing folds,crushed areas, imperfections on either face, tears in either thetop or bottom material surrounding the cementitious materi
42、al,or other distortions not representative of the sampled lot.8.3.2 All sample cutting should be carried out in a clean areafree of debris, and preferentially with a surface covering tocollect any loose cementitious powder which may come fromthe material during cutting. The samples should be cut usi
43、ng adry rotary diamond saw to avoid a second hydration of thesamples which may affect results. The edges should be cutsquare and not notched or damaged by the cutter in the areathat will be between the testing fixture supports.8.3.3 Cure each GCCM sample specimen in accordancewith the recommendation
44、s provided by the manufacturerbefore testing.8.3.4 GCCM samples shall be prepared in accordance withPractice D8030/D8030M with a sufficient number of speci-mens prepared for testing.8.3.5 It is important that the GCCM specimens be flat toobtain repeatable measurements using this procedure. If aspeci
45、men is determined to have substantial curvature, thatspecimen must be discarded.Anew specimen must be obtainedto replace it for measurement. In the case of laboratory-hardened samples, each bar shall have a tolerance of flatness of5 mm (each surface shall lie between two parallel planes witha 5-mm s
46、eparation) and in the case of field sample, each barshall have a tolerance of flatness of 8 mm.9. Procedure9.1 Measure the specimen thickness, at four points along theline of break for an average result. This measurement may becompleted either before or after load testing using the thicknessgage.9.2
47、 Measurement of the Initial and Final Breaking Load andInitial and Final Deflection:9.2.1 Set up a uniform deflection rate on the flexural testingmachine such that the initial breaking load will occur in thespecimen between 5 and 30 s.9.2.2 The error in the load reading shall not exceed 1 % ofthe ma
48、ximum load.9.2.3 The supports for the three-point flexural fixture arecylindrical on the specimen contact surface with a 3.2-mm(18-in.) minimum radius and a 12.7-mm (12-in.) maximumradius. These support points must be designed so that theycannot exert longitudinal constraints (rocker-type bearingedg
49、es, rollers, etc.). The loading surface must have a similaredge bearing.9.2.4 The test span shall be 100 6 1.6 mm (4 6116 in.) andthe load line and support shall be parallel.NOTE 1Alternate test specimen dimensions and span may be used,provided that the ratio of the test span to specimen thickness is not lessthan 18, and that the actual span used is reported.9.2.5 Mount a micrometer reading or an equally sensitiveapparatus to bear on the loading member or on the specimen atmid span to determine the deflection of the specimen at thecenter of th
