ASTM_D_6916_-_06c_2011.pdf

Designation:D691606c(Reapproved 2011)Standard Test Method forDetermining the Shear Strength Between SegmentalConcrete Units(Modular Concrete Blocks)1This standard is issued under the fixed designation D6916;the number immediately following the designation indicates the year oforiginal 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.1.Scope1.1 This test method is used to determine the shear strengthbetween two layers of segmental concrete block units used inconstruction of reinforced soil retaining walls.The test iscarried out under conditions determined by the user thatreproduce the facing system at full-scale.The results of a seriesof tests are used to define a relationship between shear strengthdeveloped between segmental concrete units and normal load.1.2 This is a performance test used to determine propertiesfor design of retaining wall systems utilizing segmental con-crete units and soil reinforcing geosynthetics,either geotextilesor geogrids.The test is performed on a full-scale constructionof the facing system and may be run in a laboratory or the field.1.3 The values stated in SI units are regarded as thestandard.The values stated in inch-pound units are providedfor information only.1.4 This standard may involve hazardous materials,operations,and equipment.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 applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D448 Classification for Sizes of Aggregate for Road andBridge ConstructionD4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for GeosyntheticsD4595 Test Method for Tensile Properties of Geotextiles bythe Wide-Width Strip MethodD6637 Test Method for Determining Tensile Properties ofGeogrids by the Single or Multi-Rib Tensile Method3.Terminology3.1 Definitions:3.1.1 displacement criteria,na user prescribed maximummovement,mm(in.),of the top segmental concrete unit outfrom the back of lower segmental concrete units.3.1.2 geosynthetic,na planar product manufactured frompolymeric material used with soil,rock,earth,or other geo-technical engineering related material as an integral part of aman-made project,structure or system.D44393.1.3 granular infill,ncoarse grained soil aggregate usedto fill the voids in and between segmental concrete units.3.1.4 peak shear strength,nthe maximum shear capacitybetween segmental concrete units.3.1.5 segmental concrete depth,nthe segmental concreteunit dimension perpendicular to the wall face.3.1.6 segmental concrete unit(modular concrete block),na concrete unit manufactured specifically for mortarless,dry-stack retaining wall construction.3.1.7 segmental concrete unit width,nthe segmental con-crete unit dimension parallel to the wall face.3.2 For definition of other terms relating to geosynthetics,refer to Terminology D4439.4.Summary of Test Method4.1 In this test method,segmental concrete units are as-sembled in two rows(layers).The bottom row is laterallyrestrained.The top row is loaded vertically to a constantsurcharge load and the interface is sheared at a constant rate ofdisplacement until a drop of load after the peak load occurs.The test may be run with the geosynthetic reinforcementsandwiched between the two rows of segmental concrete unitsto determine the shear strength between segmental concreteunits at the connection between the units and the geosyntheticreinforcement.5.Significance and Use5.1 The shear strength between segmental concrete units(with and without geosynthetic reinforcement)and is used indesign of reinforced soil retaining walls.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 2003.Last previous edition approved in 2006 as D691606c.DOI:10.1520/D6916-06CR11.2For referenced ASTM standards,visit the ASTM Web Site,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 web site.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 This test is used to determine the shear strength for thedesign of the facing stability of segmental retaining walls.Performing a series of these shear tests at varying normal loadspermits development of a relationship between shear strengthand normal load.This relationship may be linear,bi-linear,orsome other complex mathematical expression.5.3 This shear strength test