ASTM_D_6638_-_11.pdf

Designation:D663811Standard Test Method forDetermining Connection Strength Between GeosyntheticReinforcement and Segmental Concrete Units(ModularConcrete Blocks)1This standard is issued under the fixed designation D6638;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 connectionproperties between a layer of geosynthetic reinforcement andsegmental concrete block units used in construction of rein-forced soil retaining walls.The test is carried out underconditions determined by the user that reproduce the connec-tion system at full-scale.The results of a series of tests are usedto define a relationship between connection strength for asegmental unit-geosynthetic connection system and normalload.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 connection 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 GeosyntheticsD4495 Test Method for Impact Resistance of Poly(VinylChloride)(PVC)Rigid Profiles by Means of a FallingWeightD6637 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 geosynthetic reinforcement outfrom the back of 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.(D4439)3.1.3 granular infill,ncoarse grained soil aggregate usedto fill the voids in and between segmental concrete units.3.1.4 peak connection strength,nthe maximum tensilecapacity of the connection between geosynthetic reinforcementand segmental concrete units.3.1.5 segmental concrete unit(modular concrete block),na concrete unit manufactured specifically for mortarless,dry-stack retaining wall construction.3.1.6 segmental concrete unit width,nthe segmental con-crete unit dimension parallel to the wall face and coincidentwith the geosynthetic reinforcement test specimen width.3.1.7 service state connection strength,n the connectiontensile capacity at a service state displacement criterion be-tween geosynthetic reinforcement and segmental concreteunits.3.2 For definition of other terms relating to geosynthetics,refer to Terminology D4439.4.Summary of Test Method4.1 One end of a wide geosynthetic reinforcement testspecimen is attached to dry stacked segmental concrete blockunits assembled as specified by the user.The other end of the1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal PropertiesCurrent edition approved June 1,2011.Published July 2011.Originally approvedin 2001.Last previous edition approved in 2007 as D6638 07.DOI:10.1520/D6638-11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 test specimen is attached to a clamp,which is part of a constantrate of extension tensile loading machine.The top course ofsegmental concrete block units is then loaded vertically to aconstant normal load and the geosynthetic is then tensionedunder constant rate of displacement until a sustained loss ofconnection capacity and/or excessive movement(greater than150 mm)of the reinforcement out from the connection.4.1.1 Peak connection capacity,and tensile capacity after auser prescribed displacement criteria has occurred,is used todefine connection strength based on peak and service statecriteria respectively.Both these values may be obta