ASTM_C_1738_-_C_1738M_-_14.pdf

Designation:C1738/C1738M14Standard Practice forHigh-Shear Mixing of Hydraulic Cement Pastes1This standard is issued under the fixed designation C1738/C1738M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the high-shear mixing of hydrauliccement pastes.1.2 The values stated in SI units or inch-pound units are tobe regarded as the standard.Within the text,the inch-poundunits are shown in brackets.The values stated in each systemare not exact equivalents;therefore,each system shall be usedindependently of the other.Combining values from the twosystems may result in nonconformance with the standard.1.3 This standard does not purport to address all of thesafety concerns,if 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 regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C219 Terminology Relating to Hydraulic CementC305 Practice for Mechanical Mixing of Hydraulic CementPastes and Mortars of Plastic ConsistencyC511 Specification for Mixing Rooms,Moist Cabinets,Moist Rooms,and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic Cements2.2 Non-ASTM Standard:3ANSI/API Recommended Practice 10B-2(formerly 10B)Recommended Practice for Testing Well Cements3.Terminology3.1 DefinitionsFor definitions of terms used in thisspecification,refer to Terminology C219.3.2 Definitions of Terms Specific to This Standard:3.2.1 mixing,high-shear,vof pastes,the process of blend-ing dry and liquid materials in a container using blades rotatingaxially at speeds at or above 420 rad/s 4000 rpm.4.Summary of Practice4.1 The practice describes the mixing of hydraulic cementpaste in a high-shear mixer with a cooling jacket or othermethod to control the temperature of the paste.This procedureis derived from the ANSI/API standard and the followingreports:(1)R.Helmuth,L.M.Hills,D.A.Whiting,S.Bhattacharja,AbnormalConcretePerformanceinthePresenceofAdmixtures,RP333,Portland Cement Association,Skokie,Illinois,USA,1995,92 pages and(2)C.F.Ferraris,Measurement of the rheological proper-ties of cement paste:a New Approach,Int.RILEM Conf.The role of Admixtures in High Performance Concrete,ed.by J.G.Cabrera and R.Rivera-Villareal,Monterrey(Mexico),March 1999.pp.333-342,or(3)C.Ferraris,K.Obla,R.Hill,The influence of mineraladmixtures on the rheology of cement paste and concrete,Cement and Concrete Research Vol.31/2,pp.245-255(2001).5.Significance and Use5.1 This practice is useful in laboratory research on rheol-ogy of hydraulic cement systems as it has been shown toprovide a paste with rheological properties similar to thoseobtained in a concrete from which the aggregate had beenremoved.4Mixing of paste using C305 is not satisfactory as thepaste is not thoroughly mixed,due to the absence of sand.Inthis practice the shear imparted to the cement paste is signifi-cantly higher than in C305 and therefore it is known ashigh-shear mixing.6.Apparatus6.1 MixerComposed of an electrical motor,a mixingcontainer and a tachometer with the motor speed controlledautomatically(rheostat adjustment of speed will not be accept-able).The blades are attached to the bottom of the container1This practice is under the jurisdiction ofASTM Committee C01 on Cement andis the direct responsibility of Subcommittee C01.22 on Workability.Current edition approved April 1,2014.Published May 2014.Originallyapproved in 2011.Last previous edition approved in 2013 as C1738/C1738M-13.DOI:10.1520/C1738_C1738M-14.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4R.Helmuth,L.M.Hills,D.A.Whiting,S.Bhattacharja,Abnormal ConcretePerformance in the Presence of Admixtures,RP333,Portland Cement Association,Skokie,Illinois,USA,1995,92 pages.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 and rotate axially.The power of the motor shall be sufficient toensure that the speeds of the mixer loaded with 500.0 g 1.1 lbof cement and water shall maintain a preset rotational speed at420 rad/s 4000 rpm and 1047 rad/s 10 000 rpm.The speedshall be maintained within 5%of the preset speeds.NOTE1A variable speed mixer capable of controlling the speed by afeedback loop within a range of 0 rad/s