1、Designation: C1738 11Standard Practice forHigh-Shear Mixing of Hydraulic Cement Pastes1This standard is issued under the fixed designation C1738; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript 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
3、 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
4、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 S
5、tandards: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 S
6、pecification 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 Cementsi3. Terminology3.1 DefinitionsFor definitions of terms
7、 used in this speci-fication, 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 Practi
8、ce4.1 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,
9、Abnormal Concrete Performance in the Presence of Admix-tures, 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 Concret
10、e, 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 p
11、ractice 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 thor
12、oughly 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 controlle
13、dautomatically (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,
14、 2011. Published June 2011.2For 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
15、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.1Copyright ASTM In
16、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 400
17、0 rpm and 1260 rad/s 12 000 rpm. The speedshall be maintained within 5 % of the preset speeds.NOTE 1A variable speed mixer capable of controlling the speed by afeedback loop within a range of 0 rad/s 0 rpm to 1360 rad/s 13 000 rpmis recommended, however, a mixer with a minimum of preset two speeds42
18、0 rad/s 4000 rpm and 1260 rad/s 12 000 rpm loaded is acceptable.6.2 Cooling UnitA water bath with an outside circulatingoption, capable of controlling the temperature to 61C 61Ffor the specified temperature range of 5-50C 40-120F overthe duration of the test.6.3 Mixing Container with the Blade Assem
19、bly5A 1-L 1qt container, lid and blade specifically designed for use withthe mixer motor. The blade assembly shall be constructed insuch a manner that the blade can be removed for weighing andchanging. The blade shall be weighed initially and thenperiodically, replaced with a new blade when a 10 % m
20、ass losshas occurred. Replace the blade if obvious blade deformationhas occurred. If the mix temperature is to be controlled by aseparate cooling unit, the container shall also be equipped witha cooling system (see Note 2) that can be connected to thecooling unit.NOTE 2The cooling system could be ei
21、ther an integral part of the baseof the container or a coil wrapped around the container.6.4 ThermometersA partial immersion thermometer read-able 0.5C 1F and accurate to 60.5C 6 1F when testedat 23C 73F with a the range of 5-50C 40-120F.6.5 Cementitious Feeding SystemA feeding system, ca-pable of a
22、dding the total quantity of cementitious material intothe mixing container, within 60 s (see Note 3).NOTE 3A vibratory feeder or a lid mounted funnel is suitable for thispurpose.6.6 Timing DeviceStop watch or other suitable timingdevice accurate to 61 s when tested over a one-minuteinterval.6.7 Top-
23、Pan BalanceComplying with SpecificationC1005 having a capacity of at least of 1 kg 2 lb andreadability and accuracy of 0.01 g 210-5lb.6.8 ScraperThe scraper shall consist of a semi rigidrubber blade attached to a handle about 150 mm 6 in. long.The blade shall be about 75 mm 3 in. long, 50 mm 2 in.wi
24、de, and tapered to a thin edge about 2 mm 0.08 in. thick.7. Temperature and Humidity7.1 The temperature and humidity of the mixing room shallconform to the requirements of Specification C511.7.2 The cooling unit flow rate and temperature shall beadjusted so that the temperature of the cement paste,
25、aftermixing, is within the specified range (see Note 4).NOTE 4Typically water temperatures of 15 6 2C 59 6 4F arerequired for a cement paste temperature of 21 6 2C706 4F. Higheror lower temperature water could be used to simulate hot or cold weatherconcrete. The references4,6provide a more detailed
26、explanation on how toselect the cooling temperature.8. Materials and Proportioning8.1 The materials and their proportions and quantities shallconform to the requirements contained in the particular methodfor which the paste is being prepared.9. Procedure9.1 Place the mixing container on the mixer an
27、d if appli-cable, connect the hoses to the cooling unit.9.2 If using an external cooling unit, adjust the temperatureto the desired temperature and turn on the water supply to thejacketed bottom of the mixing container.9.3 If paste temperature is to be controlled by the mix water,prepare required qu
28、antity of water, at the desired temperatureand maintain until needed.9.4 Loading of the Mixer:9.4.1 Add the specified quantity of dry cementitious mate-rials in their correct proportions to the cementitious feeder.9.4.2 Add the correct amount of water to the mixingcontainer, cover with lid and begin
29、 mixing at the first presetspeed (420 rad/s 4000 rpm) allowing water temperature tostabilize throughout.9.4.3 Turn off mixer and remove lid. Insert thermometerinto the water being careful not to let the tip of the thermometertouch the mixing container. If the measured temperature is notcorrect for t
30、he desired paste temperature, perform the follow-ing, as applicable.9.4.3.1 If using an external cooling unit, place lid on themixing container and continue mixing at the first preset speed(420 rad/s 4000 rpm), periodically checking the temperature,as previously described, until the water has reache
31、d the desiredtemperature. Adjust the cooling unit temperature, if needed.9.4.3.2 If using mix water for temperature control, com-pletely empty water from mixing container and replace withthe required quantity of water that has been adjusted fortemperature. Repeat 9.4.2 and 9.4.3 above, as needed, un
32、til thewater has reached the desired temperature.9.4.4 As soon as the water reaches the desired temperature,start mixing at the first preset speed (420 rad/s 4000 rpm) andusing the cementitious feeder, begin adding the dry materials tothe mixing container. The feeding of dry materials should beunifo
33、rm and completed in approximately 60 s.9.5 Initial Mixing:9.5.1 As soon as the dry material addition is complete,attach the lid to the mixing container and switch to the secondpreset speed (1260 rad/s 12 000 rpm).5The sole source of supply of the container and blades known to the committeeat this ti
34、me is (Specialty Containers manufactured by Waring Products, TorringtonCT (http:/ If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee, which
35、you may attend. The SS510C One Liter Cool Base Container withthe blade assembly is considered to conform to these requirements6Taylor P.C., Johansen V.C., Graf L. A., Kozikowski R. L., Zemajtis J. Z.,Ferraris C. F., “Identifying Incompatible Combinations of Concrete Materials;Volume I high-shear mix
36、ing; hydraulic cement;rheologyASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof in
37、fringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this stan
38、dard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your v
39、iews known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C1738 113
