ASTM C115-2010 Standard Test Method for Fineness of Portland Cement by the Turbidimeter《用浊度计测定硅酸盐水泥细度标准试验方法》.pdf

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1、Designation: C115 10Standard Test Method forFineness of Portland Cement by the Turbidimeter1This standard is issued under the fixed designation C115; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb

2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers determination of the fineness ofportland cement as represented by a calculated measure ofspecific surface, express

3、ed as square centimetres of totalsurface area per gram, or square metres of total surface area perkilogram, of cement, using the Wagner turbidimeter.21.2 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

4、standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents;

5、therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard. Values in SI units or inch-pound units shallbe obtained by measurement in SI units or inch-pound unitsor by appropriate conversion, using the Rules for

6、 Conversionand Rounding given in IEEE/ASTM SI 10 of measurementsmade in other units. Values are stated in SI units wheninch-pound units are not used in practice.2. Referenced Documents2.1 ASTM Standards:3C114 Test Methods for Chemical Analysis of HydraulicCementC430 Test Method for Fineness of Hydra

7、ulic Cement by the45-m (No. 325) SieveC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsIEEE/ASTM SI 10 American National Standard for Use ofthe International System of Units (SI): The Modern MetricSystem3. Significance and Use3.1 The purpose of this

8、 test method is to determine whetheror not the hydraulic cement under test meets the Wagnerturbidimetric fineness requirements of the applicable hydrauliccement specification for which the test is being made. Finenessof the cement component is only one of the many character-istics that influence the

9、 strength capabilities of concrete.4. Apparatus4.1 Nature of ApparatusTheWagner turbidimeter consistsessentially of a source of light maintained at constant intensityand adjusted so that approximately parallel rays of light passthrough a suspension of the cement to be tested and impingeupon the sens

10、itive plate of a photoelectric cell. The currentgenerated in the cell is measured by means of a microammeterand the indicated reading is a measure of the turbidity of thesuspension. General considerations indicate that turbidity is inturn a measure of the surface area of the suspended sample ofcemen

11、t. The apparatus shall consist specifically of the partsdescribed in 4.2-4.7 and shall be constructed in accordancewith the detailed design and dimensional requirements shownin Fig. 1 and Table 1, except that the case may be either ofwood or of metal.4.2 Turbidimeter, mounted in a suitable wood or m

12、etal caseincluding the following features:4.2.1 Source of LightThe source of light (Fig. 1) shallconsist of a concentrated-filament electric lamp of between 3and 6 cd operated by a source of constant emf. The lamp shallbe mounted rigidly in the socket. A clean, bright parabolicmetallic reflector sha

13、ll be rigidly mounted behind the lamp,focused so that approximately parallel rays of light will passthrough the sedimentation tank and impinge upon the photo-electric cell. The light intensity shall be regulated by tworheostats of approximately 6 and 30 V, respectively, and theyshall possess such ch

14、aracteristics that uniform changes in light1This test method is under the jurisdiction ofASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.25 on Fineness.Current edition approved Feb. 1, 2010. Published March 2010. Originallyapproved in 1934. Last previous edition appr

15、oved in 2003 as C11596a(2003). DOI:10.1520/C0115_C0115M-10.2The sole source of supply of the apparatus known to the committee at this timeis the Wagner turbidimeter. If you are aware of alternative suppliers, please providethis information to ASTM International Headquarters. Your comments will recei

16、vecareful consideration at a meeting of the responsible technical committee,1whichyou may attend. This turbidimeter was developed by L. A. Wagner, ResearchAssociate of the Cement Reference Laboratory, National Institute of Standards andTechnology, Washington, DC. A description of the apparatus and t

17、he originalmathematical derivations of formulas used are given in the paper: Wagner, L.A., “ARapid Method for the Determination of the Specific Surface of Portland Cement,”Proceedings , ASTM, ASTEA, Vol 33, Part II, 1933, p. 553.3For referenced ASTM standards, visit the ASTM website, www.astm.org, o

18、rcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,

19、 West Conshohocken, PA 19428-2959, United States.intensity may be obtained over the full range of resistance. Therheostats shall be mounted in parallel with each other and inseries with the lamp.4.2.2 Heat-Absorbing DeviceThe light shall pass througha suitable heat absorbing device before entering t

20、he sedimen-tation tank in order that radiant heat from the beam shall beabsorbed, the device being either (1) a water cell or (2)aspecial heat-absorbing glass filter. The water cell shall be madefrom 76-mm 3-in. outside diameter seamless brass tubing,3-mm 18-in. thick wall, 102-mm 4 in. in length wi

21、th glasswindows sealed in the ends. The cell shall contain a hole forfilling with distilled water. The hole shall be sealed with ametal plug. The cell, when mounted on the movable shelf, mayhave the plug in either the top or bottom position. Theheat-absorbing device shall be so arranged that essenti

22、ally allrays of light entering the sedimentation tank shall first passthrough the heat-absorbing device.4.2.3 Retarding FilterA light-retarding glass or otherdevice shall be provided that will reduce the intensity of lightfrom that corresponding to 100 Ato a reading of 20 to 30 A.The light intensity

23、 shall be uniformly retarded over the entirearea of that portion of the cell which is exposed to light duringa test. The retarding filter shall be mounted in a carrier on theshield and shall be capable of being swung out of the light pathby means of a handle.4.2.4 Sedimentation TankThe sedimentation

24、 tank shall beeither (1) constructed of 5 to 6-mm 316 to14-in. plate glass orborosilicate glass cemented or sealed together to form arectangular tank, or (2) a molded glass tank having wallsapproximately 5-mm 316 in. thick with plane surfaces. Theinside dimensions of the rectangular tank shall be 51

25、 mm by 38mm by 203 mm 2 in. by 112 in. by 8 in. in height. Thepermissible variation on the inside dimensions of the tank shallbe 62.5 mm 0.1 in. in length and 60.76 mm 0.03 in. inwidth. The 51-mm faces of the tank shall be equidistant within0.25 mm 0.1 in. at all points. A mark shall be placed on th

26、eside of the tank to indicate a volumetric content of 335 mL,which is the level to which the tank will be filled in a test. Atank filled to the mark with clear kerosine and placed in theturbidimeter light beam shall yield uniform microammeterreadings, within 60.1 A, for the entire usable portion of

27、thetank.4.2.5 Photoelectric CellThe means of measuring the lightintensity shall be a sensitive photoelectric cell connecteddirectly to a microammeter. A hood with a horizontal slot 13mm 12 in. in height by 35 mm 138 in. in width shall bemounted over the photoelectric cell. The front of the hood shal

28、lbe 25 6 1mm16116 in. in front of the face of the cell. Theface of the photocell shall be parallel to the tank faces within0.5 mm 0.02 in.4.2.6 ShieldAmetallic shield having a slot 16 mm 58 in.in height by 38 mm 112 in. in width, as indicated in Fig. 1,shall be placed between the heat absorbing devi

29、ce and thesedimentation tank.4.2.7 Elevating DeviceThe source of the light, the heat-absorbing device, the photoelectric cell, the retarding filter, andthe shield shall be mounted on a movable shelf which may beraised or lowered by two connected lead screws, and whichmay be readily and accurately ad

30、justed so that the turbidity ofthe suspension may be determined at any desired depth. Thecenter of the light source, the heat absorbing device, thephotocell, the center of the slots of the metal shield, and thehood shall be on a straight line which is parallel to the shelf.The sedimentation tank sha

31、ll be mounted on a base which isindependent of the rest of the apparatus so that the tank shall befree from vibration caused by moving the shelf. Care shall betaken that the shelf shall be level at all points of elevation andthat the tank shall be normal to the shelf. The distance betweenthe tank an

32、d the edges of the opening in the shelf shall vary notmore than 0.4 mm 164 in. between the “3050” and “0”positions. The level of the light beam with reference to thesurface of the suspension shall be indicated by a pointer whichwill travel along a scale mounted on the cabinet. The zero ofthe scale s

33、hall indicate that position at which the center lines ofthe slots for the light beam are at the same elevation as thesurface of the liquid in the tank when filled to the 335-mLlevel. The lines on the scale to be marked 7.5, 10, 15, 20, 25,and 3050, shall be located at distances from the zero markequ

34、al to suspension depth values, h,inTable 2.The scale, whencompared with a standard scale accurate to within 0.1 mm at allpoints, shall not show a deviation at any point greater than 0.25mm and shall indicate the positions at which the pointer shouldbe located when turbidity readings for these values

35、 of h aretaken. The interior of the turbidimeter cabinet and the exteriorsurfaces of the shelf, the parabolic reflector, the heat absorbingdevice, the shield, and the photoelectric cell hood shall bepainted with a dull flat black paint.NOTE 1The requirement of the 0 to 50 markings on the scale shall

36、apply only to new Wagner Turbidimeters and not to equipment in usewhich meets the other requirements of this method.4.3 Microammeters:4.3.1 DArsonval-Type Microammeters shall have a rangefrom 0 to 50 A and shall be readable to 0.1 A. Newmicroammeters shall be accurate to 60.5 % of full scale valueat

37、 any part of the scale value at any part of the scale at 25 C77 F. For microammeters, in use, the accuracy shall be thesame as for new instruments except that the accuracy at 40 and50 Ashall be 61 % of full scale. The internal resistance of theMicroammeter Internal Resistance = 90 VShunt Equivalent

38、Resistance:470 V in parallel with 100 V5470 3 100470 1 1005 82 VMeter consequently, they do not correspond with the column titles.C115 1034.6 Stirring ApparatusThe stirring apparatus shall consistof either (1) a cylindrical brush, 19 mm 34 in. in diameter andabout 45 mm 134 in. in length, with an en

39、d approximatelyfitting the contour of the bottom of a 22-mm 78-in. diametertest tube, or (2) any other stirring device that will be equallyefficient in dispersion as measured by specific surface deter-minations on a standard sample. The stirring apparatus shallrotate at a speed of approximately 3500

40、 r/min.4.7 Timing BuretThe time of settling for the different-sized particles shall be obtained by use of a buret from whichkerosine is allowed to flow. The buret shall consist of a glasstube having a capillary tube fused into the lower end. Theupper end of the large tube shall be flared to serve as

41、 a funnelfor introducing kerosine into the tube. The buret shall conformto the limiting dimensions given in Table 3. The graduationlines on the buret shall be complete circles. A filter made of45-m (No. 325) wire cloth shall be used with the timing buretand a cover shall be placed over the top of th

42、e buret when it isnot in use.4.8 Weights and Weighing Devices, shall conform to therequirements of Methods C114.5. Materials5.1 Suspending LiquidClear white kerosine shall be usedwith the turbidimeter apparatus. The kerosine shall not bereused.6. Test Specimen or Sample6.1 Size of Test SampleSelect

43、the size of the sample ofcement for test so that the initial microammeter reading isbetween 12 and 20 A.NOTE 3The following approximations will be helpful in many in-stances in selecting the size of sample: 0.25 g for normal fineness cementsand 0.20 g for high fineness cements.7. Calibration7.1 Cali

44、bration of TurbidimeterCalibrate the turbidimeterapparatus in accordance with the following procedure:7.1.1 Calibration of Buret Scale:7.1.1.1 For calibration of the buret scale use a kerosinehaving a known viscosity and density for the temperature atwhich the calibration is to be made. Density and

45、viscosity ofthe kerosine should be determined. Calculate the times of flowfrom the buret that correspond to the times of settling for thedifferent sized particles, from the following equation:t 5 1,837,000h/r12r2!# 3 h/d2! (1)where:t = time of settling, or time of flow, s,h = viscosity of kerosine a

46、t the temperature of calibra-tion, P,r1= density of cement particles, Mg/m3(g/cm3) = 3.15 forportland cement (Note 4),r2= density of kerosine, Mg/m3at the temperature ofcalibration,h = depth of suspension to level of light, cm, andd = diameter of particle, m.Values of h/d2are given in Table 2.7.1.1.

47、2 Fill the buret with kerosine at the calibrating tem-perature, start a timing clock at the instant the kerosine in theburet drains past the zero line, and mark on the buret the levelsreached by the draining kerosine for each of the time intervals,t, calculated as described above. At these marks, et

48、ch perma-nent lines and numbers on the buret indicating the correspond-ing diameters (Note 5). The construction and the graduation ofthe buret shall be such that at the temperature of calibration thetime required for the kerosine to pass the permanent lines of theburet agrees with the calculated tim

49、e of settling within 1percent, except that the permissible variation shall be not lessthan 1 s.NOTE 4The density of portland cement does not vary greatly and inthis work it is considered constant at 3.15. A variation of 0.15 from thisvalue when substituted in Stokes law gives a variation of 2.5 % in thediameter of the particle measured.NOTE 5By using the calibrated buret the apparatus may be usedwithin the normal range of room temperatures without further correction,the change in rate of fl