ASTM C186-2005 Standard Test Method for Heat of Hydration of Hydraulic Cement《水硬性水泥水合热的标准试验方法》.pdf

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1、Designation: C 186 05Standard Test Method forHeat of Hydration of Hydraulic Cement1This standard is issued under the fixed designation C 186; 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 pa

2、rentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the heat ofhydration of a hydraulic cement by measuring the heat ofsolution of the dry cement and the

3、 heat of solution of a separateportion of the cement that has been partially hydrated for 7 andfor 28 days, the difference between these values being the heatof hydration for the respective hydrating period.1.2 The results of this test method may be inaccurate ifsome of the components of the hydraul

4、ic cement are insolublein the nitric acid/hydrofluoric acid solution.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 Values in SI units shall be obtained by measurement inSI units or by appropriate conversion, using the

5、 Rules forConversion and Rounding given in Standard IEEE/ASTM SI10, or measurements made in other units.1.5 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

6、health practices and determine the applica-bility or regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 109/C 109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C114 Test Methods for Chemical Analysis of HydraulicCem

7、entC 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC 1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsE11 Specification for Wire-Cloth Sieves for Testing Pur-pose

8、sIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System3. Significance and Use3.1 The purpose of this test is to determine if the hydrauliccement under test meets the heat of hydration requirement ofthe applicable hydraulic cement specification.3.2 This t

9、est may also be used for research purposes when itis desired to determine the heat of hydration of hydrauliccement at any age.NOTE 1When tests are performed for research purposes, usefuladditional information can be obtained by determining fineness, chemicaland compound compositions.3.3 Determinatio

10、n of the heat of hydration of hydrauliccements provides information that is helpful for calculatingtemperature rise in mass concrete.4. Apparatus4.1 Calorimetric Apparatus:4.1.1 CalorimeterThe calorimeter, such as that illustratedin Fig. 1 shall consist of a 0.5-L(1-pt), wide-mouth vacuum jar,with c

11、ork stopper, or other suitable non-reactive stopper held ina suitably insulated container (See 4.1.2) to keep the vacuumjar in position and to protect the jar from undue temperaturefluctuations. The vacuum jar shall be coated on the interiorwith a material resistant to hydrofluoric acid, such as a b

12、akedphenolic resin, a baked vinyl chloride acetate resin, or bees-wax. The acid-resistant coating shall be intact and free ofcracks at all times; it shall be examined frequently and renewedwhenever necessary. As another means of protecting thevacuum jar, a plastic liner of suitable size may be used

13、insteadof coating the interior of the jar. The contents of the vacuum jarshall not change more than 0.001 C/min per degree differencefrom room temperature when filled with 425 g of the acidspecified in 6.2, stoppered, and allowed to stand unstirred for30 min. The temperature for this check shall app

14、roximate thestarting temperatures to be used in making the determination.4.1.2 Insulated ContainerThe container shall have aninsulating layer of a material such as non-reactive foam, cotton,1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of

15、 Subcommittee C01.26 on Heat of Hydration.Current edition approved July 1, 2005. Published August 2005. Originallyapproved in 1944. Last previous edition approved in 1998 as C 186 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.

16、org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.or fiber-glass, which shall be at least 25 mm (1 in.) in thickn

17、essand shall encase the sides and bottom of the vacuum jar, butshall be so arranged as to permit easy removal of the jar.4.1.3 ThermometersTwo thermometers are required. Oneis a high precision thermometer required to determine tempera-ture rise associated with dissolution of cement during determi-na

18、tions. For purposes of this test method, this thermometer iscalled the solution thermometer. The other thermometer is usedfor measuring sample temperature before introduction into thecalorimeter and air temperature during the determination. Forpurposes of this test method, it is called the reference

19、 ther-mometer.4.1.3.1 Solution thermometerThe solution thermometershall be readable to 0.001 C. The solution thermometer maybe either a Beckman type (See Note 2), which is a mercury-in-glass type that only outputs temperature differentials, or adigital type that gives actual temperature outputs. If

20、a Beckmantype is used, it shall be graduated to at least 0.01 C, withreadings to 0.001 C that can be estimated by interpolationbetween these graduations. It shall also have a temperaturerange of at least 6 C.NOTE 2 If the part of the thermometer that will be in contact with thetest solution is sensi

21、tive to the nitric and hydrofluoric acids in the testsolution, then it is recommended that this part of the thermometer becoated with a resistant material to prolong the service life of thethermometer.4.1.3.2 Reference thermometerThe reference thermom-eter shall be any type that reads to a precision

22、 of at least 0.1 C.FIG. 1 CalorimeterC1860524.1.4 FunnelThe funnel through which the sample isintroduced into the calorimeter shall be glass or plastic andshall have a stem inside diameter of at least 6 mm (See Note 3).NOTE 3The minimum diameter is to prevent clogging of the pow-dered cement sample.

23、 The length of the stem will need to be adjusted sothat the sample is delivered without the tip becoming wet from the acidsolution, which will cause the funnel to become clogged and necessitateaborting the determination. The angle of the stem will need to be adjustedso that sample is not delivered o

24、nto the rotating stirrer, which will causesample to cake at the liquid line.4.1.5 Stirring AssemblyThe stirrer shall be a three-bladedpolyethylene propeller having the dimensions shown in Fig. 2,and shall extend as closely as possible to the bottom of thecalorimeter. The motor shall be of the consta

25、nt-speed type, atleast 37 W (120 hp), and shall be equipped with a geared speedreducer so that one speed, in the range of 350 to 700 r/min, canbe maintained constant.NOTE 4The stirrer shown in Fig. 2 may be readily made from acommercially available three-bladed polyethylene propeller having apropell

26、er diameter of 34 mm (138 in.), shaft diameter of 6 mm (14 in.), anda shaft length of approximately 455 mm (18 in.). The function of thestirrer is two-fold: to maintain uniform temperature throughout the liquidand to supply sufficient agitation to keep the solid in suspension in the acidmixture. Sin

27、ce a stirrer capable of keeping the solid in suspensiongenerates considerable heat in the calorimeter, it is important that thestirrer speed, and hence the rate of heat generation, be maintainedconstant. Because such constancy is difficult to achieve with other types ofmotors, a synchronous motor wi

28、th a geared speed reducer is recom-mended.4.2 MixerA moderate-speed mechanical mixer, such as amilk-shake type stirrer, capable of intimately mixing thecement and water to a uniform paste.4.3 StorageStorage space with temperature controlled at23.0 6 2.0 C (73.5 6 3.5 F).4.4 Mortar, approximately 200

29、 mm (8 in.) in diameter, andpestle for grinding the partially hydrated samples.4.5 Drying Oven, maintained at 100 to 110 C.4.6 Sieves, 150-m (No. 100) and 850-m (No. 20), con-forming to Specification E11.4.7 Crucibles, platinum, 30-mL capacity, with covers, forloss on ignition determination.4.8 Muff

30、le Furnace, or suitable burners capable of maintain-ing a temperature of 900 to 950 C.4.9 Analytical Balance and Analytical Weights, conformingto the requirements prescribed in Test Methods C114 forweighing out calorimetric samples and for loss on ignitionweighings.4.10 Weights and Weighing Devices,

31、 conforming to therequirements of Specification C 1005. The weighing deviceshall be evaluated at a total load of 1000 g.5. Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the s

32、pecifications of the Commit-tee on Analytical Reagents of the American Chemical Society,FIG. 2 StirrerC186053where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccura

33、cy of the determination.5.2 Hydrofluoric Acid (sp gr 1.15)Concentrated hydrof-luoric acid (HF).5.3 Nitric Acid (2.00 N)The 2.00 N HNO3, for use in thecalorimeter, shall be prepared and standardized in large quan-tities. Optionally, the dilute HNO3may be made up with 127mL of concentrated HNO3(sp gr

34、1.42) per litre of solution,provided that heat capacity determinations are made with eachbatch of diluted HNO3so prepared.5.4 WaxParaffin wax, or other suitable wax, for sealingvials.5.5 Zinc Oxide (ZnO)The ZnO shall be heated at 900 to950 C for 1 h, then cooled in a desiccator, ground to pass a150-

35、m (No. 100) sieve, and stored. Immediately prior to aheat capacity determination,7goftheZnOsoprepared shallbe heated for not more than 5 min at 900 to 950 C, cooled toroom temperature in a desiccator, and weighed accurately forintroduction into the calorimeter.NOTE 5The rate of solution of the ZnO v

36、aries with the preliminarytreatment. The procedure described results in a product which dissolves atabout the same rate as the dry cement.6. Determination of Heat Capacity of Apparatus6.1 To determine the heat capacity of the system (that is, thenumber of joules or calories required to raise the tem

37、peratureof the calorimeter and contents 1 C), measure the correctedtemperature rise obtained by dissolving7gofignited ZnO inthe specified acid mixture (See 6.2-6.7).6.2 Transfer approximately 400 g of the 2.00 N HNO3,which has been cooled to the temperature indicated by thelower range of the Beckman

38、n thermometer (ordinarily about 4to 5 C below room temperature), into the vacuum jar, add 8.0mL of HF (sp gr 1.15), weigh, and add sufficient additional2.00 N HNO3to bring the total weight of the solution to 425.0g. Then, assemble the calorimeter and start the stirring motor.Take care that the stirr

39、er blades or shaft do not touch thethermometer, the sides or bottom of the jar, or the cork stopper.The lower end of the funnel stem shall extend approximately 6mm (14 in.) below the lower surface of the stopper and at least12 mm (12 in.) above the level of the liquid. The upper end ofthe bulb of th

40、e Beckmann thermometer shall be at least 38 mm(112 in.) below the surface of the liquid. Place it at the samedepth in all determinations. After an initial stirring period of atleast 20 min to allow the temperature of the system to becomeuniform, record the temperature of the room to the nearest 0.1C

41、, the temperature of the acid to the nearest 0.001 C, recordthe time, and then immediately introduce the prepared ZnOthrough the funnel at a uniform rate (See Note 6). Complete theintroduction of the ZnO in not less than 1 or more than 2 min.Brush any ZnO clinging to the funnel stem into the acidmix

42、ture by means of a small “camels-hair” brush.NOTE 6The temperature of the sample shall be identical with that ofthe room when the sample is introduced into the calorimeter.6.3 Read the temperature, to the nearest 0.001 C, at 20 minand again at 40 min after beginning the introduction of thesample. Th

43、e temperature rise in the first 20 min includestemperature rise due to the heat of solution of the sample andany heat gain or heat loss to the environment. This is called thesolution period. The temperature change during the second20-min period is due to heat loss or gain to or from theenvironment.

44、It is used to correct the temperature rise in thesolution period to give the actual heat of solution of the sample.The second 20-min period is called the correction period.6.4 Calculate the corrected temperature rise as follows:Ro5u202u0(1)R 5 Ro2 u402u20!where:Ro= observed temperature rise, C,u20=

45、calorimeter temperature at the end of the solutionperiod,u0= calorimeter temperature when sample was intro-duced,R = corrected temperature rise, C, andu40= calorimeter temperature at the end of the correctionperiod.6.5 Calculate the heat capacity of the calorimeter andcontents as follows (See Note 7

46、):C 5W1072 1 0.430 2 t! 1 0.5T 2 t!#R(2)where:C = heat capacity, kJ/C,W = mass of ZnO, g,t = final temperature of the calorimeter, C (u20plustemperature, C, at which the Beckmann thermometerreading is zero),T = temperature of the ZnO (room temperature), C, whenintroduced into the calorimeter, andR =

47、 corrected temperature rise, C.NOTE 7The heat of solution of ZnO is 1072 kJ/kg (256.1 cal/g) at 30C. This value increases 0.4 kJ/kg (0.1 cal/g) for each degree decrease intemperature below 30 C. The heat capacity of ZnO is 0.5 kJ/kgK (0.12cal/gC). The heat required to bring the ZnO to the final temp

48、erature ofthe calorimeter must be included in the effective heat of solution.6.6 If more than a trace of ZnO is found adhering to the tipof the funnel or to the stopper when the calorimeter is opened,reject the test.6.7 Redetermine the heat capacity at the following times:6.7.1 When the Beckmann the

49、rmometer (if used) is reset,6.7.2 When a new coating is applied to the solution ther-mometer, stirrer, or flask,6.7.3 When a new solution thermometer, stirrer, or flask isput in service,6.7.4 When a new batch of acid is used, and3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharm