ASTM C186-17 Standard Test Method for Heat of Hydration of Hydraulic Cement.pdf

1、Designation: C186 17Standard Test Method forHeat of Hydration of Hydraulic Cement1This standard is issued under the fixed designation C186; 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 pare

2、ntheses 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 the determination of the heat ofhydration of a hydraulic cement by measuring the heat ofsolution of the dry cement and the h

3、eat 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 hydraulic

4、 cement are insolublein the nitric acid/hydrofluoric acid solution.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 Values in SI units shall be obtained by measurement inSI units or by appropriate conversion, using the Ru

5、les 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, health

6、, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.WarningFresh hydraulic cementitious mixtures are causticand may cause chemical burns to skin and tissue uponprolonged exposure.21.6 This international standard was developed in accor-dance with inte

7、rnationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3C109

8、/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C114 Test Methods for Chemical Analysis of HydraulicCementC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC1005 Specification for Reference M

9、asses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic CementsE11 Specification for Woven Wire Test Sieve Cloth and TestSievesIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System3. Significance and Use3.1 The purpos

10、e 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 test may also be used for research purposes when itis desired to determine the heat of hydration of hydrauliccement at any age.NOTE 1When

11、tests are performed for research purposes, usefuladditional information can be obtained by determining fineness, chemicaland compound compositions.3.3 Determination of the heat of hydration of hydrauliccements provides information that is helpful for calculatingtemperature rise in mass concrete.4. A

12、pparatus4.1 Calorimetric Apparatus:4.1.1 CalorimeterThe calorimeter, such as that illustratedin Fig. 1, shall consist of a 0.5 L, wide-mouth vacuum jar, with1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.26 on Heat of H

13、ydration.Current edition approved Oct. 1, 2017. Published November 2017. Originallyapproved in 1944. Last previous edition approved in 2015 as C186 15a. DOI:10.1520/C0186-17.2Section on Safety, Manual of Cement Testing, Annual Book of ASTMStandards, Vol 04.01.3For referenced ASTM standards, visit th

14、e 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Ba

15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom

16、mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1cork stopper, or other suitable non-reactive stopper held in asuitably insulated container (see 4.1.2) to keep the vacuum jarin position and to protect the jar from undue temperaturefluctuations. The vacuu

17、m jar shall be coated on the interiorwith a material resistant to hydrofluoric acid, such as a bakedphenolic 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 necess

18、ary. As another means of protecting thevacuum jar, a plastic liner of suitable size may be used insteadof coating the interior of the jar. The contents of the vacuum jarshall not change more than 0.001C/min per degree differencefrom room temperature when filled with 425 g of the acidspecified in 6.2

19、, stoppered, and allowed to stand unstirred for30 min. The temperature for this check shall approximate 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,or fiber-glass,

20、 which shall be at least 25 mm in thickness andshall encase the sides and bottom of the vacuum jar, but shallbe 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

21、 dissolution of cement during determi-nations. 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

22、 test method, it is called the reference ther-mometer.4.1.3.1 Solution thermometerThe solution thermometershall be readable to 0.001C and have an accuracy of 0.1C.The solution thermometer may be either a Beckman type (seeNote 2), which is a mercury-in-glass type that only outputstemperature differen

23、tials, or a digital type that gives actualtemperature outputs. If a Beckman type is used, it shall begraduated to at least 0.01C, with readings to 0.001C that canbe estimated by interpolation between these graduations. Itshall also have a temperature range of at least 6C.NOTE 2 If the part of the th

24、ermometer that will be in contact with thetest solution is sensitive to the nitric and hydrofluoric acids in the testsolution, then it is recommended that this part of the thermometer beFIG. 1 CalorimeterC186 172coated with a resistant material to prolong the service life of thethermometer.4.1.3.2 R

25、eference thermometerThe reference thermom-eter shall be readable to 0.1C and have an accuracy of 1C(Note 3).NOTE 3Research Report No. C01-10144contains an analysis support-ing the readability and accuracy requirements of thermometers.4.1.4 FunnelThe funnel through which the sample isintroduced into

26、the calorimeter shall be glass or plastic andshall have a stem inside diameter of at least 6 mm (see Note 4).NOTE 4The minimum diameter is to prevent clogging of the pow-dered cement sample. The length of the stem will need to be adjusted sothat the sample is delivered without the tip becoming wet f

27、rom 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 onto the rotating stirrer, which will causesample to cake at the liquid line.4.1.5 Stirring AssemblyThe stirrer

28、 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 constant-speed type, atleast 37 W, and shall be equipped with a geared speed reducerso that one speed, in the range

29、of 5.8 to 11.7 rev/s, can bemaintained constant.NOTE 5The stirrer shown in Fig. 2 may be readily made from acommercially available three-bladed polyethylene propeller having apropeller diameter of 34 mm, shaft diameter of 6 mm, and a shaft lengthof approximately 455 mm. The function of the stirrer i

30、s two-fold: tomaintain uniform temperature throughout the liquid, and to supplysufficient agitation to keep the solid in suspension in the acid mixture.Since a stirrer capable of keeping the solid in suspension generatesconsiderable heat in the calorimeter, it is important that the stirrer speedand,

31、 hence the rate of heat generation, be maintained constant. Becausesuch constancy is difficult to achieve with other types of motors, asynchronous motor with a geared speed reducer is recommended.4.2 MixerA moderate-speed mechanical mixer, such as amilk-shake type stirrer, capable of intimately mixi

32、ng thecement and water to a uniform paste.4.3 StorageStorage space with temperature controlled at23.0 6 2.0C.4.4 Mortar, approximately 200 mm in diameter, and pestlefor grinding the partially hydrated samples.4.5 Drying Oven, maintained at 100 to 110C.4.6 Sieves, 150 m (No. 100) and 850 m (No. 20),

33、con-forming to Specification E11.4.7 Crucibles, platinum, 30 mL capacity, with covers, forloss on ignition determination.4.8 Muffle Furnace, or suitable burners capable of maintain-ing a temperature of 900 to 950C.4.9 Analytical Balance and Analytical Weights, conformingto the requirements prescribe

34、d in Test Methods C114 forweighing out calorimetric samples and for loss on ignitionweighings.4.10 Weights and Weighing Devices, conforming to therequirements of Specification C1005. The weighing deviceshall be evaluated at a total load of 1000 g.4Supporting data have been filed at ASTM Internationa

35、l Headquarters and maybe obtained by requesting Research Report RR:C01-1014. ContactASTM CustomerService at serviceastm.org.FIG. 2 StirrerC186 1735. Reagents and Materials5.1 Purity of ReagentsReagent-grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reage

36、nts shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening thea

37、ccuracy of the determination.5.2 Hydrofluoric Acid (sp gr 1.15)Concentrated hydroflu-oric 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 with127 mL of concentrated HNO3(s

38、p gr 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 to950C for 1 h, then cooled in a desiccator, ground to pass a

39、150 m (No. 100) sieve, and stored. Immediately prior to a heatcapacity determination,7goftheZnOsoprepared shall beheated for not more than 5 min at 900 to 950C, cooled to roomtemperature in a desiccator, and weighed accurately for intro-duction into the calorimeter.NOTE 6The rate of solution of the

40、ZnO varies 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 required to raise the temperatur

41、e of thecalorimeter and contents 1C), measure the corrected tempera-ture rise obtained by dissolving7gofignited ZnO in thespecified 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 Beckmann ther

42、mometer (ordinarily about 4to 5C below room temperature), into the vacuum jar, add8.0 mL of HF (sp gr 1.15), weigh, and add sufficient additional2.00 N HNO3to bring the total weight of the solution to425.0 g. Then, assemble the calorimeter and start the stirringmotor. Take care that the stirrer blad

43、es 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 approximately6 mm below the lower surface of the stopper and at least12 mm above the level of the liquid. The upper end of the bulbof the Beckmann thermometer sh

44、all be at least 38 mm belowthe surface of the liquid. Place it at the same depth in alldeterminations.After an initial stirring period of at least 20 minto allow the temperature of the system to become uniform,record the temperature of the room to the nearest 0.1C, thetemperature of the acid to the

45、nearest 0.001C, record the time,and then immediately introduce the prepared ZnO through thefunnel at a uniform rate (see Note 7). Complete the introduc-tion of the ZnO in not less than 1 or more than 2 min. Brushany ZnO clinging to the funnel stem into the acid mixture bymeans of a small “camels-hai

46、r” brush.NOTE 7The 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 0.001C, at 20 minand again at 40 min after beginning the introduction of thesample. The temperature rise in the first 20 mi

47、n 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. It is used to correct the temperature

48、 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:Ro5 202 0(1)R 5 Ro2 402 20!where:Ro= observed temperature rise, C,20= calorimeter temperature at the end of t

49、he solutionperiod,0= calorimeter temperature when sample was introduced,R = corrected temperature rise, C, and40= calorimeter temperature at the end of the correctionperiod.6.5 Calculate the heat capacity of the calorimeter andcontents as follows (see Note 8):C 5W107210.430 2 t!10.5T 2 t!#R(2)where:C = heat capacity, kJ/C,W = mass of ZnO, g,t = final temperature of the calorimeter, C (20plustemperature, C, at which the Beckmann thermometerreading is zero),T = temperature of the ZnO (room temperature),