1、Designation: C186 13Standard 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. 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 he
3、at 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 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 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 and hea
6、lth practices and determine the applica-bility or regulatory limitations prior to use.Warning: Fresh hydraulic cementitious mixtures are causticand may cause chemical burns to skin and tissue uponprolonged exposure.22. Referenced Documents2.1 ASTM Standards:3C109/C109M Test Method for Compressive St
7、rength 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 Masses and Devices forDetermining Mass
8、 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 purpose of this test is to determine if the
9、 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 tests are performed for research purp
10、oses, 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. Apparatus4.1 Calorimetric Apparatus:4.
11、1.1 CalorimeterThe calorimeter, such as that illustratedin Fig. 1 shall consist of a 0.5-L(1-pt), wide-mouth vacuum jar,with cork 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 temp
12、eraturefluctuations. The vacuum 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 frequen
13、tly and renewedwhenever necessary. 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 0.001 C/min per degree differencefrom room temperature when filled with 42
14、5 g of the acid1This test method is under the jurisdiction of ASTM Committee C01 on Cementand is the direct responsibility of Subcommittee C01.26 on Heat of Hydration.Current edition approved Dec. 15, 2013. Published February 2014. Originallyapproved in 1944. Last previous edition approved in 2005 a
15、s C186 05. DOI:10.1520/C0186-13.2Section on Safety, Manual of Cement Testing, Annual Book of ASTMStandards, Vol 04.01.3For 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 t
16、o the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1specified in 6.2, stoppered, and allowed to stand unstirred for30 min. The temperature for this check shall approximate thestarti
17、ng 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, which shall be at least 25 mm (1 in.) in thicknessand shall encase the sides and bottom of the vacuum jar, butsh
18、all 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-nations. For purposes of this test method, this thermometer iscalle
19、d 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 ther-mometer.4.1.3.1 Solution thermometerThe solution thermomete
20、rshall 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 a Beckmantype is used, it shall be graduated to at least 0.01 C,
21、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 theFIG. 1 CalorimeterC186 132test solution is sensitive to the nitric and hydrofluoric aci
22、ds 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 of at least 0.1 C.4.1.4 FunnelThe funn
23、el 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. The length of the stem will need to be adjusted sothat the samp
24、le 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 onto the rotating stirrer, which will causesample to cake at the
25、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 constant-speed type, atleast 37 W (120 hp), and shall be equipped with
26、 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 apropeller diameter of 34 mm (138 in.), shaft diameter of 6 mm (14 in.),
27、 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. Since a stirrer capable of keeping the solid in suspensiongenerates
28、 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 with a geared speed reducer is recom-mended.4.2 MixerA moderate-sp
29、eed 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 mm (8 in.) in diameter, andpestle for grinding the partially hy
30、drated 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 Muffle Furnace, or suitable burners capable of maintain-ing a temper
31、ature 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, conforming to therequirements of Specification C1005. The weigh
32、ing 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 thatFIG. 2 StirrerC186 133all reagents shall conform to the specifications of the Commit-tee on Analytic
33、al Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Hydrofluoric Acid (sp gr 1.15)Concen
34、trated 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 with 127mL of concentrated HNO3(sp gr 1.42) per litre of solution,provided that heat capacity determin
35、ations 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-m (No. 100) sieve, and stored. Immediately prior to aheat capaci
36、ty 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 varies with the preliminarytreatment. The procedure described res
37、ults 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 temperatureof the calorimeter and contents 1 C), measure the correc
38、tedtemperature 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 Beckmann thermometer (ordinarily about 4to 5 C below room temperature),
39、 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 stirrer blades or shaft do not touch thethermometer, the sides or bot
40、tom 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 the Beckmann thermometer shall be at least 38 mm(112 in.) below th
41、e 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, the temperature of the acid to the nearest 0.001 C, recordthe
42、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 acidmixture by means of a small “camels-hair” brush.NOTE 6The temperatu
43、re 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. The temperature rise in the first 20 min includestemperature rise
44、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 rise in thesolution period
45、 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 the solutionperiod,0= calori
46、meter 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 7):C 5W107210.430 2 t!10.5T 2 t!#R(2)where:C = heat capacity, kJ/C,W =
47、 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), C, whenintroduced into the calorimeter, andR = corrected temperature rise, C.NOTE 7The heat of solution of ZnO is 1072 k
48、J/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 temperature ofthe calorimeter must be included in the effective heat of soluti
49、on.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 thermometer (if used) is reset,6.7.2 When a new coating is applied to the solutionthermometer, stirrer, or flask,6.7.3 When a new solution thermometer, stirrer, or flask isput in service,4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D
