1、Designation: C 688 08Standard Specification forFunctional Additions for Use in Hydraulic Cements1This standard is issued under the fixed designation C 688; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number 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 specification covers methods to investigate theeffectiveness of a material to beneficially change the propertiesof hydraulic ce
3、ments when the material is incorporated duringmanufacture of the cement.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 The effect of additions in cement may markedly changeproperties other than those they are intended t
4、o modify. Thisspecification is designed to test for such changes. Table 1 setsforth values for those properties of cement pastes and mortarsthat would permit a judgment of the changes effected by anaddition. Likewise, Table 2 sets forth similar criteria forconcrete. Certain additions may be found ef
5、fective for morethan one purpose as indicated in 3.1.4 and 3.1.5.2. Referenced Documents2.1 ASTM Standards:2C 39/C 39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC78 Test Method for Flexural Strength of Concrete (UsingSimple Beam with Third-Point Loading)C 109/C 109M Test
6、 Method for Compressive Strength ofHydraulic Cement Mortars (Using 2-in. or 50-mm CubeSpecimens)C 143/C 143M Test Method for Slump of Hydraulic-Cement ConcreteC 150 Specification for Portland CementC 151 Test Method for Autoclave Expansion of HydraulicCementC 157/C 157M Test Method for Length Change
7、 of Hard-ened Hydraulic-Cement Mortar and ConcreteC 187 Test Method for Normal Consistency of HydraulicCementC 219 Terminology Relating to Hydraulic CementC 226 Specification for Air-Entraining Additions for Use inthe Manufacture of Air-Entraining Hydraulic CementC 232 Test Methods for Bleeding of C
8、oncreteC 234 Test Method for Comparing Concretes on the Basisof the Bond Developed with Reinforcing Steel (Discontin-ued 2000)3C 266 Test Method for Time of Setting of Hydraulic-Cement Paste by Gillmore NeedlesC 403/C 403M Test Method for Time of Setting of ConcreteMixtures by Penetration Resistance
9、C 451 Test Method for Early Stiffening of Hydraulic Ce-ment (Paste Method)C 465 Specification for Processing Additions for Use in theManufacture of Hydraulic CementsC 595 Specification for Blended Hydraulic CementsC 596 Test Method for Drying Shrinkage of Mortar Con-taining Hydraulic CementC 666/C 6
10、66M Test Method for Resistance of Concrete toRapid Freezing and ThawingC 845 Specification for Expansive Hydraulic CementC 1157 Performance Specification for Hydraulic Cement3. Terminology3.1 Definitions:3.1.1 accelerating additiona functional addition that ac-celerates the setting or early strength
11、, or both, of concrete andmortar.3.1.2 retarding additiona functional addition that retardsthe setting of concrete and mortar.3.1.3 set-control additiona functional addition composedessentially of calcium sulfate in any hydration state fromCaSO4to CaSO42H2O.3.1.4 water-reducing additiona functional
12、addition usedto reduce the quantity of mixing water required to produceconcrete and mortar of a given consistency.3.1.5 water-reducing and accelerating additiona func-tional addition that reduces the quantity of mixing waterrequired to produce concrete of a given consistency and thataccelerates the
13、setting or early strength development, or both,of concrete and mortar.3.1.6 water-reducing and retarding additiona functionaladdition that reduces the quantity of mixing water required to1This specification is under the jurisdiction of ASTM Committee C01 onCement and is the direct responsibility of
14、Subcommittee C01.20 on Additions.Current edition approved Dec. 1, 2008. Published January 2009. Originallyapproved in 1971. Last previous edition approved in 2005 as C 688 00(2005).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or
15、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Int
16、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.produce concrete and mortar of a given consistency andsimultaneously retards the setting of concrete and mortar.NOTE 1This section is intended to provide a specification that may beapplied to calcium sulf
17、ates as defined in Terminology C 219.NOTE 2It should be realized that some calcium sulfates, particularlysome byproduct calcium sulfates, have produced cements with undesiredset behavior after storage.4. Ordering Information4.1 The purchaser shall specify the type of functionaladdition desired.5. Ma
18、terials5.1 CementsThe cements used in the evaluation of theaddition shall be as described in Section 4.1 of SpecificationC 465 with the following exceptions:5.1.1 At least one of the Type I cements shall contain notless than 9 percent tricalcium aluminate (C3A).5.1.2 Disregard the last sentence of S
19、ection 3.1.6 of Speci-fication C 465 and substitute the following: “ Each controlcement shall comply with all the requirements in the specifi-cation (C 150, C 595, C 845, and C 1157) applicable to thattype of cement. The method shall be adequate for the qualita-tive and quantitative determination of
20、 the addition in thefinished cement, and shall be fully described in the report of thetests on the addition.”5.2 AggregatesThe aggregates used in the evaluation ofthe addition shall be in accordance with the Aggregates portionof the Materials section of Specification C 465, using propor-tions specif
21、ied in Concrete Mixtures section of that specifica-tion.6. General Requirements General Requirements6.1 The cement, mortar, and concrete in which each of theadditions is used shall conform to the respective requirementsprescribed in Table 1 and Table 2, except that if the test cementfails to meet th
22、e requirements of Table 1, but possesses all therequirements listed in Table 2, then the requirements of Table2 shall govern approval of the addition.6.2 The trade name, source, and character of the materialshall be specified and the means for the quantitative determi-nation of the proposed addition
23、 in the finished cement, shall befurnished by the manufacturer or seller of the addition, and theresults of such pertinent quantitative analysis shall form a partof the record of tests of the addition.6.3 At the request of the purchaser of an addition for aspecific functional purpose, the manufactur
24、er shall state inwriting the content of any substance which is known to orbelieved to impair other desirable properties of the cement orconcrete.TABLE 1 Criteria for Evaluating Neat Cement and Mortar Containing Functional Cement AdditionsTestsType of AdditionWater Reducing Retarding AcceleratingWate
25、r-Reducingand RetardingWater-Reducing andAcceleratingSet-ControlNormal consistency, deviation from control,percentage pointsA1.0 min +1.0 max +1.0 max 1.0 min 1.0 mm 61.0 maxStandard consistency (flow) deviation fromcontrol, percentage pointsA4.0 min +2.0 max +2.0 max 4.0 min 4.0 min 62.0 maxSetting
26、 time, (Gillmore) deviation from control,h:minInitialAt least . 1:00 laterB1:00 laterB.Not more than 1:00 earlier 3:30 later 1:30 earlier 3:30 later 1:30 earlier 1:00 earliernor nor nor nor1:30 later 1:30 later 1:30 later 1:30 laterSetting time, Vicat InitialCAt least . 0:50 laterB. . .Not more than
27、 0:50 earlier 2:50 later 1:15 earlier 0:50 laterB1:15 earlier 0:50 earliernor nor nor nor1:15 later 1:15 later 2:50 later 1:15 later 1:15 laterFinalNot more than 1:00 earlier 3:30 later 1:00 earlier 3:30 later 1:00 earlier 1:00 earliernor nor nor nor1:30 later 1:30 later 1:30 later 1:30 laterCompres
28、sive strength, min, percent of control:D1 day in moist air 110 90 125E90 125F1 day in moist air, 2 days in water 110 90 125E100 1251 day in moist air, 6 days in water 110 90 100 110 1101 day in moist air, 27 days in water 110 95 95 110 110Autoclave Expansionmax increase in % change in length compare
29、dto control0.10 0.10 0.10 0.10 0.10 0.10Drying Shrinkage of Mortarmax % change in length compared to control 0.020 0.020 0.030 0.020 0.020 0.020AThe minus sign indicates that the percentage of water required shall be less than that of the control cement by at least the indicated percentage points.BO
30、r 50 % later, whichever is the lesser.CEither Vicat or the Gillmore time of setting method shall be used at the choice of the manufacturer.DThe compressive strength of mortar containing the test cement shall be not less than 95 % of that attained at any previous test age. The objective of this limit
31、 is torequire that the strength of mortar containing the addition under test shall not decrease with age.EIn cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.FThe grand average of the 1, 3, 7, and 28-day strengths shall be not less than 95 %
32、of the grand average for the corresponding control cement.C6880826.4 The additions shall be evaluated by comparing cementscontaining the “test addition” to cements ground from similarclinkers from the same source. Those cements without testadditions are referred to in this specification as “controlc
33、ements.”6.4.1 Special Provisions for Set-Control Additions Con-forming to 3.1.3:6.4.1.1 The additions shall be evaluated by comparingcements containing the “test addition” to control cementsground from similar clinkers from the same source and underthe same grinding conditions with the mill temperat
34、ures beingwithin 6 3 C (5 F) of the same value. The control cementsshall be produced with calcium sulfate at any hydration statehaving a past record of satisfactory usage as an addition forportland cement.6.4.1.2 Each test cement shall contain sufficient test additionCaSO4to produce a sulfur trioxid
35、e (SO3) content that differs byno more than 0.24 percentage points from that of the controlcement. The SO3shall be expressed as a percentage of the massof the cement and reported to the nearest 0.01 %.6.4.1.3 The test cements containing the additions shallconform to the requirements of 8.1 and Table
36、 1. The cementsneed not be tested in concrete according to the requirements of8.2 and Table 2.6.5 The amount of addition that is incorporated into thecement for evaluation purposes shall be such as to produce thedesired effects as listed in Table 1. When these tests showcompliance with the requireme
37、nts of this specification, theaddition shall be used only in amounts up to the maximumamount tested in any one of the five cements used in theevaluation. For a cement requiring more than the establishedamount, a separate compliance test on this one cement can bemade which will then establish the new
38、 maximum amountwhich can be used.TABLE 2 Criteria for Evaluating Concrete Containing Functional Cement AdditionsATestsType of AdditionWater Reducing Retarding AcceleratingWater-Reducingand RetardingWater-Reducingand AcceleratingWater content, max, percent of control 95 . . 95 95Time of setting, (pen
39、etration) deviation fromcontrol, h:min:InitialAt least . 1:00 laterB1:00 laterBNot more than 1:00 earlier 3:30 later 3:30 earlier 3:30 later 3:30 earliernorFinal 1:00 laterNot more than 1:00 earlier 3:30 later . 3:30 later .nor1:30 laterCompressive strength, min, percent ofcontrol:C1 dayD110 85 125E
40、100 1253 days 110 85 125E100 1257 days 110 90 100 110 11028 days 110 90 95 110 1103 months 100 90 95 100 1001 year 100 90 95 100 100Flexural strength, min, percent ofcontrol:C1 dayD100 85 110 90 1103 days 100 85 110 100 1107 days 100 90 100 100 10028 days 100 90 90 100 1003 months 100 90 90 100 1001
41、 year 100 90 90 100 100Bond strength, percent of control:28 days 100 90 100 100 100Volume change, expressed as change inlength, max, increase over control,percentage points:28 days 0.010 0.010 0.030 0.010 0.0103 months 0.010 0.010 0.030 0.010 0.0101 year 0.010 0.010 0.030 0.010 0.010Durability facto
42、r, min, percent of controlF80 80 80 80 80AThe values in the table are intended to allow for normal variation in test results. For example, the object of the 90 % compressive strength requirement for a retardingaddition is to require a level of performance comparable to that of the reference concrete
43、.BOr 50 % later, whichever is the lesser.CThe compressive and flexural strength of the concrete containing the addition under test at any test age shall be not less than 90 % of that attained at any previoustest age. The objective of this limit is to require that the compressive or flexural strength
44、 of the concrete containing the addition under test shall not decrease with age.DOne-day strengths applicable only to Type III cement. One-year strength tests shall be made; however, the addition may be approved after completion of the 3-monthstrength results, at the discretion of the purchaser.EIn
45、cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.FThis requirement is applicable only when the addition is to be used in air-entrained concrete.C6880836.6 The cement produced with the functional additionsshown in Section 3 shall comply with t
46、he specification for therespective cement and the ordinarily determined properties ofcement paste, mortar, or concrete made with the cementcontaining the test addition shall not differ from these sameproperties of the cement paste, mortar, or concrete made withthe control cement as indicated by the
47、standard tests, except asprovided in Table 1 and Table 2.6.7 Generally, the addition rates required for functionalpurposes are several times greater than those needed forprocessing purposes and the resultant increase in flowability, orlubricity, from these increased addition rates may cause suffi-ci
48、ent reduction in mill retention time to affect significantly theparticle size distribution of the treated cement. The testaddition may, in instances where the full-scale tests haveshown reduced mill retention time to be significant, be deter-mined for acceptance purposes by making supplementarylabor
49、atory or pilot batch mill grinds.6.8 Furthermore, the effect of the addition on the propertiesof the cement, mortar, or concrete shall be within the limits ofSection 8 and Table 1 and Table 2. In the event tests areconducted by making laboratory or pilot batch mill tests, thisfact shall be entered in the report as specified in Section 9, andthe specific tests shall be indicated.6.9 After it has been documented once by the test resultsthat a specific trade name and source of an addition have metthe requirements of this specification, further tests shall bewaived
