1、Designation: C 917 05Standard Test Method forEvaluation of Cement Strength Uniformity From a SingleSource1This standard is issued under the fixed designation C 917; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses 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 is intended for use in instances inwhich the purchaser desires information on the strength uni-formity of
3、a hydraulic cement produced at a single source. It isintended that this test method normally be used for thepredominant cement manufactured at a cement plant. Guide-lines for sampling, testing, presentation of results, and evalu-ation are given.1.2 The values stated in inch-pound units are to be reg
4、ardedas the standard. The values in parentheses are for informationonly.1.3 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 health practices and determine t
5、he applica-bility of 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)C 150 Specification for Portland CementC 219 Terminology Relating to Hydraulic CementC
6、595 Specification for Blended Hydraulic CementsC 1157 Performance Specification for Hydraulic CementE 456 Terminology Relating to Quality and Statistics3. Terminology3.1 DefinitionsFor definitions of terms relating to this testmethod, refer to Terminologies C 219 and E 456.4. Significance and Use4.1
7、 This test method is designed to present in a standardizedformat information on the variability of strength of cementfrom a single source over a period of time. It can be applied toall hydraulic cements covered in Specifications C 150, C 595,and C 1157.NOTE 1It should be recognized that concrete str
8、ength variability isinfluenced by other factors in addition to cement strength variability.5. Sampling5.1 All sampling shall be performed by quality control ortesting personnel or someone specifically trained for thispurpose.5.2 Take random grab samples from delivery units or duringthe loading or un
9、loading process. Delivery units larger than125 tons (115 Mg) shall be sampled during loading orunloading. If samples are taken during loading or unloading,the two or more portions that are to be composited to make asample shall be taken during the transfer to no more than 125tons (115 Mg) of cement.
10、 Identify samples by the date onwhich the cement they represent was shipped or received.NOTE 2Standard statistical procedures are recommended for ensuringthat samples are selected by a random procedure. These procedures can beused to select the days within a month or within a week that samples willb
11、e taken. Then the delivery unit or the time of day can be chosenrandomly.5.3 If taken from a truck or rail car, take at least twoseparate 5-lb (approximately 2.3-kg) grab samples and thor-oughly mix together to obtain a minimum 10-lb (4.5-kg) testsample. Sample only through hatches in the top of the
12、 unit.Remove approximately a 12-in. (300-mm) layer of cement.Make a hole before obtaining a sample to avoid collecting dustcollector material that may be discharged into the delivery unitafter the cement flow ceases.5.4 If taken from another point in the loading or unloadingprocess, the sample shall
13、 consist of a minimum of two separate5-lb (approximately 2.3-kg) grab samples thoroughly mixedtogether or at least 10 lb (4.5 kg) as accumulated by acontinuous sampler. Take care to avoid segregation and con-tamination of samples taken from screws, pneumatic systems,or air slides.5.5 When samples ar
14、e taken at the cement plant andshipments or rate of production of the cement exceeds 25 000tons (23 000 Mg) per month, take samples at a rate of at leastten per month and at least two per week.When shipment or rate1This test method is under the jurisdiction ofASTM Committee C01 on Cementand is the d
15、irect responsibility of Subcommittee C01.27 on Strength.Current edition approved Feb. 1, 2005. Published February 2005. Originallyapproved in 1979. Last previous edition approved in 1998 as C 91798.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
16、at serviceastm.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.of production of the cement is less than 25 000
17、tons (23 000Mg) per month, take samples at a rate of at least one per 2500tons (2300 Mg). When samples are taken at the cement plant,in no instance shall samples be taken more frequently than oneper 200 tons (180 Mg) of cement shipped or received, exceptthat sampling of consecutive shipments is perm
18、itted when theyresult from randomization.6. Procedure6.1 Test all samples for 7- and 28-day compressive strengthin accordance with Test Method C 109/C 109M using threespecimens for each test age. To be comparable, all tests used ina single evaluation must be made in a single laboratory andpreferably
19、 by the same laboratory operator.NOTE 3When separate evaluations of a single source are made by twoor more laboratories, additional tests of a standard cement or exchange ofportions of the same sample of cement may be necessary to determinedifferences in testing that are likely to be obtained in the
20、 differentlaboratories. Five or more batches may be necessary to obtain a validcomparison between laboratories. Statistical techniques must be used toassess the validity of differences that might be obtained. Participation inthe Cement Proficiency Sample Program of the CCRL by both laborato-ries wil
21、l be helpful in resolving differences that are found.6.1.1 When two laboratories exchange portions of the samesample and prepare single batches, results from the twolaboratories shall not differ by more than 18.7 % of the averageof the two laboratories (see Test Method C 109/C 109Mmultilaboratory d2
22、s). If a larger number of samples areexchanged the difference in average strength shall not exceed18.7/=n % of the overall average strength, where n is thenumber of samples exchanged and tested by each laboratory.Amore precise calculation is outlined in Appendix X1.6.2 Mix duplicate batches of morta
23、r to determine the effectof testing variations on the uniformity of results made in asingle laboratory. Make duplicate batches on a day differentfrom the original batch of mortar.6.2.1 When a uniformity testing program is started onshipments from a single source, make duplicate batches ofmortar from
24、 every third cement sample. When duplicate testshave been made from a minimum of five cement samples,calculate the average range, R , for the available duplicates,then calculate standard deviation and coefficient of variationfor testing according to 7.1.3 and 7.1.4, respectively. Increasethe number
25、of duplicate batches used in the calculation untilthe results of ten cement samples are used in the calculation.After that time, use only the ten most recent results of duplicatetesting in the calculation of the standard deviation and coeffi-cient of variation for testing. See Table 1.6.2.2 When at
26、least ten sets of duplicate batches have beenmade and the coefficient of variation for testing is less than4.0 %, the frequency of testing duplicate batches can bereduced to one out of ten consecutive cement samples. Resumetesting one sample out of three if the coefficient of variationlater exceeds
27、4.0 %. If the coefficient of variation for testingexceeds 5.5 %, the data are of questionable precision, andlaboratory procedures and equipment should be thoroughlyexamined.6.2.3 Use the results of duplicate tests indicating acceptableprecision to estimate the single-laboratory testing variation for
28、all other types of cement tested in that laboratory during thesame period of time, provided that duplicate tests have beenmade on at least one sample per month.7. Calculation7.1 The calculations shall include the following:7.1.1 Average Strength:X 5X11 X21 .1 Xnn(1)where:X = average strength,X1,X2,.
29、,Xn= strength of individual tests, each ofwhich is composed of the average ofcubes in accordance with Test MethodC 109/C 109M, andn = number of individual samples.7.1.2 Total Standard Deviation:St5X12 X!21X22 X!21 .1Xn2 X!2n 2 1!(2)where:St= standard deviation, psi.7.1.3 Standard Deviation For Testi
30、ng:Se5 0.862RSe= standard deviation estimated from tests of dupli-cate batches mixed in a single laboratory,R = range, the difference between the strengths of theduplicate batches from a single sample (all num-bers are positive),R = average of the individual ranges, R, for the preced-ing ten tests o
31、f duplicate batches. See 6.2.1 if fewerthan ten ranges are available, and0.862 = range coefficient for duplicate tests of the samesample of cement.7.1.4 Coeffcient of Variation for Testing:Ve5 100 Se/Xwhere:Ve= coefficients of variation estimated from tests of dupli-cate batches mixed in a single la
32、boratory, andX = average of the strengths of the duplicate batches fromwhich R is calculated.7.1.5 Standard Deviation Corrected For Testing Variations:Sc5 =St22 Se2(3)where:Sc= net standard deviation of cement corrected for testingerror,St= total standard deviations for all tests included in thecalc
33、ulation, andSe= standard deviation of duplicate tests run on splitsample to evaluate testing error.The addition of the subscript 28 or 7 indicates the type ofstrength data used in the calculation.C 917052NOTE 4Values for averages and standard deviations can be calculatedby other methods that are ava
34、ilable in ASTM STP 15 D.3Electroniccalculators are available for obtaining these statistics directly.TABLE 1 Calculation of Standard Deviation for TestingDateSampleNumber7-Day Data AverageARangeBRCSeDVeENoteTest A Test Bpsi (MPa) psi (MPa) psi (MPa) psi (MPa) psi (MPa) psi (MPa)01 /06 3 4900 (33.7)
35、4960 (34.2) 4930 (34.0) 60 (0.41) . . . . . . . . . . . . . . . . . .01 /16 6 4580 (31.5) 4670 (32.2) 4625 (31.8) 90 (0.62) . . . . . . . . . . . . . . . . . .01 /30 9 4650 (32.0) 4850 (33.4) 4750 (32.7) 200 (1.37) . . . . . . . . . . . . . . . . . .02 /05 12 4400 (30.3) 4510 (31.1) 4455 (30.7) 110
36、(0.75) . . . . . . . . . . . . . . . . . .02 /13 15 4380 (30.2) 4300 (29.6) 4340 (29.9) 80 (0.55) 108 (0.74) 93 (0.64) 2.02 % Av. 502 /21 18 4700 (32.4) 4770 (32.8) 4735 (32.6) 70 (0.48) 102 (0.70) 88 (0.60) 1.89 % Av. 603 /04 21 4470 (30.8) 4610 (31.7) 4540 (31.3) 140 (0.96) 107 (0.73) 92 (0.64) 2.
37、00 % Av. 703 /14 24 4030 (27.7) 3970 (27.3) 4000 (27.5) 60 (0.41) 101 (0.69) 87 (0.60) 1.92 % Av. 803 /19 27 4970 (34.2) 4820 (33.2) 4895 (33.7) 150 (1.03) 107 (0.73) 92 (0.63) 2.01 % Av. 903 /27 30 4550 (31.3) 4530 (31.2) 4540 (31.3) 20 (0.13) 96 (0.67) 84 (0.58) 1.84 % Av. 10 (6)04 /30 40 4750 (32
38、.7) 4920 (33.9) 4835 (33.3) 170 (1.17) 109 (0.75) 94 (0.65) 2.06 % Av. last 1005 /31 50 5030 (34.6) 4820 (33.2) 4925 (33.9) 210 (1.44) 121 (0.83) 104 (0.72) 2.27 % Av. last 1006 /29 60 4830 (33.3) 4720 (32.5) 4775 (32.9) 110 (0.75) 112 (0.77) 97 (0.67) 2.10 % Av. last 1007 /28 70 4400 (30.3) 4460 (3
39、0.7) 4430 (30.5) 60 (0.41) 107 (0.73) 92 (0.64) 2.00 % Av. last 1008 /30 80 4550 (31.3) 4460 (30.7) 4505 (31.0) 90 (0.62) 108 (0.74) 93 (0.64) 2.02 % Av. last 1009 /25 90 4930 (34.0) 5000 (34.4) 4965 (34.2) 70 (0.48) 108 (0.74) 93 (0.64) 2.01 % Av. last 1010 /26 100 4950 (34.1) 4820 (33.2) 4885 (33.
40、6) 130 (0.89) 107 (0.73) 92 (0.64) 1.97 % Av. last 1011 /25 110 4670 (32.2) 4720 (32.5) 4695 (32.3) 50 (0.34) 106 (0.73) 91 (0.63) 1.93 % Av. last 1012 /21 120 4450 (30.6) 4520 (31.1) 4485 (30.9) 70 (0.48) 96 (0.67) 84 (0.58) 1.80 % Av. last 10DateSampleNumber28-Day DataAverageARangeBRCSeDVeENoteTes
41、t A Test Bpsi (MPa) psi (MPa) psi (MPa) psi (MPa) psi (MPa) psi (MPa)01 /06 3 6370 (43.9) 6620 (45.6) 6495 (44.7) 250 (1.72) . . . . . . . . . . . . . . . . . .01 /16 6 6250 (43.1) 6020 (41.5) 6135 (42.3) 230 (1.58) . . . . . . . . . . . . . . . . . .01 /30 9 6050 (41.7) 6120 (42.2) 6085 (41.9) 70 (
42、0.48) . . . . . . . . . . . . . . . . . .02 /05 12 6020 (41.5) 6230 (42.9) 6125 (42.2) 210 (1.44) . . . . . . . . . . . . . . . . . .02 /13 15 5600 (38.6) 5420 (37.3) 5510 (38.0) 180 (1.24) 188 (1.29) 162 (1.12) 2.67 % Av. 502 /21 18 5500 (37.9) 5530 (38.1) 5515 (38.0) 30 (0.20) 162 (1.11) 139 (0.96
43、) 2.33 % Av. 603 /04 21 6320 (43.5) 6280 (43.3) 6300 (43.4) 40 (0.27) 144 (0.99) 124 (0.86) 2.06 % Av. 703 /14 24 5920 (40.8) 6010 (41.4) 5965 (41.1) 90 (0.62) 138 (0.94) 119 (0.82) 1.97 % Av. 803 /19 27 6300 (43.4) 6050 (41.7) 6175 (42.5) 250 (1.72) 150 (1.03) 129 (0.89) 2.14 % Av. 903 /27 30 6350
44、(43.7) 6410 (44.2) 6380 (44.0) 60 (0.41) 141 (0.97) 122 (0.84) 2.00 % Av. 10 (6)04 /30 40 6050 (41.7) 5940 (40.9) 5995 (41.3) 110 (0.75) 127 (0.87) 109 (0.75) 1.82 % Av. last 1005 /31 50 6670 (46.0) 6530 (45.0) 6600 (45.5) 140 (0.96) 118 (0.81) 102 (0.70) 1.68 % Av. last 1006 /29 60 6350 (43.7) 6190
45、 (42.6) 6270 (43.2) 160 (1.10) 127 (0.87) 109 (0.75) 1.80 % Av. last 1007 /28 70 6500 (44.8) 6300 (43.4) 6400 (44.1) 200 (1.37) 126 (0.86) 109 (0.75) 1.78 % Av. last 1008 /30 80 6200 (42.7) 6150 (42.4) 6175 (42.5) 50 (0.34) 113 (0.77) 97 (0.67) 1.58 % Av. last 1009 /25 90 6630 (45.7) 6540 (45.1) 658
46、5 (45.4) 90 (0.62) 119 (0.82) 103 (0.71) 1.63 % Av. last 1010 /26 100 6230 (42.9) 6010 (41.4) 6120 (42.2) 220 (1.51) 137 (0.94) 118 (0.81) 1.88 % Av. last 1011 /25 110 5920 (40.8) 6020 (41.5) 5970 (41.1) 100 (0.68) 138 (0.95) 119 (0.82) 1.90 % Av. last 1012/21 120 . . . . . . . . . . . . . .Notes: I
47、nitially one out of three samples are tested in duplicate until at least ten duplicate test results are available.AAverage of the test results A and B.BAbsolute difference between tests A and B.CAverage range is calculated for a minimum of five duplicate tests. Subsequently, ranges of the ten most r
48、ecent duplicate tests are averaged.DStandard deviation for testing is calculated as in 7.1.3: Se= 0.862 3 R .ECoefficient of variation for testing is calculated as in 7.1.4: Ve= 100 Se/ X . Note that X is the average strength of the duplicate batches from which R is determined.8. Report8.1 Sufficien
49、t information shall be provided to identify thecement sampled including:8.1.1 Name of manufacturer and location,8.1.2 Type of cement or other identification,8.1.3 Location of sampling,8.1.4 Laboratory designation, and8.1.5 Period of time represented by the report.8.2 For ongoing programs, the minimum period covered bythe report shall include all strength tests made in the precedingthree months, but in no instance less than that period of timenecessary to include 28-day strength tests of 20 consecutivesamples.3Manual on Presentation of Data and Control Chart Analysis, ASTM
