1、Designation: C 1585 04Standard Test Method forMeasurement of Rate of Absorption of Water by Hydraulic-Cement Concretes1This standard is issued under the fixed designation C 1585; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. 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 used to determine the rate ofabsorption (sorptivity) of water by hydraulic cement concret
3、eby measuring the increase in the mass of a specimen resultingfrom absorption of water as a function of time when only onesurface of the specimen is exposed to water. The exposedsurface of the specimen is immersed in water and water ingressof unsaturated concrete dominated by capillary suction durin
4、ginitial contact with water.1.2 The values stated in SI units are to be regarded as thestandard.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 p
5、ractices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 31/C 31M Practice for Making and Curing Concrete TestSpecimens in the FieldC 42/C 42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC 125 Term
6、inology Relating to Concrete and ConcreteAggregatesC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 642 Test Method for Density, Absorption, and Voids inHardened ConcreteC 1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use
7、in the PhysicalTesting of Hydraulic Cements3. Terminology3.1 For definitions of terms used in this standard, refer toTerminology C 125.4. Significance and Use4.1 The performance of concrete subjected to many aggres-sive environments is a function, to a large extent, of thepenetrability of the pore s
8、ystem. In unsaturated concrete, therate of ingress of water or other liquids is largely controlled byabsorption due to capillary rise. This test method is based onthat developed by Hall3who called the phenomenon “watersorptivity.”4.2 The water absorption of a concrete surface depends onmany factors
9、including: (a) concrete mixture proportions; (b)the presence of chemical admixtures and supplementary ce-mentitious materials; (c) the composition and physical charac-teristics of the cementitious component and of the aggregates;(d) the entrained air content; (e) the type and duration ofcuring; (f)
10、the degree of hydration or age; (g) the presence ofmicrocracks; (h) the presence of surface treatments such assealers or form oil; and (i) placement method includingconsolidation and finishing. Water absorption is also stronglyaffected by the moisture condition of the concrete at the time oftesting.
11、4.3 This method is intended to determine the susceptibilityof an unsaturated concrete to the penetration of water. Ingeneral, the rate of absorption of concrete at the surface differsfrom the rate of absorption of a sample taken from the interior.The exterior surface is often subjected to less than
12、intendedcuring and is exposed to the most potentially adverse condi-tions. This test method is used to measure the water absorptionrate of both the concrete surface and interior concrete. Bydrilling a core and cutting it transversely at selected depths, theabsorption can be evaluated at different di
13、stances from theexposed surface. The core is drilled vertically or horizontally.4.4 This test method differs from Test Method C 642 inwhich the specimens are oven dried, immersed completely in1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is
14、the direct responsibility of SubcommitteeC09.66 on Resistance to Fluid Penetration.Current edition approved Feb. 1, 2004. Published March 2004.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
15、lume information, refer to the standards Document Summary page onthe ASTM website.3Hall, C., “Water Sorptivity of Mortars and Concretes: A Review,” Magazine ofConcrete Research, Vol. 41, No. 147, June 1989, pp. 51-61.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocke
16、n, PA 19428-2959, United States.water at 21C, and then boiled under water for 5 h. In this testmethod, only one surface is exposed to water at room tempera-ture while the other surfaces are sealed simulating waterabsorption in a member that is in contact with water on oneside only. Test Method C 642
17、, on the other hand, is used toestimate the maximum amount of water that can be absorbedby a dry specimen and therefore provides a measure of thetotal, water permeable pore space.5. Apparatus5.1 Pan, a watertight polyethylene or other corrosion-resistant pan large enough to accommodate the test spec
18、imenswith the surfaces to be tested exposed to water.5.2 Support Device, rods, pins, or other devices, which aremade of materials resistant to corrosion by water or alkalinesolutions, and which allow free access of water to the exposedsurface of the specimen during testing. Alternatively, thespecime
19、ns can be supported on several layers of blotting paperor filter papers with a total thickness of at least 1 mm.5.3 Top-pan Balance, complying with Specification C 1005and with sufficient capacity for the test specimens and accurateto at least 6 0.01 g.5.4 Timing Device, stop watch or other suitable
20、 timingdevice accurate to 6 1s.5.5 Paper Towel or Cloth, for wiping excess water fromspecimen surfaces.5.6 Water-Cooled Saw, with diamond impregnated blade tocut test specimens from larger samples.5.7 Environmental Chamber, a chamber allowing for aircirculation and able to maintain a temperature of
21、50 6 2C anda relative humidity at 80 6 3 %. Alternatively, an oven able tomaintain a temperature of 50 6 2C and a dessicator largeenough to contain the specimens to be tested is permitted. Therelative humidity (RH) is controlled in the dessicator at 80 60.5 % by a saturated solution of potassium bro
22、mide. Thesolubility of potassium bromide is 80.2 g/100 g of water at50C. The solution shall be maintained at the saturation pointfor the duration of the test. The presence of visible crystals inthe solution provides acceptable evidence of saturation.5.8 Polyethylene Storage Containers, with sealable
23、 lids,large enough to contain at least one test specimen but not largerthan 5 times the specimen volume.5.9 Caliper, to measure the specimen dimensions to thenearest 0.1 mm.6. Reagents and Materials6.1 Potassium Bromide, Reagent Grade, required if theoven and dessicator system described in 5.7 is us
24、ed.6.2 Sealing Material, strips of low permeability adhesivesheets, epoxy paint, vinyl electricians tape, duct tape, oraluminium tape. The material shall not require a curing timelonger than 10 minutes.6.3 Plastic Bag or Sheeting, any plastic bag or sheeting thatcould be attached to the specimen to
25、control evaporation fromthe surface not exposed to water. An elastic band is required tokeep the bag or sheeting in place during the measurements.7. Test Specimens7.1 The standard test specimen is a 100 6 6 mm diameterdisc, with a length of 50 6 3 mm. Specimens are obtained fromeither molded cylinde
26、rs according to Practices C 31/C 31M orC 192/C 192M or drilled cores according to Test MethodC 42/C 42M. The cross sectional area of a specimen shall notvary more than 1 % from the top to the bottom of the specimen.When cores are taken, they should be marked (see Note 1) sothat the surface to be tes
27、ted relative to the original location inthe structure is clearly indicated.NOTE 1The surface to be exposed during testing shall not be markedor otherwise disturbed in such a manner as may modify the absorption rateof the specimen.7.2 The average test results on at least 2 specimens (Note 2)shall con
28、stitute the test result. The test surfaces shall be at thesame distance from the original exposed surface of the con-crete.NOTE 2Concrete is not a homogeneous material. Also, an exteriorsurface of a concrete specimen seldom has the same porosity as theinterior concrete. Therefore, replicate measurem
29、ents are taken on speci-mens from the same depth to reduce the scatter of the data.8. Sample Conditioning8.1 Place test specimens in the environmental chamber at atemperature of 50 6 2C and RH of 80 6 3 % for 3 days.Alternatively, place test specimens in a dessicator inside anoven at a temperature o
30、f 50 6 2C for 3 days. If the dessicatoris used, control the relative humidity in the dessicator with asaturated solution of potassium bromide (see 5.7), but do notallow test specimens to contact the solution.NOTE 3To control the RH using the potassium bromide solution, thesolution should be placed i
31、n the bottom of the dessicator, to ensure thelargest surface of evaporation possible.8.2 After the 3 days, place each specimen inside a sealablecontainer (as defined in 5.8). Use a separate container for eachspecimen. Precautions must be taken to allow free flow of airaround the specimen by ensuring
32、 minimal contact of thespecimen with the walls of the container.8.3 Store the container at 23 6 2C for at least 15 daysbefore the start of the absorption procedure.NOTE 4Storage in the sealed container for at least 15 days results inequilibration of the moisture distribution within the test specimen
33、s and hasbeen found4to provide internal relative humidities of 50 to 70 %. This issimilar to the relative humidities found near the surface in some fieldstructures.5,69. Procedure9.1 Remove the specimen from the storage container andrecord the mass of the conditioned specimen to the nearest 0.01g be
34、fore sealing of side surfaces.4Bentz D. P., Ehlen M. A., Ferraris C. F., and Winpigler J. A., “Service LifePrediction Based on Sorptivity for Highway Concrete Exposed to Sulfate Attack andFreeze-Thaw Conditions,” FHWA-RD-01-162, 2001.5DeSouza S. J., Hooton R. D., and Bickley J. A., “Evaluation of La
35、boratoryDrying Procedures Relevant to Field Conditions for Concrete Sorptivity Measure-ments,” Cement Concrete Aggr 19: (2), Dec 1997, pp. 59-63.6DeSouza S. J., Hooton R. D., and Bickley J. A., “A Field Test for EvaluatingHigh Performance Concrete Covercrete Quality,” Can J Civil Eng, 25: (3), Jun19
36、98, pp. 551-556.C15850429.2 Measure at least four diameters of the specimen at thesurface to be exposed to water. Measure the diameters to thenearest 0.1 mm and calculate the average diameter to thenearest 0.1 mm.9.3 Seal the side surface of each specimen with a suitablesealing material. Seal the en
37、d of the specimen that will not beexposed to water using a loosely attached plastic sheet (see6.2). The plastic sheet can be secured using an elastic band orother equivalent system (see Fig. 1).9.4 Use the procedure below to determine water absorptionas a function of time. Conduct the absorption pro
38、cedure at 236 2C with tap water conditioned to the same temperature.9.5 Absorption Procedure:9.5.1 Measure the mass of the sealed specimen to thenearest 0.01 g and record it as the initial mass for waterabsorption calculations.9.5.2 Place the support device at the bottom of the pan andfill the pan w
39、ith tap water so that the water level is 1 to 3 mmabove the top of the support device. Maintain the water level 1to 3 mm above the top of the support device for the duration ofthe tests.NOTE 5One method for keeping the water level constant is to installa water-filled bottle upside down such that the
40、 bottle opening is in contactwith the water at the desired level.9.5.3 Start the timing device and immediately place the testsurface of the specimen on the support device (see Fig. 1).Record the time and date of initial contact with water.9.5.4 Record the mass at the intervals shown in Table 1 after
41、first contact with water. Using the procedure in 9.5.5, the firstpoint shall be at 60 6 2 s and the second point at 5 min 6 10s. Subsequent measurements shall be within 6 2 min of 10min, 20 min, 30 min, and 60 min. The actual time shall berecorded to within 6 10 s. Continue the measurements everyhou
42、r, 6 5 min, up to 6 h, from the first contact of the specimenwith water and record the time within 6 1 min. After the initial6 h, take measurements once a day up to 3 days, followed by3 measurements at least 24 h apart during days 4 to 7; take afinal measurement that is at least 24 h after the measu
43、rement at7 days. The actual time of measurements shall be recordedwithin 6 1 min. This will result in seven data points for contacttime during days 2 through 8. Table 1 gives the target times ofmeasurements and the tolerances for the times.9.5.5 For each mass determination, remove the test speci-men
44、 from the pan, stop the timing device if the contact time isless than 10 min, and blot off any surface water with adampened paper towel or cloth. After blotting to remove excesswater, invert the specimen so that the wet surface does notcome in contact with the balance pan (to avoid having to drythe
45、balance pan). Within 15 s of removal from the pan, measurethe mass to the nearest 0.01 g. Immediately replace thespecimen on the support device and restart the timing device.10. Calculations10.1 The absorption, I, is the change in mass divided by theproduct of the cross-sectional area of the test sp
46、ecimen and thedensity of water. For the purpose of this test, the temperaturedependence of the density of water is neglected and a value of0.001 g/mm3is used. The units of I are mm.I 5mta/d, (1)where:I = the absorption,mt= the change in specimen mass in grams, at the time t,a = the exposed area of t
47、he specimen, in mm2, andd = the density of the water in g/mm3.10.2 The initial rate of water absorption (mm/s1/2) is definedas the slope of the line that is the best fit to I plotted against thesquare root of time (s1/2). Obtain this slope by using least-squares, linear regression analysis of the pl
48、ot of I versustime1/2. For the regression analysis, use all the points from 1min to 6 h, excluding points for times after the plot shows aclear change of slope. If the data between 1 min and6hdonotfollow a linear relationship (a correlation coefficient of lessFIG. 1 Schematic of the ProcedureC158504
49、3than 0.98) and show a systematic curvature, the initial rate ofabsorption cannot be determined.NOTE 6Appendix X1 gives an example of absorption data and theresults of regression analysis.10.3 The secondary rate of water absorption (mm/s1/2)isdefined as the slope of the line that is the best fit to I plottedagainst the square root of time (s1/2) using all the points from1 d to 7 d. Use least-square linear regression to determine theslope. If the data between 1 d and 7 d do not follow a linearrelationship (a correlation coefficient of less than 0.98) andshow a systematic
