1、Designation: C1585 11Standard Test Method forMeasurement of Rate of Absorption of Water by Hydraulic-Cement Concretes1This standard is issued under the fixed designation C1585; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. 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 test method is used to determine the rate ofabsorption (sorptivity) of water by hydraulic cement concreteb
3、y 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 specimen isconditioned in an environment at a standard relative humidityto induce a consistent moisture condition in the capillary
4、poresystem. The exposed surface of the specimen is immersed inwater and water ingress of unsaturated concrete is dominatedby capillary suction during initial contact with water.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard
5、.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 the applica-bility of regulatory limitations prior to use.2. Referenced
6、Documents2.1 ASTM Standards:2C31/C31M Practice for Making and Curing Concrete TestSpecimens in the FieldC42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of ConcreteC125 Terminology Relating to Concrete and Concrete Ag-gregatesC192/C192M Practice for Making and Curing Concr
7、eteTest Specimens in the LaboratoryC642 Test Method for Density, Absorption, and Voids inHardened ConcreteC1005 Specification for Reference Masses and Devices forDetermining Mass and Volume for Use in the PhysicalTesting of Hydraulic Cements3. Terminology3.1 For definitions of terms used in this sta
8、ndard, refer toTerminology C125.4. 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 system. In unsaturated concrete, therate of ingress of water or other liquids is largely controlled byab
9、sorption 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 including: (a) concrete mixture proportions; (b)the presence of chemical admixtures and supplementary c
10、e-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) the degree of hydration or age; (g) the presence ofmicrocracks; (h) the presence of surface treatments
11、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.4.3 This method is intended to determine the susceptibilityof an unsaturated concrete to the penetratio
12、n 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 intendedcuring and is exposed to the most potentially adverse condi-tions. This test method is used to
13、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 distances from theexposed surface. The core is drilled vertically or horizontally.4.4 This test method di
14、ffers from Test Method C642 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 the direct responsibility of SubcommitteeC09.66 on Concretes Resistance to Fluid Penetration.Current edi
15、tion approved July 1, 2011. Published August 2011. Originallyapproved in 2004. Last previous edition approved in 2004 as C1585041. DOI:10.1520/C1585-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSta
16、ndards volume 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. 51-61.1*A Summary of Changes section appears at the end of this standard.Copyrig
17、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, 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 i
18、n a member that is in contact with water on oneside only. Test Method C642, 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
19、or other corrosion-resistant pan large enough to accommodate the test specimenswith 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 th
20、e exposedsurface of the specimen during testing. Alternatively, thespecimens 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 C1005and with sufficient capacity for the test specimens and acc
21、urateto at least 6 0.01 g.5.4 Timing Device, stop watch or other suitable 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 c
22、hamber allowing for aircirculation and able to maintain a temperature of 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 controlle
23、d in the dessicator at 80 60.5 % by a saturated solution of potassium bromide. 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
24、evidence of saturation.5.8 Polyethylene Storage Containers, with sealable 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, Reagen
25、t Grade, required if theoven and dessicator system described in 5.7 is used.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 Sheeti
26、ng, any plastic bag or sheeting thatcould be attached to the specimen to 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, wit
27、h a length of 50 6 3 mm. Specimens are obtained fromeither molded cylinders according to Practices C31/C31M orC192/C192M or drilled cores according to Test Method C42/C42M. The cross sectional area of a specimen shall not varymore than 1 % from the top to the bottom of the specimen.When cores are ta
28、ken, they should be marked (see Note 1)sothat the surface to be tested 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
29、 The average test results on at least 2 specimens (Note 2)shall constitute 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 s
30、ame porosity as theinterior concrete. Therefore, replicate measurements 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, pl
31、ace test specimens in a dessicator inside anoven at a temperature of 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 u
32、sing the potassium bromide solution, thesolution should be placed in 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 mus
33、t be taken to allow free flow of airaround the specimen by ensuring 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 in
34、equilibration of the moisture distribution within the test specimens 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 and
35、record the mass of the conditioned specimen to the nearest 0.01g before 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 SulfateAttack andFreeze-Thaw Conditions,” FHWA-RD-01-162, 2001.
36、5DeSouza S. J., Hooton R. D., and Bickley J. A., “Evaluation of LaboratoryDrying 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 Perform
37、ance Concrete Covercrete Quality,” Can J Civil Eng, 25: (3), Jun1998, pp. 551-556.C1585 1129.2 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 su
38、rface of each specimen with a suitablesealing material. Seal the end 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 determin
39、e water absorptionas a function of time. Conduct the absorption procedure 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
40、Place the support device at the bottom of the pan andfill the pan with 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 co
41、nstant is to installa water-filled bottle upside down such that the 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
42、water.9.5.4 Record the mass at the intervals shown in Table 1 afterfirst 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 sh
43、all berecorded to within 6 10 s. Continue the measurements everyhour, 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 t
44、o 7; take afinal measurement that is at least 24 h after the measurement 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
45、times.9.5.5 For each mass determination, remove the test speci-men 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 no
46、tcome in contact with the balance pan (to avoid having to drythe 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
47、 divided by theproduct of the cross-sectional area of the test specimen 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 i
48、n specimen mass in grams, at the time t,a = the exposed area of the 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 s
49、lope by using least-squares, linear regression analysis of the plot 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 ProcedureC1585 113than 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 secondar
