ASTM C1741-2012 Standard Test Method for Bleed Stability of Cementitious Post-Tensioning Tendon Grout《胶接后拉钢筋束水泥浆的漏铸稳定性的标准试验方法》.pdf

1、Designation: C1741 12Standard Test Method forBleed Stability of Cementitious Post-Tensioning TendonGrout1This standard is issued under the fixed designation C1741; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re

2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is designed to determine the bleedstability of freshly-mixed cementitious grout under staticpressure.1.2 Uni

3、tsThe values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard.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-

4、priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. (WarningFreshhydraulic cementitious mixtures are caustic and may causechemical burns to skin and tissue upon prolonged exposure.)22. Referenced Documents2.1 ASTM Standards:3C125 Terminology Re

5、lating to Concrete and Concrete Ag-gregatesC938 Practice for Proportioning Grout Mixtures forPreplaced-Aggregate Concrete3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology C125.3.2 Definitions of Terms Specific to This Standard:3.2.1 bleed stability,

6、nof cementitious grout, resistance tobleeding.3.2.2 bleeding, nof cementitious post-tensioning tendongrout, autogenous flow of mixing water within, or its emer-gence from, newly placed grout; caused by the settlement ofthe solid materials within the grout and the filtering action ofstrands and wires

7、 when subjected to static pressure andcapillary action.3.2.3 grout, nmixture of cementitious material and water,with or without aggregate and admixtures, proportioned toproduce a pourable consistency without segregation of theconstituents.3.2.4 post-tensioning, adjreferring to a method of pre-stress

8、ing in which prestressing steel is tensioned after theconcrete has gained sufficient strength.4. Significance and Use4.1 This test method is designed to evaluate the bleedstability of a freshly-mixed grout under static pressure. It canbe used in both the laboratory to qualify grout materials and int

9、he field as a quality control test. When used to qualify groutmaterials, replicate tests may be specified. It is intended thatthe test pressure, acceptance criteria, and number of replicatetests be set forth in the contract documents if this test methodis referenced. These values will normally vary

10、depending onthe vertical rise of the post-tensioning tendon.NOTE 1Appendix X1 includes a reference for an example of testpressures and bleeding limits.4.2 The procedure for this test was developed by Schokkeret al.4based on previous work by Schupack.55. Apparatus5.1 The apparatus consists of a comme

11、rcially availablepressure filtration funnel, stand, pressure supply with gauge,pressure regulator, valve, drip wick, and bleed water collectioncontainer as shown in Fig. 1 and Fig. 2.5.1.1 Filtration FunnelA 47-mm diameter stainless steelpressure filtration funnel with a nominal capacity of 200 mL a

12、sshown in Fig. 2. The filtration funnel shall have removablethreaded caps at both ends with a stem for connection of the1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.41 on Hydraulic Cement Grou

13、ts.Current edition approved June 1, 2012. Published July 2012. Last previousedition approved in 2011 as C174111a. DOI: 10.1520/C1741-12.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol. 04.02.3For referenced ASTM standards, visit the ASTM we

14、bsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Schokker, A. J., B.D. Koester, J.E. Breen, and M. E. Kreger, “Development ofHigh Performance Grouts for Bonde

15、d Post- Tensioned Structures,” Research Report1405-2, Center for Transportation Research, October 1999.5Schupack, M. “Admixture for Controlling Bleed in Cement Grout Used inPost-Tensioning,” Precast/Prestressed Concrete Institute Journal, Nov.-Dec. 1974, pp. 1-10.1Copyright ASTM International, 100 B

16、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.gas supply and a 7.0 6 0.5 mm inside diameter stem 90 6 1mm long for escape of water. The base of the vessel shallcontain a 35 6 1 mm diameter stainless steel 45 m (No. 325)screen that supports a 47 mm diameter Type A/E b

17、orosilicateglass filter (1-m pore size) as shown in Fig. 2. The screen shallbe inserted with the woven side against the glass filter, and thefunnel gasket shall be placed above the glass filter as shown inFig. 2. The glass filter shall cover the screen across the insideFIG. 1 Test ApparatusFIG. 2 47

18、-mm Filtration Funnel with 200 mL Nominal CapacityC1741 122diameter of the bottom cap and be located under the gasketwhen under pressure. Secure the bottom cap before filling thefiltration funnel with grout. The funnel is placed in the standafter it is filled.5.1.2 StandThe filtration funnel shall b

19、e attached to astand capable of holding the funnel in the vertical position withadequate space for the bleed water collection container. Thebottom stem of the filtration funnel shall be inserted into thebleed water collection container.5.1.3 Gas SupplyAn air or other inert gas pressure supplywith a

20、pressure regulator, an in-line shutoff valve, and pressuregauge shall be firmly attached to the top stem of the filtrationfunnel. The pressure gauge shall be capable of reading pres-sures up to 700 kPa with 20 kPa graduation marks.5.1.4 Metal Drip WickA metal paper clip or suitable thinmetal wire or

21、 rod shall be bent to direct the water squeezed outof the filtration funnel into the collection vessel.NOTE 2A wire of approximately 1 mm diameter has been foundsatisfactory for the drip wick.5.1.5 Bleed Water Collection ContainerThe bleed watercollection container shall consist of a 10-mL transpare

22、ntgraduated cylinder with 0.2-mL graduation marks.6. Sample Preparation6.1 Grout shall be mixed in accordance with the manufac-turers instructions or in accordance with Practice C938 if noother instructions are provided. For field quality control testing,the grout shall be mixed using the same equip

23、ment andprocedure as used for the installation of the material.7. Procedure7.1 Fill the filtration funnel with freshly-mixed grout within5 min after completion of grout mixing.7.2 Screw the top stem cap on the funnel hand tight whilekeeping the funnel in an upright position.7.3 Place the funnel in t

24、he stand.7.4 Connect the gas supply (gas pressure at 0 kPa).7.5 Allow grout to rest in the funnel for 10 min (630 s) aftergrout placement.7.6 Increase pressure to the specified pressure level (620kPa) within 30 s.7.7 Hold at the specified pressure for 5 min (65 s) unless alonger time is specified.NO

25、TE 3This test can be kept at the designated pressure beyond 5 minto confirm the long term bleed stability of the grout and this deviationshould be noted in the report.7.8 Release the pressure and tip the filtration funnel slightlyto break the surface tension and allow the bleed waterremaining in the

26、 exit stem to be collected as part of the bleedvolume to be measured.7.9 Measure the volume of the collected bleed water to thenearest 0.2 mL at the end of the hold time.7.10 If a complete loss of pressure occurs before completionof the 5-min hold period, the test is considered invalid for thespecif

27、ied pressure level.NOTE 4Loss of pressure in this test generally occurs as a “blowout”or complete loss of pressure with gas blowing out of the stem.8. Report8.1 Report the bleed volume as a percentage of the nominalsample volume as follows:% Bleeding 5bleed mL!200 mL3 100 (1)8.2 Report the pressure

28、used for the test and the duration forwhich the pressure was applied.8.3 If replicate tests are specified, report each test resultindividually.9. Precision and Bias9.1 PrecisionThe standard deviation obtained by oneoperator has been determined to be 0.03 % bleeding by volumebased on three replicate

29、tests at 140 kPa for a grout with anaverage bleeding of 1.6 % by volume. For a grout tested at 220kPa with an average bleeding of 0.6 % by volume, the standarddeviation obtained by one operator has been determined to be0.17 % based on three replicate tests.NOTE 5An interlaboratory study will be cond

30、ucted and a completeprecision statement will be available by 2015.9.2 BiasNo statement on bias is being made because thereis no accepted reference material suitable for determining thebias in this test method.10. Keywords10.1 bleed stability; bleed water; bleeding; grout; post-tensioning; pressureC1

31、741 123APPENDIX(Nonmandatory Information)X1. REFERENCE FOR SPECIFICATION LIMITS FOR PRESSURIZED BLEED TESTX1.1 When tested using the pressurized bleed test, themaximum percentage of permitted bleeding in grout should bespecified in contract documents. Normally, the specificationrequirements for test

32、 pressure and maximum percentage bleed-ing will differ depending on the vertical rise of the post-tensioning tendons being used.X1.2 The bleed limits for the test pressures based on workby Hamilton, Schokker, and Schupack6should result in groutwith little or no bleeding for the given vertical rise.

33、These bleedlimits apply to the grout sample tested in accordance with thistest method for a duration of 5 min of applied pressure and donot represent the permitted amount of bleeding when the groutmixture is used in the actual structure.ASTM International takes no position respecting the validity of

34、 any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to

35、revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Y

36、our comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is co

37、pyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.

38、org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).6Hamilton, H. R., A. J. Schokker, and M. Schupack, “Estimating Post-Tensioning Grout Bleed Resistance Using a Pressure- Filter Test,” Precast/Prestressed Concrete Institute Journal, March-April 2002, pp. 32-39.C1741 124