AASHTO PP 58-2012 Standard Practice for Static Segregation of Hardened Self-Consolidating Concrete (SCC) Cylinders.pdf

1、TS-3c PP 58-1 AASHTO Standard Practice for Static Segregation of Hardened Self-Consolidating Concrete (SCC) Cylinders AASHTO Designation: PP 58-12 1. SCOPE 1.1. This method covers procedures for determining the static segregation resistance (stability) of self-consolidating concrete (SCC) using hard

2、ened test specimens. 1.2. The concrete used to make the molded specimens shall be sampled after all on-site adjustments have been made to the mixture proportions, including the addition of mix water and admixtures. 1.3. The text of this standard references notes and footnotes that provide explanator

3、y information. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements for this standard. 1.4. The values stated in SI units are to be regarded as the standard. 1.5. This standard does not purport to address all of the safety concerns, if any, associ

4、ated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 205M/M 205, Molds for Forming Concrete Test Cylinders

5、 Vertically R 60, Sampling Freshly Mixed Concrete T 22, Compressive Strength of Cylindrical Concrete Specimens T 24M/T 24, Obtaining and Testing Drilled Cores and Sawed Beams of Concrete 3. SIGNIFICANCE AND USE 3.1. This method provides a visual assessment of static segregation resistance of SCC usi

6、ng a Hardened Visual Stability Index (HVSI) to evaluate molded or cored hardened concrete cylinders cut lengthwise in two. 3.2. If the specimens are made and cured as specified herein, the resulting static segregation test data are able to be used for the following purposes: 3.2.1. Acceptance testin

7、g for specified static segregation limits; 3.2.2. Checking the adequacy of mixture proportions to resist static segregation; and 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c PP 58-2 AASHTO 3.2.3

8、. Quality control. 4. APPARATUS 4.1. Molds, Cylinder150- by 300-mm (6- by 12-in.) cylinder molds for casting concrete test specimens shall conform to the requirements of M 205M/M 205. 4.2. Small ToolsHandheld wood or metal float or trowel. 4.3. SawThe saw shall have a diamond or silicon-carbide cutt

9、ing edge and shall be capable of cutting specimens without excessive heating or shock. 4.4. Core DrillThe core drill shall conform to the requirements of T 24M/T 24. 4.5. A suitable container for filling specimen molds with SCC. Note 1Experience has shown pails and plastic cylinder molds to be suita

10、ble containers. 5. SAMPLING CONCRETE 5.1. Samples of freshly mixed SCC used to fabricate test specimens under this standard shall be obtained in accordance with R 60. 5.2. Cored test specimens taken from hardened self-consolidating concrete under this standard shall be obtained in accordance with T

11、24M/T 24, except for the following: 5.2.1. Cored test specimens may be taken so that the axis is perpendicular or parallel to the concrete as it was originally placed, and 5.2.2. Cored test specimens shall have a minimum diameter of 50 mm (2 in.) and sufficient length to assess extent of static segr

12、egation resistance. 5.3. Record the identification of the test specimens with respect to the location of the concrete represented and the time of casting. 6. MOLDING AND CURING SPECIMENS OF FRESHLY MIXED SCC 6.1. Making Specimens: 6.1.1. A minimum of two fresh test specimens shall be molded as near

13、as practicable to the place where they are to be stored. If it is not practicable to mold the specimens where they will be stored, move them to the place of storage immediately after strike off. Place molds on a rigid surface free from vibration and other disturbances. The supporting surface shall b

14、e level to within 20 mm/m (0.25 in./ft). 6.1.2. Specimen molds shall be filled in one lift, poured using a suitable container without vibration, rodding, or tapping. 6.1.3. Strike off the surface of the concrete level with the top of the mold using a float or trowel. 6.2. Curing: 2013 by the America

15、n Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c PP 58-3 AASHTO 6.2.1. Immediately after molding and finishing, the specimens shall be capped with a plastic cylinder lid and stored for a period up to 24 h at a minimum

16、 temperature of 16C (60F). 7. PROCEDURE 7.1. Before subjecting the specimens to sawing, they either shall have a minimum curing period of 24 h or shall attain a minimum compressive strength of 6200 kPa (900 psi) according to T 22. 7.2. Specimens shall be sawn lengthwise down the center. If a specime

17、n cannot be satisfactorily sawed smooth for lack of curing, then the remaining specimen(s) shall remain undisturbed for an additional minimum curing period of 24 h before being subjected to sawing. 7.3. Make a visual assessment of the cut planes of the hardened concrete cylinder or core using the cr

18、iteria in Table 1 and illustrated in Figures 1 through 8. The cut planes shall be wetted to facilitate visual inspection. For cores taken perpendicular to the concrete as it was originally placed, the “top” and “bottom” of the cut plane shall be oriented parallel to the direction of placement. Table

19、 1Hardened Visual Stability Index (HVSI) HVSI Criteria 0, stable No mortar layer at the top of the cut plane and no variance in size and percent area of coarse aggregate distribution from top to bottom. 1, stable Slight mortar layer, less than or equal to 6 mm ( in.) tall, at the top of the cut plan

20、e and slight variance in size and percent area of coarse aggregate distribution from top to bottom. 2, unstable Mortar layer, less than or equal to 25 mm (1 in.) tall, at the top of the cut plane and distinct variance in size and percent area of coarse aggregate distribution from top to bottom. 3, u

21、nstable Clearly segregated as evidenced by a mortar layer greater than 25 mm (1 in.) tall and considerable variance in size and percent area of coarse aggregate distribution from top to bottom. 8. REPORT 8.1. Report the following information: 8.1.1. Identification number; 8.1.2. Location of concrete

22、 represented; 8.1.3. Date and time of molding; 8.1.4. HVSI for each hardened specimen; and 8.1.5. Results of any other tests on the fresh concrete and any deviations from the standard test methods. 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Du

23、plication is a violation of applicable law.TS-3c PP 58-4 AASHTO Single Coarse Aggregate Mixture Uniformly Graded Coarse Aggregate Mixture Figure 1HVSI = 0, Stable Figure 2HVSI = 0, Stable 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication

24、is a violation of applicable law.TS-3c PP 58-5 AASHTO Single Coarse Aggregate Mixture Uniformly Graded Coarse Aggregate Mixture Figure 3HVSI = 1, Stable Figure 4HVSI = 1, Stable 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a viola

25、tion of applicable law.TS-3c PP 58-6 AASHTO Single Coarse Aggregate Mixture Uniformly Graded Coarse Aggregate Mixture Figure 5HVSI = 2, Unstable Figure 6HVSI = 2, Unstable 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation o

26、f applicable law.TS-3c PP 58-7 AASHTO Single Coarse Aggregate Mixture Uniformly Graded Coarse Aggregate Mixture Figure 7HVSI = 3, Unstable Figure 8HVSI = 3, Unstable 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.