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Publication Number: FHWA-RD-07-052
Date: September 2007

Long Term Pavement Performance Project Laboratory Materials Testing and Handling Guide

Protocol P70
Test Method for Petrographic Examinationof Hardened Concrete (Pc10)

This LTPP Protocol covers the procedures for the petrographic examination of samples of hardened concrete. The test shall be carried out in accordance with ASTM C856-04 as described by the following.

1. SCOPE

1.1 Samples examined as part of this procedure will be concrete cores obtained from in-service pavement sections. Reference in the protocol to "concrete constructions" refers only to these samples for the purposes of LTPP testing.

1.3 Annex A1 for identifying locations where alkali-silica gel may be present will not be performed as part of this test procedure.

3. QUALIFICATONS OF PETROGRAPHERS AND USE OF TECHNICIANS

3.1 The qualifications outlined in the standard are not part of this test method per se. However, these qualifications may be used in the selection of a laboratory to perform the testing.

4. PURPOSES OF EXAMINATION

4.2.8 Delete

4.2.9 Delete

4.2.12 Delete

4.4 Delete

4.5 Delete

5. APPARATUS

5.2 For Specimen Preparation:

5.2.1 Diamond Saw - Slabbing saw with an automatic feed and blade large enough to make at least a 175-mm (6.9-inch) cut in one pass.

5.2.3 Horizontal Lap Wheel or Wheels, steel, cast iron, or other metal lap, at least 400 mm (15.7 inches) in diameter and large enough to grain a 100 by 150-mm (4 by 6-inch) area.

5.2.5 Polishing Wheel, at least 200 mm (7.9 inches) in diameter and two-speed

5.2.8 Abrasives - Silicon carbide grits, 150-µm (5.9 mils), 63-µm (2.5 mils), 31-µm (1.2 mils), 16-µm (0.6 mils), and 12-µm (0.5 mils); optical finishing powders such as M-303, M-204, M-309; polishing powders as needed.

5.2.10 Canada balsam or Lakeside 70 cement for impregnating concrete and mounting thin sections plus appropriate solvent.

7. SAMPLES

7.1 The minimum sample size will be a 150-mm (6-inch) diameter core and the full depth of the pavement.

7.2 Samples from Constructions

7.2.3 The information provided with the samples should include:

7.2.3.1 The location and original orientation of each specimen

7.2.3.2 Delete

7.2.3.3 Delete

7.2.3.4 Delete

7.2.3.5 Age of the structure

7.2.3.6 Delete

7.2.3.7 Delete

7.2.3.8 Prevalent distresses on the pavement section

7.2.3.9 Delete

7.3 Delete

13. REPORT

13.1 Following information shall be recorded for each test:

13.1.1 Sample Identification shall include: Laboratory Identification Code, LTPP Region, State, State Code, SHRP ID, Layer Number, Field Set Number, Sample Area Number, Sample Location Number, and LTPP Sample Number.

13.1.2 Test Identification shall include: LTPP Test Designation, LTPP Protocol Number, Laboratory Test Number, and Test Date.

13.2 All photographs will be taken with a digital camera with a minimum level of resolution of 1280 x 960 pixels.

13.3 Each picture will be stored in an electronic file using the following naming convention:

SSSHRPFSLLOC_NN.jpg

Where: SS = State code

SHRP = SHRP ID for site

FS = field set

L = layer number

LOC = location number

NN = image number

13.4 Comments shall include LTPP standard comment code (s) as shown in Section 4.3 of this Guide, and any other note as needed.

LTPP LABORATORY MATERIAL HANDLING AND TESTING
LABORATORY MATERIAL TEST DATA
PETROGRAPHIC EXAMINATION OF HARDENED CONCRETE
TEST DATA SHEET T70

PORTLAND CEMENT CONCRETE LAYER
LTPP TEST DESIGNATION PC10/LTPP PROTOCOL P70

LABORATORY PERFORMING TEST:______________________________________________________________

LABORATORY IDENTIFICATION CODE: __ __ __ __

REGION _________________ STATE ___________________ STATE CODE __ __

EXPERIMENT NO _____ SHRP ID __ __ __ __

SAMPLED BY: ______________________________________________ FIELD SET NO. __

DATE SAMPLED: __ __-__ __-__ __ __ __ SAMPLING AREA No: SA- _____

TEST DATE: __ __-__ __-__ __ __ __

1. LAYER NUMBER (FROM LAB SHEET L04 AND FORM T01B) __

2. LOCATION NUMBER __ __ __

3. LABORATORY TEST NUMBER __

4. LTPP SAMPLE NUMBER __ __ __ __

COARSE AGGREGATE INFORMATION

5. MINERALOGY, AS PERCEPTIBLE ______________________________________

6. MAXIMUM grain size DIMENSION, mm __ __ __

7. Minimum grain size dimension, mm __ __

4. TYPE (1 = gravel, 2 = crushed stone, 3 = mixed (1 and 2), 4 = Other) __

If type = other: ______________________________________

5. Percentage of coarse aggregate, % __ __

6. SHAPE ______________________________________

7. PACKING ______________________________________

8. Grading (1 = even, 2 = uneven, 3 = excess, 4 = deficiency of size(s)) __

9. Parallelism of long axes of exposed sections

(1 = normal to direction or placement, 2 = parallel to finished surface) __

10. Surface texture _____________________________________

11. Interangular bond _____________________________________

12. Percentage of concrete breaking through aggregate, % __ __ __

13. Is breaking occuring through one predominant type of aggregate (y/n) __

if y, what kind? _____________________________________

14. Percentage of aggregate with boundary voids __ __ __

15. is breaking occuring through one predominant type of aggregate (y/N) __

If y, what kind? _____________________________________

16. additional information:______________________________________________________________

____________________________________________________________________________________________

FINE AGGREGATE INFORMATION

17. MINERALOGY, AS PERCEPTIBLE ______________________________________

18. TYPE (1 = NATURAL SAND, 2 = MANUFACTURED SAND, 3 = MIXED, 4 = OTHER) __

IF TYPE = OTHER : ______________________________________

19. DISTRIBUTION ______________________________________

20. PARTICLE SHAPE ______________________________________

21. GRADING ______________________________________

22. PERFERRED ORIENTATION ______________________________________

23. SURFACE TEXTURE ______________________________________

24. ADDITIONAL INFORMATION:______________________________________________________________

__________________________________________________________________________________________

MATRIX

25. COLOR __________________________________

26. color distribution (1 = mottled, 2 = even, 3 = gradational changes) __

27. fractures present:

(1 = through aggregate, 2 = around aggregate, 3 = no fracturing observed) __

28. contact of matrix with aggregate: (1 = close, 3 = aggregate not dislodged with fingers or probe, 4 = boundary openings frequent, 5 = broundary openings rare) __

if boundary openings present: Width __ __ mm, EMPTY (Y/N) __

29. CRACKS PRESENT BEFORE SPECIMEN PREPARATION (Y/N) __

30. CRACKS PRESENT AFTER SPECIMEN PREPARATION (Y/N) __

31. MINERAL ADMIXTURES (Y/N) __

IF YES, THEN TYPE: __________________________________

32. CONTAMINATION: _________________________________

33. BLEEDING: ______________________________________

34. ADDITIONAL INFORMATION:______________________________________________________________

__________________________________________________________________________________________

VOIDS

35. PERCENTAGE OF VOIDS, % __

36. PREDOMINANT VOID SHAPE (1 = SPHERICAL, 2 = ELLIPSOIDAL, 3 = IRREGULAR, 4 = DISK-SHAPED, 5 = OTHER) __

IF OTHER, DESCRIPTION : _________________________________

37. PROPOROTION OF SPHERICAL TO NONSPHERICAL VOIDS, % __ __ __

38. DISTRIBUTION _________________________________

39. GRADING _________________________________

40. PARALLELISM OF LONG AXES OF IRREGULAR VOIDS

VOIDS PARALLEL TO EACH OTHER (Y/N) __

VOIDS PARALLEL TO LONG AXES OF COARSE AGGREGATE (Y/N) __

41. COLOR CHANGE BETWEEN VOIDS AND MATRIX (Y/N) __

42. VOID CONDITION (1 = EMPTY, 2 = FILLED, 3 = LINED, 4 = PARTLY LINED) __

(1 = through aggregate, 2 = around aggregate, 3 = no fracturing observed) __

43. INTERIOR SURFACE OF VOIDS (1 = LIKE REST OF MATRIX, 2 = DULL, 3 = SHINING) __

44. LININGS IN VOIDS (1 = ABSENT, 2 = RARE, 3 = COMMON IN MOST) __

45. CONDITION OF LININGS (1 = ABSENT, 2 = COMPLETE, 3 = PARTIAL) __

46. LINING COLOR (1 = NO LININGS, 2 = COLORLESS, 3 = COLORED) __

47. LINING SHAPES (1 = NO LININGS, 2 = SILKY TUFTS, 3 = HEXAGONAL TABLETS, 4 = GEL) __

48. ADDITIONAL INFORMATION ON LININGS:__________________________________________________

________________________________________________________________________________________

49. UNDERSIDE VOIDES OR SHEETS OF VOIDS ARE: 1= UNCOMMON, 2 = SMALL, 3 = COMMON,

4 = ABUNDANT __

50. ADDITIONAL INFORMATION ON VOIDS:____________________________________________________

_________________________________________________________________________________________

GENERAL INFORMATION AND COMMENTS

51. PHOTOGRAPHS TAKEN (Y/N) __

52. NUMBER OF PHOTOGRAPHS __

53. COMMENT CODES __ __ __ __ __ __ __ __ __ __ __ __

54. ADDITIONAL COMMENT:___________________________________________________________________

____________________________________________________________________________________________

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SUBMITTED BY, DATECHECKED AND APPROVED, DATE
____________________________________________________________
LABORATORY CHIEF
Affiliation______________________
Affiliation______________________

 

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The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
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