A354 BD Rod Testing Program. Bahjat Dagher, PE Material Engineering & Testing Services

Transcription

1 QC/QA Process & A354 BD Rod Testing Program Bahjat Dagher, PE Material Engineering & Testing Services

2 Outline Section I: Introduction Section II: Fabrication Process Section III: Quality Assurance Section IV: Testing Program for SAS Rods 2

3 Section I: Introduction ti 2,306 anchor rods 17 groups of rods Top of Tower Top of W2 East Cable Band East Saddle Anchorage Top of E2 Bottom of Tower 3

4 A354 Gr BD Anchor Rods SAS 4

5 A354 Gr BD Anchor Rods SAS 320 Rods 96 Rods 224 Rods 192 Rods 96 Rods 336 Rods 274 Rods 25 Rods 108 Rods 4 Rods 90 Rods 388 Rods 36 Rods 32 Rods 18 Rods 24 Rods 43 Rods 5

6 A354 Gr BD Anchor Rods SAS 0.7 Fu 0.7 Fu 0.7 Fu 0.7 Fu 0.6 Fu 04Fu Fu Fu Fu Fu 0.1 Fu 0.48 Fu 0.37 Fu 0.1 Fu 0.2 Fu 0.16 Fu 0.1 Fu 6

7 Section II Fabrication bi Process 7

8 Fabrication Process Steel Mill Shipment of material from the mill to the fabricator 8

9 Fabrication Process Heat Steel Mill Treatment t Quenched & tempered Oven heated Induction coil Hardness, strength, grain size, other properties 9

10 Fabrication Process Steel Mill Heat Treatment t Threading All rod threads were cut with the exception of: E2 Bearing Top Rods (B1, B2, B3, B4) Rolled PWS Anchor Rods (80%) Rolled Tower Saddle Tie Rods Rolled B14 Cable Band Anchor Rods Rolled 10

11 Fabrication Process Heat QC Steel Mill Threading Treatment t Testing Mechanical Properties per ASTM A354 MT performed on rods specified by CCO 91 11

12 Fabrication Process Steel Mill Heat Treatment t Threading QC Testing Galvanizing Dry blast cleaned to a near white finish (SP-10) prior to galvanizing per ASTM A123 12

13 Section III Quality Assurance 13

14 Quality Assurance Audit Facility audits in 2007 and 2008 Audit performed by Caltrans Final results of audits: Pass 14

15 Quality Assurance Audit Source Inspection In-process inspection Thread dimensional verification Magnetic Particle Testing 15

16 Quality Assurance Audit Source Inspection Document Verification Document verification Certificate of Compliances Mill Test Reports QC test results 16

17 Quality Assurance Audit Source Inspection Document Verification QA Sampling Defined in state letter dated July 14, 2008 One full size sample per heat Two reduced size samples per heat 17

18 Quality Assurance Audit Source Inspection Document Verification QA Sampling QA Testing Tests performed: Full size tension Reduced section tension Hardness Coating thickness 18

19 Quality Assurance Audit Source Inspection Document Verification QA QA METS Sampling Testing Release Orange Tag Material conforms to contract requirements Blue Tag Material does not conform to contract requirements but accepted as fit for purpose 19

20 QC/QA Documentation 20

21 Section IV Testing Program for SAS Rods 21

22 Testing Program Contract Specified QC/QA Tensioning & Monitoring of Remaining Rods Test I Field Hardness Test (in-situ) it Test II Laboratory Test Test III Full Size Test Test IV Stress Corrosion Test (Dr. Townsend) Test V Incremental Step Loading Test (Dr. Raymond) Test VI Slow Rate & Sustained Loading Test (Dr. Gorman) 22

23 Tensioning & Monitoring of Remaining i Rods 2010 anchor rods tensioned in April Rods were monitored using Acoustic Emissions No cracks were detected t d 23

24 Test I: Field Hardness Test (in-situ) it UCI Test Method 1,361 Rods tested on bridge 24

25 287 Rods 224 Rods Test I: Field Hardness 96 Rods 138 Rods 270 Rods 20 Rods 20 Rods 226 Rods 36 Rods 16 Rods 8 Rods 12 Rods 25

26 Test I: Field Hardness Test (in-situ) it Performed in-situ Cleaned from oil, grease, and rust Top surface galvanizing i removed by grinding 26

27 Test I: Field Hardness Test (in-situ) it Top surface sanded to achieve profile 15 µm or less Roughness verified with a profile meter 27

28 Test I: Field Hardness Test (in-situ) it Multiple points on each rod Multiple readings at each point Verified against a calibrated block 28

29 Test I: Field Hardness Test (in-situ) it Rod 29

30 Test II: Laboratory Testing Hardness Test Spectrochemical Analysis Charpy Impact Test (if available) 30

31 Test II: Laboratory Testing 12 Rods 7 Rods 43 Rods 2 Rods 2 Rods 6 Rods 3 Rods 2 Rods 1 Rod 31

32 Test II: Laboratory Testing - Samples Sample Sample 76 mm Sample 19 mm 185 mm 32

33 Test II Rockwell C Hardness 12.5 mm thick sample Test at 3 mm increments and one location at R/2 in each quadrant Hardness tests at 3mm increments and one in each quadrant, Typ 33

34 Test II Rockwell C Hardness Average hardness values for PWS Anchor Rods and Tower Saddle Tie Rods Rockwell C Hard ness Average (Item 7) Average (Item 8) Field 28.0 Field 26.0 Laboratory 26.0 Laboratory 24.0 ASTM Req ASTM Req Location (in.) Location (in.) ness Rockwell C Hard 34

35 M Shape Curve Investigation Tilting of sample during testing of the edges Testing of longitudinal samples Similar il results observed 35

36 M Shape Curve Investigation Decarburization ASTM F2328 tests performed No evidence of decarburization Microstructural Examination At the HRC indentations In progress 36

37 Test II Chemical Analysis Spectrochemical analysis Min. 3 samples per rod: Center, perimeter, R/2 All tested rods met A354 BD chemical requirements 37

38 Test II Charpy Impact Test 10 x 10 specimens 3 to 4 Rods 6 specimens along circumference 2 Rods 3 specimens along circumference 6 specimens total 38

39 Test II Charpy Impact Test 60 Data points are averages of several tests from multiple samples 40F 70F ft t-lbs Item #3 Item #4 Item #7 Item #8 Item #9 Heat 1 Item #9 heat 2 Item #12 Item #13 Item #15 40F F

40 Test III: Full-Size Tension Testing Full-Size Tension Test Reduced-Size Tension Test Rockwell C Hardness Knoop Micro-Hardness Charpy Impact Test Metallurgical Analysis Microstructural Analysis Galvanization Chemistry 40

41 4 Rods 2 Rods Test III: Full Size Testing 4 Rods 1Rod 1Rod 1 Rod 1 Rod 1 Rod 41

42 Test III Full Size Tension Test Loaded to failure at a constant rate. 42

43 Test III Full Size Tension Test Full size samples selected from 8 groups for tension Tens sile Stress s ksi GROUP 2 GROUP 3 GROUP 4 GROUP 7 GROUP 8 GROUP 11 GROUP 12 GROUP

44 Test III: Full-Size Testing Specimens are extracted from a full size rod. Tensiles Charpies Knoo p HRC Chem 44

45 Test III Reduced d Size Tension Test Reduced size tension tests /

46 Test III Reduced d Size Tension Test 170 Tensile Stress ksi Group 2 Group 3 Group 4 Group 7 Group 8 Group

47 Test III Metallurgical l Analysis Metallurgical and Fracture Analysis Scanning electron microscope (SEM) 47

48 Test III Metallurgical Analysis Region 1 Fracture Initiation areas indicate ductile tearing as a result of tensile overload. 48

49 Test III Metallurgical Analysis Region 2 Propagation area shows fracture features of both cleavage & ductility. 49

50 Test III Metallurgical Analysis Region 3 Final Fracture areas show dimpled ductile features. 50

51 Test III Microstructural t Analysis Inclusions and banding in steel 51

52 QUESTIONS 52