Section 13 Bolting 13.1 High Strength Structural Bolting 1 Field Tests 6 Rotational Capacity Test for Long Bolts 7 Rotational Capacity Test for Short Bolts 23 Verification Tests 30 Job Inspection Torque 34 Field Inspection 36 Other Types of Bolt Situations 39
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Section 13
Bolting 13.1 High Strength Structural Bolting 1
Field Tests 6
Rotational Capacity Test for Long Bolts 7 Rotational Capacity Test for Short Bolts 23 Verification Tests 30 Job Inspection Torque 34 Field Inspection 36 Other Types of Bolt Situations 39
High Strength Structural Bolts 13.1
January, 2011 1
High Strength Structural Bolting
Steel Girder Construction
• High strength structural bolts are installed using the Turn-of-Nut Method.
• DTI’s are not used.
High Strength Structural Bolts 13.1
January, 2011 2
What Is High Strength Bolting & Why Is It Important?
• A325 or A490 Bolts are tightened to a prescribed tension to produce enough Friction force in a connection to resist imposed loads.
• High Strength Connections (slip critical connections) do not rely on bearing between the bolt and plate material to transfer loads. They rely on Friction.
High Strength Field BoltingTheory & Behavior
010203040506070
00.0
5 0.10.1
5 0.2 0.3
Elongation (in.)
Tens
ion
(kip
s) Direct TensionLubricatedAs ReceivedWeatheredCleaned
A325 Load/Elongation Curve
High Strength Structural Bolts 13.1
January, 2011 3
High Strength Field Bolting
Bolt Types:
A325 – High Strength Bolts for Structural Steel Joints (Most common bolt type)
A307 – Carbon Steel Bolts (NOT USED IN HIGH STRENGTH BOLTING APPLICATIONS)
High Strength Field Bolting
A325 Bolt Types:
Type 1 (Medium Carbon) 1/2” to 1 1/2”
Type 3 (Weathering) 1/2” to 1 1/2”
A325 Strength Requirements:
Diameter (in.) Yield (ksi) Tensile (ksi)
1/2” - 1” 92 120
1 1/8” - 1 1/2” 81 105
High Strength Structural Bolts 13.1
January, 2011 4
High Strength Field BoltingBolt Type Matching Nut
A325 A563 A194
Type 1 (Plain) C, D, DH 2, 2H
Type 1 (Galvanized) DH 2H
Type 3 (Weathering) C3, DH3
Note: All Nuts For High Strength Fasteners are Heavy Hex.
Non Heat Treated Nuts: Proof Load Stress = 150 ksi
Heat Treated Nuts: Proof Load Stress = 175 ksi
High Strength Field Bolting
Rockwell Nut Hardness Requirements:
Grade Min. Max.
C, C3 B78 (70 ksi) C38 (170 ksi)
D B84 (80 ksi) C38 (170 ksi)
2 B84 (80 ksi) n/a
2H, DH, DH3 C24 (120 ksi) C38 (170 ksi)
High Strength Structural Bolts 13.1
January, 2011 5
High Strength Field Bolting
Hardened Steel Washers:
• ASTM F436
• Type 1 – Carbon Steel (Plain or Galvanized)
• Type 3 – Weathering Steel
• Rockwell Hard. Values: 38 to 45 (Plain) - 170 ksi26 to 45 (Galvanized) - 125 ksi
High Strength Field BoltingField Inspection, Storage, Product Testing
Field Inspection - No ODOT Lab Report
2 Samples each, Size, Length Grade, and Lot for…
• MTR Review
• Tensile & Hardness Tests
• Geometry & Product Markings
• Coating Thickness
• Manufacturer Rotational Capacity Test
• Lubrication (Black – Oily to the touch)(Galv. – Dry Visible Dye)
High Strength Structural Bolts 13.1
January, 2011 6
Field Tests
Field Tests At The Project Site
• Rotational Capacity Tests For Long Bolts
• Rotational Capacity Tests For Short Bolts
• Verification Testing
• Job Inspection Torque (Turn-of-Nut Method)
TURN-OF-NUT METHOD (LONG BOLTS)
PROCESSES PURPOSE
1. Rotational Capacity Test Checks bolts for proper lubrication & for damage during storage or transit 2. Contractor Personnel Verification Test Demonstrates that Contractor's equipment & procedure will tighten bolts to proper tension 3. Determine Job Inspection Torque Determines torque value to be used in the random field inspection 4. Random Field Inspection Checks bolt installation on structure using the Job Inspection Torque
(02560.60 (a)) 2. Assemble fastener with 3-5 threads within the grip3. Snug tight (10% of Required Fastener Tension in Table 560-1); Tolerance= -0 kips, +2 kips4. Mark the bolt, nut & plate5. Tighten to Required Fastener Tension & record torque (torque must not exceed T=0.25PD) (P in lbs, D in ft)6. Turn nut to twice the rotation in Table 560-3 (tension must exceed 115% of Required Fastener Tension)7. Remove nut and check threads
(00560.29 (c)(1 & 5)) 2. Snug tight (Plies of joint in firm contact, full effort on 12" spud wrench; 10% of RFT< Tension < 50% of RFT)3. Mark the bolt, nut & plate4. Tighten nut to the rotation in Table 560-3 (max. of 10 seconds with impact wrench)5. Verify tension is 5% greater than Required Fastener Tension
(00560.29 (d)) 2. Place in Skidmore & tighten to Required Fastener Tension in Table 560-13. Measure torque required to turn the nut 5 degrees (1" @ 12" radius)4. Average the 3 tests to determine the Job Inspection Torque
4. Random Field Inspection 1. Select at random 10% of the tensioned bolts in each connection (2 minimum)
(00560.29 (d)) 2. Apply Job Inspection Torque. If none turn, the connection passes.3. If one or more fasteners turn, job inspection torque all fasteners in the connection.4. Re-tension & inspect all fasteners that turned when applying the Job Inspection Torque.
734-2629 Summary (11-2010) Construction Forms Website: http://www.oregon.gov/ODOT/Hwy/Construction/ConstForms1.shtml
HIGH STRENGTH BOLTING SUMMARY
TURN-OF-NUT METHOD (SHORT BOLTS)
PROCESSES PURPOSE
1. Rotational Capacity Test Checks bolts for proper lubrication & for damage during storage or transit 2. Contractor Personnel Verification Test Demonstrates that Contractor's equipment & procedure will tighten bolts to proper tension3. Determine Job Inspection Torque Determines torque value to be used in the random field inspection4. Random Field Inspection Checks bolt installation on structure using the Job Inspection Torque
(02560.60 (a)) 2. Assemble fastener with 3-5 threads within the grip3. Snug tight (10% of max allowable torque < Torque < 20% of MAT, MAT=1.15(0.25PD)) (P in lbs, D in ft)4. Mark socket5. Tighten nut to rotation in Table560-3 & record torque (torque must not exceed T=1.15(0.25PD)6. Turn nut to twice the rotation in Table 560-37. Remove nut and check threads
(00560.29 (c)(1 & 5)) 2. Snug tight (Joint plies in firm contact, full effort on spud wrench; 10% of MAT< Torque < 50% of MAT3. Mark the bolt, nut & plate4. Tighten nut to the rotation in Table 560-35. Verify torque is 5% greater than recorded torque @ turn requirement
(00560.29 (d)) 2. Snug tight (10% of max allowable torque < Torque < 20% of MAT, MAT=1.15(0.25PD)) (P in lbs, D in ft)3. Mark the bolt, nut & plate4. Tighten nut to the rotation in Table 560-33. Measure torque required to turn the nut 5 degrees (1" @ 12" radius)4. Average the 3 tests to determine the Job Inspection Torque
4. Random Field Inspection 1. Select at random 10% of the tensioned bolts in each connection (2 minimum)
(00560.29 (d)) 2. Apply Job Inspection Torque. If none turn, the connection passes.3. If one or more fasteners turn, job inspection torque all fasteners in the connection.4. Re-tension & inspect all fasteners that turned when applying the Job Inspection Torque.
734-2630 Summary (11-2010) Construction Forms Website: http://www.oregon.gov/ODOT/Hwy/Construction/ConstForms1.shtml
HIGH STRENGTH BOLTING SUMMARY
High Strength Structural Bolts 13.1
January, 2011 7
Rotational Capacity Test for Long Bolts
View Rotational Capacity Test for Long Bolts
High Strength Structural Bolts 13.1
January, 2011 8
Rotational-Capacity Test Equipment
Skidmore-Wilhelm or Equivalent
• Calibrated Yearly
Standard Torque Wrench
• 1000 ft. lb. Capacity
• Calibrated Yearly
Rigid Steel Joint
• Short Bolt Fasteners
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Ro-Cap Sample 1: Required Fastener Tension = Lbs. (Table 00560-1)Snug Tight = Lbs. (0.10 x Req. Fastener Tension): Tol. = -0 kips + 2 kipsMeasured Torque = Ft.-Lbs. @ Required Fastener Tension (Go to Insp. Torque)Maximum Allowable Torque = Ft.-Lbs. (T < 0.25PD); (P in Lbs., D in Ft.)Measured Tension = Lbs. @ Turn (2x Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.15 X Required Fastener Tension)
Sample 1 Results:Ro-Cap Sample 2: Required Fastener Tension = Lbs. (Table 00560-1)Snug Tight = Lbs. (0.10 x Req. Fastener Tension): Tol. = -0 kips + 2 kipsMeasured Torque = Ft.-Lbs. @ Required Fastener Tension (Go to Insp. Torque)Maximum Allowable Torque = Ft.-Lbs. (T < 0.25PD); (P in Lbs., D in Ft.)Measured Tension = Lbs. @ Turn (2x Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.15 X Required Fastener Tension)
Single turn requirement from Table 560-3 = 1/2 turn
Twice rotation = 2 (1/2 turn) = 1 full turn
Rotation Exercise
What is the turn requirement in the rotational capacity test for a bolt with a diameter = 3/4” and a bolt length = 3”?
High Strength Structural Bolts 13.1
January, 2011 21
Tension Must Exceed 115% of Proof Load
Minimum Tension Example
What is the minimum tension required for a 3/4” bolt during the Rotational Capacity Test when the nut is turned to twice the turn shown in Table 560-3?
Min. Tension = 115% of Required Fastener Tension (Table 560-3)
Min. Tension = 1.15 (28,000 lbs.)
Min. Tension = 32,200 lbs.
High Strength Structural Bolts 13.1
January, 2011 22
Minimum Tension Exercise
What is the minimum tension required for a 7/8” bolt during the Rotational Capacity Test when the nut is turned to twice the turn shown in Table 560-3?
Examine Bolt and Nut
Reject assemblies showing thread stripping or torsional failure. Elongation of the threads in the grip is normal.
High Strength Structural Bolts 13.1
January, 2011 23
Rotational Capacity Test for Short Bolts
View Short Bolt Video
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Ro-Cap Sample 1: Snug Tight, Max. Torque = Ft.-Lbs. T = 0.20(1.15 x 0.25 PD); (P in Lbs., D in Ft.)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Maximum Allowable Torque = Ft.-Lbs. (T = 1.15(0.25PD)); (P in Lbs., D in Ft.)2 x Rotation = Turn (2x Rotation In Table 00560-3)
Sample 1 Results:Ro-Cap Sample 2: Snug Tight, Max. Torque = Ft.-Lbs. T = 0.20(1.15 x 0.25 PD); (P in Lbs., D in Ft.)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Maximum Allowable Torque = Ft.-Lbs. (T = 1.15(0.25PD)); (P in Lbs., D in Ft.)2 x Rotation = Turn (2x Rotation In Table 00560-3)
What is the maximum torque allowed for a 7/8” bolt at the specified turn in Table 560-3?
Turn Nut to Twice the Rotation in Table 560-3
High Strength Structural Bolts 13.1
January, 2011 30
Examine Bolt and Nut
Verification Testing
Turn-of-Nut Method
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Verification Sample 1: Sample 1 Results:Meas. Tension @ Snug Tight = Lbs.; (Plies Of Joint In Firm Contact);
= (Full Effort On Spud Wrench); (<50% Req'd Fastener Tension)50% Of Req'd Fast. Tension = Lbs. (0.5 x Value From Table 00560-1)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Tension = Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.05 x Required Fastener Tension From Table 00560-1)
Verification Sample 2: Sample 2 Results:Meas. Tension @ Snug Tight = Lbs.; (Plies Of Joint In Firm Contact);
(Full Effort On Spud Wrench); (<50% Req'd Fastener Tension)50% Of Req'd Fast. Tension = Lbs. (0.5 x Value From Table 00560-1)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Tension = Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.05 x Required Fastener Tension From Table 00560-1)
Verification Sample 3: Sample 3 Results:Meas. Tension @ Snug Tight = Lbs.; (Plies Of Joint In Firm Contact);
(Full Effort On Spud Wrench); (<50% Req'd Fastener Tension)50% Of Req'd Fast. Tension = Lbs. (0.5 x Value From Table 00560-1)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Tension = Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.05 x Required Fastener Tension From Table 00560-1)
Verification Results:
Comments:
Inspector Cert No. Title
Witness: Date
734-2749 (10-2009) Construction Forms Website: http://www.oregon.gov/ODOT/Hwy/Construction/ConstForms1.shtml
HIGH STRENGTH BOLTS VERIFICATION TEST
(TURN OF NUT METHOD FOR LONG BOLTS)
Pass Fail
Accept Reject
Pass Fail
Pass Fail
High Strength Structural Bolts 13.1
January, 2011 31
Verification Testing for Long Bolts Turn-of-Nut Method
1. Sample 3 Bolt/Washer/Nut Assembles
2. Snug the bolt using method to be used on the structure (plies of joint in firm contact; full effort on 12” spud wrench; < 50% req’d. fast. tension)
3. Mark the Bolt/Nut/Plate
4. Tighten nut to rotation in Table 560-3
5. Verify tension is 5% greater than proof load
Turn-of-Nut Verification TestingLong Bolt Example
Diameter = ¾”
Length = 3”
Required Rotation (Turns) = 1/3
Required Fastener Tension = 28,000 lbs
Req’d Verification Tension = (105%) Req’d Fast Tension
Verification Testing for Short Bolts Turn-of-Nut Method
1. Sample 3 Bolt/Washer/Nut Assembles
2. Snug the bolt using method to be used on the structure (plies of joint in firm contact; full effort on 12” spud wrench; < 50% max. allowable torque)
3. Mark the Bolt/Nut/Plate
4. Tighten nut to rotation in Table 560-3
5. Verify torque is 5% greater than recorded torque at turn requirement
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Verification Sample 1: Sample 1 Results:Measured Torque @ Snug Tight = Ft.-Lbs.; (Plies Of Joint In Firm Contact);
(Full Effort On Spud Wrench); (<50% Max. Allowable Torque)50% Of Max. Allowable Torque = Ft.-Lbs.; T=0.5(0.25 PD); (P in Lbs., D in Ft.)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Torque Required = Ft.-Lbs. (1.05 x Avg RoCap Torque @ Rotation In Table 00560-3)
Verification Sample 2: Sample 2 Results:Measured Torque @ Snug Tight = Ft.-Lbs.; (Plies Of Joint In Firm Contact);
(Full Effort On Spud Wrench); (<50% Max. Allowable Torque)50% Of Max. Allowable Torque = Ft.-Lbs.; T=0.5(0.25 PD); (P in Lbs., D in Ft.)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Torque Required = Ft.-Lbs. (1.05 x Avg RoCap Torque @ Rotation In Table 00560-3)
Verification Sample 3: Sample 3 Results:Measured Torque @ Snug Tight = Ft.-Lbs.; (Plies Of Joint In Firm Contact);
(Full Effort On Spud Wrench); (<50% Max. Allowable Torque)50% Of Max. Allowable Torque = Ft.-Lbs.; T=0.5(0.25 PD); (P in Lbs., D in Ft.)Measured Time = Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Maximum Allowable Time = 10 Seconds (From Snug Tight To Turn Rotation In Table 00560-3)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Minimum Torque Required = Ft.-Lbs. (1.05 x Avg RoCap Torque @ Rotation In Table 00560-3)
Verification Results:
Comments:
Inspector Cert No. Title
Witness: Date
734-2750 (10-2009) Construction Forms Website: http://www.oregon.gov/ODOT/Hwy/Construction/ConstForms1.shtml
HIGH STRENGTH BOLTS VERIFICATION TEST
(TURN OF NUT METHOD FOR SHORT BOLTS)
Pass Fail
Accept Reject
Pass Fail
Pass Fail
High Strength Structural Bolts 13.1
January, 2011 33
Marking method
Turn of the Nut Method
Chuck method
• Monitor turn of wrench chuck
• Requires two-person installation
Marked Bolt Connection
High Strength Structural Bolts 13.1
January, 2011 34
Nuts Turned ½ Turn
Job Inspection Torque
Turn-of-Nut Method
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Ro-Cap Sample 1: Required Fastener Tension = Lbs. (Table 00560-1)Snug Tight = Lbs. (0.10 x Req. Fastener Tension): Tol. = -0 kips + 2 kipsMeasured Torque = Ft.-Lbs. @ Required Fastener Tension (Go to Insp. Torque)Maximum Allowable Torque = Ft.-Lbs. (T < 0.25PD); (P in Lbs., D in Ft.)Measured Tension = Lbs. @ Turn (2x Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.15 X Required Fastener Tension)
Sample 1 Results:Ro-Cap Sample 2: Required Fastener Tension = Lbs. (Table 00560-1)Snug Tight = Lbs. (0.10 x Req. Fastener Tension): Tol. = -0 kips + 2 kipsMeasured Torque = Ft.-Lbs. @ Required Fastener Tension (Go to Insp. Torque)Maximum Allowable Torque = Ft.-Lbs. (T < 0.25PD); (P in Lbs., D in Ft.)Measured Tension = Lbs. @ Turn (2x Rotation In Table 00560-3)Minimum Tension Required = Lbs. (1.15 X Required Fastener Tension)
Job Inspection Torque = Ft.-Lbs. (Average Of Three Inspection Torque Samples)
Comments:
Inspector Cert No. Title
Contractor's Representative Date
734-2629 (10-2010) Construction Forms Website: http://www.oregon.gov/ODOT/Hwy/Construction/ConstForms1.shtml
HIGH STRENGTH BOLTS ROTATIONAL CAPACITY TEST & JOB INSPECTION TORQUE
(TURN OF NUT METHOD FOR LONG BOLTS)
280003000
438
32200
280003000
438
32200
28000
28000
28000
#DIV/0!
Pass Fail
Accept Reject
Pass Fail
3/4 inch
High Strength Structural Bolts 13.1
January, 2011 35
Job Inspection Torque for Long Bolts (Turn of Nut)
1. Sample 3 Bolt/Washer/Nut assembles
2. Place in skidmore and tighten to required tension in Table 560-1
3. Measure torque required to turn the nut 5 degrees (1” @ 12” radius)
4. Job inspection torque is the average of the 3 tests
Job Inspection Torque for Short Bolts (Turn of Nut)
1. Sample 3 Bolt/Washer/Nut assembles
2. Snug tight (10% of max allowable torque,
T = 1.15(0.25)PD)
2. Mark the Bolt/Nut/Plate
3. Tighten nut to rotation in Table 560-3
5. Measure torque required to turn the nut 5 degrees (1” @ 12” radius)
6. Job inspection torque is the average of the 3 tests
Project Contract No.
Company Test No.
Torque Wrench Serial No. Calibration Due Date
Skidmore Serial No. Calibration Due Date
Bolt Diameter Bolt Length Quantity
Bolt Mfg. Lot No. Heat No.
Nut Mfg. Lot No. Heat No.
Washer Mfg. Lot No. Heat No.
Ro-Cap Sample 1: Snug Tight, Max. Torque = Ft.-Lbs. T = 0.20(1.15 x 0.25 PD); (P in Lbs., D in Ft.)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Maximum Allowable Torque = Ft.-Lbs. (T = 1.15(0.25PD)); (P in Lbs., D in Ft.)2 x Rotation = Turn (2x Rotation In Table 00560-3)
Sample 1 Results:Ro-Cap Sample 2: Snug Tight, Max. Torque = Ft.-Lbs. T = 0.20(1.15 x 0.25 PD); (P in Lbs., D in Ft.)Measured Torque = Ft.-Lbs. @ Turn (Turn Rotation In Table 00560-3)Maximum Allowable Torque = Ft.-Lbs. (T = 1.15(0.25PD)); (P in Lbs., D in Ft.)2 x Rotation = Turn (2x Rotation In Table 00560-3)