751.40 LFD Widening and Repair - Revision history

Hoskir: /* 751.40.8.9.2.3 Reinforcement - Pile Cap Bents */ modified formatting

2026-01-15T21:12:06Z

751.40.8.9.2.3 Reinforcement - Pile Cap Bents: modified formatting

← Older revision		Revision as of 16:12, 15 January 2026
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	<center>[[Image:751.40_Reinforcement_-_Pile_Cap_Section_1_(Slab_Depth_less_than_16_in).gif]]</center>		<center>[[Image:751.40_Reinforcement_-_Pile_Cap_Section_1_(Slab_Depth_less_than_16_in).gif]]</center>

	~~::::::::::~~'''SECTION THRU END BENT<BR/>(Slab depth less than 16")'''		<center>'''SECTION THRU END BENT<BR/>(Slab depth less than 16")'''</center>


	<center>[[Image:751.40_Reinforcement_-_Pile_Cap_Section_2_(Slab_Depth_16_in_or_more).gif]]</center>		<center>[[Image:751.40_Reinforcement_-_Pile_Cap_Section_2_(Slab_Depth_16_in_or_more).gif]]</center>

	~~::::::::::~~'''SECTION THRU END BENT<BR/>(Slab depth 16" or more)'''		<center>'''SECTION THRU END BENT<BR/>(Slab depth 16" or more)'''</center>

Hoskir: /* 751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap */ updated per RR4034

2025-07-11T15:33:33Z

751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap: updated per RR4034

← Older revision		Revision as of 10:33, 11 July 2025
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	===751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap===		===751.40.3.2 Bent Cap Shear Strengthening using FRP Wrap===

	{\| ~~border="1"~~ class="wikitable" style="margin: 0 auto; text-align: center"		{\| class="wikitable" style="margin: 0 auto; text-align: center"
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	\| style="background:#BEBEBE" \| '''[https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings]'''		\| style="background:#BEBEBE" \| '''[https://www.modot.org/bridge-standard-drawings Bridge Standard Drawings]'''
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	Fiber Reinforced Polymer (FRP) wrap may be used for Bent Cap Shear Strengthening.		Fiber Reinforced Polymer (FRP) wrap may be used for Bent Cap Shear Strengthening. FRP wrap may also be used for seismic retrofit of existing columns, but that procedure is not discussed herein (see [[751.9_Bridge_Seismic_Design#751.9.1_Seismic_Analysis_and_Design_Specifications\|EPG 751.9.1 Seismic Analysis and Design Specifications]]).

	'''When to strengthen:''' When increased shear loading on an existing bent cap is required and a structural analysis shows insufficient bent cap shear resistance, bent cap shear strengthening is an option. An example of when strengthening a bent cap may be required: removing existing girder hinges and making girders continuous will draw significantly more force to the adjacent bent. An example of when strengthening a bent cap is not required: redecking a bridge where analysis shows that the existing bent cap cannot meet capacity for an HS20 truck loading, and the new deck is similar to the old deck and the existing beam is in good shape.		'''When to strengthen:''' When increased shear loading on an existing bent cap is required and a structural analysis shows insufficient bent cap shear resistance, bent cap shear strengthening is an option. An example of when strengthening a bent cap may be required: removing existing girder hinges and making girders continuous will draw significantly more force to the adjacent bent. An example of when strengthening a bent cap is not required: redecking a bridge where analysis shows that the existing bent cap cannot meet capacity for an HS20 truck loading, and the new deck is similar to the old deck and the existing beam is in good shape.
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	:: '''*''' ACI 440.2R: ''Guide for the Design and Construction of Externally Bonded FRP''		:: '''*''' ACI 440.2R: ''Guide for the Design and Construction of Externally Bonded FRP''

	'''Design force (net shear strength loading):''' Strengthening a bent cap requires determining the net factored shear loading that the cap beam must carry in excess of its unstrengthened factored shear capacity, or resistance. The FRP system is then designed by the manufacturer to meet this net factored shear load, or design force. The design force for a bent cap strengthening is calculated considering AASHTO LFD where the factored load is the standard Load Factor Group I load case. To determine design force that the FRP must carry alone, the factored strength of the bent cap, which is 0.85 x nominal strength according to LFD design, is subtracted out to give the net factored shear load that the FRP must resist by itself. ''NCHRP Report 678'' is referenced in the special provisions as guidelines for the contractor and the manufacturer to follow. The report and its examples use ~~AAHTO~~ LRFD. <u>Regardless, the load factor case is given and it is left to the manufacturer to provide for a satisfactory factor of safety based on their FRP system.</u>		'''Design force (net shear strength loading):''' Strengthening a bent cap requires determining the net factored shear loading that the cap beam must carry in excess of its unstrengthened factored shear capacity, or resistance. The FRP system is then designed by the manufacturer to meet this net factored shear load, or design force. The design force for a bent cap strengthening is calculated considering AASHTO LFD where the factored load is the standard Load Factor Group I load case. To determine design force that the FRP must carry alone, the factored strength of the bent cap, which is 0.85 x nominal strength according to LFD design, is subtracted out to give the net factored shear load that the FRP must resist by itself. ''NCHRP Report 678'' is referenced in the special provisions as guidelines for the contractor and the manufacturer to follow. The report and its examples use AASHTO LRFD. <u>Regardless, the load factor case is given and it is left to the manufacturer to provide for a satisfactory factor of safety based on their FRP system.</u>

	Other References:		Other References:
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	:: '''*''' International Concrete Repair Institute (ICI) ICI 03733: ''Guide for Selecting and Specifying Materials for Repairs of Concrete Surfaces''		:: '''*''' International Concrete Repair Institute (ICI) ICI 03733: ''Guide for Selecting and Specifying Materials for Repairs of Concrete Surfaces''
	:: '''*''' NCHRP Report 609: ''Recommended Construction Specifications Process Control Manual for Repair and Retrofit of Concrete Structures Using Bonded FRP Composites''		:: '''*''' NCHRP Report 609: ''Recommended Construction Specifications Process Control Manual for Repair and Retrofit of Concrete Structures Using Bonded FRP Composites''
			:: '''*''' AASHTO Guide Spec for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements, March 2023, 2nd Ed.

	===751.40.3.3 Steel HP Pile Maintenance and Repair===		===751.40.3.3 Steel HP Pile Maintenance and Repair===

Hoskir: /* 751.40.8.4.2.7 Minimum lap length for uncoated Grade 40 tension lap splices, \, L_{lap} (AASHTO 8.32) */ updated title formatting

2025-04-29T14:42:37Z

751.40.8.4.2.7 Minimum lap length for uncoated Grade 40 tension lap splices, \, L_{lap} (AASHTO 8.32): updated title formatting

← Older revision		Revision as of 09:42, 29 April 2025
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	===== 751.40.8.4.2.7 Minimum lap length for uncoated Grade 40 tension lap splices, <~~math~~>~~\, L_{~~lap}</~~math~~> (AASHTO 8.32) =====		===== 751.40.8.4.2.7 Minimum lap length for uncoated Grade 40 tension lap splices, <span style="font-family:Times New Roman;"><i>L<sub>lap</sub></i> (AASHTO 8.32) =====

	{\|border="1" style="text-align:center;" cellpadding="5" align="center" cellspacing="0"		{\|border="1" style="text-align:center;" cellpadding="5" align="center" cellspacing="0"

Hoskir: /* 751.40.8.4.2.6 Development of Uncoated Grade 40 Deformed Bars in Tension, \, L_d (AASHTO 8.25) */ updated title formatting

2025-04-29T14:37:37Z

751.40.8.4.2.6 Development of Uncoated Grade 40 Deformed Bars in Tension, \, L_d (AASHTO 8.25): updated title formatting

← Older revision		Revision as of 09:37, 29 April 2025
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	\|}		\|}

	===== 751.40.8.4.2.6 Development of Uncoated Grade 40 Deformed Bars in Tension, <~~math~~>~~\, L_d~~</~~math~~> (AASHTO 8.25) =====		===== 751.40.8.4.2.6 Development of Uncoated Grade 40 Deformed Bars in Tension, <span style="font-family:Times New Roman;"><i>L<sub>d</sub></i></span> (AASHTO 8.25) =====

Hoskir: /* 751.40.8.4.2.5 Development of Standard Hooks in Tension, Ldh (\, F_y = 60 ksi) */ updated formatting in title

2025-04-29T14:30:52Z

751.40.8.4.2.5 Development of Standard Hooks in Tension, Ldh (\, F_y = 60 ksi): updated formatting in title

← Older revision		Revision as of 09:30, 29 April 2025
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	(*) Lap splices for #14 and #18 bars are not permitted except as column to footing dowels.		(*) Lap splices for #14 and #18 bars are not permitted except as column to footing dowels.

	===== 751.40.8.4.2.5 Development of Standard Hooks in Tension, Ldh (<~~math~~>~~\, F_y~~</~~math~~> = 60 ksi) =====		===== 751.40.8.4.2.5 Development of Standard Hooks in Tension, Ldh (<span style="font-family:Times New Roman;"><i>F<sub>y</sub></i> = 60 ksi</span>) =====

	The development length, <math>\, L_{dh}</math>, is measured from the critical section to the outside edge of hook. The tabulated values are valid for both epoxy and uncoated hooks.		The development length, <math>\, L_{dh}</math>, is measured from the critical section to the outside edge of hook. The tabulated values are valid for both epoxy and uncoated hooks.

Hoskir: /* 751.40.8.4.2.4 Development and Lap Splice Lengths - Bars in Compression (\, F_y = 60 ksi) */ updated formatting in title

2025-04-29T14:29:10Z

751.40.8.4.2.4 Development and Lap Splice Lengths - Bars in Compression (\, F_y = 60 ksi): updated formatting in title

← Older revision		Revision as of 09:29, 29 April 2025
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	Use development and tension lap splices of <math>\, f'_c</math> = 4 ksi for concrete strengths greater than 4 ksi.		Use development and tension lap splices of <math>\, f'_c</math> = 4 ksi for concrete strengths greater than 4 ksi.

	===== 751.40.8.4.2.4 Development and Lap Splice Lengths - Bars in Compression (<~~math~~>~~\, F_y~~</~~math~~> = 60 ksi) =====		===== 751.40.8.4.2.4 Development and Lap Splice Lengths - Bars in Compression (<span style="font-family:Times New Roman;"><i>F<sub>y</sub></i> = 60 ksi</span>) =====

Hoskir: /* 751.40.8.4.2.3 Development and Tension Lap Splice Lengths - Other Than Top Bars (\, F_y = 60 ksi) */ updated title formatting

2025-04-29T14:23:34Z

751.40.8.4.2.3 Development and Tension Lap Splice Lengths - Other Than Top Bars (\, F_y = 60 ksi): updated title formatting

← Older revision		Revision as of 09:23, 29 April 2025
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	Use development and tension lap splices of <math>\, f'_c</math> = 4 ksi for concrete strengths greater than 4 ksi.		Use development and tension lap splices of <math>\, f'_c</math> = 4 ksi for concrete strengths greater than 4 ksi.

	===== 751.40.8.4.2.3 Development and Tension Lap Splice Lengths - Other Than Top Bars (<~~math~~>~~\, F_y~~</~~math~~> = 60 ksi) =====		===== 751.40.8.4.2.3 Development and Tension Lap Splice Lengths - Other Than Top Bars (<span style="font-family:Times New Roman;"><i>F<sub>y</sub></i> = 60 ksi</span>) =====

Hoskir: /* 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars ( F_y = 60 ksi) */ updated title formatting

2025-04-29T14:21:43Z

751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars ( F_y = 60 ksi): updated title formatting

← Older revision		Revision as of 09:21, 29 April 2025
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	Mechanical bar splices may be used in situations where it is not possible or feasible to use lap splices. Mechanical bar splices shall meet the criteria of AASHTO Article 8.32.2. Refer to the manufacturers literature for more information on the design of mechanical bar splices.		Mechanical bar splices may be used in situations where it is not possible or feasible to use lap splices. Mechanical bar splices shall meet the criteria of AASHTO Article 8.32.2. Refer to the manufacturers literature for more information on the design of mechanical bar splices.

	===== 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars ( <~~math~~>~~F_y~~</~~math~~> = 60 ksi) =====		===== 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars (<span style="font-family:Times New Roman;"><i>F<sub>y</sub></i> = 60 ksi</span>) =====

Hoskir: /* 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars (\, F_y = 60 ksi) */

2025-04-29T13:56:44Z

751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars (\, F_y = 60 ksi)

← Older revision		Revision as of 08:56, 29 April 2025
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	Mechanical bar splices may be used in situations where it is not possible or feasible to use lap splices. Mechanical bar splices shall meet the criteria of AASHTO Article 8.32.2. Refer to the manufacturers literature for more information on the design of mechanical bar splices.		Mechanical bar splices may be used in situations where it is not possible or feasible to use lap splices. Mechanical bar splices shall meet the criteria of AASHTO Article 8.32.2. Refer to the manufacturers literature for more information on the design of mechanical bar splices.

	===== 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars (<math>\, F_y</math> = 60 ksi) =====		===== 751.40.8.4.2.2 Development and Tension Lap Splice Lengths - Top Bars ( <math>F_y</math> = 60 ksi) =====

Hoskir: updating formatting and split into two pages because the Math API was getting to many requests and creating errors.

2025-04-28T17:46:46Z

updating formatting and split into two pages because the Math API was getting to many requests and creating errors.

← Older revision		Revision as of 12:46, 28 April 2025
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	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.1.4_Design_Assumptions\|751.40.8.12.1.4 Design Assumptions]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.1.4_Design_Assumptions\|751.40.8.12.1.4 Design Assumptions]]
	:[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2_Reinforcement\|751.40.8.12.2 Reinforcement]]		:[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2_Reinforcement\|751.40.8.12.2 Reinforcement]]
	::[[751.40.8.12.2.1 General]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.1_General\|751.40.8.12.2.1 General]]
	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.2_Anchorage_of_Piles_for_Seismic_Performance_Categories_B,_C_&_D\|751.40.8.12.2.2 Anchorage of Piles for Seismic Performance Categories B, C & D]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.2_Anchorage_of_Piles_for_Seismic_Performance_Categories_B,_C_&_D\|751.40.8.12.2.2 Anchorage of Piles for Seismic Performance Categories B, C & D]]
	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.3_Beam_Reinforcement_Special_Cases\|751.40.8.12.2.3 Beam Reinforcement Special Cases]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.3_Beam_Reinforcement_Special_Cases\|751.40.8.12.2.3 Beam Reinforcement Special Cases]]

← Older revision		Revision as of 12:46, 28 April 2025
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	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.1.4_Design_Assumptions\|751.40.8.12.1.4 Design Assumptions]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.1.4_Design_Assumptions\|751.40.8.12.1.4 Design Assumptions]]
	:[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2_Reinforcement\|751.40.8.12.2 Reinforcement]]		:[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2_Reinforcement\|751.40.8.12.2 Reinforcement]]
	::[[751.40.8.12.2.1 General]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.1_General\|751.40.8.12.2.1 General]]
	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.2_Anchorage_of_Piles_for_Seismic_Performance_Categories_B,_C_&_D\|751.40.8.12.2.2 Anchorage of Piles for Seismic Performance Categories B, C & D]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.2_Anchorage_of_Piles_for_Seismic_Performance_Categories_B,_C_&_D\|751.40.8.12.2.2 Anchorage of Piles for Seismic Performance Categories B, C & D]]
	::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.3_Beam_Reinforcement_Special_Cases\|751.40.8.12.2.3 Beam Reinforcement Special Cases]]		::[[751.40_LFD_Widening_and_Repair_(CONTINUED)#751.40.8.12.2.3_Beam_Reinforcement_Special_Cases\|751.40.8.12.2.3 Beam Reinforcement Special Cases]]