770.7 Maintenance of Bridge Superstructure - Revision history

Smithk: Updated website link for increased security

2021-10-26T16:20:44Z

Updated website link for increased security

← Older revision		Revision as of 11:20, 26 October 2021
Line 52:		Line 52:

	==770.7.2 Concrete Deck Maintenance==		==770.7.2 Concrete Deck Maintenance==
	Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. For steel plate and back filled work, review [[616.6 Temporary Traffic Control Zone Devices (MUTCD 6F)#616.6.46 STEEL PLATE AHEAD Sign (WO8-24) (MUTCD 6F.46)\|EPG 616.6.46 Steel Plate Ahead Signs]] and [~~http~~://epg.modot.org/index.php?title=616.8_Typical_Applications_%28MUTCD_6H%29#Listing_of_Typical_Applications_for_Maintenance Typical Applications 616.8.47a and 616.8.47b].		Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. For steel plate and back filled work, review [[616.6 Temporary Traffic Control Zone Devices (MUTCD 6F)#616.6.46 STEEL PLATE AHEAD Sign (WO8-24) (MUTCD 6F.46)\|EPG 616.6.46 Steel Plate Ahead Signs]] and [https://epg.modot.org/index.php?title=616.8_Typical_Applications_%28MUTCD_6H%29#Listing_of_Typical_Applications_for_Maintenance Typical Applications 616.8.47a and 616.8.47b].

	Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.		Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.

Smithk at 20:14, 18 August 2020

2020-08-18T20:14:11Z

← Older revision		Revision as of 15:14, 18 August 2020
Line 26:		Line 26:
	\|[http://library.modot.mo.gov/RDT/reports/Ri98021/RDT02003.pdf Report 2002]		\|[http://library.modot.mo.gov/RDT/reports/Ri98021/RDT02003.pdf Report 2002]
	\|-		\|-
	\|'''See also:''' [~~http~~://www.modot.~~gov~~/~~services/OR/byDate.htm Innovation Library~~]		\|'''See also:''' [https://www.modot.org/research-publications Research Publications]
	\|}		\|}
	==770.7.1 General Bridge Deck Maintenance==		==770.7.1 General Bridge Deck Maintenance==

Smithk: /* 770.7.2 Concrete Deck Maintenance */ updated link

2016-07-22T13:14:57Z

770.7.2 Concrete Deck Maintenance: updated link

← Older revision		Revision as of 08:14, 22 July 2016
Line 52:		Line 52:

	==770.7.2 Concrete Deck Maintenance==		==770.7.2 Concrete Deck Maintenance==
	Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. For steel plate and back filled work, review [[616.6 Temporary Traffic Control Zone Devices (MUTCD 6F)#616.6.46 STEEL PLATE AHEAD Sign (WO8-24) (MUTCD 6F.46)\|EPG 616.6.46 Steel Plate Ahead Signs]] and [[616.~~23 Traffic Control for Field Operations~~#~~TA-47a Excavations with Steel Plate or Backfill - Undivided Highway\|~~Typical Applications 616.8.47a]] and ~~[[616.23 Traffic Control for Field Operations#TA-47a Excavations with Steel Plate or Backfill - Divided Highway\|~~616.8.47b]].		Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. For steel plate and back filled work, review [[616.6 Temporary Traffic Control Zone Devices (MUTCD 6F)#616.6.46 STEEL PLATE AHEAD Sign (WO8-24) (MUTCD 6F.46)\|EPG 616.6.46 Steel Plate Ahead Signs]] and [http://epg.modot.org/index.php?title=616.8_Typical_Applications_%28MUTCD_6H%29#Listing_of_Typical_Applications_for_Maintenance Typical Applications 616.8.47a and 616.8.47b].

	Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.		Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.

Smithk: /* 770.7.4 Bituminous Mat Resurfacing */ Per Bridge, revision to match guidance with current bridge asphalt overlay seal coat policy.

2014-06-06T16:05:16Z

770.7.4 Bituminous Mat Resurfacing: Per Bridge, revision to match guidance with current bridge asphalt overlay seal coat policy.

← Older revision		Revision as of 11:05, 6 June 2014
Line 114:		Line 114:
	The deck shall be coated with a seal coat or double seal coat application as described under [[#770.7.3 Seal Coat Resurfacing\|Seal Coat Resurfacing]] prior to asphaltic mat application. The seal chips should extend to the curblines for asphaltic mat overlays.		The deck shall be coated with a seal coat or double seal coat application as described under [[#770.7.3 Seal Coat Resurfacing\|Seal Coat Resurfacing]] prior to asphaltic mat application. The seal chips should extend to the curblines for asphaltic mat overlays.

	Type A asphaltic concrete is preferred for use on bridges on heavy traffic routes. It is preferred for use on all bridges, but a Type C mix may be used for bridges on medium or low traffic routes. The maximum aggregate size should be 1/2 in. The mat material should not be too rich or this will cause the mat to shove under traffic.		Type A asphaltic concrete is preferred for use on bridges on heavy traffic routes. It is preferred for use on all bridges, but a Type B mix may be used for bridges on medium or low traffic routes. The maximum aggregate size should be 1/2 in. The mat material should not be too rich or this will cause the mat to shove under traffic.

	The asphaltic concrete shall be placed with asphalt pavers. Other mixes may be placed with pavers or motorgraders; however, asphalt pavers are preferred. The mat shall be rolled as soon as possible with special attention being given to the area along the curbs and around the curb outlets as traffic will not assist in rolling this area. Curb outlets shall be cleaned of mat after rolling and before the asphalt has set. It is extremely important to obtain a smooth riding surface and one which will drain properly.		The asphaltic concrete shall be placed with asphalt pavers. Other mixes may be placed with pavers or motorgraders; however, asphalt pavers are preferred. The mat shall be rolled as soon as possible with special attention being given to the area along the curbs and around the curb outlets as traffic will not assist in rolling this area. Curb outlets shall be cleaned of mat after rolling and before the asphalt has set. It is extremely important to obtain a smooth riding surface and one which will drain properly.

Smithk at 14:45, 7 August 2013

2013-08-07T14:45:21Z

← Older revision		Revision as of 09:45, 7 August 2013
Line 38:		Line 38:
	{\|style="padding: 0.3em; margin-left:9px; border:2px solid #a9a9a9; text-align:left; font-size: 95%; background:#f5f5f5" width="370px" align="right"		{\|style="padding: 0.3em; margin-left:9px; border:2px solid #a9a9a9; text-align:left; font-size: 95%; background:#f5f5f5" width="370px" align="right"
	\|-		\|-
	\|<center>'''Ground-Penetrating Radar'''</center>		\|<center>'''Ground Penetrating Radar'''</center>
	\|-		\|-
	\|[[image:770.7.1.jpg\|right\|210px]]Travelers may see a van similar to this one driving on and around bridges. It belongs to a company called [http://penetradar.com/ Penetradar]. They use ground-penetrating radar to evaluate pavement, as in this image from their website. It also efficiently analyzes bridge decks similar to a giant CAT scan or MRI. Information gathered helps to identify problems within the bridge before a single cut is made in the pavement. This helps the repair contractor know what is to be faced before opening the surface. Fewer surprises make for less stressful, more profitable work. It also helps MoDOT. Fewer surprises make for fewer last-minute (often expensive) fixes and keep work zone time to a minimum. Perhaps most of all, it helps motorists. When contractors know what they will face, they can work and get out of drivers' way more quickly.		\|[[image:770.7.1.jpg\|right\|210px]]Travelers may see a van similar to this one driving on and around bridges. It belongs to a company called [http://penetradar.com/ Penetradar]. They use ground penetrating radar to evaluate pavement, as in this image from their website. It also efficiently analyzes bridge decks similar to a giant CAT scan or MRI. Information gathered helps to identify problems within the bridge before a single cut is made in the pavement. This helps the repair contractor know what is to be faced before opening the surface. Fewer surprises make for less stressful, more profitable work. It also helps MoDOT. Fewer surprises make for fewer last-minute (often expensive) fixes and keep work zone time to a minimum. Perhaps most of all, it helps motorists. When contractors know what they will face, they can work and get out of drivers' way more quickly.
	\|}		\|}

Smithk: ground-penetrating radar genral info added

2013-08-07T14:16:53Z

ground-penetrating radar genral info added

← Older revision		Revision as of 09:16, 7 August 2013
Line 36:		Line 36:

	2. Surface and crack sealers, chip seals and other wearing surfaces to minimize deck wear and assist in preventing further deterioration or possible damage from ice control chemicals.		2. Surface and crack sealers, chip seals and other wearing surfaces to minimize deck wear and assist in preventing further deterioration or possible damage from ice control chemicals.
			{\|style="padding: 0.3em; margin-left:9px; border:2px solid #a9a9a9; text-align:left; font-size: 95%; background:#f5f5f5" width="370px" align="right"
			\|-
			\|<center>'''Ground-Penetrating Radar'''</center>
			\|-
			\|[[image:770.7.1.jpg\|right\|210px]]Travelers may see a van similar to this one driving on and around bridges. It belongs to a company called [http://penetradar.com/ Penetradar]. They use ground-penetrating radar to evaluate pavement, as in this image from their website. It also efficiently analyzes bridge decks similar to a giant CAT scan or MRI. Information gathered helps to identify problems within the bridge before a single cut is made in the pavement. This helps the repair contractor know what is to be faced before opening the surface. Fewer surprises make for less stressful, more profitable work. It also helps MoDOT. Fewer surprises make for fewer last-minute (often expensive) fixes and keep work zone time to a minimum. Perhaps most of all, it helps motorists. When contractors know what they will face, they can work and get out of drivers' way more quickly.
			\|}

	3. Bituminous mat overlays are used to level uneven decks. This work may be performed by district routine maintenance crews or by contract. Since the overlay is adding dead load to the structure, the bridge must be evaluated and approved for the overlay by the Bridge Division. Repairs to these mats must be made with materials similar to the original material, that is, asphaltic concrete mix must be used to patch or repair asphaltic concrete mats except for temporary repairs in an emergency. A seal coat or double seal coat to waterproof the deck should be placed before placing a mat overlay.		3. Bituminous mat overlays are used to level uneven decks. This work may be performed by district routine maintenance crews or by contract. Since the overlay is adding dead load to the structure, the bridge must be evaluated and approved for the overlay by the Bridge Division. Repairs to these mats must be made with materials similar to the original material, that is, asphaltic concrete mix must be used to patch or repair asphaltic concrete mats except for temporary repairs in an emergency. A seal coat or double seal coat to waterproof the deck should be placed before placing a mat overlay.

Smithk: /* 770.7.2 Concrete Deck Maintenance */ Per Traffic, guidance on use and installation of steel plates on high-speed roadways

2012-10-10T17:10:46Z

770.7.2 Concrete Deck Maintenance: Per Traffic, guidance on use and installation of steel plates on high-speed roadways

← Older revision		Revision as of 12:10, 10 October 2012
Line 46:		Line 46:

	==770.7.2 Concrete Deck Maintenance==		==770.7.2 Concrete Deck Maintenance==
	Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. ~~They must be anchored securely to the deck~~ and ~~appropriate signing erected~~.		Concrete deck repairs range from crack sealing to full depth repairs. Emergency partial depth repairs may temporarily be made with bituminous materials. Permanent repairs should be scheduled as soon as possible. Full depth failure should be repaired immediately. In an extreme emergency, where traffic or weather condition make it impossible to do this, the short term use of steel plates is acceptable. For steel plate and back filled work, review [[616.6 Temporary Traffic Control Zone Devices (MUTCD 6F)#616.6.46 STEEL PLATE AHEAD Sign (WO8-24) (MUTCD 6F.46)\|EPG 616.6.46 Steel Plate Ahead Signs]] and [[616.23 Traffic Control for Field Operations#TA-47a Excavations with Steel Plate or Backfill - Undivided Highway\|Typical Applications 616.8.47a]] and [[616.23 Traffic Control for Field Operations#TA-47a Excavations with Steel Plate or Backfill - Divided Highway\|616.8.47b]].

	Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.		Failures less than 1 in. deep are called spalls. Failures over 1 in. deep but that do not go through the deck are classed as partial depth.

EPG-Admin: Structural Steel ASTM A441 has been withdrawn

2009-12-08T19:17:58Z

Structural Steel ASTM A441 has been withdrawn

← Older revision		Revision as of 14:17, 8 December 2009
Line 1:		Line 1:
	The bridge superstructure consists of that portion of the bridge above the bearings. Maintenance consists of repairs to the deck, handrail, curbs, floor system and structural members. Maintenance of structural members is normally minor unless members are damaged by collision or fire. Major damage to structural members which may affect the load carrying capacity must be reported immediately to Central Office Bridge Maintenance. If any doubt exists as to safety, the bridge should be closed until an inspection can be made and the damages determined.		The bridge superstructure consists of that portion of the bridge above the bearings. Maintenance consists of repairs to the deck, handrail, curbs, floor system and structural members. Maintenance of structural members is normally minor unless members are damaged by collision or fire. Major damage to structural members which may affect the load carrying capacity must be reported immediately to Central Office Bridge Maintenance. If any doubt exists as to safety, the bridge should be closed until an inspection can be made and the damages determined.

	Girder ends under open expansion joints of all steel bridges should be flushed regularly to remove snow and ice control chemicals, dirt and debris. Truss members in the splash zone and lower chords should also be regularly flushed. Bridges with ~~A-588~~ weathering steel do not retain the protective oxide layer in the presence of snow and ice control chemicals. Therefore, it is important to regularly [[771.2 Bridge Cleaning and Flushing\|clean and flush]] these bridges under open joints.		Girder ends under open expansion joints of all steel bridges should be flushed regularly to remove snow and ice control chemicals, dirt and debris. Truss members in the splash zone and lower chords should also be regularly flushed. Bridges with ASTM A709 weathering steel do not retain the protective oxide layer in the presence of snow and ice control chemicals. Therefore, it is important to regularly [[771.2 Bridge Cleaning and Flushing\|clean and flush]] these bridges under open joints.
	{\|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#ffddcc" width="210px" align="right"		{\|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#ffddcc" width="210px" align="right"
	\|-		\|-

EPG-Admin: Added Links to Innovation Library.

2009-04-07T15:27:36Z

Added Links to Innovation Library.

@@ Line 2: / Line 2: @@
 Girder ends under open expansion joints of all steel bridges should be flushed regularly to remove snow and ice control chemicals, dirt and debris. Truss members in the splash zone and lower chords should also be regularly flushed. Bridges with A-588 weathering steel do not retain the protective oxide layer in the presence of snow and ice control chemicals. Therefore, it is important to regularly [[771.2 Bridge Cleaning and Flushing|clean and flush]] these bridges under open joints.
+{|style="padding: 0.3em; margin-left:15px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#ffddcc" width="210px" align="right"
 ==770.7.1 General Bridge Deck Maintenance==
 The maintenance of bridge decks must be timely and performed to a high standard to prevent further deterioration and to protect the investment. Repair of holes or deterioration must be done immediately and not delayed for approval at the time of the annual bridge inspection. Bridge decks that present unusual problems may require contract repair.

EPG-Admin: More accurate references to organizational structure - Central Office bridge maintenance and regional bridge maintenance.

2008-11-21T15:36:28Z

More accurate references to organizational structure - Central Office bridge maintenance and regional bridge maintenance.

← Older revision		Revision as of 10:36, 21 November 2008
Line 1:		Line 1:
	The bridge superstructure consists of that portion of the bridge above the bearings. Maintenance consists of repairs to the deck, handrail, curbs, floor system and structural members. Maintenance of structural members is normally minor unless members are damaged by collision or fire. Major damage to structural members which may affect the load carrying capacity must be reported immediately to ~~the division office~~. If any doubt exists as to safety, the bridge should be closed until an inspection can be made and the damages determined.		The bridge superstructure consists of that portion of the bridge above the bearings. Maintenance consists of repairs to the deck, handrail, curbs, floor system and structural members. Maintenance of structural members is normally minor unless members are damaged by collision or fire. Major damage to structural members which may affect the load carrying capacity must be reported immediately to Central Office Bridge Maintenance. If any doubt exists as to safety, the bridge should be closed until an inspection can be made and the damages determined.

	Girder ends under open expansion joints of all steel bridges should be flushed regularly to remove snow and ice control chemicals, dirt and debris. Truss members in the splash zone and lower chords should also be regularly flushed. Bridges with A-588 weathering steel do not retain the protective oxide layer in the presence of snow and ice control chemicals. Therefore, it is important to regularly [[771.2 Bridge Cleaning and Flushing\|clean and flush]] these bridges under open joints.		Girder ends under open expansion joints of all steel bridges should be flushed regularly to remove snow and ice control chemicals, dirt and debris. Truss members in the splash zone and lower chords should also be regularly flushed. Bridges with A-588 weathering steel do not retain the protective oxide layer in the presence of snow and ice control chemicals. Therefore, it is important to regularly [[771.2 Bridge Cleaning and Flushing\|clean and flush]] these bridges under open joints.
Line 12:		Line 12:
	2. Surface and crack sealers, chip seals and other wearing surfaces to minimize deck wear and assist in preventing further deterioration or possible damage from ice control chemicals.		2. Surface and crack sealers, chip seals and other wearing surfaces to minimize deck wear and assist in preventing further deterioration or possible damage from ice control chemicals.

	3. Bituminous mat overlays are used to level uneven decks. This work may be performed by maintenance crews or by contract. Since the overlay is adding dead load to the structure, the bridge must be evaluated and approved for the overlay by the Bridge Division. Repairs to these mats must be made with materials similar to the original material, that is, asphaltic concrete mix must be used to patch or repair asphaltic concrete mats except for temporary repairs in an emergency. A seal coat or double seal coat to waterproof the deck should be placed before placing a mat overlay.		3. Bituminous mat overlays are used to level uneven decks. This work may be performed by district routine maintenance crews or by contract. Since the overlay is adding dead load to the structure, the bridge must be evaluated and approved for the overlay by the Bridge Division. Repairs to these mats must be made with materials similar to the original material, that is, asphaltic concrete mix must be used to patch or repair asphaltic concrete mats except for temporary repairs in an emergency. A seal coat or double seal coat to waterproof the deck should be placed before placing a mat overlay.

	4. Resurfacing with concrete or replacement or patching of concrete floors is performed by district crews or by contract. Asphaltic materials should not be used for making permanent repairs in concrete decks.		4. Resurfacing with concrete or replacement or patching of concrete floors is performed by district special crews or by contract. Asphaltic materials should not be used for making permanent repairs in concrete decks.

	5. Repair or replacement of timber decks may be performed by district ~~crews~~ or ~~Maintenance Division Bridge Maintenance~~ crews.		5. Repair or replacement of timber decks may be performed by district special or regional bridge maintenance crews.

	6. Epoxies may be used for sealing cracks. Accelerated concrete, epoxy mortar and micro-cements may be used for patching holes or spalled areas. This work should be performed by district crews trained in the use of these materials ~~by Maintenance Division Bridge Maintenance personnel~~ in accordance to the manufacturers recommendations.		6. Epoxies may be used for sealing cracks. Accelerated concrete, epoxy mortar and micro-cements may be used for patching holes or spalled areas. This work should be performed by district special or regional bridge maintenance crews trained in the use of these materials in accordance to the manufacturers recommendations.

	==770.7.2 Concrete Deck Maintenance==		==770.7.2 Concrete Deck Maintenance==
Line 33:		Line 33:
	Regardless of the permanent patching material to be used, the procedures are basically the same. The area around the failure should be sounded to determine the limits of the failure. The area should be marked and sawed with a concrete saw. Care must be taken not to cut the reinforcing steel. On a deck with an asphaltic overlay, it should be removed wider than the deck area to be patched. The patch can then be finished smooth and flush with the deck and the overlay properly compacted.		Regardless of the permanent patching material to be used, the procedures are basically the same. The area around the failure should be sounded to determine the limits of the failure. The area should be marked and sawed with a concrete saw. Care must be taken not to cut the reinforcing steel. On a deck with an asphaltic overlay, it should be removed wider than the deck area to be patched. The patch can then be finished smooth and flush with the deck and the overlay properly compacted.

	~~Voids~~ tubes of voided slab bridges which are opened during concrete removal shall be formed to prevent filling the void tube with patching material. The ~~Maintenance Division office~~ may be contacted for assistance in forming methods.		Void tubes of voided slab bridges which are opened during concrete removal shall be formed to prevent filling the void tube with patching material. The Central Office bridge maintenance may be contacted for assistance in forming methods.

	The total deck repairs made to bridges with concrete superstructures (main supporting element for span) such as voided slabs, concrete box girders, concrete girders, etc., shall be limited to 100 sq. ft. per span per day. This shall also apply to culverts. This limit does not apply to bridges with steel superstructures. If extensive repairs are required, a special repair plan should be requested from ~~the assistant division engineer -~~ bridge maintenance.		The total deck repairs made to bridges with concrete superstructures (main supporting element for span) such as voided slabs, concrete box girders, concrete girders, etc., shall be limited to 100 sq. ft. per span per day. This shall also apply to culverts. This limit does not apply to bridges with steel superstructures. If extensive repairs are required, a special repair plan should be requested from Central Office bridge maintenance.

	A 65 pound class breaking hammer is to be used to remove the broken and deteriorated concrete to a depth below the top reinforcing steel. Loose concrete and pack rust shall be cleaned from exposed steel. All loose material is to be removed from the hole and fine particles blown out with compressed air. Additional reinforcing steel may be added where needed.		A 65 pound class breaking hammer is to be used to remove the broken and deteriorated concrete to a depth below the top reinforcing steel. Loose concrete and pack rust shall be cleaned from exposed steel. All loose material is to be removed from the hole and fine particles blown out with compressed air. Additional reinforcing steel may be added where needed.
Line 49:		Line 49:
	If slab reinforcement in precast concrete slab panels must be replaced, use #3 or #4 bars at the same spacing as existing reinforcement. If it is necessary to splice longitudinal slab reinforcement, use a 12 in. lap splice.		If slab reinforcement in precast concrete slab panels must be replaced, use #3 or #4 bars at the same spacing as existing reinforcement. If it is necessary to splice longitudinal slab reinforcement, use a 12 in. lap splice.

	Should the stems of precast concrete slab panels have shear cracks at the ends of panels, as shown above, ~~the division office~~ should be contacted before repairs are attempted.		Should the stems of precast concrete slab panels have shear cracks at the ends of panels, as shown above, Central Office Bridge Maintenance should be contacted before repairs are attempted.

	==770.7.3 Seal Coat Resurfacing==		==770.7.3 Seal Coat Resurfacing==
Line 60:		Line 60:
	The bituminous material shall be EA90P or CRS-2P liquid asphalt for bridges on all routes. It is permissible to use No-Strip with these asphalts. The asphalt shall be applied to the entire deck at the necessary application rate which is normally 0.3 to 0.4 gallon per square yard. The interiors of curb outlets should be sprayed thoroughly with asphalt and it is not objectionable to apply asphalt to the vertical faces of the curbs. Care must be taken not to spray asphalt on any steel members. All expansion joints should be covered prior to sealing. Tar paper should be used to provide a neat beginning and ending of the seal.		The bituminous material shall be EA90P or CRS-2P liquid asphalt for bridges on all routes. It is permissible to use No-Strip with these asphalts. The asphalt shall be applied to the entire deck at the necessary application rate which is normally 0.3 to 0.4 gallon per square yard. The interiors of curb outlets should be sprayed thoroughly with asphalt and it is not objectionable to apply asphalt to the vertical faces of the curbs. Care must be taken not to spray asphalt on any steel members. All expansion joints should be covered prior to sealing. Tar paper should be used to provide a neat beginning and ending of the seal.

	The cover material shall be Iron Mountain Trap Rock, Joplin chat or similar material approved by the ~~division office~~. The gradation shall be: 100% passing 1/2" sieve, 95-100% passing 3/8" sieve, 0-10% passing #4 sieve, and 0-1% passing #200 sieve.		The cover material shall be Iron Mountain Trap Rock, Joplin chat or similar material approved by the Maintenance Division. The gradation shall be: 100% passing 1/2" sieve, 95-100% passing 3/8" sieve, 0-10% passing #4 sieve, and 0-1% passing #200 sieve.

	The cover material should be applied immediately after the asphalt and rolled. The application rate should provide a single rock thickness. It is not to be applied in the curb outlet, or for a distance of two feet from the vertical face of the curb.		The cover material should be applied immediately after the asphalt and rolled. The application rate should provide a single rock thickness. It is not to be applied in the curb outlet, or for a distance of two feet from the vertical face of the curb.
Line 101:		Line 101:

	==770.7.6 Steel Decks==		==770.7.6 Steel Decks==
	Steel grid and structural plate decks normally require little maintenance. If the floor sections separate from the stringers, they can be repaired by jacking or loading the deck down to the stringers and bolting or re-welding. ~~Division~~ concurrence is required prior to non-emergency repairs to steel grid or structural plate decks.		Steel grid and structural plate decks normally require little maintenance. If the floor sections separate from the stringers, they can be repaired by jacking or loading the deck down to the stringers and bolting or re-welding. Central Office bridge maintenance concurrence is required prior to non-emergency repairs to steel grid or structural plate decks.

	==770.7.7 Expansion Joint Maintenance==		==770.7.7 Expansion Joint Maintenance==
Line 108:		Line 108:
	The useful service life of many expansion joints can be extended by periodic cleaning with compressed air or high pressure water. Normal sweeping and flushing operations will usually not remove the incompressible materials which damage all types of expansion devices.		The useful service life of many expansion joints can be extended by periodic cleaning with compressed air or high pressure water. Normal sweeping and flushing operations will usually not remove the incompressible materials which damage all types of expansion devices.

	Many expansion device units can be saved from complete failure if problems are detected early and corrective measures taken immediately. This is especially true for elastomeric units where anchor failures are common. Failure to act quickly could result in extensive damage to the device and to the surrounding bridge deck. Some accelerated mortar materials will not perform well in areas of high stress such as at expansion devices. ~~The Maintenance Division office will be~~ able to recommend suitable materials for extreme service areas.		Many expansion device units can be saved from complete failure if problems are detected early and corrective measures taken immediately. This is especially true for elastomeric units where anchor failures are common. Failure to act quickly could result in extensive damage to the device and to the surrounding bridge deck. Some accelerated mortar materials will not perform well in areas of high stress such as at expansion devices. Central Office bridge maintenance is able to recommend suitable materials for extreme service areas.

	Expansion devices occasionally become loose. Loose joints can be detected by observing their sound under traffic and/or observing the absence of dirt in the countersunk areas around the bolts.		Expansion devices occasionally become loose. Loose joints can be detected by observing their sound under traffic and/or observing the absence of dirt in the countersunk areas around the bolts.
Line 127:		Line 127:
	Damaged or deteriorated handrail should be replaced immediately and a stock of handrail materials should be kept on hand for this purpose.		Damaged or deteriorated handrail should be replaced immediately and a stock of handrail materials should be kept on hand for this purpose.

	The high cost of aluminum products and the high theft rate for aluminum necessitates the following repair guidelines for aluminum railing. See the figure below for determining if railing is ornamental or high strength structural railing. Contact ~~the division office~~ if additional information is required.		The high cost of aluminum products and the high theft rate for aluminum necessitates the following repair guidelines for aluminum railing. See the figure below for determining if railing is ornamental or high strength structural railing. Contact Central Office bridge maintenance if additional information is required.

	[[Image:770.7 Aluminum Handrail Types.gif]]		[[Image:770.7 Aluminum Handrail Types.gif]]
Line 137:		Line 137:
	2. Double or Single High Strength Rail		2. Double or Single High Strength Rail
	:A. Minor Damage - repair for appearance.		:A. Minor Damage - repair for appearance.
	:B. Major Damage - submit a report immediately with details of damage or theft. Include the width of the curb, height of railing and any other information which might affect the decision to replace or remove the remainder of the handrail. Bridge division and bridge maintenance will review and compare the standards. No handrail will be removed to create a substandard height.		:B. Major Damage - submit a report immediately with details of damage or theft. Include the width of the curb, height of railing and any other information which might affect the decision to replace or remove the remainder of the handrail. Bridge division and Central Office bridge maintenance will review and compare the standards. No handrail will be removed to create a substandard height.

	3. Combination Traffic and Bicycling Railing or Pedestrian Fence		3. Combination Traffic and Bicycling Railing or Pedestrian Fence
Line 147:		Line 147:

	==770.7.9 Bearings==		==770.7.9 Bearings==
	Various types of bearing plates, neoprene pads, rollers and rockers are presently being used. ~~Division repair~~ crews can reset bearing plates which have slipped out of place by jacking up the girder slightly, removing, cleaning, lubricating with graphite, and returning the plates to their proper position. Under no circumstances are sledge hammers to be used in an attempt to drive the bearing plates back into position. It cannot be done without burring the plates, thereby adding to the work when the job is performed correctly. All bearings are to be kept free of dirt and pack rust in order that they may function properly.		Various types of bearing plates, neoprene pads, rollers and rockers are presently being used. Regional bridge maintenance crews can reset bearing plates which have slipped out of place by jacking up the girder slightly, removing, cleaning, lubricating with graphite, and returning the plates to their proper position. Under no circumstances are sledge hammers to be used in an attempt to drive the bearing plates back into position. It cannot be done without burring the plates, thereby adding to the work when the job is performed correctly. All bearings are to be kept free of dirt and pack rust in order that they may function properly.

	Access plates of roller nests under long spans should be taken off, all dirt and debris removed, the roller nest lubricated and the access plates repositioned by ~~division~~ crews when necessary.		Access plates of roller nests under long spans should be taken off, all dirt and debris removed, the roller nest lubricated and the access plates repositioned by regional bridge maintenance crews when necessary.

	[[Category:770 Maintenance of Bridges\|770.07]]		[[Category:770 Maintenance of Bridges\|770.07]]