603 - Concrete Pavement Restoration - Revision history

JohnsonN23: /* Aggregate Base */ misplaced info

2017-04-19T15:14:24Z

Aggregate Base: misplaced info

JohnsonN23: /* Removing Old Concrete */ addition of content according to CA 2013-09

2017-04-19T15:06:57Z

Removing Old Concrete: addition of content according to CA 2013-09

JohnsonN23: /* Removing Old Concrete */ added new text

2017-04-05T14:59:32Z

Removing Old Concrete: added new text

Greenes2: /* Dowel Bar Retrofit (DBR) */

2015-05-08T15:35:51Z

Dowel Bar Retrofit (DBR)

Greenes2: /* Swiss Hammer */

2015-05-08T15:34:07Z

Swiss Hammer

Greenes2: /* Transverse Joints */

2015-05-08T15:33:33Z

Transverse Joints

Greenes2: /* Pavement Reinforcement */

2015-05-08T15:32:58Z

Pavement Reinforcement

Greenes2 at 17:58, 18 September 2014

2014-09-18T17:58:32Z

Greenes2: /* Strength Requirements */

2014-04-30T16:34:00Z

Strength Requirements

Greenes2: /* Strength Requirements */

2014-04-29T16:23:30Z

Strength Requirements

← Older revision		Revision as of 15:14, 19 April 2017
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	Any low base caused by the Contractor’s operation will be filled with concrete at the Contractor’s expense.		Any low base caused by the Contractor’s operation will be filled with concrete at the Contractor’s expense.
−
−	All efforts should be made to not disturb the aggregate base material during removal of the existing concrete pavement and preparation of the site for concrete placement. If the base is disturbed, the contractor should be instructed to restore it to the required density and elevation. Depending on the severity of disturbance, this may require that the contractor install and compact additional base course aggregate. The department will not pay separately for this work required to correct these deficiencies as a result of the contractors operations.
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← Older revision		Revision as of 15:06, 19 April 2017
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	Any low base caused by the Contractor’s operation will be filled with concrete at the Contractor’s expense.		Any low base caused by the Contractor’s operation will be filled with concrete at the Contractor’s expense.

		+	All efforts should be made to not disturb the aggregate base material during removal of the existing concrete pavement and preparation of the site for concrete placement. If the base is disturbed, the contractor should be instructed to restore it to the required density and elevation. Depending on the severity of disturbance, this may require that the contractor install and compact additional base course aggregate. The department will not pay separately for this work required to correct these deficiencies as a result of the contractors operations.
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@@ Line 164: / Line 164: @@
 Repair isolated spalls of 10 in2 and greater per [http://mdotcf.state.mi.us/public/specbook/files/2012/602%20Conc%20Pavt%20Construction.pdf Standard Specification 602.03.P.1].
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 ====[[#Intermediate Saw Cuts|Intermediate Saw Cuts]]====

← Older revision		Revision as of 15:35, 8 May 2015
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	* Sand Patch test to verify macro texture depth		* Sand Patch test to verify macro texture depth

−	~~{{top}}~~
−
−	~~===[[#Dowel Bar Retrofit (DBR)\|Dowel Bar Retrofit (DBR)]]===~~
−
−	Dowel bar retrofit commonly referred to as DBR is a repair procedure typically used on concrete pavement that exhibits intermittent transverse cracking. This repair is typically used to restore load transfer at the location of the crack.
−
−	Dowel bar retrofits are not appropriate for all pavements that have transverse cracking. Good candidate concrete pavements that should be retrofit have little or no spalling at the surface of the crack to be repaired. The crack should also be level, not faulted, from one side to the other. Attempting to DBR a pavement that exhibits spalled or faulted joints will result in failure of the DBR. Contact the Materials Unit at Construction Field Services Division for questions regarding the appropriate use of DBR.
−
−	~~{{top}}~~
−
−	~~====[[#Slot Cutting\|Slot Cutting]]====~~
−
−	* Slots shall be cut using a diamond-bladed saw machine.
−	* The machine shall typically be capable of cutting a minimum of three slots simultaneously that are centered over the crack.
−	* Slots shall also be centered over the crack or as directed by the Engineer.
−	* If the crack wanders, the slots shall be cut to have a specified minimum overlap of the dowel bar on each side of the crack according to the specification.
−	*The Contractor shall visibly mark the cracks along their length so that the slot cutter can see them to properly place the slots.
−
−	~~{{top}}~~
−
−	~~====[[#Removal of Concrete\|Removal of Concrete]]====~~
−
−	* The concrete remaining in the slots after sawing shall be removed with lightweight chipping hammers no greater than 30 lbs.
−	* The Contractor must provide manufacturer specifications to verify the capacity of the chipping hammers is no greater than 30 lbs.
−	* Concrete shall be removed in such a manner so as to prevent any pavement fractures caused by the removal operations.
−	* If the Contractor is allowed to use chipping hammers larger than 30 lbs., micro cracking of the remaining concrete will occur.
−
−
−	~~{{top}}~~
−
−	~~====[[#Spall Repair\|Spall Repair]]====~~
−
−	* Minor spalls, intermediate and major spalls shall be repaired using the patching material used to backfill the slot in accordance with [http://mdotcf.state.mi.us/public/specbook/files/2012/603%20Conc%20Pavt%20Restoration.pdf Section 6] of the Standard Specifications for Construction.
−
−	~~{{top}}~~
−
−	~~====[[#Slot Cleaning\|Slot Cleaning]]====~~
−
−	* Any loose concrete shall be vacuumed or removed from the slot and all surfaces shall be dry, abrasive blast cleaned.
−	* Any exposed steel shall be blast cleaned to remove any rust or laitance.
−	* Immediately prior to placement of the dowels and patching material, the slots shall be final cleaned with moisture-free, oil-free compressed air having a minimum pressure of 90 psi.
−
−	~~{{top}}~~
−
−	~~====[[#Dowel Bar Placement\|Dowel Bar Placement]]====~~
−
−	* After final cleaning, the crack shall be sealed with a bond breaker tape or joint sealant to prevent the patching material from entering the crack.
−	* When aligned correctly, dowels shall be true to the pavement surface and parallel to the pavement centerline.
−	* Bond release agents shall be applied over the entire dowel bar prior to placing the dowel bar into the slots.
−	* Any bond release agent spilled on any slot surface shall be immediately removed and the slot surface cleaned.
−
−	~~{{top}}~~
−
−	~~====[[#Patching\|Patching]]====~~
−
−	* The patching material shall be mixed with a portable or mobile mixer.
−	* The patching material shall then be consolidated using a hand-held vibrator or as recommended by the manufacturer.
−	* The surface of the patch shall be finished flush with the surrounding concrete and cured according to manufacturer’s recommendations.
−	* The surface must be finished flush with the surrounding surface even if diamond-grinding of the concrete surface is to occur afterward.
−	* The slot walls and bottom must be dry before placement of the patching material, unless otherwise recommended by the manufacturer.
−	* The patching material can be tested as necessary to verify that the mixture meets the specification.
−
−	~~{{top}}~~
−
−	~~====[[#Opening to Traffic\|Opening to Traffic]]====~~
−
−	~~The patching material shall be cured for the minimum time required by the contract specification before placing any vehicle loads on the repair.~~
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← Older revision		Revision as of 15:34, 8 May 2015
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	[[File:Table603-01.png\|600px\|thumbnail\|center\|Table 1: Modulus of Rupture Factors (F)]]		[[File:Table603-01.png\|600px\|thumbnail\|center\|Table 1: Modulus of Rupture Factors (F)]]
−
−	~~{{top}}~~
−
−	~~====[[#Swiss Hammer\|Swiss Hammer]]====~~
−
−	If a Swiss hammer is going to be used as an indicator of in-place strength of the patch, before the first beam is unmolded and tested, take 16 readings with the Swiss hammer for calibration. When the specified strengths are achieved, the inspector should have the approximate cure time and a Swiss hammer number to be used on the repairs for opening to traffic. The Swiss hammer should be recalibrated with a new set of beams weekly, or any time the mix is changed

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@@ Line 203: / Line 203: @@
 Transverse joints in pavement, shoulders and curb repairs will be the type shown on the plans.  Where existing curbs are to be left in place and expansion space is provided in the adjacent lane repair, an expansion joint (Esc) will be constructed in the curb by sawing and chipping out the existing concrete.  It is important that the width of the joint be equal to the width of the joint in the adjacent lane repair.  The Esc joint will align with the expansion joint in the repair.  The expansion joint filler will be shaped to fit the existing curb cross section.
-Expansion joint filler, for the Erg joints, will be 1 inch wide and extend the full depth of the patch minus 1-1/2 inch. Holes drilled into the joint filler must fit snugly around the dowel bars.  After October 15, the joint filler will extend the full depth of the patch until the joint is to be sealed.  At that time, the top 1-1/2 inch of the filler will be removed to form the joint reservoir for sealing.
+Expansion joint filler, for the Erg joints, will be 1 inch wide and extend the full depth of the patch minus 1-1/2 inch. Holes drilled into the joint filler must fit snugly around the dowel bars.  The joint filler will extend the full depth of the patch until the joint is to be sealed.  At that time, the top 1-1/2 inch of the filler will be removed to form the joint reservoir for sealing.
 Care must be taken to ensure that the holes drilled into the existing slab for dowel bars are true to the horizontal and vertical planes of the roadway.  Dowels not in alignment will restrict the Crg or Erg joints from working properly.  Some adjustment may be needed in the drilling machine for proper alignment of the dowel bars, or to ensure that the holes miss the reinforcement steel in the existing pavement.

← Older revision		Revision as of 15:32, 8 May 2015
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	Type P-NC concrete utilizing a Type C or Type E (non-chloride) set accelerator is the preferred patching mixture for use on MDOT projects. Use the manufacturer’s requirements for these set accelerators with the specified cement content to achieve a minimum flexural strength of 300 psi within the contract open-to-traffic time as determined for the project.		Type P-NC concrete utilizing a Type C or Type E (non-chloride) set accelerator is the preferred patching mixture for use on MDOT projects. Use the manufacturer’s requirements for these set accelerators with the specified cement content to achieve a minimum flexural strength of 300 psi within the contract open-to-traffic time as determined for the project.
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−
−	~~====[[#Pavement Reinforcement\|Pavement Reinforcement]]====~~
−
−	~~Pavement reinforcement is accepted for use by laboratory testing. The reinforcement should be stored off the ground. If contaminated, the reinforcement must be cleaned thoroughly before use.~~
−
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← Older revision		Revision as of 17:58, 18 September 2014
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	[[Category:Construction Manual]]		[[Category:Construction Manual]]
−	~~[[Category:Division 6]]~~

← Older revision		Revision as of 16:34, 30 April 2014
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	[[File:FIG603-01.png\|600px\|thumbnail\|center\|Beam Measurements]]		[[File:FIG603-01.png\|600px\|thumbnail\|center\|Beam Measurements]]

−	When using a concrete beam tester with center point loading the flexural strength equation above may be simplified using the modulus of rupture factors in table 1. The simplified equation is as follows:	+	When using a concrete beam tester with center point loading and a 16 inch span length (L), the flexural strength equation above may be simplified using the modulus of rupture factors in table 1. The simplified equation is as follows:

← Older revision		Revision as of 16:23, 29 April 2014
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		+	[[File:EQ603-01.png\|300px\|thumbnail\|center\|Flexural Strength of Concrete (Using Simple Beam With Center Point Loading):]]
		+
		+	Where:
		+
		+	:R = modulus of rupture or flexural strength in psi
		+	:P = maximum applied load in lbs
		+	:L = span length in inches
		+	:b = average specimen width in inches
		+	:d = average specimen depth in inches
		+
		+
		+	Calculate the average specimen width (b) and depth (d) by measuring the width and depth at each end of the beam and taking the average of those measurements.
		+
		+	[[File:FIG603-01.png\|600px\|thumbnail\|center\|Beam Measurements]]
		+
		+	When using a concrete beam tester with center point loading the flexural strength equation above may be simplified using the modulus of rupture factors in table 1. The simplified equation is as follows:
		+
		+
		+	[[File:EQ 603-02.png\|300px\|thumbnail\|center\|Simplified Center Point Flexural Strength Equation ]]
		+
		+	Where:
		+	:F = modulus of rupture factor in in²
		+
		+
		+	[[File:Table603-01.png\|600px\|thumbnail\|center\|Table 1: Modulus of Rupture Factors (F)]]
		+
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		+
		+	====[[#Swiss Hammer\|Swiss Hammer]]====
		+
		+	If a Swiss hammer is going to be used as an indicator of in-place strength of the patch, before the first beam is unmolded and tested, take 16 readings with the Swiss hammer for calibration. When the specified strengths are achieved, the inspector should have the approximate cure time and a Swiss hammer number to be used on the repairs for opening to traffic. The Swiss hammer should be recalibrated with a new set of beams weekly, or any time the mix is changed

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