7-120 Section 712. Bridge Rehabilitation — Concrete
712.01 Description
This work consists of removing concrete and patching or resurfacing with concrete patching or overlay mixtures and removing, replacing, and retrofitting expansion joints and structural concrete portions of existing bridges.
712.02 Materials
Provide materials in accordance with the following sections : Granular Material, Class II .................................................................... 902 Fine Aggregate 2MS ............................................................................. 902 Polypropylene Fibers ............................................................................ 903 Insulating Blankets ................................................................................ 903 Latex Admixtures .................................................................................. 903 Steel Reinforcement ............................................................................. 905 Bar Reinforcement ................................................................................ 905 Anchor Bolts .......................................................................................... 908 Geotextiles ............................................................................................ 910 Water ..................................................................................................... 911 Epoxy Resin Adhesive .......................................................................... 914 Epoxy Mortar ......................................................................................... 914 Mechanical Expansion Anchors ............................................................ 914 Concrete, Grade 3500, 3500HP, 4500, and 4500HP .......................... 1004 Mortar and Grout ................................................................................. 1005 Structures Patching Mixtures .............................................................. 1006 SFMC Overlay Mixtures ...................................................................... 1006 LMC Overlay Mixtures ........................................................................ 1006 Do not use chloride admixtures . Provide Grade 3500 concrete for filler walls. Provide Type H -1 grout selected from the Qualified Pr oducts List for use under masonry plates. Provide silica fume modified concrete (SFMC) or latex modified concrete (LMC) for concrete bridge deck overlay. Provide concrete containing natural aggregate with a maximum absorption of 2.50% in accordance with ASTM C127. Do not use slag aggregate. Provide adhesive anchors, mechanical expansion anchors, and mechanical reinforcement splices selected from the Qualified Products List . Select dry abrasive for blast cleaning from the Qualified Products List. MDOT Standard Specifications for Construction Section 712 7-121 Provide embedded galvanic anodes selected from the Qualified Products List. Provide threaded reinforcing bars with threaded couplers that are approved by the manufacturer for use w ith the product. Provide aluminum -filled epoxy mastic from a manufacturer from the Qualified Products List (915 Coating Systems for Steel Structures, Hanger Assemblies , and End Diaphragms).
712.03 Construction
A.Equipment
1.Equipment for Preparation of Existing Concrete
a.Sawing Equipment . Use sawing equipment capable of sawing concrete to the depth required by the contract.
b.Scarifying Equipment . Use a power -operated, mechanical scarifier capable of removing the concrete surface to at least ¼ inch deep wit h each pass . Attach a short ski, shoe, or other device to the cutter head to limit the cut depth.
c.Blast Cleaning Equipment . Use blast -cleaning equipment that uses abrasive or high-pressure water to remove rust scale from reinforcing bars and small chips of loosened concrete.
d.Superstructure Concrete Removal Equipment . Obtain the Engineer ’s written approval for the proposed sequence and method of removal before removing portions of the bridge superstructure. Use equipment for removing superstructure concrete in accordance with the following: Removing Superstructure Concrete on Steel Beams. Machine-mounted hydraulic or pneumatic equipment may be used in areas on the bridge decks between steel beams/girders . For re moval of superstructure concrete over steel beams, l imit the impact energy of machine-mounted hydraulic or pneumatic hammers to a maximum rating of 2,000 foot-pounds . Removing Superstructure Concrete on Prestressed Concrete I Beams, Spread Box Beams, Bulb Tee Beams, or 1800 Beams. Machine-mounted hydraulic or pneumatic equipment may be used in areas of the bridge deck between the beams and to remove sidewalks, curbs, barriers, and railings . Use manual pneumatic hammers to remove the bridge deck over prestressed concrete beams and diaphragms and to MDOT Standard Specifications for Construction Section 712 7-122 remove concrete diaphragms . Limit manual pneumatic hammers to 60 -pound maximum. Removing Superstructure Concrete on Prestressed Concrete Side -By-Side Box Beams. Do not use machine-mounted hydraulic or pneumatic equipment on full or partial deck removals or to remove sidewalks, curbs, barriers, and railings that rest directly on the prestressed concrete beams . Machine -mounted hydraulic or pneumatic equipment may be used to remove sidewalks, curbs, barriers, and raili ngs that do not rest directly on prestressed concrete beams . Use hydrodemolition or manual pneumatic hammers to remove concrete decks, sidewalks, curbs, barriers, and railings that rest directly on prestressed concrete beams . Limit manual pneumatic hammers to 60-pound maximum. Removing Superstructure Concrete at Expansion and Construction Joints on Concrete Beam Bridges . Do not use machine-mounted hydraulic or pneumatic equipment for removing superstructure concrete around expansion or construction joints on concrete beam bridges . Manual pneumatic hammers limited to 60-pound maximum may be used. Removing Superstructure Concrete at Expansion and Construction Joints on Steel Beam Bridges . Machine-mounted hydraulic or pneumatic equipment may be used on steel beam bridges . Limit the impact energy of machine-mounted hydraulic or pneumatic hammers to a maximum rating of 300 foot-pounds or an Association of Equipment Manufacturers (AEM) / Construction I ndustry Manufacturers Association (CIMA ) Tool Energy Rating of 130 foot-pounds . Use a conical or moil point . Do not use machine-mounted hydraulic or pneumatic hammers for removing joints within 12 inches of beam edges or within 6 inches of transverse saw cut lines. Use machine- mounted hydraulic or pneumatic hammers before constructing bridge deck overlays . Manual pneumatic hammers limited to 60-pound maximum may be used.
2.Hydrodemolition Equipment
a.Equipment Description . Use equipment that operates at a nois e level less than 90 dbA, as measured from a distance of 50 feet. Use potable water in hydrodemolition operations . Use equipment MDOT Standard Specifications for Construction Section 712 7-123 shielding to prevent injury or damage from flying debris in accordance with subsection 104.07.B.
b.Equipment Demonstration . The E ngineer will designate two trial areas on the bridge deck for the Contractor to demonstrate that equipment, personnel, and methods of operation produce results satisfactory to the Engineer. Complete required scarifi cation before the demonstration. The first trial area consists of 30 square feet of sound concrete, as determined by the Engineer . For shallow overlays, c alibrate equipment to remove sound concrete to the depth shown on the plans . For deep overlays, calibrate equipment to remove sound concret e to the depth of the top surface of the top reinforcing bars . Top surface of reinforcing bars must be exposed over 75% of the trial area. Move the equipment to a second trial area that consists of deteriorated or defective concrete and determine whether the calibration for sound concrete will completely remove the unsound concrete. If the equipment does not completely remove the unsound concrete, obtain another piece of equipment and perform another demonstration. The project completion date will not be a djusted due to delays in obtaining equipment. Begin production removal only if the Engineer determines that results are satisfactory . If the Engineer determines that equipment does not adequately remove concrete, the Engineer may require equipment recalibr ation during production work.
3.Concrete Overlay Surface Construction Equipment . Provide hand tools for placing freshly mixed concrete. Use a finishing machine with a self -propelled screed, at least one powered roller, augers, and vibratory pan set at a vibration rate recommended by the manufacturer . Use a finishing machine capable of moving forward and backward under positive control. Raise screeds to clear the screeded surface if traveling in reverse. Obtain the Engineer ’s approval for modifications to the finishing equipment. Operate the screed on longitudinal screed rails capable of carrying imposed loads between supports with a deflection no greater than 1⁄16 inch. Use rail sections, straight within ⅛ inch ov er 10 feet. Place the rail sections within 1⁄16 inch of the required screed grade . Attach MDOT Standard Specifications for Construction Section 712 7-124 rails to the surface to allow vertical adjustments and removal without damage to the new surface. Use vibratory equipment to consolidate hand -finished areas and along construction joints and bulkheads . For areas with epoxy -coated, or other coated, reinforcement, use a vibrator with a rubber -coated head. Alternative types of vibrating or oscillating screeds may be used if approved by the Engineer.
4.Joint Cleaning Equipment
a.Air Compressors . Use compressors with oil -free and moisture -free air and a nozzle pressure of at least 90 psi.
b.Abrasive Blasting Equipment . Use abrasive blasting equipment capable of cleaning as required, with a nozzle pressure of at least 90 psi. Use nozzles sized for the width of joint and replace them if enlarged by wear.
5.Adhesive Injection Equipment . Inject adhesive with positive displacement equipment with fixed ratio and automatic mixing of two components at the nozzle. Use equipment with drain- back plugs and a nozzle arrangement capable of adhesive injection at a pressure no greater than 120 psi without defacing concrete.
6.Blast Cleaning Equipment . Use blast -cleaning equipment with dry abrasive or high-pressure water to remove laitance and deleterious material, including old curing material and pavement marking paint.
B.False Decking . Construct false decking in accordance with subsection
706.03 B.
C.Superstructure Concrete Removal . Mark out beam and diaphragm locations before beginning removal operations . If removing decks, sidewalks, curbs, barriers, and railings, do not damage the concrete and steel portions of the superstructure to be retained. Repair damage to retained portions to the Engineer ’s satisfaction at no additional cost to the Department . If damage occurs, submit a corrective action plan to the Engineer for review and approval prior to beginning repairs . Repairs for damage affecting structural elements must be designed by a Prof essional Engineer licensed in the State of Michigan. If incorporating part of the deck into new construction, make a 1-inch-deep saw cut on the top and bottom of the deck at the limits of removal shown on the plans. If sawing to section the deck for remov al, cut no greater than 90% of the full depth of the deck over beams to avoid cutting the top flange. MDOT Standard Specifications for Construction Section 712 7-125 Saw cut vertical steel reinforcement in the front and back of sidewalks, curbs, barriers, and railings before removal. On prestressed concrete spread box beams , bulb tee beams, and 1800 beams, saw cut the deck between the beams full depth, parallel to the beams, and remove in sections.
D.Removal or Revisions to Bridge Deck Joints and Joint Glands. Remove or extend and modify existing bridge deck joints as shown in the contract . Clean structural steel exposed during concrete removal in accordance with SSPC -SP 3, Power Tool Cleaning . Apply two coats , 5 mils dry film thickness each , for a total of 10 mils with an aluminum -filled epoxy mastic . Field measure the existing bridge deck joint and the existing bridge before ordering materials. For revisions to existing expansion joint devi ces, field weld the new joint device to the existing joint device in accordance with sub section
707.03 E.7. Clean the exposed steel expansion joint device to remain in
accordance with SSPC -SP 2, Hand Tool Cleaning. Repair damaged coating in accordance with subsection 716.03.E . Protect the work and environment in accordance with section 715. Install the gland in accordance with the manufacturer ’s recommendations . Provide a continuous neoprene gland to replace the existing gland. Determine the correct seal manufacturer from field inspection. Fabricate the gland to conform to the contour of the bridge deck , all upturns , and the field-measured dimensions of the joints . At an intersection of strip seal joints , fabricate the intersection joint such that bot h the longitudinal and transverse joints are continuous . Use lubricant and adhesive to install and seal the joint as recommended by the manufacturer . Remove and reinstall portions of existing guardrail to access joints for removal.
E.Scarifying Bridge Decks
1.Scarifying . Close the structure to traffic . Scarify the concrete surface requiring an overlay to at least ¼ inch deep. Do not scarify deeper than 1 inch above the top of the top reinforcing bar . If the use of a scarifier is not practical, remove concrete using hand methods . Do not damage steel reinforcement. Locate the steel reinforcement with a pachometer or other Department approved method before scarifying in locations as approved by the Engineer. MDOT Standard Specifications for Construction Section 712 7-126 Do not scarify within 6 feet of new deck overlay until the overlay cures at least 48 hours. Allow only construction vehicles required to conduct the work onto scarified surfaces.
2.Determination of Unsound Concrete . After structure scari fying and cleaning, the Engineer will mark areas of unsound concrete.
F.Hand Chipping . Use hand methods to remove concrete next to exposed reinforcing steel, concrete from spalled areas, unsound concrete from Engineer -marked areas , epoxy patches, HMA patches, and other unsound material, as determined by the Engineer. Do not hand chip within 6 feet of new overlay until it cures at least 48 hours. Blast clean to remove scale or accumulated rust from steel reinforc ement .
1.Hand Chipping Bridge Deck Concrete . For areas requiring patching or leveling, remove concrete (sound and unsound) and other detrimental material, as determined by the Engineer, using manual pneumatic hammers, scarifying machines, or milli ng. Blast clean the area. If directed by the Engineer, saw cut the area requiring patching or filling on decks not requiring overlay to the required line and depth. If deep hand chipping is required, remove concrete to at least ¾ inch below exposed steel reinforcement . If areas requiring patching lie next to a joint , install edge forms to the grade shown on the plans . If full -depth removal of deck portions is required, install false decking in accordance with subsection 706.03.B. Remove loose material from the area requiring patching and clean with oil-free , compressed air . Flush the area with clean water under pressure and remove excess water by air blasting immediately before applying patching mixture. Clean structural steel exposed during concrete removal in accordance with SSPC -SP 3, Power Tool Cleaning. Coat exposed structural steel with two coats, 5 mils dry film thickness each, for a total of 10 mils with an aluminum -filled epoxy mastic before recasting concrete. Protect the work and environment in accordance with section 715.
2.Hand Chipping Concrete Other Than Deck Concrete . Remove unsound or loose concrete with air hammers or other Department -approved methods . Saw cut areas requiring patching or filling to an edge depth of at least 1 inch along a line determined by the Engineer . Remove concrete to at least 3 inches measured from the concrete surface. Remove concrete from exposed steel MDOT Standard Specifications for Construction Section 712 7-127 reinforc ement to provide clearance of at least ¾ inch around the steel reinforcement . Blast clean and blow out the area with oil -free, compressed air. If areas requiring patching lie next to joints, install edge forms to the line shown on the plans . Remove loose material from areas requiring patching and cleaning with oil -free, compressed air . Flush the ar ea with clean water under pressure and remove excess water by air blasting immediately before applying patching mixture. Place patches in accordance with subsection 712.03.O.
G.Hydrodemolition . Remove deck concrete and concrete patches with high-pressure water jets . If hydrodemolition is not practical, use hand methods to remove areas. Remove HMA patches in accordance with subsection 501.03. Remove patches by hydrodemolition, 60-pound pneumatic hammers, or other equipment approved by the Engineer . Clean debris from the deck before beginning the first pass of concrete hydrodemolition. If using hydrodemolition equipment to remove HMA patches, complete work before the first pass for concrete removal. Use hydrodemolition to the limits shown on the plans or as determined by the Engineer. If the plans show limits of hydrodemolition, make one pass of the hydrodemolisher to remove sound concrete to the depth and limits required. Avoid removing sound concrete beyond the required depth. Remove deteriorated or defective concrete within the limits required. The Engineer will determine and mark areas of unsound concrete remaining after the first pass, as specified in subsection 712.03.E.2. Remove unsound areas with a second pass of the hydrodemolisher, 60-pound pneumatic hammers, or other equipment approved by the Engineer . Make the second pass with the hydrodemolition equipment calibrated the same as for the first pass. Remove concrete debris by hand or mechanical methods immediately after hydrodemolition . Remove debris that settles on or adheres to the surface of sound concrete, at no additional cost to the Department. Avoid damage to remaining sound concrete or exposed steel reinforcement . Heavy equipment, including concrete trucks and vacuum trucks for removing concrete debris, are not allowed on hydrodemolished surfaces of the deck . Following debris removal and before placing overlay, blast clean the surface with abrasive or water to remove bond-breaking MDOT Standard Specifications for Construction Section 712 7-128 residue or loose material from concrete surfaces and rust from steel reinforcement. Clean structural steel exposed during concrete removal in accordance with SSPC -SP 3, Power Tool Cleaning, and apply two coats, 5 mils dry film thickness each, for a total of 10 mils with an aluminum -filled epoxy mastic. Protect the work and environment in accordance with section 715. Sample, test, monitor, manage, neutralize, and discharge hydrodemolition runoff water from bridge decks . Collect, filter, and dispose of runoff water generated by hydrodemolition. Obtain the required permits and comply with regulations concerning runoff water disposal . Do not allow runoff water to create a hazard to the adjacent or underlying traveled roadway surfaces . Protect existing berm slopes from scouring by water jet or runoff water . Do not allow runoff water, filtered or unfiltered, to enter storm sewers, bridge drain downspouts, or bridge approach downspouts . Do not discharge runoff water, filtered or unfiltered, into surface water, floodplains, or wetlands. In areas with enclosed drainage systems or areas where the contract does not allow runoff discharge, collect, haul, and dispose of runoff water as a liquid industrial waste in accordance with section 107.
H.End Header Replacement . Remove the end header of bridge decks and rebuild decks and adjacent approaches in the removal area, as shown in the contract.
I.Exposed Steel Reinforcement . Blast clean to remove scale or accumulated rust from steel reinforcement . Supplement broken or missing reinforcement and bars that have lost one-fourth or more of the original bar diameter by splicing in new bars with a lap length of 35 bar diameters or as directed by the Engineer . If the bond between existing concrete and reinforcing steel is destroyed, remove concrete next to the bar to at least ¾ inch deep, except on bridge decks with lower bar mat clearances that make this impractical . Do not displace or damage exposed steel reinforcement . Remove exposed waterstops . Adjust steel reinforcement to provide cover as shown on the plans. Wire tie exposed, untied steel reinforcement bar laps and intersections as follows :
1.Bar Laps. Tie bar laps within 3 inches of each end of the lap. If sound concrete bonded to steel reinforcement prohibits tying bar laps, remove concrete to tie the bars as required.
2.Bar Inte rsections. Tie bar intersections at every third intersection. If sound concrete bonded to steel reinforcement prohibits tying a bar intersection or tying the third intersection, tie the next nearest MDOT Standard Specifications for Construction Section 712 7-129 intersection. Do not remove sound concrete bonded to steel reinforcement to tie the required bar intersections.
J.Anchoring Reinforcing Bars or Bolts with Adhesive . Drill holes, remove unsound concrete and dust, fill drilled holes with adhesive, and install reinforcing bars or bolts in accordance with the manufact urer’s recommendations except as modified by the contract . Place adhesive when the concrete and steel temperature is at least 50°F and rising. Indirect artificial heat may be used to warm the concrete and bars or bolts . The temperature of the concrete and bars or bolts must be maintained until the adhesive is fully cured. Maintain concrete and steel surfaces that the adhesive will contact , free of contamination.
1.Anchoring Bars or Bolts . Propose complete details of drilling, cleaning, and bonding systems for anchoring reinforcement or bolts and submit for the Engineer ’s approval before use. The minimum embedment depth must be 9 times the anchor diameter for threaded rods or bolts and 12 times the anchor diameter for reinforcing bars . Propose a dril ling method that does not cut or damage existing steel reinforcement . Prepare at least three proof tests per anchor diameter and type in the same orientation in which they will be installed on the existing structure on a separate concrete block representat ive of the existing structure concrete . Install proof test anchors in the presence of the Engineer . The Engineer will conduct the proof testing of the proposed systems. The Engineer will base approval of the anchoring system on the following criteria:
a.Proo f tests show that 125% of the bar yield strength can be developed;
b.Bars bond to the concrete at least 90% of the embedded bar length and circumferential area; and
c.Average bar slippage at yield strength does not exceed 1⁄16 inch. Locate the steel reinforcem ent with a pachometer or other Department -approved method before drilling holes . Remove loose concrete, dust, dirt, and oil from holes by flushing with water under pressure and mechanical agitation. Blow out the holes with oil -free, compressed air and dry before applying adhesive. Clean steel reinforcement of loose scale, rust, oil, and dirt and dry before installation. Prepare adhesive for installation in the hole in accordance with the manufacturer ’s directions. Place adhesive in the hole to completely fill the space between bar and hole surface for the entire hole depth. MDOT Standard Specifications for Construction Section 712 7-130 2. Field Testing . Conduct field testing during the first production day at three locations selected by the Engineer . Provide adequate notice to allow the Engineer to witness thi s field testing . Use a tension testing device for unconfined testing in accordance with ASTM E488/E488M . Provide a copy of a certified calibration for the tension testing device. Update the calibration annually . The Engineer may conduct random pull-out tes ts for acceptance. In order to be considered passing tests, field tests performed by the Contractor and random tests performed by the Engineer must show that 90% of the bar yield strength develops with less than 1⁄16 inch slip. Repair damage to epoxy coating.
K.Mechanical Expansion Anchored Bolts . Propose a drilling method that does not damage or cut existing steel reinforc ement . Locate steel reinforcement by a pach ometer or other Department -approved method before drilling the holes . Drill holes of the size and depth recommended by the bolt manufacturer except as modified by the contract . Remove unsound concrete. Clean the hole with oil -free, compressed air, brush it, and clean out with air again. Do not elongate holes . The Engineer will conduct proof test ing of the proposed anchors.
1.Anchoring Bolts . Provide a copy of the manufacturer ’s product data sheet and installation procedure for the anchors, showing the ultimat e load of the anchor at the required embedment depth. Prepare the proof test anchors on a separate concrete block representative of the existing structure concrete . The anchors must develop the proof loads specified in Table 712-1. Table 712- 1: Anchor Bolt Proof Tensile Loading Diameter (inch) Load (lb) ⅜ 3,500 ½ 6,400 ⅝ 10,200 ¾ 15,000 ⅞ 20,800
2.Field Testing . Conduct field testing during the first production day at three locations selected by the Engineer . Provide adequate notice to allow the Engineer to witness the field testing. Use a tension testing device in accordance with ASTM E488/E488M . Provide a copy of a certified calibration for the tension testing device. Update the calibration annually . In order to be considered passing tests, fiel d tests MDOT Standard Specifications for Construction Section 712 7-131 must show that the anchor provides a pull -out resistance of at least 50% of the proof tensile load at 1⁄16 inch slippage. The Engineer may conduct random pullout tests at 50% of the proof tensile load for acceptance.
L.Mechanical Reinforcement Splicing
1.Preparation of Bar Ends . Saw or shear bars requiring splicing. Straighten the ends of sheared bars . Remove burrs, paint, oil, rust, scale, or other deleterious material from surfaces . Use wire brushes, abrasive blasting, or other Department -approved methods to clean 2 inches beyond sleeve locations immediately before splicing. Obtain the Engineer ’s approval for bar end surface preparations before installation.
2.Installation . Install mechanical reinforcement splices in accordance with the manufacturer ’s procedure. Submit the installation procedure, including manufacturer approvals, to the Engineer for review before beginni ng splicing. If using epoxy -coated steel reinforcement, epoxy coat mechanical reinforcement splices in accordance with ASTM A775/A775M . If the installation procedure does not damage a pre-applied epoxy coating, provide epoxy -coated splices . After installat ion, epoxy coat exposed surfaces of mechanical reinforcement splices and attached reinforcing steel, including damaged coatings and exposed threads, in accordance with subsection 706.03.E.8. Protect the threads of threaded couplers with internal plastic coupler protectors or other manufacturer -approved methods . Protect the threads on the reinforcing bars with plastic bar end protectors or other Department -approved methods . Adjust flanged or asymmetrical couplers to minimize infringement on the required clear cover.
3.Testing . Provide adequate notice to allow the Engineer to witness the test splicing . Use tests to establish a splicing procedure. Provide two test splices on the largest bar size. Demonstrate to the Engineer that splices have a tensile s trength of 125% of the bar yield strength and that high strength splices have a tensile strength of 150% of the bar yield strength. Provide sample bars 12 inches long for the required tests . If the exterior of existing reinforcing steel for splicing is cor roded or deformed, the Engineer may require additional qualification testing on the bars . The Department will test all test splices.
M.Forming . Provide forms to enable placement of concrete mixture. If approved by the Engineer, suspend forms from existing reinforcing bars using wire ties . In large removal areas, support forms by blocking from the MDOT Standard Specifications for Construction Section 712 7-132 beam flanges . Install forms for vertical patches in no greater than 4-foot-high sections with the form tops no more than 4 feet above the concrete level as the pour progresses . Remove forms upon completion of the work.
N.Protection and Cleaning of Deck Areas to be Overlaid . Maintain areas of removed unsound concrete and patches free of slurry produced by wet sawing or wet scarifying . Drain slurry away from completed areas . Remove slurry from prepared areas before resurfacing. Before placing overlay, blast clean the deck and the edges of previously placed overlays to expose coarse aggregate and obtain a sound surface for bonding the overlay to the deck . Blast clean with abrasive or water under high pressure. Minimize and c ontrol dust from abrasive blasting operations . Methods for dust control may include the use of water -blasting or vacuum equipment. Complete the final deck preparation and allow the Engineer time to inspect the deck condition before placing overlay . Obtain written approval from the Engineer for placing concrete overlay. Do not allow traffic on the prepared deck before overlay placement. Clean and wet the deck surface 1 hour before placing overlay mixture and keep surface damp throughout the pour . Remove standing water from depressions, holes, or concrete removal areas with oil -free, compressed air.
O.Mixing, Placing, Finishing, and Curing Concrete Patches . Machine mix patching mixture with equipment specified in subsection 1006.03. Provide mixture in quantities to allow placing and finishing before initial set. Prepare and test work progress specimens, as necessary, in accordance with section 1002. Moisten surface without leaving free water, and prime the existing concrete. Place patching mixture. On bridge decks with LMC mixes, use a stiff bristle brush to apply the initial layer of mixture onto the wetted, prepared surface. Apply an even coating to vertical and horizontal surfaces . Limit the rate of progress so brushed material does not dry before covering with overlay material . Do not use material for brushing if no mortar remains in the mix. For bridge decks, place the patching mixture into the area, vibrat e uniformly, and finish with a wood float . After finishing, texture the patched surface to uniformly roughen the surface. MDOT Standard Specifications for Construction Section 712 7-133 For patches on surfaces other than decks, place concrete and consolidate. The Engineer may direct the use of small hand vibrators or the vibration of the forms. Immediately after final finishing each patch, apply a layer of wet burlap soaked in water for at least 12 hours to exposed concrete surfaces . Place a 4-mil-thick layer of polyethylene film over the burlap to protect the top surfaces from evaporation. Membrane curing compounds may be used for patches of non-LMC . Forms may be left in place with burlap covering exposed areas for curing. Keep patches of non-LMC covered until concrete attains a flexural strength of 550 psi but not less than 5 days for regular strength patching mixtures or no t less than 24 hours for high-early -strength patching mixtures. Maintain patches with regular strength LMC continuously damp for the first 48 hours . Remove curing material at the end of the 48- hour wet cure period and allow concrete to air cure for an additional 48 hours . Maintain patches with high-early -strength LMC continuously damp for at least 24 hours. If the air temperature falls below 50°F, the Engineer may require additional curing time t o ensure that concrete attains a flexural strength of 550 psi. If completing concrete repairs in cold weather, protect concrete in accordance with subsection 712.03.R. Do not place additional concrete on reinforced substructure concrete until reinforced substructure concrete cures for at least 3 days and attains at least 70 % of the required minimum 28-day flexural or compressive strength. Do not use mechanical attachments to support forms until concrete attains at least 70% of the required minimum 28-day f lexural or compressive strength. The Engineer may lower the concrete strength required for attaching forms after reviewing calculations submitted by a Professional Engineer licensed in the State of Michigan, showing that imposed loads will not exceed 70% of the concrete strength at the time the load is applied.
P.Mixing, Placing, Finishing , and Curing Latex Modified Concrete (LMC) Overlay Mixtures. Prepare and test work progress specimens, as necessary, in accordance with section 1002. Keep equipment off patches until patches attain a flexural strength of at least 550 psi. Place LMC overlay mixtures at night in accordance with subsection
706.03 I.
MDOT Standard Specifications for Construction Section 712 7-134 Form expansion joints and dams through the overlay . Install bulkheads to the required grade and profile before placing concrete mixture. Do not cast full depth across the joint. Place screed rails and fasten to ensure that new surfaces are finished to the required profile. Provide horizontally and vertically stable supporting rails. Do not treat screed rails with parting compound. Remove and reinstall portions of existing thrie beam guardrail required for access to screed the deck. Texture and finish deck surfaces to the tolerances specified in subsections 706.03.M.3 and 706.03.M.4. Proportion ingredients and mix at the project site in clean mixers . Provide concrete uniform in composition and consistency . Produce mix at a rate that allows finishing to continue at a steady pace with final finishing completed before the formation of the plastic surface film . Brush the initial layer of mixture onto the wetted, prepared surface and apply even coating to vertical and horizontal surfaces . Limit the rate of progress so brushed material does not dry before covering with overlay material . Do not use material for brushing if no mortar remains in the mix. Place the mixture at least ¼ inch above the final grade. Consolidate and finish to the final grade. Hand finish with a float along the edge of the pour or on small areas . Use a small quantity of latex grout to aid hand floating if necessary . Finish joints with an edge tool, except next to metal expansion dams, curbs, previously placed lanes, and edges requiring sawing. Grind to remove minor irregularities. After the mixture stiffens, separate screed rails and construction bulkheads from the new material by passing a pointing trowel along the inside face. Cut with the trowel the entire depth and length of rails . Do not separate metal expansion dams from the overlay. Cover the finished surface with a single layer of clean, wet burlap when the surface can support it without deformation. Place a polyethylene film at least 4 mils thick on the wet burlap within 1 hour of covering the concrete with burlap, and wet cure the surface for 48 hours . Do not form or cast succeeding portions onto the bridge deck prior to completion of the 48- hour wet cure. Remove excess or ponding cure water prior to casting succeeding portions. Burlap-polyethylene (Burlene) sheets may be substituted for polyethylene film if approved by the Engineer . Place the polyethylene side down against the wet burlap. MDOT Standard Specifications for Construction Section 712 7-135 At the end of the 48-hour wet cure period, remove curing material and allow the surface to air cure for an additional 48 hours . Do not allow curing water runoff to enter surface water . Keep traffic off the surface for at least 96 hours after placement .
Q.Mixing, Placing, Finishing, and Curing S ilica Fume Modified (SFMC) Concrete Overlays. Prepare and test work progress specimens, as necessary, in accordance with section 1002. Keep equipment off patches until patches attain a flexural strength of at least 550 psi. Place SFMC overlay mixtures at night in accordance with subsection 706.03.I. Form expansion joints and dams through the overlay . Install a bulkhead to the required grade and profile before placing the concrete mixture. If joint is cast prior to the overlay, do not cast full depth across the joint . If joint placement is integral with overlay placement, cast joints full depth. Place screed rails and fasten to ensure that new surfaces are finished to the required profile. Provide horizontally and vertically stable supporting rails. Do not treat screed rails with parting compound. Remove and reinstall portions of existing thrie beam guardrail required for access to screed the deck. Mix and place a 4-cubic -yard trial batch at the batch plant, or at the project site as directed by the Engineer, at least 3 days before full production. Notify the Engineer of the time and location of the trial batch at least 24 hours before batching. Proportion trial batches in accordance with the adjusted mix design, using the same materials as in the production mixture. The Engineer will consider the trial batch successful if slump test results are within 1 inch of the required range and the air content test results are within 1.0% of the required range. If trial batches do not meet the requirements, discard and repeat the batching at no additional cost to the Department . Proportion and mix SFMC using a ready -mixed or central -mixed batch plant in accordance with subsection 1006.03 . Discharge trucks on the project within 1 hour of charging at the plant. Wet the prepared deck 1 hour before placing the SFMC overlay with a spray application of water . Use clean, oil -free, compressed air to remove water collected in depressions . Maintain a moistened surface throughout the pour. Hand vibrate SFMC mixture placed in localized areas deeper than 3 inches . Draw a probe vibrator horizontally through the concrete, parallel to the transverse reinforcing bars, at intervals no greater than 18 inches . MDOT Standard Specifications for Construction Section 712 7-136 Vibrate ahead of the finishing machine. Provide a locator system to assist the operator in finding deep removal areas, and coordinate with the Engineer. Texture and finish deck surfaces to the tolerances specified in subsections
706.03 M.3 and 706.03.M.4.
Apply a continuous fog spray of water to the screeded and finished concrete. Provide fogging equipment capable of spreading a fine mist over concrete surfaces without ponding water . Continue fogging behind the final floating operation until placement and activation of the wet cure system. Do not fog concrete surfaces to aid surface finishing. Prepare clean, contaminate-free burl ap by soaking in clean water for at least 12 hours before beginning concrete placement . Immediately before use, drape or suspend the burlap sheeting vertically to remove excess water . Cover concrete surfaces with wet burlap when the concrete surface can support it without deformation. Do not allow in- place burlap to dry . Do not use b urlap- polyethylene ( Burlene) or other products with impervious surfaces. Install a network of soaker hoses over wet burlap when the concrete surface will support it without deformation. Use soaker hoses perforated throughout the lengths within the curing limits . Use non-perforated hose outside the curing limits . Connect to a water supply that meets the requirements of section 911. Ensure that soaker hoses apply cure water uniform ly and continuously cover the entire bridge deck surface without moving the hoses . Prevent excessive localized water discharge. Demonstrate to the Engineer that soaker hose systems provide uniform coverage of the entire deck surface. Place a layer of 4-mil-thick polyethylene film over the entire deck surface and soaker hose system . Overlap seams in the polyethylene at least 10 inches . Activate the system and maintain complete and uninterrupted wet curing. Control water runoff to prevent a hazard to traffic or soil erosion. Do not allow curing water runoff to enter surface waters. Maintain the wet cure for at least 7 days after concrete placement . Do not remove wet cure systems based on 7- day compressive strengths reached in less than 7 days . Do not form or cast succeeding portions onto the overlay prior to completion of the 7-day continuous wet cure . Remove excess or ponding cure water prior to casting of succeeding structure portions. Do not allow heavy equipment on the deck overlay until the overlay concr ete is in place at least 7 days and attains at least 70% of the required minimum 28-day f lexural or compressive strength. MDOT Standard Specifications for Construction Section 712 7-137 R. Cold Weather Limitations for Placing SFMC or LMC Overla y Mixtures. Complete overlays and other work within required temperatures . Place LMC or SFMC concrete between April 1 and November 1 unless approved otherwise by the Engineer . Maintain concrete at a temperature of at least 4 5°F. Place overlay mixtures if the air temperature and concrete substrate are at least 40°F and rising and the air temperature during the curing period is forecast ed to remain above 35°F . Use insulating blankets if the air temperature during the curing period i s forecast ed to fall below 45°F . Overlap blankets at least 12 inches . Place the insulating blankets on top of the wet curing system . Leave insulating blankets in place for the duration of the wet curing period. For LMC overlays, i f the air temperature is forecast ed to fall below 45°F during the remainder of the curing period, extend the curing period until the concrete attains a flexural strength of at least 550 psi. Cure for the full curing period, regardless of strength gain.
S.Hot Weather Limitations for P lacing Overlay Mixtures. Cast concrete overlay mixtures when evaporation does not exceed 0.15 pounds per square foot per hour in accordance with Figure 706- 1. Cast overlay concrete when air temperature remains below 85°F . Supply Department -approved equipment for determining the relative humidity and wind velocity on the project.
T.Construction Limitations for Placing Overlay Mixtures. For delays no greater than 1 hour, protect the end of the concrete pour from drying with several layers of wet burlap. For del ays greater than 1 hour, install a construction dam or bulkhead. If restarting the overlay placement before the concrete cures, leave a 3-foot gap between bulkheads . Blast clean and cast the gap the next working day. Protect freshly placed concrete from rain as approved by the Engineer . Stop placement operations if rain starts . The Engineer may direct the removal of material damaged by rain. Remove screed rails after the concrete takes initial set . Protect edges of new surfaces from damage during screed rail removal. Cure overlays and repair areas for at least 48 hours before scarifying, hydrodemolition, or chipping within 6 feet. Outline repair areas with saw cuts extending to the depth of the overlay before removal and repair.
U.Repairing Cracks by Pressure Injection . Repair cracks as shown on the plans or directed by the Engineer. MDOT Standard Specifications for Construction Section 712 7-138 1. Preparation of Cracked Surfaces. Remove leaching deposits from cracks by abrasive blasting or wire brushing as directed by the Engineer . Apply a temporary seal, with entry ports for adhesive, along the clean, dry crack without defacing the concrete surface. The seal must contain the pumped adhesive . Space ports farther apart than the estimated crack depth and close enough to allow adhesive material to travel between ports.
2.Flushing Cracks . If directed by the Engineer, flush cracks with water by pressure washing through injection ports . Wash out concrete laitance or contaminants in the crack . Remove free water by blowing air through the crack after flushing.
3.Temperature Limitations for Injection . Perform injection when concrete and ambient air temperatures are above 50°F . The Engineer may approve lower injection temperatur es if the adhesive material manufacturer ’s recommendations support lower injection temperatures.
4.Injection of Cracks. Begin injection at the lower entry port and continue until adhesive is visible at the port directly above or next to the pumping port . Stop injection and seal the port . Transfer the injector to the next port and continue injection until the crack fills . Inject from both sides of a cracked member to complete crack repair . Prevent leakage of the adhesive from the crack after injection compl etion.
5.Adhesive Cure and Removal of Temporary Seal . Cure adhesive at temperatures of at least 50°F for the minimum cure time recommended by the manufacturer . Remove the seal or grind flush with the concrete surface. The Engineer may allow the temporary sea l to remain in place for injected areas not visible. Clean areas repaired by injection of surface contamination caused by injections.
V.Water Repellent Treatment . Apply penetrating water -repellent treatment in accordance with subsection 706.03.S.
W.Cleaning and Coating Exposed Structural Steel . Clean and coat areas of visible rust, rust breakthrough, and blistered, peeling, or scaling paint as identified by the Engineer . Clean structural steel exposed during concrete removal in accordance with SSPC SP3 , Power Tool Cleaning, and brush coat with 5 to 10 mils of aluminum -filled epoxy mastic or clean and coat in accordance with section 715. Protect the work and environment in accordance with section 715. The Engineer will inspect the following surfaces to decide the necessity of cleaning and coating: MDOT Standard Specifications for Construction Section 712 7-139 1. The tops and edges of top flanges and beam ends if removing the entire deck above steel beams;
2.The edges of top flanges if using metal deck forms ; and
3.Metal surfaces exposed during removal of backwall portions or full deck removal. Complete cleaning and coating of exposed structural steel before installing deck forms and shear developers.
X.Grouting Under Masonry Plates. Propose procedures for grouting under masonry plates to the Engineer for approval . Demonstrate to the Engineer by full -scale test that the grout placement procedures result in 90% surface area contac t based on the contact areas of the masonry plate and concrete surface. Do not begin the grouting operation until underlying concrete achieves 70% of the required minimum 28-day flexural or compressive strength. Form the space for grouting and clean the su rface . Mix, place, and cure grout in accordance with the manufacturer ’s recommendations. After curing, remove forming material to allow inspection of the grouted space. Do not apply load to the grout until cu ring is complete.
Y.Galvanic Anodes. Use Portland cement -based repair mortars, concrete, and bonding agents . Do not use non-conductive repair materials, including epoxy, urethane, and magnesium phosphate. Install galvanic anodes to existing uncoated reinforcement along the perimeter of the repair, spaced as shown on the plans and in accordance with the manufacturer ’s recommendations . Do not space anodes more than 24 inches apart . Provide ¾ -inch clearance between anodes and substrate to allow repair material to encase anodes. Secure galvanic anodes as close as possible to the patch edge using anode tie wires . Tighten tie wires to prevent free movement. If tying anodes onto a single uncoated steel reinforcing bar or covering with less than 1½ inches of concrete, place anodes under the uncoated reinforc ing steel . Secure anodes to uncoated reinforcing steel according to the manufacturer ’s recommendations If 1½ inches of concrete covers the anode, a nodes may be placed at the intersection between two uncoated bars and secure d to each bar. MDOT Standard Specifications for Construction Section 712 7-140 Confirm electrical connection between anode tie wires and uncoated reinforcing steel with a multi -meter . Ensure a direct current (DC) resistance of no greater than 1 ohm. Confirm electrical continuity of exposed, uncoated reinforcing steel in the repair area. Steel reinforcement is considered continuous if the DC resistance is not greater than 1 ohm. If the DC resistance is greater than 1 ohm, establish electrical continuity with uncoated steel tie wire. Obtain verification of installation of galvanic anodes from the Engineer before concrete placement.
712.04 Measurement and Payment
Pay Item Pay Unit Scarifying ....................................................................................... Square Yard Latex Conc Surface, Rem .............................................................. Square Yard Hand Chipping, Shallow ................................................................ Square Yard Hand Chipping, Deep .................................................................... Square Yard Hand Chipping, Full Depth ............................................................... Cubic Foot Hand Chipping, Other Than Deck .................................................... Cubic Foot Hydrodemolition, First Pass ........................................................... Square Yard Hydrodemolition, 2nd Pass ............................................................ Square Yard Structures, Rehabilitation, Rem Portions (Structure Identification) .. Lump Sum End Header Replacement ......................................................................... Foot Deck Joint, Rem ........................................................................................ Foot Bridge Joint, Revise Expansion Device .................................................... Each Bridge Joint, Strip Seal Gland Replacement .............................................. Foot Adhesive Anchoring of Vertical Bar, __ inch ............................................. Each Adhesive Anchoring of Horizontal Bar, __ inch ......................................... Each Bolt, Adhesive Anchored, __ inch ............................................................ Each Bolt, Mechanical Expansion Anchored, __ inch ........................................ Each Reinforcement, Mechanical Splice ............................................................ Each Patch, Full Depth ............................................................................. Cubic Yard Patching Mortar or Conc ................................................ Cubic Foot,Cubic Yard Patching Conc, (type) ...................................................................... Cubic Yard Patch, Forming .............................................................................. Square Foot Flushing Cracks, Water .............................................................................. Foot Structural Crack, Repr ............................................................................... Foot Filler Wall Conc ................................................................................ Cubic Yard Top Flanges and Beam Ends, Clean and Coat .............................. Square Yard Bridge Deck Surface Construction ................................................. Square Yard Conc, Silica Fume Modified ............................................................. Cubic Yard Conc, Bridge Deck Ovly ................................................................... Cubic Yard Masonry Plate, Grout ................................................................................ Each MDOT Standard Specifications for Construction Section 712 7-141 Embedded Galvanic Anode ...................................................................... Each
A.Scarifying . The Engineer will measure Scarifying to the limits shown o n the Plans, including joints and drain castings.
B.Latex Concrete Surface, Removal . The unit price for Latex Conc Surface, Rem includes the cost of removing LMC bridge deck surfaces to a depth of 3 inches or to the top mat of steel reinforcement . The Department will pay for removing unsound LMC at or below the top mat of steel reinforcement at the unit price for relevant hydrodemolition pay items.
C.Hand Chipping
1.Hand Chipping, Shallow . Hand Chipping, Shallow appli es to removing bridge deck concrete from the surface to the midpoint of the top bar of the top mat of the steel reinforcement . The Engineer will measure Hand Chipping, Shallow based on areas marked by the Engineer . The unit price for Hand Chipping, Shallow includes the cost of all perimeter sawcuts, removal of material, blast cleaning steel reinforcement , and preparing the area for patching.
2.Hand Chipping, Deep . Hand Chipping, Deep applies to removing bridge deck concrete from the surface to at least ¾ inch below the bottom of exposed steel . The Engineer will measure Hand Chipping, Deep based on areas marked by the Engineer . The unit price for Hand Chipping, Deep includes the cost of all perimeter sawcuts, removal of material, blast cleaning steel reinforcem ent, preparing the area for patching, cleaning and coating exposed structural steel, and protecting the work and the environment during cleaning.
3.Hand Chipping, Full Depth . Hand Chipping, Full Depth applies to removing bridge deck concrete full depth. The Engineer will measure Hand Chipping, Full Depth based on areas marked by the Engineer . The unit price for Hand Chipping, Full Depth includes the cost of all perimeter sawcuts, removal of material, blast cleaning steel reinforcement, preparing the area for patching, cleaning and coating exposed structural steel, and protecting the work and the environment during cleaning.
4.Hand Chipping, Other Than Deck . Hand Chipping, Other Than Deck applies to removing concrete but does not apply to removing deck top surfac es, regardless of depth. The Engineer will measure Hand Chipping, Other Than Deck based on areas marked by the Engineer . The unit price for Hand Chipping, Other Than Deck includes the cost of all perimeter sawcuts, removal of material, blast cleaning steel reinforcement , and preparing the area for patching. MDOT Standard Specifications for Construction Section 712 7-142 5. Hydrodemolition . The Engineer will measure Hydrodemolition, First Pass to the limits shown on the plans without deducting areas of expansion joint devices and drain castings. The uni t price for Hydrodemolition, First Pass includes the cost of removing concrete, including concrete removed during the successful hydrodemolition equipment demonstration; tying exposed steel reinforcement ; cleaning and coating exposed structural steel ; and protecting the work and the environment during cleaning. The unit price for Hydrodemolition, 2nd Pass includes the cost of hand chipping to remove concrete, including LMC , below steel reinforcement. The Department will pay for removing HMA patches as HMA P atch, Rem in accordance with subsection 501.04.
D.Reinforcing
1.Reinforcement, Steel . The Engineer will measure, and the Department will pay for , steel reinforcement as Reinforcement, Steel of the type required in accordance with subsection 706.04. The Engineer will measure dual bars of equivalent section as the required size. The unit price for Reinforcement, Steel includes the cost of providing and splicing in new bars to replace corroded or removed bars . The Department will not pay for replacing reinforcement damaged by Contractor operations.
2.Adhesive Anchoring of Vertical and Horizontal Bars . The unit prices for Adhesive Anchoring of Vertical Bar and Adhesive Anchoring of Horizontal Bar , of the sizes required, includes the cost of providing adhesive, drilling and cleaning holes, filling holes with adhesive, installing bars, and testing. The unit price for Reinforcement, Steel of the type required includes the cost of providing reinforcing bars . The Department will pay for each bar end requiring anchoring as a separate unit.
3.Reinforcement, Mechanical Splice. The Engineer will measure, and the Department will pay for , Reinforcement, Mechanical Splice by the number of units required. If increased coupler lengths compensate for inferior deformations on existing bars, the Department will increase the unit price on a pro-rated basis, based on the length of the increase in inches. MDOT Standard Specifications for Construction Section 712 7-143 The unit price for Reinforcement, Mechanical Splice includes the cost of preparing test samples, preparing steel reinforcement for splicing, installing couplers, and applying epoxy coating. The unit prices for Reinforcem ent, Steel of the required type include the cost of threaded reinforcing bars used with threaded couplers.
E.Bolt, Adhesive Anchored . The unit price for Bolt, Adhesive Anchored includes the cost of providing bolts and adhesive, drilling and cleaning holes, filling holes with adhesive, installing bolts, and testing.
F.Bolt, Mechanical Expansion Anchored . The unit price for Bolt, Mech anical Expansion Anchored includes the cost of providing bolts, drilling and cleaning holes, installing bolts and testing
G.Structures, Rehabilitation, Remove Portions . The unit price for Structures, Rehabilitation, Rem Portions includes the cost of removing materials as shown on the p lans, saw cuts required for removal, and disposal of materials in accordance with subsection 204.03.B.
H.End Header Replacement . The unit price for End Header Replacement includes the cost of removing and replacing end headers, al ong with portions of decks, backwalls, and approach pavements as shown on the plans.
I.Structural Crack, Repair . The Engineer will measure Structural Crack, Repr along the length of crack injected along one surface only . The unit price for Structural Crack, Repr includes the cost of preparing cracks, installing temporary seals and ports, providing and injecting the epoxy adhesive, removing temporary seals, and cleaning finished surfaces. If the Engineer requires additional cleaning and flushing of the cracks after placing temporary seals and entry ports, the Department will pay for this work as Flushing Cracks, Water .
J.Deck Joint, Removal . The Engineer will measure Deck Joint, Rem to the limits shown on the plans . The unit price for Deck Joint, Rem includes the cost of removing expansion and construction joints, cleaning and coating exposed structural steel, removing deck joint concrete, regardless of deck thickness and diaphragm locations , removing barrier, sidewalk and brush block concrete, protec ting the work and environment during cleaning, and removing and reinstalling portions of existing guardrail required to remove the joint . The Department will pay for removal required beyond the limits shown on the plans as extra work. Bridge Joint , Revise Expansion Device will be measured as each. The unit price for Bridge Joint, Revise Expansion Device includes field MDOT Standard Specifications for Construction Section 712 7-144 welding , cleaning, and coating the expansion joint device. The Engineer will measure each joint end separately. Bridge Joint, Strip Seal Gland Replacement will be measured to the limits shown on the plans . The unit price for Bridge Joint, Strip Seal Gland Replacement includes the cost of removing the existing gland and any associated appurtenances, cleaning the expansion joint device, protectin g the work and environment during cleaning, and providing and installing the replacement glands, lubricants and adhesives , and any associated appurtenances.
K.Patching . The Engineer will measure Patch, Full Depth based on the volume of the hole requiring fil ling. The unit price for Patch, Full Depth includes the cost of forming, providing, placing, consolidating, finishing, and curing the patching mixture. If using Patch, Full Depth in conjunction with overlay, the Department will only pay for patching the ar ea shown on the plans . If full -depth patches are required in areas not shown on the plans , unit prices for Conc, Bridge Deck Ovly or Conc, Silica Fume Modified will include the cost of the concrete material required to fill the full depth patches. For full -depth patches not shown on the plans, the Department will pay for cleaning and coating exposed structural steel, forming (excluding forming required for joint replacement), form removal, and cleanup as extra work . The Department will pay for maintaining traffic under the structure to repair the full -depth patch as extra work. The Engineer will measure Patching Mortar or Conc or Patching Conc , regardless of the type of mortar or concrete, by volume in place. The unit prices for Patching Mortar or Conc or Patching Conc include the cost of providing, mixing, placing, vibrating, finishing, and curing. The contract will specify the grade or type of patching material for Patching Conc pay items. The Engineer will measure Patch, Forming based on the area of removed concrete. The unit price for Patch, Forming includes the cost of forming to retain patching material, except on full -depth patches on bridge decks.
L.Bridge De cks
1.Bridge Deck Surface Construction . The Engineer will measure Bridge Deck Surface Construction within the limits shown on the plans without deducting areas of expansion devices and drain castings . The unit price for Bridge Deck Surface Construction includes the cost of blast cleaning decks ; consolidating, finishing, MDOT Standard Specifications for Construction Section 712 7-145 texturing, and curing surfacing mixtures ; and removing and reinstalling portions of existing guardrails required for access to screed the deck.
2.Concrete, Silica Fume Modified . The Engineer wil l document the quantity of SFMC and measure based on batch plant tickets with deductions for material wasted or rejected. The unit price for Conc, Silica Fume Modified includes the cost of providing and placing overlay concrete on prepared deck substrate, providing insulating blankets, and the required trial batch. The Department will not make quantity adjustments or pay for additional trial batches.
3.Concrete, Bridge Deck Overlay . The Engineer will document the quantity of SFMC and measure based on batch plant tickets with deductions for material wasted or rejected. The unit price for Conc, Bridge Deck Ovly includes the cost of providing and placing overlay concrete on prepared deck substrate, providing insulating blankets, and the required trial batch. The Department will not make quantity adjustments or pay for additional trial batches. The Engineer will measure the quantity of LMC mixture by the surfacing mixture volume used for the partial -depth patching and overlay . The Engineer will determine the quantity from the theoretical yield of the design mix and the quantity documented on the ticket printout for concrete placed and yield tests performed and will make deductions for material wasted or rejected. The unit price for Conc, Bridge Deck Ovly includes the cost of providing and placing surfacing mixture and insulating blankets.
M.Top Flanges and Beam Ends, Clean and Coat . The Engineer will measure Top Flanges and Beam Ends, Clean and Coat based on the limits shown on the plans or determined by the Engineer . The unit price for Top Flanges and Beam Ends, Clean and Coat includes the cost of cleaning and prime coating top flanges and beam end areas and protecting the work and env ironment during cleaning.
N.Filler Wall Concrete . The Engineer will measure Filler Wall Conc based on plan quantities . The unit price for Filler Wall Conc includes the cost of forming walls with weepholes and forming footin gs with drain holes; providing, placing, finishing, and curing concrete for filler walls, footings, and filler wall extensions; providing and placing expansion joint filler, granular material Class II, and 4-inch concrete slab between walls; and covering drain holes with geotextile. MDOT Standard Specifications for Construction Section 712 7-146 O. Embedded Galvanic Anodes . The unit price for Embedded Galvanic Anodes includes the cost of providing and installing anodes in concrete. The Department will pay the Contractor after the Engineer verifies installation as required.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 484–510 of 1,146.