2433Structure Renovation

2433.1DESCRIPTION

This Work consists of widening, rebuilding, crack sealing, or restoring Structures, including removal as shown on the Plans and in the Special Provisions.

2433.2MATERIALS - BLANK

2433.3CONSTRUCTION REQUIREMENTS

A General A.1 Explosives Do not use explosives to remove any portion of a Structure being widened or reconstructed. The Contractor may use explosives to remove Material not directly connected to the remaining Structure as approved in writing by the Engineer and in accordance with 1711, “Use of Explosives.” A.2 Field Measurements Consider the dimensions of the old Structure as shown on the Plans as approximate. Before making shop drawings and before manufacturing, take measurements of the old Structure to ensure proper joining of the old and new Work. Ensure elevations taken from existing Plans are adjusted to elevation datum used for construction. Provide the measurements to the Engineer. Show field measurements on the shop drawings. B Removal and Disposal Requirements Remove and dispose of Materials encountered in the renovation of existing Structures in accordance with 2442, “Removal of Existing Bridges,” meeting the requirements of the MnDOT Regulated Material Management-Building Demolition/Relocation website and the following: Stabilize peeling lead paint by coating with a lead paint encasement product listed on the APL to prevent the peeling paint from flaking during demolition, or scrape and contain the peeling paint . If encasing, apply 16 mils of paint. If applying paint on a Bridge over water, attach a diaper apron or other containment method if necessary to prevent drips of paint from contaminating the water. Remove old concrete or stone masonry within the limits shown on the P lans and without damaging the remaining Structure. Make saw cuts at least 1 inch deep on faces exposed to view to produce a straight line between new and old concrete. Cut keyways into the concrete that remains in place without damaging the remainder of the Structure as shown on the Plans. Do not impair the supporting capacity of the foundation soil and do not damage the remaining Structure if removing piling located within the new footing area.

If old piles interfere with the planned spacing of new piles, drive the old piling to determine bearing capacity and suitability for use in the new construction, as directed by the Engineer . Unless otherwise required by the Contract, the Department will pay for extra pile driving as Extra Work in accordance with 1402, “Contract Revisions.” B.1 Remove Slab Remove and dispose of delaminated or unsound concrete Bridge deck surfaces and other areas of the Superstructure identified for partial removal in the Plans and by the Engineer, in accordance with the Plans and the following: After traffic control has been established, the Engineer will sound the deck and identify removal locations by defining the areas for repair. Remove only that portion of the deck that has been defined for repair by the Engineer. Restrict removal to methods which, in the Engineer’s judgment, will not damage the Structure. Restrictions for the power Equipment:

satisfactory performance on the type of Work for which it is to be used. If permitted by the Engineer, use newly developed power Equipment on a performance basis, but discontinue such usage if so directed by the Engineer.

above the top Layer of reinforcement; except that the Engineer may permit the use of up to a Nominal 60 pound hammer by individual operators on a performance basis, but discontinue such usage if the Engineer determines that the heavier hammers are creating additional delamination, or that they are not being used with proper discretion.

depth removal is specifically defined by the Engineer.

below the top Layer of reinforcing bars unless full depth removal is specifically defined by the Engineer. Ensure that the edges of removal areas are near vertical and clean immediately before placing the concrete patching mix. After removal operations are completed, clean the removal area of remaining loose concrete by sandblasting. Clean exposed reinforcing bars by sandblasting to remove loose rust. Tightly adherent rust and mill scale may remain on the surface. Remove spent sa nd and debris. Follow provisions of 1717, “Air, Land, and Water Pollution,” as supplemented by Special Provisions, referring to MPCA Rule 7011.0150 as it relates to sandblasting and or concrete removal operations. Leave deck reinforcement steel in place as it was before concrete removal, unless otherwise directed by the Engineer. Replace reinforcement bars damaged by Contractor’s operations, as directed by the Engineer, unless the Engineer deems that the bars can be salvaged. The Engineer may deem bars that are damaged by Contractor’s operations as salvageable. Where salvageable, propose methods to the Engineer to restore bars to as near the original condition as possible or replace affected portions of bars. The costs incurred for replacement or salvage is included in the applicable remove concrete pay item. All costs for damaged reinforcement are at no cost to the Department.

Do not perform removal in any area until the perimeters for removal in that area have been defined by the Engineer for that type of removal. Dispose of Materials removed in accordance with 2104.3C, “Removal Operations.” C Concrete Construction Perform concrete construction in accordance with 2401, “Concrete Bridge Construction,” and the following:

and in accordance with the manufacturer’s installation recommendations

at least 2 feet of the adjoining portion of the old concrete to blend the finish o f the new with the old Work

and depth in accordance with the manufacturer’s recommendations C.1 Bridge Deck Crack Sealing Process Perform crack sealing on new or existing Bridge deck surfaces in accordance with the following process:

Cleaning and Mapping Cracks.”

mapping 72 square feet of representative area results in 20 linear feet. Other Bridge Roadway, Sidewalk, trail, median, and approach panel surfaces will be considered Low crack density.

Epoxy by Chase Method.”

Methacrylate (MMA) Flood Seal.”

crack sealing treatment may be evaluated separately under the same procedure as defined in 2433.3C.2, “Deck Cleaning and Mapping Cracks.”

sealing cracks according to 2433.3C.3, “Seal Cracks with Epoxy by Chase Method” and after any sealing in 2433.3C.5, “Methyl Methacrylate (MMA) Flood Seal.” C.2 Deck Cleaning and Mapping Cracks This Work consists of cleaning the Bridge deck and Sidewalk for evaluation of crack density in advance of the crack sealing operations. Any grinding or Bridge deck planing should occur in advance of this phase. Where tining is the surface texture on new Bridge surfaces, AMS curing compound may be present. Crack sealing will not require removal of the curing compound for cracks less than 0.017 inches wide unless treating surfaces that are more than 1 year old. The Contractor is required to:

approach panels, Bridge joints, and Sidewalks. Bridge joint cleaning may require hand-operated Equipment such as blowers and power washers to thoroughly clean. Dispose of any loose Material removed from swept and cleaned areas in accordance with 2104.3C.3, “Concrete and Masonry Structures”

selected locations as detailed below

widths of ACI 224R-01, “Control of Cracking in Concrete Structures”

6-foot areas documenting crack pattern and density

Engineer. Based on observed crack density, a sealing treatment per Contract requirements will be authorized by the Engineer The Engineer will locate 2 areas to represent the general cracking condition of the deck after cleaning at locations so that a 72 square foot area is located in a 12 foot longitudinal by 6 foot transverse area near midspan; and a 72 square foot area 6 foot in width located between 24-feet and 12-feet from center of a pier (if multiple spans). The above locations are general guidelines and actual locations will be selected by the Engineer, but in cases will be in a Traffic Lane to capture crack density. Power wash representative areas. During the deck drying process produce a 1 foot grid at the designated locations. Record crack frequency and the crack size range according to Table 2433.3-1. Table 2433.3-1 Crack Width Ranges and Color Designations Crack Classification Crack Width Pen Color A1 < 0.010 inch Black A2 0.010 inch – 0.016 inch Red B1 0.017 inch – 0.024 inch Green B2 > 0.025 inch Blue

Record mapping on grid-lined engineering paper demarked with 1 inch squares and 1/10 inch increments, where 1 inch paper Scale represents 1 foot measurement on Bridge deck surface. Record with clarity the general crack path in the appropriate color from Table 2433.3-1. Map cracks with an accuracy of ± 6 inches for path and using the largest portion of the crack width as the size. Re-evaluate crack size on Bridge deck every 2 feet when mapping and determine corresponding color of pen for recording. A sample crack map will be furnished on request. Compute length of cracks in each crack classification category to the nearest 1/10 of a foot. Sum the length of cracks. Present crack mapping records and crack lengths to the Engineer at least 2 Business Days prior to performing any Bridge deck sealing. The Engineer will review the length of cracks based on interpretation of the submitted crack maps. Follow the 2433.3C.1, “Bridge Deck Crack Sealing Process,” for determination of sealing method. Where varying crack levels exist within a 200-foot or longer Bridge, crack evaluation may be performed at 50-foot intervals to substantiate a switch in crack sealing treatments. C.3 Seal Cracks with Epoxy by Chase Method This Specification covers crack sealing to:

with 2433.3C.1,”Bridge Deck Crack Sealing Process

2433.3C.1,”Bridge Deck Crack Sealing Process Seal cracks 0.010 inches and larger. Cracks smaller than 0.010 inches, as measured at the crack’s widest segment, on finished Roadway surfaces and Sidewalks will not require sealing. When applied on finished concrete Roadway surfaces, apply epoxy in a width not exceeding 2 inches. When applied on a structural slab which is to receive a concrete wearing course, apply epoxy in a cured width not exceeding 1 inch. Furnish only one of the Materials listed on the APL, Bridge, “Bridge Surface and Crack Sealers.” A product may be selected from either the “High Elongation Epoxy Crack Sealers” or “High Strength Epoxy Crack Sealers” categories. Apply in accordance with the requirements listed on the APL, except that when applied under a concrete wearing course only 1 application pass is required. C.4 Surface Preparation and Application C.4.a When applied on final concrete surface including existing surfaces Do not apply crack sealants to concrete surfaces less than 21 Calendar Days old except on new decks immediately prior to opening to traffic. No greater than 21 Calendar Days prior to application:

where applicable. Locate and mark cracks appearing on the top surface visible from 5 feet above deck surface, and as directed by the Engineer

waterblast to remove curing compound and other contaminants that would impede the adhesion of the sealant. Provide shielding as necessary to prevent dust or debris from striking vehicular traffic. Collect debris and other Material removed from the surface and cracks, and dispose of it in accordance with applicable federal, state, and local regulations

sealer

a compressor unit with a minimum pressure of 365 cubic feet per minute, over the cracks to be sealed to remove dust and debris. Provide shielding as necessary to prevent dust or debris from striking vehicular traffic. Use a suitable oil trap between the air supply and nozzle. Use ASTM D4285, Standard Test Method for Indicating Oil or Water in Compressed Air, to ensure the compressed air is oil and moisture free. Have the Engineer approve the prepared surface prior to applying the sealer. Seal the entire length of cracks 0.010 inches or greater in width as measured at its widest segment. Protect expansion joints and prevent the crack sealant from contacting the strip seal glands. Protect striping and traffic markings from marring sealant application ,

and reduction in reflective properties. Replace any striping and traffic markings that are marred by sealant, at no cost to the Department. Fill cracks with an approved crack sealer following the manufacturer's recommendations, and as otherwise directed by the Engineer. Where traffic is to be placed on crack sealer before curing is complete, broadcast to refusal oven dried 30 grit or similar sand into wet, uncured resin. Clear and remove unbonded sand or grit . Remove excess sand that causes concern for traction or braking from Bridge deck, including deck joints, as directed by the Engineer. C.4.b When applied to structural slab prior to placing new wearing course Locate cracks after shotblasting or other abrasive surface preparation completed for a concrete wearing course appearing on the top surface, and as directed by the Engineer. Fill located cracks with an approved crack sealer following the manufacturer's recommendations, and as otherwise directed by the Engineer. Ensure the sealer is cured prior to preceding pre-wetting of the deck, as required for placement of a low slump concrete wearing course. Control the application of the crack sealer such that the maximum width of crack sealant does not exceed 3/4 inch. If exceeding the permitted width of 3/4 inch, remove excess by means of surface grinding to prevent debonding of concrete wearing course. Air dry a wet deck for a minimum of 24 hours before applying the sealer. Have the Engineer accept the prepared surface prior to applying the sealer. C.4.c Application Weather Limitations Do not apply sealer Materials during wet weather conditions or if adverse weather conditions are anticipated within 3 hours of the completion of sealer application. Provide forecast from the National Weather Service website to the Engineer 3 hours before placement. The Engineer will review the forecast for the following:

duration, nor up to 2 hours after the anticipated completion of the placement.

window. Do not mix or apply any of these products at temperatures lower or higher than those specified in their product literature. Apply the crack seal at the coolest time of the day within these limitations. C.5 Methyl Methacrylate (MMA) Flood Seal This Work consists of furnishing and applying a protective MMA sealer, as authorized by the Engineer. Do not apply crack sealants to concrete surfaces less than 21 Calendar Days old unless otherwise ready to open to traffic. Prior to MMA flood seal application, seal cracks greater than 0.040 inches with approved epoxy in conformance with 2433.3C.3, “Seal Cracks with Epoxy by Chase Method.” Prior to the MMA flood sealant application, prefill cracks 0.024 inch to 0.040 inches wide with same sealer as used in flood seal or a pre-promoted version of the sealer. Where sealant soaks-in/withdraws from top of crack, place fine grade abrasive sand (20/40 abrasive) in

crack and reapply MMA sealant to seal to top of crack. When sealant has not retreated after gel time, the crack is considered prefilled. Do not fill crack with sand beyond top of concrete surface. Apply an approved MMA to Bridge deck between gutterlines. At least 14 Calendar Days before the start of the Work, provide the Engineer with the sealer manufacturer's written instructions for application and use. C.5.a Materials C.5.a(1) Epoxy Furnish only one of the Materials listed on the APL, Bridge, Bridge Surface and Crack Sealers. A product may be selected from either the “High Elongation Epoxy Crack Sealers” or “High Strength Epoxy Crack Sealers” categories. Apply in accordance with the requirements listed on the APL , except that when applied under a concrete wearing course only one application pass is required. C.5.a(2) MMA Sealant Furnish only one of the Materials on the APL, Bridge, Bridge Surface and Crack Sealers, “Methacrylate Resin Crack Sealers.” C.5.a(3) Broadcast Sand Provide a commercial quality dry blast sand with 95 percent passing the No. 8 Sieve and 95 percent retained on the No. 20 Sieve. C.5.a(4) Fine Grade Sand Provide fine grade abrasive sand for (20/40 abrasive) prefilling large cracks unable to be prefilled with sealant alone. Submit sand Material data to the Engineer for review and address written comments. Submit storage and use Plan to the Engineer documenting procedures for maintaining dry sand and within gradation requirements above. C.5.b Surface Preparation Clean areas to be sealed by removing dirt, dust, oil, grease, curing compounds, laitance, or other contaminants that would prevent adhesion and c rack penetration of the sealant. Where AMS curing compound is present on the Roadway surface, shotblast the areas to be sealed. Collect debris and other Material removed from the surface and cracks and dispose of it in accordance with 2104.3D, “Disposal of Materials and Debris.” Perform a visual inspection of the Roadway surface. Locate and mark all cracks greater than 0.024 inches appearing on the top for prefilling. Immediately before applying the sealer direct a 125 psi air blast, from a compressor unit with a minimum pressure of 365 cubic feet per minute, over the entire surface to remove all dust and debris paying special attention to carefully clean all deck cracks. Use a suitable oil trap between the air supply and nozzle. Use ASTM D4285 Standard Test Method for Indicating Oil or Water in Compressed Air, to ensure the compressed air is oil and moisture free. Provide shielding as necessary to prevent dust or debris from striking vehicular traffic.

Air dry a wet deck for a minimum of 72 hours before applying the sealer. Have the Engineer accept the prepared surface prior to applying the sealer . C.5.c Sealant Manufacturer Support A technical representative from the sealer manufacturer must be present during the first Project application on a Contract. The need for the manufacturer’s representative may be waived if the Contractor provides evidence and reference contracts for Work involving at least 5 Bridges treated with the same products and within the last two years. Contractor experience record in no way relieves the Contractor from applying in accordance with this Specification and as recommended by the manufacturer. Prior to application of the sealant, hold a meeting with the manufacturer's representative and the Engineer to discuss necessary safety precautions and application considerations. The manufacturer’s representative must be available to answer safety and installation questions. C.5.d Weather Limitations Do not apply sealer Materials during wet weather conditions or if adverse weather conditions are anticipated within 12 hours of the completion of sealer application. Provide a forecast from the National Weather Service website to the Engineer 3 hours before placement. The Engineer will review the forecast for the following:

duration, nor up to 12 hours after the anticipated completion of the placement.

window. Do not mix or apply any of these products at temperatures lower or higher than those specified in their product literature. Apply the crack seal at the coolest time of the day within these limitations. C.5.e MMA Flood Seal Application Do not apply crack sealants to concrete surfaces less than 21 Calendar Days old unless getting ready to open to traffic. Application by spray methods will not be permitted during windy conditions, if the Engineer predicts unsatisfactory results. Do not thin or alter the MMA crack sealer unless specifically required in the manufacturer's instructions. Mix the sealer before and during its use as recommended by the manufacturer. Distribute the sealant as a flood coat in a gravity-fed process by broom, roller, or with a spray bar near the surface so the spray pattern and coverage rates are reasonably uniform to the satisfaction of the Engineer. Apply the sealant at a minimum rate of 90 square feet per gallon unless a lower dosage is recommended by the manufacture in writing and accepted by the Engineer. Protect expansion joints and prevent the crack sealant from contacting the strip seal glands. Protect striping and traffic markings from marring, sealant application , and reduction in reflective properties. Replace any striping and traffic markings that are marred by sealant, at no cost to the Department.

Prior to completion of gel time of the flood seal (within 15 minutes) and before broadcasting sand, broom uncured sealant in the direction of tining or deck grooves to promote maintenance of the deck texture for traction. Broadcast sand to refusal into uncured resin to create traction and absorb sealant that is not penetrating into cracks. Broadcast approved sand into the wet, uncured resin no sooner than 20 minutes after applying resin but within gel time of product. Apply approved sand at a minimum rate of 250 pounds per 1000 square feet. Allow the sealant to dry/cure according to the manufacturer's instructions. Do not allow vehicular traffic onto the treated areas until the sealer has dried/cured and the treated surfaces provide safe skid resistance and traction. Remove non -adhered sand from Bridge deck and joints by power sweeping the deck and vacuuming the joints. Traffic or Equipment will be allowed on the sealed deck after the Engineer has determined:

traffic D Reinforcement Steel Place reinforcement steel in accordance with 2472, “Metal Reinforcement,” and the following:

bars that extend through the cut line closer than 40 bar diameters to the cut line

the removal of old concrete, install an approved bolt anchor or clamp capable of developing the strength of the damaged bar, at no additional cost to the Department and as directed by the Engineer E Structural Steel Construction Provide structural steel manufactured in accordance with 2471, “Structural Metals.” Erect structural steel in accordance with 2402, “Steel Bridge Construction,” and the following:

shop. Ream the holes to proper size in the field after assembly. If making the holes for these connections in the field, clamp the parts together and drill the holes using the holes in the old steel as a template. Do not use a flame-cutting torch to make the holes

beams in contact with new timber or concrete, and coat with primer in accordance with 2478, “Organic Zinc-Rich Paint System,” or as directed by the Engineer. Allow the paint to dry for at least 24 hours

primer paint in accordance with 2478, “Organic Zinc-Rich Paint System,” before permanently connecting to the new steel F Masonry Construction Construct masonry as shown on the Plans. Make connections to old stone masonry at the old mortar joints . Step the joints to old stone masonry as directed by the Engineer.

Clean mortar and loose or fractured Material from old stone masonry at the joint before placing the new masonry. Immediately before placing new concrete or stone masonry, wet the surface of the old masonry. G Timber Construction Perform timber construction in accordance with 2403, “Wood Bridge Construction,” and the following:

the timber

Material meeting the requirements of AWPA M4 to contact surfaces, except treat new treated timber and designated old Structure parts with oil paint. Allow each application of preservative to dry for at least 2 hours before applying the next coat

2433.4METHOD OF MEASUREMENT

A Structure Removals The Engineer will measure Structure removals by lump sum. B Item Removals The Engineer will measure removal of specified items by the unit of measure for the C ontract Item as shown on the Plans and in accordance with the following: B.1 Lump Sum The Engineer will measure item removals by lump sum, including the entire item as required by the Contract or as approved by the Engineer. B.2 Mass The Engineer will measure removal of Structural steel by weight in accordance with 2402.4A, “Weight.” B.3 Length The Engineer will measure the length of item removals longitudinally along the center of the unit and within the limits shown on the Plans or approved by the Engineer. B.4 Area The Engineer will measure the MMA Flood Seal to the nearest square foot of concrete area sealed as designated by the Engineer. B.5 Volume The Engineer will measure item removal by volume, except for timber, on the basis of actual dimensions of the unit as removed. The Engineer will measure timber based on Nominal sizes and actual lengths. B.6 Each The Engineer will measure item removal by each complete item removed for the required Work.

C Deck Cleaning and Mapping Deck cleaning and mapping will be measured to the nearest square foot only for existing Bridge Roadway surfaces, and Sidewalk where applicable, where surfaces are cleaned for crack sealing operations in accordance with 2433.3C.2, “Deck Cleaning and Mapping Cracks.” Bridge surfaces, Sidewalk surfaces, and Roadway surfaces constructed within the same Contract are not eligible for measurement. D Seal Cracks by Chase Method with Epoxy Sealing cracks in the deck surface will be measured by volume in gallons of epoxy sealer applied to the cracks that have been designated by the Engineer to be sealed. Cracks sealed by the Contractor that have not been designated by the Engineer will not be measured for payment. Cracks that have been sealed at a width greater than 2 inches will be measured and the pay quantity will be reduced at a pro - rated rate using the ratio of 1 gallon for every 450 linear feet of cracks that were sealed in excess of 2 inches wide. E MMA Flood Seal Cracks Measurement will be made to the nearest square foot of concrete area sealed by MMA f lood seal as designated by the Engineer. Prefilled cracks immediately ahead of flood sealing will be compensated by addition of 0.002 square feet of MMA flood seal per gallon used in prefilling cracks with MMA sealant. When MMA Flood Seal is directed to seal concrete work placed within the Contract, the Department will share in the increased cost of MMA flood coat application by executing a Change Order to compensate the Contractor according to the following rates:

deck area sealed by MMA Flood Seal (methyl methacrylate).

area sealed by MMA Flood Seal (methyl methacrylate). The above compensation rates are compensation in full for costs of furnishing and applying the sealer to the bridge decks, as described above, including surface preparation, traffic control, and incidentals thereto. Cleanup of excess sand in joints and on bridge deck will not be paid for separately. Restoration of damaged or marred striping will be considered incidental to the above work F Anchorages The Engineer will separately measure Anchorages of each type shown on the P lans by the number of units complete in place. G Placing Used Materials The Engineer will separately measure the placement of used Materials by the unit of measure for the Contract Item as shown on the Plans and in accordance with place used items.

2433.5BASIS OF PAYMENT

The Contract Unit Price for deck removal includes the cost of cleaning and painting steel formerly in contact with the deck where paint is not tightly adhered and sound, unless otherwise shown on the P lans. Sound paint is defined as primer meeting 2478, “Organic Zinc-Rich Paint System,” DFT requirements that remains tightly adhered after scraping with a dull putty knife.

The Department will pay for Structure renovation on the basis of the following schedule: Item No. Item Unit

2433.501 Structure Removals lump sum

1 Place Used* lump sum

1 Remove* lump sum

2 Remove* each

2 Place Used* each

2 Anchorages Type___ each

3 Remove* linear foot

3 Place Used* linear foot

6 Seal Cracks with Epoxy by Chase Method gallon

7 Remove* cubic yard

8 Place Used* pound

8 Remove* pound

2433.518 Remove* square foot

8 Deck Cleaning and Mapping square foot

8 MMA Flood Seal square foot

2433.522 Place Used* MBM ǁ

* Specify item name ǁ 1000 board feet measure