518Structural Concrete Repair

518.01 Description This work shall consist of repairing existing structural concrete as

shown on the Plans and/or as directed by the Resident. Repairing structural concrete shall include removal and disposal of deteriorated concrete, cleaning exposed reinforcing steel, cleaning of concrete surfaces in repair areas, application of bonding agent and placing and curing repair material. All work shall be in conformance with applicable provisions of Sections 202, 502, and 503. Upward Facing Surfaces are defined as any concrete surfaces where the slope is less than or equal to 15 percent from the horizontal. Overhead Surfaces are defined as any concrete surfaces where the slope is overhanging more than 15 percent from plumb. All other surfaces shall be defined as Vertical Surfaces.

518.02 Repair Materials A material that has been NTPEP tested and from the

Department’s Qualified Products List (QPL) of Rapid Setting Concrete Patching Materials may be used instead of concrete for any depth of placement, at the Contractor’s option, providing that all requirements of the manufacturer’s published recommendations are met. All materials used for repair of concrete or reinforcing steel shall meet the applicable requirements of Division 700 as specified in Standard Specification Sections 502 and 503, respectively. When concrete is used as the repair material, it shall conform to the requirements of Table 1 of Section 502.05 for Class A Concrete. Where the depth of placement is less than 1 inch, the repair material used shall be one of the products listed on the Department’s QPL of Rapid Setting Concrete Patching Materials. Where the depth of placement is equal to or greater than 1 inch, the Contractor may use concrete as the repair material. When concrete is used, the coarse aggregate shall conform to the requirements of the following tables. Thickness of Placement Coarse Aggregate Gradation Designation 1 to 3 inches 3 to 6 inc hes > 6 inches SP-1-7 x SP-1-78 x SP-2-8 x SP-2-89 x Class AA x Class A or AA x x Coarse Aggregate Gradation Designation Sieve Designation Percent By Weight Passing a Square Mesh Sieve ¾ in ½ in ⅜ in No. 4 No. 8 No. 16 No. 50 No.200 SP-1-7 100 90-100 40-70 0-15 0-5 - - 0-1.5 SP-1-78 100 90-100 40-75 5-25 0-10 0-5 - 0-1.5 SP-2-8 100 85-100 10-30 0-10 0-5 - 0-1.5 5-122 SP-2-89 100 90-100 20-55 5-30 0-10 0-5 0-1.5 A bonding material shall be used for bonding fresh concrete or patching material to existing hardened concrete. The bonding material shall consist of the following, except that, in the case where patching materials from the QPL are used in the repair areas, the manufacturer’s published recommendations regarding application and use of bonding materials shall take precedence:

518.03 Removal of Unsound Concrete Removal of existing concrete shall be

accomplished without damage to the portion of the structure that is to remain. The deteriorated or delaminated concrete shall first be removed from areas designated by the Resident. The initial classification of an area as sound concrete does not prevent its subsequent reclassification upon further inspection. After the initial removal of unsound concrete, the Resident shall inspect the area again to determine whether additional areas of unsound concrete were revealed by removal operations and if additional concrete removal is required in the areas to be repaired. This process shall continue until additional areas of unsound concrete are not revealed. After the Resident has determined that the deteriorated concrete has been completely and satisfactorily removed, the perimeter of each cavity created by the removal of concrete shall be saw cut to a minimum depth of ⅝ inch, unless a lesser depth is required to avoid reinforcing steel. The saw cut shall be approximately perpendicular to the original surface. Edges of the cavity shall not be feathered. Unless otherwise approved by the Resident, the equipment used for removal of unsound concrete shall be chipping hammers weighing a maximum of 35 pounds and only chisel point bits will be allowed. The surface area and depth of removal for concrete repairs shall be subject to the approval of the Resident. 5-123 Deteriorated concrete shall be removed to one of the following depths, whichever is greatest:

518.04 Reinforcing Steel All existing reinforcing steel exposed by concrete removal,

which is to remain in the structure , shall be cleaned of all loose rust by sand blasting, wire brushing, machine wire brushing or other methods approved by the Resident. Where reinforcing steel is to remain in the structure, care shall be taken to prevent damage to the reinforcing steel or its bond to the surrounding concrete. All existing main reinforcing steel which is broken, or has lost 25 percent, or more, of its original cross sectional area, shall be supplemented with new reinforcing steel. The total area of supplemental bars plus existing bars with section loss shall have the same total area as the original bar. Supplementary reinforcing steel shall be lap spliced a minimum length of 30 bar diameters for bars with section loss of up to 75 percent of the original bar area, and per Section 503, Reinforcing Steel, for all other bars. Reinforcing steel shall be wired to the existing steel or, where designated by the Resident, the existing reinforcing steel shall be cut and supplementary reinforcing steel spliced in with tension couplers.

518.05 Surface Preparation The surfaces to receive repair material shall be free of oil,

solvent, grease, dirt, loose particles and foreign matter. Cleaning of repair areas shall be performed by sandblasting or other methods approved by the Resident. All surfaces receiving new material are to be sandblasted not more than 36 hours ahead of the placement of the repair material, or as per the bonding agent manufacturer’s recommendations. Any sandblasted areas that have been rained on, exposed to high humidity or fog, or contaminated in any other manner shall be sandblasted again before the repair material is applied. All debris from the cleaning operations shall be thoroughly removed from the cleaned surfaces and adjacent areas using compressed, dry, air, prior to the application of repair materials. All air compressor lines used for cleaning of repair areas shall be equipped with effective oil traps.

518.06 Application of Bonding Agent When bonding grout is used on repair of upward

facing surfaces the following shall apply, except that, in the case where products from the Department’s QPL of Rapid Setting Concrete Patching Materials are used in the repair areas, the manufacturer’s published recommendations regarding application and use of 5-124 bonding materials shall take precedence. Once a workable consistency has been reached, additional water shall not be added. The grout must be used or discarded within 30 minutes of the time water is added to the mix. The grout shall be applied no greater than ⅛ inch thick with stiff bristled, nylon, street brooms. The Contractor shall prevent the grout from drying by beginning the grout application immediately prior to the concrete placement and limiting the area of grout application ahead of concrete placement. If the grout begins to dry prior to concrete placement, additional grout may be brushed on the area as directed by the Resident. Should the grout become thoroughly dry it shall be removed by sand blasting or other methods as approved by the Resident. When a product from the Department’s QPL of Concrete Bonding Agents is used, it shall be applied in accordance with the manufacturer’s published recommendations.

518.07 Placing Repair Materials When concrete is used as the repair material the

provisions of Section 502 shall apply. Additionally, concrete shall not be placed when either the ambient air temperature or the existing concrete temperature is below 45 degrees Fahrenheit. When a patching material is used, the Contractor shall follow the manufacturer’s published recommendations for mixing and placing the material. Forms shall be erected to the neat lines of the existing structure and the new concrete placed. For overhead and vertical repair areas, sufficient concrete shall be removed to ensure that air within the area to be patched can effectively escape during the placement of the repair material.

518.08 Curing Curing of concrete shall conform to the requirements of Section 502. For

Overhead and Vertical Surfaces, curing compounds may be used, in accordance with the manufacturer’s requirements. Patching materials shall be cured in accordance with the manufacturer’s published recommendations.

518.09 Inspection The Contractor shall make provisions to allow safe access to the

work for the Resident in order to inspect the work, facilitate ongoing inspection of the work and to measure the work for payment purposes.

518.10 Method of Measurement Repair of structural concrete is divided into repair

areas less than 8 inches in depth and repair areas 8 inches in depth or greater. The repair depth shall be considered the average thickness of an individual repair area. The Resident shall make the final determination as to whether the average depth of repair is less than 8 inches, or 8 inches or greater. Concrete repair will be measured for payment by the square foot of all surfaces repaired where the average depth of repair is less than 8 inches, complete and accepted. Concrete repair will be measured for payment by the cubic yard for all repairs where the average depth of repair is 8 inches or greater, complete and accepted. The quantity will be determined from the theoretical yield of the design mix, or in the case of transit mixed concrete, by delivery ticket, as directed by the Resident. 5-125 Supplementary reinforcing steel will be measured for payment by the pounds of steel provided and installed and paid for under Item 503.12, Reinforcing Steel, Fabricated and Delivered, and Item 503.13 Reinforcing Steel, Placing, respectively, except that Reinforcing Steel, Placing, will be measured for payment as 1.5 times the actual number of pounds placed. Reinforcing steel required to supplement reinforcing steel damaged by the Contractor shall be supplied and installed at the Contractor’s expense. Tension couplers will be measured for payment as the number of splices satisfactorily installed and accepted. Payment will be made under Item 503.17, Mechanical/Welded Splices. Couplers required to repair reinforcing steel damaged by the Contractor shall be provided and installed at the Contractor’s expense. Temporary support beams or girders required to repair bridge seats or pier caps will be paid for separately, as approved by the Resident.

518.11 Basis of Payment The repair of structural concrete will be paid for at the

contract unit price as indicated in the Schedule of Items for the respective Contract item involved. The following will be included in the unit price for the respective concrete items, complete and accepted: Removal of existing concrete; cleaning of existing reinforcing steel to remain in the structure; cleaning of existing concrete surfaces in repair areas; furnishing and installing bonding materials; providing, installing and removal of all formwork; furnishing and placing new concrete or other approved concrete patching materials in areas where existing concrete is removed; curing of concrete or patching materials; disposal of all demolition material and debris. Payment for any staging, platforms or lifts required by the Contractor to gain access to the work in order to perform the work, or to provide access to the Resident in order to inspect or measure the work, shall be considered incidental to related Contract items unless the Contract provisions specify separate payment for such access devices. Fabrication, delivery and placing of reinforcing steel, and mechanical couplers if required, will be paid for under separate Contract items. The payment for each Contract item will also be full compensation for furnishing all materials, labor, equipment, and all other incidentals necessary to complete the work. Payment will be made under: P a y I t e m P a y U n i t

518.50 Repair of Upward Facing Surfaces- to Reinforcing Steel Square Foot

< 8 inches

518.51 Repair of Upward Facing Surfaces- below Reinforcing Steel Square Foot

5-126 < 8 inches

518.52 Repair of Upward Facing Surfaces > 8 inches C u b i c Y a r d

518.60 Repair of Vertical Surfaces < 8 inches S q u a r e F o o t

518.61 Repair of Vertical Surfaces > 8 inches C u b i c Y a r d

518.70 Repair of Overhead Surfaces < 8 inches S q u a r e F o o t

518.71 Repair of Overhead Surfaces > 8 inches C u b i c Y a r d

SECTION 519 - EXPANSION DEVICES – ASPHALTIC PLUG JOINT

519.01 Description This work consists of furnishing and installing asphaltic plug joint

systems at the locations shown on the Plans, in accordance with these Specifications, and as directed by the Resident. This work shall include furnishing, installation, and removal of all bond breaking materials used to prevent asphalt pavement layers from adhering to waterproofing membrane, all temporary header(s) installed with the intent to form the asphaltic plug joint channel, and all preparation required for the installation of the asphaltic plug joint. This work shall also include having the approved manufacturer provide a qualified technical representative to supervise the installation of the joint systems. The representative shall instruct, train, and supervise the Contractor’s personnel in the proper methods of installation. All costs associated with this service shall be included in the unit price of the work.

519.02 Submittals Prior to construction, the Contractor shall submit the following to

the Resident for review and approval:

519.03 Materials An asphaltic plug joint system from Department’s Qualified Products

List for Expansion Devices – Non-Modular (Asphaltic Plug Joints) shall be used. 5-127 The bridging plate shall be ASTM A36 steel, a minimum of 1/4 inch thick, and galvanized. Holes for the centering nails shall be approximately 1 foot center to center along the centerline of plates. Centering nails shall be 16d or larger and hot dip galvanized in accordance with ASTM A153.

519.04 Installation The asphaltic plug joint system shall be installed in accordance with

the manufacturer’s latest instructions and this specification. Manufacturer’s representatives shall be present during the entire installation to ensure satisfactory results are obtained. The asphaltic plug joint system shall allow total joint movement for up to 2 inches. The installation shall be centered over the expansion joint gap as indicated on the Plans. It shall not be installed when ambient or substrate temperatures are below 40°F, when rain is imminent, or as directed by the Resident. The area shall be free of dirt, dust, moisture, petroleum, or solvents that might contaminate the joint materials or reduce the bond of the joint system to the substrate or vertical faces. The use of compressed air and heat may be required to dry the area before installing the joint system. The asphalt pavement layers shall be removed to the required dimensions shown on the plans. The asphalt pavement shall be sawcut to a depth that will not damage the waterproofing membrane, but permit the removal of the asphalt pavement layer. The pavement layer shall be removed in a manner that will not damage the waterproofing membrane. Bond breakers such as interlayers and fabrics, or temporary header(s), may be used with new hot mix asphalt placements to avoid unnecessary sawcuts and protect the waterproofing membrane from damage. The method of attaching temporary header(s) to the concrete deck shall be approved by the Resident. The use of a temporary header shall not be allowed if it will need to be anchored into a precast prestressed concrete member. Should a concrete levelling course be required before installing the bridging plates, and the membrane layer is removed in the process, it shall be replaced before the asphaltic plug joint system is installed. Vertical surfaces of the asphalt pavement layers shall be cleaned to remove all water, dust, or other contaminates. Backer rods shall be installed in expansion joint openings at a minimum of 1 inch depth or as indicated on the Plans. Unless otherwise specified by the asphaltic plug joint system manufacturer, liquid asphalt binder meeting the requirements of a 64-28 or 58-28 PGAB shall be used to coat the membrane and bridging plate surfaces. The binder shall be heated to 350°F to 410°F, or a safe temperature as recommended by manufacturer. Heating kettles shall be equipped with continuous agitation system, temperature controller, calibrated thermometer, and double steel jacket with an oil layer in between, to prevent scorching of the binder. During application, the temperature of the binder shall be maintained at a minimum of 350°F, but not greater than 410°F. It shall be 5-128 poured and leveled into the expansion joint openings until overfilled, and the excess binder spread over the area covered by the bridging plates. Steel bridging plates shall be placed from curb to curb on the roadway portion of expansion joints. The plates shall be centered over the joint opening. Centering nails shall be placed in pre-drilled holes and hammered in to secure the plates. Once the bridging plates are installed, liquid asphalt binder shall be poured and leveled over the bridging plates and adjacent membrane surfaces in a manner that ensures full coverage. Areas with excessive application, such as pooling of liquid, should be removed or dispersed along the joint area. Asphaltic plug joint system aggregate shall be heated in a ro tating drum mixer to a minimum of 350°F but not greater than 410°F, or as recommended by the manufacturer. The thermoplastic polymeric modified asphalt binder shall be added to the mixer to pre-coat the aggregates. Coated aggregate shall be placed into blockouts in layers as recommended by the manufacturer. Blockouts shall be overfilled with coated aggregate as required to compensate for compaction. Equipment for compaction shall be as recommended by the manufacturer. Additional thermoplastic polymeric modified asphalt binder shall be screeded over the compacted joint to fill all surface voids. Top dressing aggregate shall be applied per the manufacturer’s recommendation. Plastic compound shall be used for repairing overcuts in bituminous concrete. Cleaning, mixing, and application shall be in conformance to the manufacturer’s instructions. Vehicular traffic may pass over finished joints two-hours after compaction, or as recommended by the manufacturer.

519.05 Method of Measurement A new Asphaltic Plug Joint system installation will be

measured by the linear foot along the top surface of installed joints to the limits shown on the Plans. Preparation of surfaces for the proposed joint system including cutting, grinding, and cleaning will not be measured separately for payment, but shall be incidental to the Asphaltic Plug Joint.

519.06 Basis of Payment A new Asphaltic Plug Joint system installation will be paid

for at the Contract unit price per linear foot, which price shall be full compensation for all labor, materials, equipment, and incidentals required for furnishing and installing the Asphaltic Plug Joint system as shown on the Plans, in accordance with these Specifications, and as directed by the Resident. Payment shall also include all work required to repair the concrete deck where anchors were used with a temporary header, and all patching needed for the waterproofing membrane. 5-129 Payment will be made under: Pay Item Pay Unit

519.60 Expansion Device - Asphaltic Plug Joint Linear F oot

Structural Concrete Repair in other states

• Iowa 2426 · Structural Concrete Repair
• Utah 03924 · Structural Concrete Repair
• Vermont 580 · STRUCTURAL CONCRETE REPAIR