611Type A milling will be measured in square yards of surface area and will be paid for at the contract unit price per square yard for the depth specified. This price shall include performing milling, handling, and disposing of waste, replacing any damaged reinforcing steel, and determining steel cover to avoid damaging steel. (Type) Hydro-demolition will be measured in square yards for the depth specified and will be paid for at the contract unit price per square yard. This price shall include preparing a work plan and containment system; shielding protection; test patches for and calibration of the hydro-demolition equipment and recalibration (if necessary); removing and disposing of all unsound and loose concrete; sounding the deck after hydro-demolition; removing any additional concrete necessary after sounding; cleaning reinforcing steel; replacing any damaged reinforcing steel; collecting, filtering, and disposing of waste water in accordance with all applicable environmental laws and regulations; any required environmental permits and documentation to comply with such laws and regulations. Furnish silica fume concrete, latex modified concrete, high early strength latex modified concrete, very-early-strength latex-modified concrete, or Class A4 bridge deck concrete will be measured in cubic yards and will be paid for at the contract unit price per cubic yard. Measurement for overlay concrete produced by batch mixers will be determined by truck tickets, assuming a 95 percent yield or, when produced by automatic mobile mixers, measurement will be by metered ticket. Reduction in the quantity of overlay concrete eligible for payment will be made for any volume of waste. This price shall include producing the mixture, all handling, delivering to the work site, and trial batching. Additional concrete beyond the depth range of the pay item that is requested to address cross slope and other surface irregularities and rideability issues shall be at the direction of the Engineer. Only those volumes of additional concrete that are approved by the Engineer prior to placement of the overlay will be considered for payment. Place silica fume concrete, latex modified concrete, high early strength latex modified concrete, very-early-strength latex-modified concrete, or Class A4 bridge deck concrete overlay will be measured in square yards and will be paid for at the contract unit price per square yard on a plan quantity basis. This price shall include preparing the surface, placing, handling, finishing, and curing the concrete. No additional compensation will be made for placing concrete beyond the depth range specified. Payment will be made under: ————————————————————————————Pay Item Pay Unit———————————————————————————— Remove asphalt concrete overlay Square yard Type A milling (Depth) Square yard (Type) Hydro-demolition (Depth) Square yard Furnish (Type) concrete (Depth Range) Cubic yard Place (Type) concrete overlay Square yard———————————————————————————— SECTION 426—REP AIRING EXISTING STEEL STRUCTURES
426.01 Description
This work shall consist of repairing existing steel structures in accordance with these specifications and in conformity with the details shown on the plans or established by the Engineer.426.01 612426.02—Materials
a.Structural steel and bolts shall conform to Section 226.
b.Bearing material and bearing pads shall conform to Section 237.
c.Coating materials shall conform to Section 231.
d.Welding Electrodes shall be selected from the VDOT Materials Division’ s Approved List 9 or as approved by the State Materials Engineer in writing.
426.03 Procedures
Welding shall consist of field welding of structural steel bridge elements.
a.All welding shall be performed in accordance with AWS D1.5, Section 407, and the AWS D1.1. requirements for cyclically loaded structures. This shall include requirements for joint geometry, surface preparation, electrodes, processes, preheating, inspection and acceptance.
b.Areas to be welded shall be preheated to a minimum temperature of 150 degrees F . Preheat, interpass temperature maintenance, and post-heat shall be contiguous operations.
c.Welding shall utilize the Shielded Metal Arch Welding (SMAW) process with low hydrogen electrodes.
d.Upon completion of welding, members that are designated as fracture critical shall be post-weld heat- treated in accordance with AWS D1.5, Chapter 12.
e.All welds shall be inspected by an AWS-certified welding inspector (CWI) in accordance with the bridge welding code, AWS D1.5. Acceptability of welds shall be a condition for payment. Fillet welds shall be tested by magnetic particle testing (MT) in accordance with AWS requirements and VTM 31. All other welds shall be tested with radiography (RT) in accordance with AWS and VTM
29.The inspections shall be performed by a non-destructive testing technician certificated, at a minimum, as Level II by the Society for Non Destructive Testing. Reports of the results of weld tests shall be provided to the Engineer at the time of acceptance. Imperfections, inclusions, or other defects shall be corrected and the weldmet shall be retested until the weld has been shown to be free of defects. All inspection, testing, and subsequent welding shall be at the Contractor’ s expense.
f.All new welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans. Surface Preparation: Prior to performing repairs to structural steel members, all areas that will be ground, heated, or welded shall be cleaned so that the existing coating system will be removed to bare metal. The minimum area to be cleaned shall be 12 inches beyond the outermost point that will be ground, heated, or welded. This cleaning shall be performed in accordance with the Environmental Protection and Health and Safety requirements of Section 411. After completion of repairs, affected areas shall be cleaned and coated using the coating system specified on the plans and in accordance with Section 411. Color shall match existing as approved by the Engineer.426.02 613(a) Grinding Minor Defects shall consist of removing burrs, nicks, gouges, scrapes, etc. from designated structural steel members by grinding. Burrs, nicks, gouges, dings, scrapes, etc. on structural steel members requiring repair shall be ground down to a surface finish of 125 microinches per inch rms and tapered to the original surface using a 10:1 slope. Grinding shall be performed in a direction that is parallel to the centerline of the member. Surface quality shall conform to ASTM A6. Nondestructive testing methods (magnetic particle and or dye penetrant) shall be utilized to confirm that the repaired areas do not contain any cracks and or tears in the base metal or welds. This testing is to be performed by the Contractor (or his representative) in the presence of the Engineer. If cracks and or tears are still evident, these areas shall be repaired in accordance with these specifications until all observed defects are repaired. Removal of base metal by this technique shall be limited to no more than 2% of the cross-sectional area of the element (e.g. flange) being repaired. Areas requiring additional removal of base material shall be repaired in accordance with the Engineer’ s instructions. Areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.
b.Damaged Structural Steel Heat-Straightening shall consist of heat-straightening damaged sections of the existing structural steel beams and girders as shown in the Contract, or as designated by the Engineer. Heat-straightening shall be performed in accordance with the provisions herein and FHWA-IF-99-004 (with ERRATA). Prior to commencement of this work the Contractor shall submit proposed straightening procedures, including jacking forces, locations, and heating patterns to the Engineer for approval. Heat shall be applied to no more than one beam/girder at any given time.
1.Heat-Straightening Construction Requirements The repair of the damaged steel girders shall be performed by a Contractor with written demonstrated experience in the heat-straightening of impact damaged bridge members. Prior to beginning the work, the Contractor, or the Contractor’ s subcontractor, shall provide recent heat-straightening project experience performed on similar type bridge structures within the last five years including the owner’ s contact name(s) and telephone number(s). In addition to this project experience, the Contractor shall submit the resumes of key personnel designated to perform the heat-straightening repairs. The repair shall be directly supervised by a person with at least 5 years successful experience in heat-straightening repairs of comparable bridge structures. The Contractor shall provide the Engineer with written documentation of past experience before beginning the repair work. No work shall be scheduled for the repair of the damaged steel girders until the Engineer approves the designated contractor and/or personnel proposed to complete the repairs. Following approval of the proposed contractor, a work plan for the heat-straightening shall be submitted to the Engineer for review and approval. The work plan shall be developed after the Contractor has conducted a field inspection to include determination/verification of mea - surements necessary to prepare the heat-straightening plan. No work shall commence until the work plan submittal has been reviewed and accepted by the Engineer. This work plan shall include, at a minimum, the following information: • Proposed schedule of repairs including the locations, time and anticipated duration of each repair. Schedule shall include a statement that field measurements have been made.426.03 614 • Equipment and material lists including, but not limited to, heating torches and tips (type and diameter), oxygen and gas fuel tanks, hoses, timber blocking/wedges, hydraulic jacks, access scaffolding, and any necessary safety equipment. • The proposed steel temperature monitoring devices such as contact thermometers, pyrometric sticks, etc. • Details of the type and method of proposed heat-straightening including the heat patterns (vee, strip, line, etc.) and their limits. Vee heats shall have a maximum base width of 6”. Included with this information also shall be the number of cycles/heats and the number of heats occurring simultaneously. • Location, number, and magnitude of the restraint forces supplied by jacks. • Method and equipment for repairing impact dings, gouges, and nicks. • Proposed method and material(s) for repairing any spalled concrete and edge gap between the top flange and deck soffit. Procedures using forces that result in stresses over the yield stress of the material at the applied temperature, such as Hot Mechanical Straightening and Hot Working, are prohibited. The heat-straightening shall be performed in a manner such that the final straightened girder retains as little residual stresses as possible. Heat-straightening shall not commence under periods of precipitation unless a suitable waterproof enclosure is provided subject to the approval of the Engineer. Following the heat-straightening procedure, nondestructive testing methods (magnetic particle and/or dye penetrant) shall be utilized to confirm that the repaired areas do not contain any cracks and/or tears in the flanges, webs, cover plates, welds or connections. This testing shall be performed by the Contractor (or his representative) in the presence of the Engineer.
2.Equipment Fuel for heating shall be an oxygen-fuel combination. The choice of the fuel may be propane, acetylene or a similar fuel. Heat application shall be by either single or multiple orifice tips only. The maximum tip size is limited to 1 inch diameter. The Contractor shall verify temperatures during heat-straightening with temperature sensitive crayons, a pyrometer, or an infrared non-contact thermometer. The Contractor shall provide the heat indicating device, and make it immediately available to the Engineer when the Engineer requests it to monitor the work. Use either hydraulic or mechanical jacks, come-alongs or other force application devices for restraining movement.
3.Crack And Gouge Repairs All burrs, nicks, gouges, dings, scrapes repairs shall be performed in accordance with Section 426.03(a).426.03 615All web cracks shall be arrested by drilling in accordance with Section 426.03(l) or (m) as specified on the plans or directed by the Engineer.
4.Application of Heat Apply heat to the member with vee (triangular shaped) heats or line heats to the flange and with vee, line or strip heats to the web. The base (the open end) of individual vee heats shall not exceed one-half of the plate width or 6 inches, whichever is less. A series of heats applied consecutively to different elements of the member at the same cross section is referred to as a heating pattern. Select heating patterns and sequences to match the type of damage and cross section shape of the element. Temperature of the steel during heat-straightening shall not exceed 1100°F . The steel tem - perature shall be monitored continuously. All plastic yield zones, and only plastic yield zones, shall be heated using the approved heating patterns. The heating torches shall be manipulated to guard against overheating. Occasional heating interruptions of one minute or more may be required for thick flanges to allow the heat to distribute evenly into the flange. After each successive heating cycle, the steel shall be allowed to cool to below 250°F prior to beginning the next heating cycle. Forced cooling (e.g., water, compressed air, etc.) will not be permitted. The heat-straightening shall be accomplished with as little force as possible. Mechanical hot straightening will not be allowed. Restraints shall not resist contraction during the cooling phases and shall not produce local buckling of a compression element during the heating phases. All bends, creases, folds, and dents of the member shall be eliminated. Vee heats shall be shifted over the zone of yielded material on successive heating patterns. Simultaneous vee heats may be used provided that the clear spacing between vees is greater than the width of the plate element. Following the heat-straightening procedure, the Contractor shall provide the Engineer with a record of all the heat patterns applied to each girder under repair.
5.Application Of Restraining Forces Only use restraining forces to restrain the members or elements against undesired movement associated with expansion during the cycles of applying heats. Place restraining forces to restrain the member during the heating process. As the straightening occurs during cooling, the forces should be relieved. The maximum allowable jacking force for members shall be calculated in accordance with the methods outlined in US DOT report no. FHWA-IF-99-004, “Heat-Straightening Repairs of Damaged Steel Bridges” (with ERRATA). Before work begins the Contractor shall submit all details and calculations of restraining forces, signed and sealed by a Professional Engineer currently licensed to practice engineering in the Commonwealth of Virginia, to the Engineer for approval. Details shall include, but not be limited to, a plan showing the location of the restraining forces, details for the restraining devices and their connectivity/contact with the structure. Submittal shall also include a statement from the Engineer of Record indicating that the calculations and details are based on field measurements performed by the Contractor or Contractor’ s representative. No increasing in the restraining force will be allowed during heating or until the steel is cool to the touch between heats.426.03 616Assume that the existing steel has a yield strength of 36,000 psi, unless bridge was built prior to 1940, or use a different yield strength if it is specified in the Contract. No deflection shall be allowed for other bridge members being used as supports for the restraining force. For repairs of local flange bending, the restraining force is limited to that which produces no visible deflection of the unheated flange
6.Tolerances Completed tolerances for straightness of the bottom flange shall be within 1/2 inch of horizontal at the flange edge and 5/8 inch of horizontal sweep in 20 feet at the point of impact. The completed tolerances for the web shall be less than the smaller of 1/100th of the web depth or 3/8 inch, out of vertical alignment. Localized deflections or deviations in web shall be no more than 1/4 inch as measured with a straightedge held vertically and horizontally against the web. These tolerances shall be met before any cross frames are replaced. In no case shall the beams/girders be forced into position and then attached to the cross frame to hold the member in position.
7.Inspection After the completion of straightening, the surface shall be carefully inspected for evidence of fracture by dye penetrant, magnetic particle, or other approved non-destructive testing method. The inspection shall be performed by a Non-destructive testing technician certified, at a minimum, as Level II by the Society for Non Destructive Testing. The Contractor shall ensure that the testing is scheduled so that the Engineer will be available to witness this testing. The Engineer shall be immediately notified if there is any evidence of fracture. Remove minor (< 1/2 inch long) cracks found by this inspection by grinding in accordance with procedures specified here-in. Larger cracks found will be reviewed by the Engineer and repaired as directed by the Engineer.
8.Coating Restore the coating on the damaged areas in accordance with Section 411 as directed by the Engineer. Match the color of the finish coat to the existing paint color.
c.Ultrasonic Impact Treatment shall consist of applying ultrasonic impact treatment (UIT) to certain locations of welds on the bridge where indicated in the plans..
1.UIT Contractor Qualifications The Contractor shall engage a firm competent and proficient in the use of ultrasonic impact treatment. The UIT firm shall have had experience with similar types of work on treatment of bridge details in previous projects. To that end a list of projects, their locations, key person - nel directly involved in performance and supervision of the work and the names of a current contact person for each of the projects shall be submitted for approval by the Engineer prior to beginning the work.
2.Equipment Requirements The UIT firm shall furnish complete UIT tooling requirements, including, but not limited to 2 electronic control units with power source (one of these units shall be backup unit), 2 UIT 426.03 617tools, all required tool tip sets; additional treatment pins, as required; closed circuit cooling system; complete set of extension cables and cooling hoses; all necessary adjustment and maintenance tools for the UIT system; and all equipment consumables required during the application of UIT. The UIT shall be performed using equipment with a frequency of either 27 kHz or 36 kHz, using a power output rating of at least 800 Watts. The Contractor shall furnish all necessary safety equipment, including, but not limited to, safety harnesses, vests, glasses, earplugs, etc. to safely perform the work. The Contractor shall furnish all necessary permits, means of access, and 110 V , 60 Hz, 3 HW AC with a minimum of three outlets power supply.
3.Training If the Contractor’ s personnel have not been previously certified and trained as operators of the UIT equipment by the UIT firm, then the UIT firm shall provide training for the Contrac - tor’ s personnel. The training includes the setup of all necessary equipment and the establish - ment of quality control procedures. Specifically, the UIT firm shall provide:
a.A technical procedures manual defining the treatment methodology and parameters for the successful operation of the tool to achieve the desired results.
b.A technical procedure inspection guide covering the details of the quality assurance (QA) program to be conducted to ensure that the treatment methodology has been applied in accordance with the instructions given in the technical procedures manual.
c.UIT treatment training of Contractor personnel. A minimum of two individuals shall be trained on-site with a comprehensive training program on the general operation of the tool and the guidelines for the technical treatment application for this project.
d.Quality inspection training of Contractor personnel. A minimum of two individuals, other than those applying the treatment, shall be trained to carry out complete and thorough inspections of the treatment being undertaken.
e.On-site expertise and presence, to certify the treatment methodology, the training of the Contractor personnel, and for technical support. The Contractor shall furnish adequate personnel assigned to the UIT work and shall devote these resources exclusively to the work to its completion.
4.Procedures The application of UIT shall follow the weld toe. The entire weld body and weld toe regions at any ends of the weld shall be treated within a radial distance of 1”. Prior to the application of UIT the welds must be inspected. The Contractor shall notify the Engineer immediately of any visible weld defects or cracks at or near the weld.
d.Modify Steel Beam/Girder End shall consist of trimming (flame cutting) and removing the ends of steel beams and/or girders, in order to obtain the proper clearance from the ends of steel beams and/ or girders to the abutment backwall, in accordance with Section 413, the plans, and the requirements herein.426.03 618The proper clearance between the end of the steel beam and/or girder and the abutment backwall shall be as specified on the plans or as directed by the Engineer. After trimming, the end of the beam/girder shall be parallel to the face of the backwall. Newly cut beam end shall be straight, true and free of burs. The cost of jacking and supporting beams shall be paid for under the pay item, Jacking and Blocking. The coating on the beam and/or girder ends shall be restored, including coating damaged by the repair process using the Coating System specified on the plans and in accordance with Section 411 as directed by the Engineer. Match the color of the finish coat to the existing paint color.
e.Replace Bearing shall consist of removing existing bridge bearings and placing new elastomeric bridge bearings. This work shall be performed in accordance with Sections 408 and 413, the details herein, and the following:
1.This work shall consist of removing existing welds, removing and disposing of existing bearing components and anchor bolts, furnishing, painting and installing new bearing assemblies (sole plate, elastomeric bearing pad, anchor bolts, washers and nuts), placing and inspecting new welds, cleaning and applying paint to new bearings and any disturbed areas, and providing environmental, worker health and safety protection, and disposal of material.
2.The Department will classify existing structures on the plans as either a Type A or Type B structure according to Section 411. If not specified on the Plans or elsewhere in the Contract as a Type A structure, the Contractor shall assume the existing structure is classified as a Type B structure.
3.A plan for installing new anchor bolts shall be submitted to the Engineer for review and approval.
4.Beams shall be jacked a minimum distance as specified on the plans in order to relieve the load on the bearings. The cost of jacking and supporting beams shall be paid for under the pay item Jacking and Blocking.
5.Remove fillet weld between beam flange and sole plate, and remove the existing bearing assembly. Remove a portion of existing anchor bolts in accordance with the details.
6.Grind bottom of bottom flange to remove burrs. Clean bottom of flange in accordance with Section 411.04(a) Method 5.
7.Place the new laminated elastomeric bearing.
8.Install new anchor bolts, nuts, and washers.
9.Fillet-weld sole plate to beam flange. The Contractor shall inspect new welds by magnetic particle testing in the presence of the Engineer.426.03 619 10. The bearing assemblies shall be painted in the shop with the system specified on the plans. The new welds and all disturbed areas shall be cleaned and coated using the Coating Sys - tem specified in the plans. Sole plate shall not be painted on the surface in contact with the elastomeric bearing.
11.Materials and fabrication shall be in accordance with the applicable requirements of Section 408. Steel in sole plates and other steel components of the bearings, except as noted on the details, shall be ASTM A709 Grade 36. Grout and adhesive material for anchor bolts shall be from the VDOT Materials Division’ s Approved Product List 29.
12.The Contractor shall verify heights of existing bearing assemblies prior to preparing shop drawings.
13.Immediately before casting the new anchor bolts in the high-strength grout and mortar, the holes shall be thoroughly cleaned to the satisfaction of the Engineer.
f.Reset Existing Rocker Expansion Bearing shall consist of removing existing welds connecting sole plate to girder; grinding girder flange to remove burrs; positioning rocker bearing assembly in a truly plumb position; welding sole plate to girder; inspecting new welds; cleaning and applying paint to new welds and disturbed areas; and providing environmental, worker and safety protection, and disposal of material in accordance with Sections 408 and 413, and the details herein. The following procedure shall be adhered to when resetting the bearings:
1.Each of the girders shall be jacked enough to relieve pressure from bearing, by an amount specified on the plans. The cost of jacking and supporting beams shall be paid for under the pay item Jacking and Blocking.
2.Remove existing filet welds connecting sole plate to girder.
3.Grind bottom flange to remove burrs. Clean bottom of flange in accordance with Section 411.04(a) Method 5.
4.Position the rocker assembly in a truly plumb position at 60 degrees F .
5.Release jacks at that girder.
6.Using a fillet weld as specified on the plans, re-weld sole plate to girder flange. New welds shall be inspected by magnetic particle testing to be performed by the Contractor.
7.All new welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.
8.The existing structure is designated a Type B structure in accordance with Section 411.
g.Modify Existing Rocker Expansion Bearing shall consist of changing a bearing from expansion to fixed by welding a 3/4 inch diameter round stock bar between the rocker and the rocker plate; cleaning and applying paint to new welds and disturbed areas; and providing environmental, worker health and safety protection, and disposal of material in accordance with Sections 408 and 413 and the details herein.426.03 620All new welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.
h.Modify Existing Fixed Bearing shall consist of changing a bearing from fixed to expansion by removing nuts and washers; removing existing welds as necessary; cutting the pintle; enlarging slots in sole plate; adjusting the position of the bearing; placing and testing new welds as necessary; re-installing existing washers; furnishing and placing new nuts; cleaning and applying paint to new welds and disturbed areas; and providing environmental, worker health and safety protection, and disposal of material in accordance with Sections 408 and 413 and the details herein. The following procedure shall be adhered to when modifying existing fixed bearings:
1.Remove existing nuts and washers.
2.Remove existing welds as necessary.
3.Jack each of the girders enough to relieve pressure from bearing, for a distance as shown on the plans. The cost of jacking and supporting beams shall be paid for under the pay item Jacking and Blocking.
4.Cut pintle.
5.Enlarge slots in sole plate.
6.Adjust position of bearing so that it is at the midpoint of movement at 60 degrees F .
7.Release jacks at that girder.
8.Place new welds as necessary. New welds shall be inspected by magnetic particle testing to be performed by the Contractor.
9.Re-install existing washers.
10.Install new nuts.
11.The new welds and all disturbed areas shall be cleaned and coated using the Coating System specified on the plans.
i.Field Welding – Fillet Welds shall consist of removing and disposing of existing welds (when required), cleaning and preparing surfaces to be welded, furnishing all necessary equipment and supplies, furnishing and placing new fillet welds of the specified size, cleaning and re-painting new welds and disturbed areas, and providing environmental and worker health and safety protection and disposal of material in accordance with the plans, Sections 407 and 413, and the AASHTO/AWS D1.5 Bridge Welding Code. Weld size shall match existing weld size or be as specified on the plans. Welds shall only be performed by welders certified in the type and position being performed. Weld positions include flat, horizontal, overhead, and vertical. Preheat, interpass temperature maintenance, and postheat shall be contiguous operations in order to ensure weld soundness. All new welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.426.03 621(j) Field Welding – Full Penetration Groove Welds shall consist of removing and disposing of existing welds (when required), cleaning and preparing surfaces to be welded, furnishing all necessary equipment and supplies, furnishing and placing new full penetration groove welds of the specified size, cleaning and re-painting new welds and disturbed areas, and providing environmental and worker health and safety protection, and disposal of material in accordance with the plans, Sections 407 and 413, and the AASHTO/AWS D1.5 Bridge Welding Code. Weld size and joint preparation shall be as specified on the plans. Prior to placement of welds, an AWS certified welding inspector shall inspect the joint penetration and certify that the gap and geometry are in accordance with the prequalified AWS weld specified. Welds shall only be performed by welders certified in the type and position being performed. Weld positions include flat, horizontal, overhead, and vertical. Preheat, interpass temperature maintenance, and postheat shall be contiguous operations in order to ensure weld soundness. Contractor shall use run-on and run-off tabs for full penetration welds. All weld backings shall be completely removed prior to acceptance of the work. All new welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.
k.Partial Beam/Girder Replacement shall consist of providing temporary support, removing and disposing of portions of existing beams/girders, furnishing and placing new structural members and full penetration groove welds in accordance with the plans, Section 407, Section 413, and the AASHTO/AWS D1.5 Bridge Welding Code. In order to obtain a straight, smooth, and proper fit for partial replacement sections, the contractor shall use a mechanical-guide when cutting and removing the damaged portion of the web or flanges in order to minimize the grinding or re-cutting of the same. Cope hole in the web may be needed to obtain a satisfactory flange weld. Cope hole shall be filled. The Contractor shall develop a plan for temporary support of the beam/girder which shall be submitted to the Engineer for review. The plan shall be signed and sealed by a Professional Engineer in accordance with Section 105.10 (c). Contractor may not support the beam section using tack welds without support tabs. Welded support/alignment tabs may be utilized with the approval of the Engineer. Temporary support welds used in conjunction with support/alignment tabs shall be ground flush after erection of partial beam replacement in accordance with Section
426.03 b.
Where the partial replacement beam meets the existing beam and a full or partial access hole is required in order to facilitate welding, the Contractor shall not fill the hole with welding or replacement metal. Fillet welds terminating in the vicinity of the access hole shall be terminated in accordance with these specifications and AWS D1.5. Carrier beams, when required, shall be installed prior to removal of the existing beam or girder section and shall not be removed until all work, including welding has been tested and accepted. Carrier beams shall be installed in accordance with the plans and shall be supported on spans adjacent to the span under repair. Carrier beams shall be supported immediately above the bearings of adjacent spans. Prior to removal of the damaged girder section the Contractor shall measure the relative elevations of the deck adjacent to the carrier beam at the 10th points along the span. These measurements shall be taken again after the beam has been repaired. All relative deck elevations shall be recorded and submitted to the Engineer.426.03 622All new structural steel and welds and areas where existing coating is disturbed shall be cleaned and re-coated using the Coating System specified on the plans.
l.Crack Repair – Drilling Crack Arrest Holes shall consist of drilling crack arrest holes at the tips of cracks using the size specified on the Plans or elsewhere in the Contract. The tip of the crack shall be identified using the magnetic particle or dye penetrant method. The drill/coring bit shall be positioned such that the trailing edge of the bit removes the crack tip. The hole shall be cylindrical and perpendicular to the surface of the steel. After drilling the hole, the surfaces around the hole shall be ground smooth to an ANSI roughness of 500 of less. The inside surface of the hole shall be coated using the coating system specified on the plans. Flame cut holes shall not be used. After completion of the repair the edge of the hole shall be examined using magnetic particle or dye penetrant methods to ensure that the crack is not extended beyond the repair area.
m.Crack Repair – Drilling Cold Expanded Holes shall consist of drilling cold expanded holes at the tips of cracks using the size specified on the Plans or elsewhere in the Contract. The tip of the crack shall be identified using the magnetic particle or dye penetrant method. The holes shall have a metal ring placed in the hole. Metal rings shall be cold expanded as necessary to create a compression field in the immediate vicinity of the crack. Metal ring and devices utilized to create compression fields shall be pre-approved by the Department for this purpose. Placement of metal ring and creation of compression field shall be performed in accordance with the equipment manufacturer’ s recommendations. After completion of the repair, the edge of the hole shall be examined using the magnetic particle or dye penetrant method to ensure that the crack has not extended beyond the repair area.
n.Crack Repair - Welding shall consist of repairing designated cracks by welding. Crack repair welding shall be performed in accordance with Section 426.03 and the following.
1.Cracks shall be fully removed by hand grinding, arc or flame gouging.
2.The root of the ground or gouged area shall be inspected by magnetic particle testing to ensure complete removal of the crack before welding.
3.If arc or flame gouging is used, the groove that is produced shall be ground to remove cutting scale before welding.
o.Jacking and Blocking Beams shall consist of supporting beams during construction and may include jacking, blocking, and other approved methods of support in accordance with the requirements herein.426.03 623The Contractor shall develop a plan for jacking, blocking, and supporting beams which shall be submitted to the Engineer for review and approval. The plan shall be signed and sealed by a Professional Engineer in accordance with Section 105.10 (c). The cost of preparing the plan shall be included in the price bid for Jacking and Blocking. Unless approved by the Engineer in writing or specified on the plans, temporary support systems shall be designed to sustain traffic loadings in addition to dead load and temporary construction loads and all other anticipated loading during work requiring the jacking and blocking of beams.
426.04 Measurement and Payment
These prices shall include surface preparation, welding where required, certified welders and welding inspectors, non-destructive testing by certified technicians, welding inspection, and other types of non- destructive testing where required, disposal of removed material, environmental and worker health and safety protection, testing, and coating steel members. Grinding Minor Defect will be measured in units of each and will be paid for at the contract unit price per each. Structural Steel Heat-Straightening will be paid for at the contract lump sum price per structure. Ultrasonic Impact Treatment will be measured in linear feet and will be paid for at the contract unit price per linear foot. Modify Steel Beam/Girder End will be measured in units of each and will be paid for at the contract unit price per each. Replace Expansion Bearing will be measured in units of each and will be paid for at the contract unit price per each. Reset Existing Rocker Expansion Bearing will be measured in units of each and will be paid for at the contract unit price per each. Modify Existing Rocker Expansion Bearing will be measured in units of each and will be paid for at the contract unit price per each. Modify Existing Fixed Bearing will be measured in units of each and will be paid for at the contract unit price per each. Field Welding – (Type and Size) will be measured in linear feet and will be paid for at the contract unit price per linear foot for the type and size specified. Partial Beam/Girder Replacement will be measured in pounds of structural steel and will be paid for at the contract unit price per pound. Crack Repair (Type) will be measured in units of each or in linear inches and will be paid for at the contract unit price per each or per linear inch for the type of repair specified. Jacking and Blocking Beam, when a pay item, will be measured in units of each per bearing location for all jack lifts at any location and will be paid at the contract unit price per each.426.04 624Payment will be made under: ————————————————————————————————— Pay Item Pay Unit————————————————————————————————— Grinding Minor Defect Each Structural Steel Heat-Straightening Lump Sum Ultrasonic Impact Treatment Linear Foot Modify Steel Beam/Girder End Each Replace Bearing Each Reset Existing Rocker Expansion Bearing Each Modify Existing Rocker Expansion Bearing Each Modify Existing Fixed Bearing Each Field Welding – (Type and Size) Linear Foot Partial Beam/Girder Replacement Pounds Crack Repair (Type) Each or Linear Inch Jacking and Blocking Beam Each—————————————————————————————————— SECTION 427—SILICONE JOINT SEALANTS
427.01 Description
This work shall consist of sealing joints, with rapid curing silicone sealant in accordance with this section and in conformity with the lines shown on the plans or as established by the Engineer.
427.02 Materials
a.Silicone Joint Sealant: Self-leveling and other silicone joint sealants shall be a Class D silicone sealant conforming to Section 212 and shall be selected from the VDOT Materials Division’ s Approved Products List 27.
b.Backer Rod: Backer Rod shall conform to Section 212.
c.Primer: Primer shall be in accordance with the silicone joint manufacturer’ s recommendations.
427.03 Procedures
a.Manufacturer’s Representative: The Contractor shall have present at the beginning of the initial joint sealing operation for each structure a manufacturer’ s representative, knowledgeable in the methods of installation of the sealant, to certify that the Contractor’ s personnel installing the material are knowledgeable and can demonstrate an ability to install the material in accordance with the manufacturer’ s recommendations. The Contractor shall also arrange to have the manufacturer’ s representative present during testing of the joint material by the Department.
b.Forming New and Reconstructed Joints: The Contractor shall form new and reconstructed joints to provide the nominal opening at the specified temperature as shown on the plans. Sides of the joints shall be parallel to each other. Edges of the joint shall be rounded to a radius of ¼ inch. The Contractor may be required to saw or grind any new or reconstructed joint having an insufficient 426.04
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 639–651 of 1,065.