451PRESTRESSED SOIL ANCHORS

451-1 Description.

Construct prestressed soil anchors consisting of a high strength steel tendon anchored to the retaining wall on one end and to the soil on the other end through a bulb of pressure injected portland cement concrete grout. Test each anchor by prestressing to the load indicated in the Contract Documents before locking off to the retaining wall. Select the prestressed soil anchor type and the installation method, and determine the bond length a nd anchor diameter. Assume responsibility for installing prestressed soil anchors that develop the load -carrying capacity indicated in the Plans in accordance with 451 -7. Provide corrosion protection for permanent prestressed soil anchors. The Engineer will not require corrosion protection for temporary prestressed soil anchors. Protect anchor tendons from corrosion as shown in the Plans in accordance with 451 -8.

451-2 Definitions.

451-3 Qualifications.

The Contractor or subcontractor performing the work described in this Section shall have installed prestressed soil anchors for a minimum of five years. At the preconstruction conference, the Contractor shall submit a list containing at least five projects, completed within the last five years, where the Contractor has installed prestressed soil anchors. Include a brief description of each project and a reference for each project listed. As a minimum, include with the reference an individual's name and current phone number. Prior to the start of work, the Contractor shall submit a list identifying his engineer, drill operators, and on -site supervisors who will be assigned to the project. Include in the list a summary of each individual ’s experience. Assign a Specialty Engineer to supervise the work with at least five years of experience in the design and construction of permanently -anchored structures. Do not use manufacturers' representatives in order to meet the requirements of this Sec tion. Provide drill operators and on - site supervisors that have a minimum of one year experience installing permanent prestressed soil anchors with the Contractor’s organization. The Engineer will approve or reject the Contractor ’s qualifications and staf f within 15 working days after receipt of the submission. Do not start work on any prestressed soil anchor wall system or order materials until receiving approval of the qualifications. The Engineer may suspend the prestressed soil anchor work if the Contr actor or subcontractor substitutes FY 2023-24 Return to Table of Contents unqualified personnel for approved personnel during construction. If work is suspended due to the substitution of unqualified personnel, the Contractor is fully liable for additional costs resulting from the suspension of work and the Department will not allow any adjustment in Contract Time resulting from the suspension of work.

451-4 Materials.

451-4.1 General: Meet the following requirements:

Concrete ................................ .............................. Section 346 Prestressed Construction ................................ .....Section 450 Structural Steel an d Miscellaneous Metals .........Section 460

451-4.2 Prestressing Steel: Use prestressed soil anchor tendons fabricated from single or

multiple elements of one of the following prestressing steels , unless otherwise shown in the Plans:

451-4.3 Anchorage Covers ( include for temporary anchors only whe n shown in the

Plans): Use exposed anchorage covers fabricated from steel or ductile cast iron with a minimum thickness of 0.10 inches. Ensure that the cover is securely attached to the anchorage device or bearing plate. If the cover is to be grease filled , ensure the cover forms a permanent watertight enclosure for the anchorage device.

451-4.4 Anchorage Devices: Use anchorage devices capable of developing 95% of the

minimum specified ultimate tensile strength of the prestressing steel tendon. Use anchora ge devices that meet the static strength requirements of Section 3.1.6(1) and Section 3.1.8(1) of the Post Tensioning Institute “Guide Specification for Post -tensioning Materials ”. Use couplers for tendon sections capable of developing 95% of the minimum s pecified ultimate tensile strength.

451-4.5 Cement Grout: Use grout for anchorage consisting of a pumpable mixture of

portland cement meeting the requirements of Section 921, sand, water, and admixtures. The Contractor may use admixtures which control ble ed, improve flowability, reduce water content, and retard set in the grout subject to the approval of the Engineer. The Contractor may only add expansive admixtures to the grout used for filling sealed encapsulations, trumpets, and anchorage covers. Do not use accelerators. Use admixtures compatible with the prestressing steels and mixed in accordance with the manufacturer's recommendations. Do not perform strength testing as system performance will be measured by proof-testing each anchor. The Department may require cylinder testing if the Contractor uses admixtures or irregularities occur in anchor testing. Cast a set of three 4 inches x 8 inches grout cylinders for each LOT in accordance with ASTM C31, except fill the cylinder molds in one layer without rodding. Use grout that attains a minimum compressive strength of 3,400 psi within seven days, when tested in accordance with ASTM C39.

451-4.6 Bearing Plate: Use bearing plates fabricated from steel meeting the

requirements of AASHTO M 270 or AST M A709.

451-4.7 Bondbreaker: Use bondbreaker fabricated from a smooth plastic tube or pipe

having the following properties:

451-4.8 Centralizers: Use centralizers fabricated from plastic, steel, or material that is

nondetrimental to the prestressing steel. Do not use wood. Ensure that the centralizer is able to support the tendon in the drill hole, and position the tendon so a minimum of 0.5 inches of grout cover is provided over the tendon bond length. In addition, locate the upper centralizer a maximum of 5 feet from the top of the tendon bond length, and locate the l ower centralizer a maximum of 12 inches from the bottom of the tendon bond length. The Engineer will not require centralizers on pressure injected tendons if the Contractor installs the anchor in coarse grained soils using grouting pressures greater than 1 50 psi. The Engineer will not require centralizers if the Contractor installs the anchors and grouts them through a hollow stem auger and maintains the hole full of stiff grout (slump less than 9 inches) during extraction of the auger.

451-4.9 Corrosion I nhibiting Grease ( include for temporary anchors only when

shown in the Plans): For corrosion inhibiting grease, meet the requirements of Section 3.2.5 of the Post Tensioning Institute Specification for Unbonded Single Strand Tendons.

451-4.10 Heat Shrinka ble Tubes: Use heat shrinkable tubes fabricated from a radiation

cross-linked polyolefin tube internally coated with an adhesive sealant. Prior to shrinking, ensure that the tube has a nominal wall thickness of 24 mils. Ensure that the adhesive sealant ins ide the tube has a nominal thickness of 20 mils.

451-4.11 Sheath ( include for temporary anchors only when shown in the Plans): Use

a sheath as part of the corrosion protection system for the unbonded length portion of the tendon fabricated from one of the following:

451-4.12 Spacers: Use spacers to separate elements of a multi -element tendon and which

permit grout to flow freely up the drill hole. Use spacers fabricated from plastic, steel, or material which is nondetrimental to the prestressing steel. Do not use wood. The Contractor may use a combination centralizer -spacer.

451-4.13 Tendon Bond Length Encapsulations ( include for temporary anchors only

when shown in the Plans): When the Contract drawings require the tendon bond l ength to be FY 2023-24 Return to Table of Contents encapsulated to provide additional corrosion protection, use encapsulation fabricated from one of the following:

451-4.14 Trumpet ( include for temporary anchors only when shown in the Plans):

Use a trumpet to provide a transition from the anchorage to the unbonded length corrosion protection fabricated from a steel pipe or tube meeting the requirements of ASTM A53 for pipe or ASTM A500 for tubing. Use a trumpet that has a minimum wall thickness of 0.125 inches for diameters up to 4 inches and 0.20 inches for larger diameters.

451-4.15 Water: Use potable water for mixing grout.

451-4.16 Grout Tube: Use a grout tube fabricated from a high density polyethylene

tube, or a PVC pipe, or a steel pipe with a 0.5 inches minimum inside diameter .

451-5 Tendon Fabrication.

Provide tendons that are either shop or field fabricated. Fabricate the tendon as shown on the approved shop drawings. Ensure that tendons are free of dirt, rust, or any other deleterious substance. Degrease the bond length. Handle and protect tendons, prior to installation, in a manner to avoid corrosion and physical damage. The Engineer will consider damage such as abrasion kinks, welds and weld splatters, cuts, and nicks which impair the proper performance of the tendon cause for rejection. Sheath tendons in the stressing length to prevent contact of the anchor tendon with the drill hole wall. The Contractor may use sheathing that consists of tubes surrounding individual tendon elements or a single tube surrounding the elements altogether. The Contractor may use sheathing material of either steel, plastic, or any other material nondetrimental to the high strength prestressing steel. The Contractor may use tape to prevent grout from entering under the sheath on individually sheathed elements. Select the type of tendon to be used. Unless otherwise shown in the Plans, size the tendon so the factored design load does not exceed 80% of the minimum specified ultimate tensile strength of the tendon. Increase the tendon size by the sacrificial steel thickness shown in the Plans. In addition, size the tendon so the maximum test load does not exceed 90% of the minimum yield strength of th e tendon. Assume responsibility for determining the bond length necessary to develop the design load indicated in the Plans or the shop drawings. Use a minimum bond length of 10 feet in rock and 15 feet in soil. Ensure that the minimum tendon bond length is 10 feet.

451-6 Installation.

451-6.1 General :

451-6.1 1 Drilling: Core drilling, rotary drilling, percussion drilling, auger

drilling, or driven casing may be used. At the ground surface, locate the drill hole within 12 inches of the location shown in the Plans or the approved shop drawings. Locate the drill hole so that the longitudinal axis of the drill hole and the longitudinal axis of the tendon are parallel. In particular, do not drill the prestressed soil anchor hole in a location that requires the tendon to be bent in order to connect the bearing plate to the supported structure. At the point of entry, FY 2023-24 Return to Table of Contents install the prestressed soil anchor within plus or minus 3 degrees of the inclination from horizontal shown in the Plans or the approved shop drawings. At the point of entry, make the horizontal angle formed by the prestressed soil anchor and the structure to within plus or minus 3 degrees of a line drawn perpendicular to the plane of the structure unless otherwise shown in the Plans or approved shop drawings. Do not allow the prestressed soil anchors to extend beyond the right-of-way or easement limits shown in the Plans.

451-6.1 2 Tendon Insertion: Insert the tendon into the drill hole to the desired

depth. When the tendon cannot be completely inserted, remove the tendon from the drill hole, and then clean or redrill the hole to permit insertion. Do not drive or force partially in serted tendons into the hole.

451-6.1 3 Installation of Trumpet and Anchorage: When corrosion protection

is required, extend that portion of the corrosion protection surrounding the unbonded length of the tendon, up beyond the bottom seal of the trumpet or 12 inches into the trumpet if no trumpet seal is provided. If the protection does not extend beyond the seal or sufficiently far enough into the trumpet, extend the corrosion protection, or lengthen the trumpet. When required, ensure that the corrosi on protection surrounding the unbonded length of the tendon does not contact the bearing plate or the anchor head during testing and stressing. If the protection is too long, trim the corrosion protection to prevent contact. Place the bearing plate and anchor head so the axis of the tendon is perpendicular to the bearing plate within plus or minus 3 degrees and the axis of the tendon passes through the center of the bearing plate. If using grout protected tendons, electrically isolate the bearing plat e, anchor head, and trumpet from the surrounding concrete, soldier pile, or any metallic element embedded in the structure. Completely fill the trumpet with corrosion inhibiting grease or grout. Trumpet grease may be placed any time during construction. Place trumpet grout after the prestressed soil anchor has been tested and stressed. Demonstrate to the Engineer that the procedures selected for placement of either grease or grout will produce a completely filled trumpet. For permanent soil anchors, c over all anchorages permanently exposed to the atmosphere with a corrosion inhibiting grease -filled or grout -filled cover. Demonstrate to the Engineer that the procedures selected for placement of either grease or grout will produce a completely filled cov er. If the Plans require restressable anchorages, use corrosion inhibiting grease to fill the anchorage cover.

451-6.2 Anchor Grouting: Provide grouting equipment that produces a grout free of

lumps and undispersed cement. Use a positive displacement grou t pump equipped with a pressure gauge to monitor grout pressures. Ensure that the pressure gauge is capable of measuring pressures of at least 150 psi or twice the actual grout pressures used, whichever is greater. Size the grouting equipment to enable the grout to be pumped in one continuous operation. Ensure that the mixer is capable of continuously agitating the grout. Inject the grout from the lowest point of the drill hole. Grout may be pumped through grout tubes, casing, hollow -stem-augers, or drill rods. The grout may be placed before or after insertion of the tendon. Record the quantity of the grout and the grout pressures. Control the grout pressures and grout takes to prevent excessive heave or fracturing. FY 2023-24 Return to Table of Contents Except where indicated below, the grou t may be placed above the top of the bond length at the same time as the bond length grout but may not be placed under pressure. Ensure that the grout at the top of the drill hole does not contact the back of the structure or the bottom of the trumpet. If the prestressed soil anchor is installed in a fine -grained soil using drill holes larger than 6 inches in diameter, place the grout above the top of the bond length after testing and stressing the prestressed soil anchor. The Engineer will allow the enti re drill hole to be grouted at the same time if it can be demonstrated that the particular prestressed soil anchor system does not derive a significant portion of its load -carrying capacity from the soil above the bond length portion of the prestressed soi l anchor. If using grout protected tendons for prestressed soil anchors anchored in rock, use pressure grouting techniques. For pressure grouting, seal the drill hole, and inject grout until a 50 psi grout pressure (measured at the top of the drill hole) can be maintained on the grout for five minutes. Upon completion of grouting, the grout tube may remain in the hole, but it must be filled with grout. After grouting, do not load the tendon for at least three days. Record the following data concerni ng the grouting operation:

451-7 Prestressed Soil Anchor Testing and Stressing.

451-7.1 General: Test each prestressed soil anchor. The Engineer will select the

prestressed soil anchors to be performance tested and those to be creep tested, and at his discretion, may increase or decrease the number of tests. Perform creep testing and performance testing at the beginning of the anchor installation, prior to installation of the remaining soil anchors, unless directed otherwise by the Engineer. In projects with multiple anchor row levels, the Engineer may request performance and creep testing at the beginning of the installation of soil anchors for subsequent levels. The purpose of these initial tests is to verify the Contractor’s installation procedures, the performance of the bond length , and the calibration of testing equipment. Perform creep testing as follows:

451-7.2 Criteria for Performing a Performance Test and a Proof Test: Raise the load

from one increment to another immediately after recording the prestressed soil anchor movement. Measure and record t he prestressed soil anchor movement to the nearest 0.001 inch with respect to an independent fixed reference point at the alignment load and at each increment of load. Monitor the load with a pressure gauge or load cell . At load increments other than the maximum test load, hold the load just long enough to obtain the movement reading. FY 2023-24 Return to Table of Contents Hold the maximum test load for at least 10 minutes. Pump the jack as necessary in order to maintain a constant load. Start the load -hold period as soon as the maximum test load is applied, and measure and record the prestressed soil anchor movement, with respect to an independent fixed reference, at 1, 2, 3, 4, 5, 6, and 10 minutes. If the prestressed soil anchor movement between 1 minute and 10 minutes exceeds 0.04 inches, hold the maximum test load for an additional 50 minutes. If extending the load -hold, record the prestressed soil anchor movements at 15 minutes, 20, 25, 30, 40, 50 and 60 minutes.

451-7.2 1 Performance Test: Perform the performance test by incrementally

loading and unloading the prestressed soil anchor in accordance with the following schedule: Performance Test Schedule Load Load AL AL 0.20 DL* 0.20 DL AL 0.40 DL 0.20 DL 0.60 DL 0.40 DL* 0.80 DL AL 0.90 DL* 0.20 DL AL 0.40 DL 0.20 DL 0.60 DL* 0.40 DL AL 0.60 DL 0.20 DL 0.80 DL 0.40 DL 0.90 DL 0.60 DL 1.00 DL* 0.80 DL* Reduce to lock -off load AL - is the alignment load. DL - is the prestressed soil anchor factored design load. Plot the prestressed soil anchor movement versus load for each load increment marked with an asterisk (*) in the performance test schedule, and plot the residual movement of the tendon at each alignment load versus the highest previously applied load.

451-7.2 2 Proof Test: Perform the proof test by incrementally loading the

prestressed soil anchor in accordance with the following schedule: Proof Test Schedule Load Load AL 0.80 DL 0.20 DL 0.90 DL 0.40 DL 1.00 DL 0.60 DL Reduce to lock -off load Compare the proof test results to the performance test results. If there is any significant variation from the performance test results, perform a performance test on the next anchor. FY 2023-24 Return to Table of Contents Plot the prestressed soil anchor movement versus load for each load increment in the proof test.

451-7.3 Criteria for Performing a Creep Test: Perform the creep test by incrementally

loading and unloading the prestressed soil anchor in accordance with the performance test schedule given above. At the end of each loading cy cle, hold the load constant for the observation period indicated in the creep test schedule below. Use the following times for reading and recording the prestressed soil anchor movement during each observation period: 1, 2, 3, 4, 5, 6, 10, 15, 20, 25, 30, 40, 50, 60, 75, 90, 100, 120, 150, 180, 210, 24 0, 270, and 300 minutes as appropriate. Start each load -hold period as soon as applying the test load. Pump the jack as necessary in order to maintain a constant load. Plot the prestressed soil anchor moveme nt and the residual movement measured in a creep test as described for the performance test above, and plot the creep movement for each load-hold as a function of the logarithm of time. Creep Test Schedule Load Observation Period (minutes.) AL 0.20 DL 10 0.40 DL 30 0.60 DL 30 0.80 DL 40 0.90 DL 60 1.00 DL 300

451-7.4 Lock-Off: Upon satisfactory completion of all testing, reduce the load to the

lock-off load, and transfer the load to the anchorage device. Use a lock -off load that is 80% of the prestressed soil anchor service load. The Contractor may completely unload the prestre ssed soil anchor prior to lock -off. After transferring the load and prior to removing the jack, take a lift-off reading. Use a lift -off reading that is within 10% of the specified lock -off load. If the load is not within 10% of the specified lock -off load, reset the anchorage, and take another lift -off reading. Repeat this process until obtaining the desired lock -off load.

451-7.5 Cutting of Tendon Protrusions: After an anchor has been accepted by the

Engineer, saw cut the portion of the anchor tendon exte nding beyond the anchorage. Take care not to damage the tendon or the tendon anchorage.

451-7.6 Prestressed Soil Anchor Load Test Acceptance Criteria: The Engineer will

accept a performance or proof -tested prestressed soil anchor with a 10 minute load hol d if the:

451-8 Corrosion Protection ( include for temporary anc hors only when shown in the Plans).

451-8.1 General: Protect prestressed soil anchors against corrosion using materials and

procedures described herein. The following materials may be used independently or in various combinations:

451-8.2 Protection Systems :

451-8.2 1 Bond Length :

451-8.2 2 Unbonded Length: For the minimum unbonded length of the tendon,

use 15 feet or as indicated in the Plans or the approved shop drawings, whichever is greater. If grouting the entire drill hole (tendon bond length and unbonded length) in one operation, provide the corros ion protection of the unbonded length by a sheath completely filled with corrosion inhibiting grease or grout, or a heat shrinkable tube internally coated with an elastic adhesive. If using grease under the sheath, make provisions to prevent the grease fro m escaping at the ends of the sheath. With grease, completely coat the tendon, fill the void between the tendon and the sheath, and fill the interstices between the wires of the 7-wire strands. Ensure that the shop drawings show how to provide a transition between the bond length and the unbonded length corrosion protection. If the sheath is grout filled, provide a separate bondbreaker that prevents the tendon from bonding to the grout surrounding the unbonded length. If providing grease -filled sheath co rrosion protection and the drill hole above the bond length is grouted after locking off the prestressed soil anchor, grout the tendon inside a second sheath.

451-8.2 3 Anchorage and Trumpet : Use non-restressable anchorage devices

except where indicated in the Plans. Provide restressable anchorages on those prestressed soil anchors designated as restressable in the Plans. Ensure that the post -tensioning supplier provides a restressable anchorage compatible with the post -tensioning system provided along wi th written recommendations concerning the restressing of the tendons. If using strand tendons, submit written recommendations from the post - tensioning supplier for seating the wedges. Include with the recommendations the minimum load required to properl y seat the wedges in the anchor head. Size the bearing plates so that:

451-9 Submittals.

Prepare and submit Shop drawings a nd a design submission describing the prestressed soil anchor system or systems intended for use to the Engineer for review and approval 30 working days prior to the commencement of the prestressed soil anchor work. Include the following in the shop drawings and design submission:

451-10 Tendon Storage and Handling.

Handle and store t endons in a manner to avoid damage or corrosion. The Engineer will consider damage to the prestressing steel as a result of abrasions, cuts, nicks, welds and weld splatter cause for rejection. Protect the prestressing steel if performing welding in the vic inity. Do not ground welding leads to the prestressing steel. Protect prestressing steel from dirt, rust, or deleterious substances. The Engineer will allow a light coating of rust on the steel. If heavy corrosion or pitting is noted, the Engineer will re ject the affected tendons. Use care in handling and storing the tendons at the site. Prior to inserting a tendon in the drill hole, examine the tendon for damage to the encapsulation and the sheathing. If, in the opinion of the Engineer, the encapsulation is damaged, repair the encapsulation in accordance with the tendon supplier’s recommendations. If, in the opinion of the Engineer, the smooth sheathing has been damaged, repair it with ultra high molecular weight polyethylene tape. Spiral wind the tape ar ound the tendon to completely seal the damaged area at a pitch that ensures a double thickness at all points.

451-11 Method of Measurement.

Unless otherwise shown in the Plans, the quantity to be paid for will be the number of prestressed soil anchors , based on the maximum anchor spacing shown in the Plans, installed and accepted. For prestressed soil anchors that do not meet the acceptance criteria, the original prestressed soil anchor and any required additional work or prestressed soil anchors will be, in sum, considered to be one prestressed soil anchor for payment purposes.

451-12 Basis of Payment.

Prices and payments will be full compensation for all work specified in this Section, including furnishing the materials necessary to complete the anchors in place and accepted. The quantity of performance and creep tests to be paid for will be the number of tests performed on accepted anchors. The cost of proof testing will be included in Item No. 451-70. No payment will be made for tests performed on una ccepted anchors. Payment will be made under: Item No. 451 - 70- Prestressed Soil Anchors - each. Item No. 451 - 70- 1 Prestressed Soil Anchor (Performance Tests) - each. Item No. 451 - 70- 2 Prestressed Soil Anchors (Creep Tests) - each. FY 2023-24 Return to Table of Contents SECTION 452 PRECAST SEGMENTAL BRIDGE CONSTRUCTION

452-1 Description.

Fabricate, store, transport and erect precast structural concrete superstructure and/or substructure segments on a prepared foundation, to the established lines and grades, in accordance with the design, dimensions and details shown on the Plans and in accordance with this Section. Reinforcing steel, embedded items and all appurtenant items are included. Base the bid on the design shown in the Plans. The work in this Section does not include longitudinally post -tensioned beams upon which a concrete sl ab is cast-in-place.

452-2 Qualification of Contractor’s Personnel .

Meet the requirements of Section 105. When mixing, handling and applying an epoxy bonding agent, provide direct supervision by a person with knowledge and experience, or trained by a tec hnical representative of the manufacturer in the use of this material. Arrange for a technical representative of the manufacturer to be at the site as an advisor at the beginning of this work. Ensure that all personnel who will be working with an epoxy bo nding agent are thoroughly familiar with the safety precautions necessary for use of this material.

452-3 Definitions.

The following definitions apply to segmental bridge construction:

452-3.1 Segment: A modular section of the superstructure and/or subs tructure

consisting of a certain cross -section shape and length as detailed in the Plans.

452-3.2 Match Cast: A precast concrete fabrication process whereby a segment

is cast against the preceding segment producing a matching interface which permits the re-establishment of the cast geometry at erection time. Match casting is accomplished by either the short line or long line casting method.

452-3.3 Short Line Casting: Casting segments one at a time in a casting cell

between a bulkhead at one end and a p reviously cast segment at the other. The first segment is cast between the bulkhead and another, temporary bulkhead.

452-3.4 Long Line Casting: Casting segments on a casting bed of sufficient

length to permit the cumulative casting of segments for the en tire length of a span or cantilever between field closure pours without repositioning the segments on the casting bed. With this method, the first segment is cast between bulkheads and successive segments are cast between a movable bulkhead on one end and the previously cast segment on the other.

452-3.5 Casting Cell: A special formwork arrangement usually consisting of a

fixed vertical bulkhead of the cross section shape at one end and adjustable soffit, side and core forms all designed and assembled int o a machine for making a single superstructure segment. A casting cell for a substructure pier shaft segment consists of exterior and interior side forms and a soffit form of the cross section shape.

452-3.6 Wet Joint System: Where segments are made in a casting cell between

two bulkheads and are not match cast. The segments are then erected in the superstructure with a narrow cast -in-place joint between each segment. (During erection, all the segments of a span or FY 2023-24 Return to Table of Contents multiple spans are supported by falsewor k, truss or other technique until the joints have gained strength and the longitudinal post -tensioning installed to make them self supporting.)

452-3.7 Span by Span (Erection): Placing a specified number of segments on a

temporary support system, aligned and post-tensioned longitudinally forming a completed span of the superstructure.

452-3.8 Balanced Cantilever (Erection): The segments are sequentially erected

alternately on either side of the pier in cantilever to a point where a closure is cast -in-place.

452-3.9 Progressive Cantilever: (Erection): The segments are erected

progressively in cantilever, in one direction, from one pier to the next, using temporary intermediate piers, or other systems as required to support the advancing cantilever betwe en piers.

452-3.10 Casting Curve: The curve of casting geometry that has to be followed

in the casting cell or bed for achieving the theoretical bridge profile and alignment after all the final structural and time dependent (creep and shrinkage) deformat ions have taken place. The casting curve is a combination of the theoretical bridge geometrical profile grade, alignment and the camber.

452-3.11 Camber: The amount by which the concrete profile at casting time must

differ from the theoretical geometric profile grade to compensate for all structural dead load, post-tensioning, all long term and time dependent deformations (creep and shrinkage) including all the intermediate erection stages and effects. (The opposite of deflections).

452-3.12 Erection El evation: The elevation at which a segment is set in the

structure at the time it is erected. (This is profile grade corrected by the amount of deflection calculated to occur from that stage onwards.)

452-4 Shop Drawings, Calculations and Manuals.

452-4.1 General: Use methods and procedures providing adequate safety to the general

public from construction/erection activities and/or falsework placed over or adjacent to traveled roadways, navigational or recreational waterways or any existing commercial, indu strial or other facility.

452-4.2 Information Required: Submit integrated detailed shop drawings, calculations,

manuals and other information, including, but not limited to, the following:

452-4.2 1 Segment Shop Drawings:

452-4.2 2 Casting Yard:

452-4.2 3 Erection Manual: Meet the requirements in 452 -8.

452-4.2 4 Manual for Geometry Control and Casting Curves: Meet the

requirements in 452 -6.3.

452-5 Materials.

452-5.1 General: Use materials which conform to this Section and the requirements

prescribed in Division III, Materials, for the particular kind and type of material specified.

452-5.2 Concrete: Use concrete as specified in Section 346 except as specifically

modified herein. Use No. 67 coarse aggregate in the concrete for segments. Screenings are not allowed as a substitute for silica sand for use in concrete for Precast Superstructure Segments.

452-5.3 Reinforcing Steel: Use ASTM A615, Grade 60 reinforcing steel which meets

the requirements of Section 415. When weld ing reinforcing steel, meet the requirements of the American Welding Society’s Structural Welding Code D1.4. The Engineer may allow shop prepared welded reinforcing grillages. Field welding of reinforcing steel is not allowed.

452-5.4 Post-Tensioning Syst ems: Use post-tensioning hardware components meeting

the requirements of Section 462 and used in field mock -up testing. Components are not interchangeable and must comply with the details of the approved shop drawings.

452-5.5 Epoxy Bonding Systems : Use only epoxy systems comprised of two

components, a resin and a hardener, with each component distinctly pigmented so that mixing produces a third color similar to the color of the precast segments and are listed on the Department ’s Approved Product List (APL). Manufacturers seeking evaluation of their products must submit an application conforming to the requirements of Section 6. In its workable state, or open time, the epoxy bonding agent must function as a lubricant for joini ng the segments. In its hardened state, the epoxy bonding agent must provide a watertight seal between the precast concrete segments. The hardened epoxy bonding agent must FY 2023-24 Return to Table of Contents provide intimate contact for stress transfer by completely filling all interstitial space between the match cast segment faces. Do not use resin or hardeners from containers which are damaged or have been previously opened. Combining of resin and hardener from bulk containers will not be permitted ; use only pre-proportioned, full containers of components. Submit instructions, from the manufacturer, for the safe storage, handling, mixing, and application of the materials.

452-6 Casting Requirements.

452-6.1 General: Ensure that all materials, details, and p rocedures are as specified

herein, as noted in the Plans, or as directed by the Engineer. Do not begin casting segments until the Engineer approves the relevant shop drawings, calculations, casting manuals, concrete forms and concreting operations and th e post- tensioning system components and layout if different from that on the Plans. (Approval of post - tensioning stressing elongations and forces for field erection operations is not required at this stage but is required prior to erection.) To use wet j oints to join cantilevers or for corrective measures, obtain the Engineer’s written approval. Give each segment an erection mark indicating its location, orientation and order in the erection sequence. Match mark abutting edges of adjacent segments. Show erection marks on the erection plans or in the erection manual.

452-6.2 Forms: Take responsibility for the design and engineering of the forms as well

as their construction. Form all exposed formed surfaces of each element of the structure with the same material to produce similar concrete surface textures, color, and appearance. Obtain the Engineer’s approval of forms prior to initiating casting operations. Build the details shown on the Plans or as amended by approved shop drawings into the forms. Repair worn, damaged, or otherwise unacceptable forms and obtain the Engineer’s approval before casting any segment. Where sections of forms are joined, ensure that offsets in flat surfaces do not exceed 1/16 inches and that offsets with corners and ben ds do not exceed 1/8 inches. Ensure that all joints in the forms and contact points with bulkheads and existing segments have good fitting seals to prevent loss of fine material and cement grout. Check and inspect forms on a regular weekly basis to ensure proper alignment and geometric accuracy. Do not use forms which fail to meet the specified casting tolerances until such corrections are made to produce segments within the specified tolerances. Use a small blockout at all locations where an external ten don enters or exits the face of the concrete at deviation blocks and diaphragms except at anchorage locations. The blockout will be approximately 2 inches larger in diameter or overall dimensions than the tendon duct and have a depth equal to at least the minimum prescribed concrete cover dimension shown in the Plans.

452-6.3 Casting Control (Geometry): Before commencing the casting operation, submit

the proposed method of geometry control for all segment casting operations to the Engineer for approval. Th is submittal must be in the form of a “Casting Manual” and include but not necessarily be limited to:

452-6.4 Preparation for Match Casting: When match casting is used, take great care in

positioning of the match cast (previously cast) segment in relation to the segment to be cast. Ensure that the match cast segment is not twist ed. Ensure that all materials to be embedded in the concrete of the new cast segment are properly positioned and supported in order to maintain their position and withstand concrete placement and consolidation without damage. Make provisions for all proj ections, recesses, FY 2023-24 Return to Table of Contents notches, openings, blockouts and the like in accordance with the Plans and approved shop drawings. Cover the abutting surface of the match cast segment with a thin film of a bond breaker consisting of flax soap and talc, or other material approved by the Engineer. Use a soap and talc mixture consisting of five parts flax soap to one part talc. The Engineer will base acceptance of a material other than soap and talc prior to casting any segments by demonstration on a large specimen consisting of a precast piece and a new cast piece with a contact facial area of at least 4 square feet .

452-6.5 Embedded Items:

452-6.5 1 General: Embedded items must be in accordance with specifications

for prestressed and post -tensioned construction and the requirements herein.

452-6.5 2 Embedded Post -Tensioning Ducts: Ensure that embedded ducts for

post-tensioning tendons and bars are positioned accurately to their required alignment. Properly fabricate and identify all ducts so that proper positio ning is assured and can be verified after casting. Utilize positive methods to ensure that ducts will not be displaced or damaged during concrete placement and consolidation. Adequately secure all embedded post - tensioning ducts to the reinforcement cage at intervals not exceeding 30 inches for steel pipes and 24 inches for plastic ducts, (Small ducts and very flexible ducts may require closer supports). Any auxiliary ties and support bars needed for these purposes will be considered incidental and at no extra cost to the project. Prevent the concrete cover requirements from being violated by any auxiliary ties and support bars. After installation in the forms, ensure that the ends of the ducts are sealed at all times to prevent entry of water, debri s and fine material. Following each pour of concrete, demonstrate that all empty ducts are free of water and are unobstructed and undamaged. Immediately prior to installation of the prestressing steel, again demonstrate to the satisfaction of the Engine er that all ducts are unobstructed and free of water and debris.

452-6.5 3 Anchorage Plates and Castings: Prior to placing concrete in the

forms, fix all tendon anchorage plates and anchorage castings in their respective position in the forms, connected to their duct and sealed to prevent mortar intrusion. Ensure that anchorage plates and castings are rigidly fixed in the forms to maintain their correct alignment and position during concrete placement and consolidation.

452-6.5 4 Reinforcing Steel: Fabricate and place reinforcing steel in accordance

with the Plans or as superseded by the approved shop drawings and as required herein. Do not cut out or remove reinforcing steel to permit proper alignment of post-tensioning ducts. Replace any bar that ca nnot be fabricated to clear the ducts by additional bars with adequate lap lengths and submit the details to the Engineer for approval. In the plane of the reinforcement parallel to the nearest surface of the concrete, ensure that bars do not vary from plan placement by more than 1 inch, nor by more than one-eighth of the spacing between bars, whichever is less. In the direction perpendicular to this plane of reinforcement, ensure that bars do not vary from plan placement by more than 1/4 inches. The top and bottom cover of reinforcing steel must be within 1/4 inches of the cover dimensioned in the Plans. The edge cover of the reinforcing steel must be within 1 inch of the cover dimensioned in the Plans.

452-6.6 Concrete Placement, Consolidation and Fini shing:

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452-6.6 1 General: Do not deposit concrete into the forms until the entire set -up

of the forms, reinforcement, ducts, anchorages and embedded items have been thoroughly inspected and checked. Do not place concrete until the Engineer is satisfied t hat all the above items have been properly inspected and checked, and the rate of producing and placing the concrete will be sufficient to complete the casting and finishing operations within the scheduled time, that experienced concrete finishers are avai lable where required for finish work and that all necessary finishing tools and equipment are on hand at the site of the work and are in satisfactory condition for use. During conveying and placement, protect concrete against undue drying or rise in tem perature and inclement weather.

452-6.6 2 Concrete Placement Equipment: Use concrete placement equipment

of a size and design which permits placing concrete within the specified time. Clean all equipment at the end of each operation or workday and, just prior to reuse, check the equipment again and clean off hardened concrete and foreign materials. Place concrete by belt conveyors and by pumping in accordance with

400-7.6 and 400 -7.7, respectively.

452-6.6 3 Concrete Placement Sequence:

452-6.6 4 Concrete Placement and Consolidation: Discharge individual loads

of concrete into the forms, and place and consolidate in the required locations. After discharge into the forms, do not bodily move concrete from place to place within the fo rms by mechanical vibrators or other similar equipment. Place and consolidate concrete with care so that post -tensioning ducts, anchorages and any other embedded items are maintained in their proper positions and are not damaged. Consolidate all conc rete using approved vibrators together with any other equipment necessary to perform the work as specified. Use internal vibrators having a minimum frequency of 8,000 vibrations per minute and sufficient amplitude to consolidate the concrete effectively. P rovide at least two stand -by vibrators in working condition for emergency use in case of malfunction. Use of external vibrators for consolidating concrete when the concrete is inaccessible for adequate consolidation by internal means. When external vibr ation is used, construct the forms sufficiently rigid to resist displacement or damage. FY 2023-24 Return to Table of Contents Vibrate concrete in a manner which avoids displacement or damage to reinforcement, post -tensioning ducts, anchorages and other embedded items. No construction joi nts are allowed within a segment, except as detailed in the Plans.

452-6.6 5 Finishing: Strike off the roadway surface of the segment with an

approved mechanical screed operated by a self contained power source. Furnish and use a straightedge at least 24 inches longer than the segment while finishing the concrete deck surface of superstructure box girder segments. Use the straightedge approximately parallel to the centerline of the segment to strike an accurate surface between the bulkhead and the top of the match cast segment at all positions across the segment width. Give all other surfaces of segments and precast components a Class 3 Finish at the precast site in accordance with 400 -15.

452-6.7 Curing:

452-6.7 1 General: Where casting cells are intended to operate on a short (daily)

cycle and it can be demonstrated to the satisfaction of the Engineer that the required initial concrete strengths for the removal of the forms, application of prestress, moving and handling of the segments and that the final concrete strength can be achieved in a timely and consistent manner, then steam curing will not be required. However, take precautions to promote proper curing by methods approved by the Engineer and in accordance with Sect ion 400. Such precautions must meet or exceed the following:

452-6.7 2 Steam Curing: Meet the requirements of Section 400 modified by the

following requirements when steam curing is used.

452-6.8 Removal of Forms: Prior to removing the forms, protect the plastic concrete

from adverse weather effects. Keep supporting forms in place until the concrete has reached the required strength for form removal as specified in the Plans, in this Section, or as approved by the Engineer. Test cylinders, made and cured in the same manner as the segment, to confirm the form release strength prior to removing form. With the Engine er’s approval, a strength curve chart may be established to determine the time necessary for achieving the required form release strength, in accordance with the specifications for form removal. Avoid cracking or damaging the segment when removing the fo rms, especially match cast surfaces and shear keys. Notify the Engineer of any damage which occurs and repair in an approved manner.

452-6.9 Test Samples: Provide additional test samples and testing for compressive

strength on precast segments and field c losure joints to control the construction activities and to ensure adequate strength of these components at various stages of their manufacture and assembly. Make test cylinders, in accordance with Section 346, cured in the same manner as the structural components to ensure adequate compressive strength has been achieved in accordance with the plan requirements for the following conditions:

452-6.10 Age at Erection: Unless otherwise approved by the Engineer, precast

components must be at least 14 days old prior to incorpo rating into the structure.

452-6.11 Tolerances:

452-6.11 1 General: The following tolerances apply to the fabrication of precast

components: FY 2023-24 Return to Table of Contents Table 452-1

452-6.11 2 Corrections: Control dimensions from segment to segment, including

cast-in-place segments, and compensate for any deviations within a single segment or series of segments so that the ov erall dimensions of the completed structure meet the dimensions and overall erection tolerances shown in the Plans and allowed by this Section.

452-6.11 3 Repairs: Repair minor breakage, spalling, or honeycomb (not over

1 inch deep) by a method approved by the Engineer. Major breakage, spalling, or honeycomb in excess of 1 inch deep is subject to the Engineer’s structural review. If found to be satisfactory, repair these areas using a method approved by the Engineer. Do not perform surface finishing or repairs on the matching joint surfaces of precast segments until after final erection of the segment, except as herein noted. If more than 20%, but less than 40% of the total contact surface of all shear keys in any single web is broken, spalled or honeycomb ed, grind the damaged areas to produce a cylindrical depression into sound concrete to a depth and width approximately equal to the shear key dimensions. Complete necessary repairs to shear keys damaged at the casting site prior to shipping the segment to the erection site. After erection of the segments adjacent to the damaged keys and prior to erection of additional segments, carefully pack the voids left by the depressions with an epoxy mortar as approved by the Engineer. With the Engineer’s approval, an alternate method of repair may be used. The Engineer will consider the segment unsatisfactory for use if more than 40% of the total contact surface of all shear keys in any single web is broken, spalled or honeycombed. Use an Engineer approved method for repairing damaged alignment keys located in the top and bottom slabs. The Engineer will consider a segment unsatisfactory for use if more than 50% of the total contact surface of all alignment keys in any element of the slab (wing overhang, central portion between webs, etc.) is broken, spalled or honeycombed. Remove and dispose segments found to be unsatisfactory and not repairable after structural review and cast a new segment at no expense to the Department. FY 2023-24 Return to Table of Contents

452-7 Precast Segment Handling, Storage and Shipment.

Handle segments with care to prevent damage. Handle segments using only the devices shown on the shop drawings for this purpose. Store all precast segments level in the upright position. Firmly support all precast segments for storage and shipment on an approved three point bearing system which does not introduce a twist under self weight. Do not stack superstructure segments one upon another unless approved by the Engineer. Prior to shipment the Engineer will thoroughly inspect each segment for d amage. Thoroughly clean the faces of all joints of laitance, bond breaking compound and any other foreign material by light sand blasting prior to shipment. Make no repairs of minor spalls or chipped areas on the joint surfaces until after erection of the segment. Upon arrival at the bridge site the Engineer will inspect each segment again. If in the Engineer’s opinion, any damage has occurred during shipment that will impair the function of the segment (structurally, aesthetically, etc.), the segment will be rejected. Replace any rejected segment with an approved segment at no cost to the Department. Provide firm support at bearing locations noted above. Fully secure the segments against shifting during transport. Provide a storage area of suitable stabilit y for the segments to prevent differential settlement of the segment supports during the entire period of storage.

452-8 Erection.

452-8.1 Erection Manual: Before commencing erection operations, submit proposals for

all segment erection operations to the Engineer for approval. This submittal must be in the form of an “Erection Manual” and include but not necessarily be limited to:

452-8.2 Erection Geometry Control:

FY 2023-24 Return to Table of Contents

452-8.2 1 General: Numerical or graphical methods may be used for alignment

control and checking during erection. Establish the key stages for checking of the erectio n in the erection manual and obtain the Engineer’s review and approval. Key stages would include, for example, setting a pier segment during cantilever erection and various intermediate points during subsequent segment erection, at span closure and upon co mpletion. Prepare a table of elevations and alignments required at each key stage of erection in accordance with the Plans, as cast geometry, camber and erection elevations for establishing erection controls and submit to the Engineer for approval. Carefully check elevations and alignments at each stage of erection and correct as required to avoid any possible accumulation of errors. If geometric corrective measures are necessary, the Engineer will require the Specialty Engineer to develop the mean s and methods to ensure the epoxy joint remains watertight and free from localized stress concentrations. The Specialty Engineer will be required to submit the corrective measures to the Engineer for approval. Use shims made of ASTM A240 Type 304 wire clot h (roving) with a maximum of 1/8 inch thickness.

452-8.2 2 Span -by-Span and Wet Joint Erection: Position each span segment

according to the final longitudinal alignment, grade, camber and cross -slope. Keep the horizontal and vertical alignment of the pie r segment within 1/16 inches of that required by the approved erection plans. Correct any deviation more than the tolerance allowed above using a method approved by the Engineer.

452-8.2 3 Balanced Cantilever and Progressive Cantilever Erection: Check

the alignment and elevations of the cantilevers, using two independent surveys, within one hour of sunrise on each day that segments are to be erected. Check the measurements made by each survey and ensure they agree to within 1/4 inches. When measurement s do not agree, discontinue erection of segments until discrepancies in measurements are resolved to the satisfaction of the Engineer. Accurate positioning of the pier segments is very important as it will establish the line and grade for cantilevers in each direction. Position each pier segment according to the final longitudinal alignment, grade and cross -slope and ensure no further erection continues until and unless these segments are properly located on the piers by the means provided. Keep the hori zontal and vertical alignments of the pier segment within 1/16 inch of the alignment values required to control points as established by the approved erection plans. Check at each key stage of erection, in accordance with approved erection procedures, t he ends of cantilevers for required elevations and alignment. Correct any deviation from the required alignment by a method approved by the Engineer.

452-8.3 Erection Tolerances:

452-8.4 Other Miscellaneous Erection Requirements:

452-8.4 1 Span -by-Span and Wet Joint Erection:

452-8 4.1.1 Cl osure Joints: Use concrete meeting the same specifications

and criteria as the concrete in the segments. Ensure that concrete reaches the minimum required strength as shown in the Plans or in the Specifications prior to stressing the continuity post - tensioning. Ensure that the closure joint forms provide tolerances as specified under 452 -6.11 Tolerances.

452-8.4 1.2 Wet Joints: Where forming joints between segments using

cast-in-place concrete, the above conditions for closure joints also apply to wet jo ints. In addition, the cast -in-place “Wet Joints” cannot be less than 3 inches wide, nor greater than 9 inches wide unless otherwise approved by the Engineer.

452-8.4 1.3 Formwork: Adequately support formwork at all wet joints

and closure joints to take all loads applied and do not remove them until the concrete in the joints has reached its required strength and the longitudinal tendons have been tensioned.

452-8.4 2 Balanced Cantilever and Progressive Cantilever Erection:

452-8.4 2.1 Deformations: For computing deformations due to time

dependent stress variations, the erection time assumptions are shown in the Plans. Deformations due to creep and shrinkage and the concrete modulus of elasticity have been computed using the FDOT’s Structures Manual edition noted in the Plans. Obtain the Engineer’s approval for method of calculating the above parameters.

452-8.4 2.2 Temperature Restrictions: Meet the requirements of

Section 926 for substrate temperatures, epoxy formulation and the rmal controls where precast segments are jointed with epoxy. Measure the substrate temperature at the mid -depth of the top slab for box girder sections or 4 inches from the top surface for slabs and other sections.

452-8.4 2.3 Permissible Loads on Canti lever: During balanced

cantilever erection, unbalance the cantilever by only one segment at any time. In addition to the unbalanced load due to one segment, the cantilevers are designed for loads applied by the erection equipment as listed in the Plans. Use alternate erection methods which comply with the assumptions in the Plans or otherwise approved by the Engineer.

452-8.4 2.4 Span Closure Joints: Use concrete for closure joints which

comply with the same specifications and criteria as the concrete in the segments. Ensure that concrete reaches the minimum required strength as shown in the Plans or in the Specifications prior to stressing the transverse or continuity post -tensioning. Ensure that the closure joint forms provide tolerances as specified for precast segments.

452-8.4 2.5 Falsework and Formwork: Support falsework and formwork

at closure pours by the cantilever ends or terminating segments of each series of segments to be joined. Secure cantilever together vertically, longitudin ally, and transversely so that the applied loads will yield equal deflections to both cantilevers. Do not remove securing devices until the closure pour concrete has reached its required strength and longitudinal continuity tendons are tensioned. Submit ca lculations and details to verify that the devices and methods have adequate rigidity and do not impose excessive loads and stresses on the structure.

452-8.4 3 Precast Box Pier Construction - Erection Tolerances:

FY 2023-24 Return to Table of Contents

452-8.5 Epoxy Jointing of Precast Segments: Furnish, mix and apply a two -component

epoxy bonding system, meeting the requirements of this Section, to the match cast faces of joints between precast concre te superstructure and/or substructure segments in accordance with the Contract Documents Prior to the use of epoxy on the project, conduct a site meeting with the Engineer and epoxy manufacturer to determine the proper formulations, storage and handling, mixing and application of the epoxy. Have the necessary materials immediately available at the location of the segment joining, in the event that the segments must be separated and cleaned or epoxy reapplied. Include in the erection manual required by this Section, details of erection and post-tensioning operations which assure that the time elapsing between mixing components of the first batch of epoxy bonding agent applied to the joining surfaces of precast concrete segments and the application of a compressive contact pressure across the joint do not exceed 70% of the open time for the particular formulation of epoxy bonding agent used. Also, include details of how the minimum, closing, contact pressure of approximately 40 psi will be applied uniformly to each joint to which epoxy is applied during the epoxy curing period. Contact pressure may be attained through combinations of weight and temporary and/or permanent post - tensioning.

452-8.5 1 Cleanliness of Surfaces to be Joined: Ensure that the app lication

surfaces are free from oil, form release agent, laitance or any other deleterious material that would prevent the epoxy bonding agent from bonding to the concrete surface. Remove laitance by light sandblasting, wire brushing. Do not destroy the su rface shape and profile of the mating surfaces. Ensure that the surfaces have no free moisture on them at the time the epoxy bonding agent is applied. Free moisture will be considered present if a dry rag, after being wiped over the surface, becomes damp .

452-8.5 2 Substrate Temperatures and Epoxy Formulation: Apply the epoxy

bonding agent only when the substrate temperature of both surfaces to be joined is between 40°F and 115°F. The formulation of the epoxy bonding agent must have an application tempe rature range that conforms to the substrate temperature of the surfaces being joined. If the mating surfaces have different substrate temperatures, then use the formulation for the higher temperature in hot weather periods. In cold weather periods, use the formulation for the lower temperature. Thermal control precautions may be taken in accordance with 452-8.5.5.

452-8.5 3 Mixing of Epoxy Bonding Agent: Mix the two components of the

epoxy bonding agent in strict accordance with the manufacturer’s instruc tions, using only full and undamaged containers. Only open the containers immediately before being combined and do not use any which have an expired shelf life. Thoroughly stir each container of component before combining the components. Combine the two co mponents and thoroughly mix until a uniform FY 2023-24 Return to Table of Contents color is achieved. Mix with a properly sized mechanical mixer operating at no more than 600 rpm or in accordance with the recommendations of the epoxy manufacturer. Do not mix until the segments to be joined a re within approximately 18 inches of their final position. Schedule mixing of the epoxy bonding agent so that the material in a batch is applied to the face of a joint within a maximum of 20 minutes after combining the components. The Engineer, at his d iscretion, may require a dry run to check the fit of two surfaces before applying the epoxy.

452-8.5 4 Mating of Segments: Immediately after each mating surface is covered

with epoxy bonding agent, bring the segments together and apply the specified comp ressive contact pressure in accordance with the approved erection procedures. The contact pressure may be increased at any time after the epoxy has taken an initial set. Do not reduce the contact pressure until the epoxy in the joint has properly hardened and cured. If the contact pressure is reduced, do not subject the joint to tensile stress. A discernable bead line of extruded epoxy bonding agent must be apparent along the exposed edges of the joint. Fill all areas of the joint which do not show a bea d of epoxy by dispensing additional epoxy, meeting the requirements of this specification, into the joint using a pneumatic gun with epoxy cartridges. Inject epoxy to a minimum depth of 1 inch. Catch and retain epoxy which is squeezed out of the joint i n areas over waterways, roadways, buildings, etc. Clean all extruded epoxy bonding agent from external visible surfaces in a way not to damage or stain the concrete surface. Do not smear surplus extruded epoxy bonding agent over large areas (areas more than 1 inch from each side of the joint), visible surfaces or surfaces to which a cover coat, Class 5 applied finish coat or similar or texturing is to be applied later. Immediately after the segments are joined, swab all embedded (internal) post-tensioning ducts or conduits passing through the joints to smooth out any extruded epoxy bonding agent. If the time between combining the components of the epoxy bonding agent and applying the compressive contact pressure exceeds 70% of the minimum open time, immediately separate the segments and clean in accordance with 45 2-8.5.6.

452-8.5 5 Thermal Controls:

452-8.5 5.1 Cooling in Hot Weather: If the substrate temperature

exceeds 115°F, do not proceed with epoxy jointing. The Contractor may take precautions to keep the mating substrate surfaces cool by shading or wetting with clean water, except that the above requirements for no moisture at th e time of application must be strictly adhered to.

452-8.5 5.2 Artificial Heating in Cold Weather: If electing to erect

segments in cold weather when the substrate temperature of the mating concrete surfaces is below 40°F, an artificial environment may be used to increase the substrate temperature subject to the following:

452-8.5 6 Failure to Comply with Time Limits or Incomplete Jointing: If the

time limit between mixing of the epoxy -bonding agent and the application of the contact pressure is exceeded, or if the joint is incompletely filled and sealed, separate the segments and remove all epoxy from the faces using spatulas and approved solvent. Do not re -apply epoxy until the faces have been properly cleaned and solvents dispersed, for a period of 24 hours.

452-8.5 7 Removal of Support to Segments :

452-8.5 7.1 Span -by-Span Erection: Ensure that precast concrete

segments remain fully supported by the erection truss or system until at least 20 hours after mixing of the last batch of epoxy bonding agent applied to any joint in the span.

452-8.5 7.2 Cantilever Erection: Independent su pport to a newly erected

cantilever segment may be removed when the epoxy bonding agent in the third previous mating joint has set. It is not necessary for the epoxy bonding agent in the new joint or the immediately previous joint to be set prior to removi ng the independent support of the new segment provided that the temporary and/or permanent post -tensioning has been installed to carry the load of the new and previous segment along with any applied construction loading as per the requirements of the erect ion system.

452-8.5 8 Record of Jointing : Record and submit to the Engineer on a weekly

basis the following information:

452-8.6 Packed Mortar Joints for Joints or Bearings: Where designated on the Plans,

place packed mortar after the joint or bearing has been set at the proper final elevation. Pressure grouting may be a llowed with the Engineer’s approval of the materials and method to be used. Mortar for packing consists of one part cement and one part fine aggregate, by volume, mixed with a non -shrink admixture as recommended by the manufacturer. Mix the dry FY 2023-24 Return to Table of Contents elements thoroughly to a uniform mixture. Add water to produce a mealy, slightly adhesive mixture. Pack the mortar until a water sheen is produced on the surface of the mortar. Build a form around the joint leaving one side open. Secure the form to withstand the required packing forces. Insert a small amount of mortar into the open joint to form a 2 inches thick bead on the opposite side of the form. Pack this bead by striking a special tool made of 1/2 inch by 2 inch steel having a length approximately 10 inches longer than the largest dimension of the joint being packed with a 2 pound hammer. Continue compaction until water begins to bleed out of the mortar. When bleeding has occurred, insert another bead of mortar and pack as described above. Continue this proce ss until the joint is filled to the limits shown in the Plans.

452-9 Traffic Railing and Median Setting.

Prior to forming the concrete traffic railing s, accurately establish the as -constructed gutter line elevations at intervals not exceeding 10 feet. Then form the base of the traffic railing and median to provide an inside vertical face which extends from the surface of the concrete structure to an ele vation located 3 inches (or as shown in the Plans) above the theoretical gutter line elevations. Maintain the plan vertical height of the traffic railing s as a minimum when variations exist between the plan profile and the actual profile of the gutter.

452-10 Bridge Deck Surface.

Provide a Class 4 Floor Finish in accordance with Section 400 for Long Bridges upon completion of superstructure segment erection and prior to opening to traffic. Install expansion joints in accordance with Section 400.

452-11 Watertight Decks.

Check all segment joints, closure joints and deck hole repairs to assure every location is watertight, upon completion of all milling and grinding activities on the riding surface. Repair all locations showing evidence of leaks by cutting a 3/8 inches wide x 5/8 inches deep groove along the leak interface. Clean and completely fill the groove with epoxy meeting the requirements of Section 926. Dispense the epoxy into the groove using a pneumatic gun and epoxy cartridges. Clean all excess epo xy bonding agent from external visible surfaces in a way not to damage or stain the concrete surface. Do not smear epoxy over areas located more than 1 inch from each side of the groove.

452-12 Method of Measurement.

Precast superstructure and substructure segment concrete, including cast -in-place concrete for closure and wet joint pours, will be measured by volume according to the quantities represented by the dimensions of the segments and cast -in-place pours on the Plans or approved shop drawings; whichever is the lesser. All reinforcement in precast superstructure and substructure segments, cast -in-place closures and wet -joints will be measured by weight according to the quantities represented by the reinforcement details in the Plans or approved shop drawings; whichever is the lesser. All permanent post -tensioning in the superstructure and substructure will be measured by weight according to the quantities represented by the details in the Plans or approved shop drawings; whichever is the lesser. FY 2023-24 Return to Table of Contents

452-13 Basis of Payment.

452-13.1 General: Payment will be in accordance with the following:

452-13.2 Precast Segments -Concrete: Payment for precast superstructure and

substructure segment concrete will be at the Contrac t bid prices per cubic yard for the various classes of concrete called for. Such prices and payments will be full compensation for manufacture, storage, transport, assembly and erection of the segments complete and in place, including filling all concrete blockouts and similar miscellaneous details. These prices and payments will also include the furnishing and the application of epoxy bonding agent and Class 5 applied finish coating when specified in the Plans, providing temporary and permanent segment a ccess details, material testing, special erection equipment, temporary post -tensioning, tools, labor and incidental items necessary for completing the work in accordance with the Plans, Specifications and approved shop drawings. Cast-in-place concrete fo r closure and wet joint pours will be paid for under these items which also include the cost of all formwork, closure devices and other temporary construction needed to make these closures and joints and cast -in-place segments or portions thereof as design ated in the Plans. Include the cost of providing a Class 4 floor finish on the bridge deck and approach slab surfaces in the cost of superstructure and approach slab concrete. The Bridge floor grooving will be measured and paid for separately. No additional payment will be made for extra concrete necessitated by approved modifications to the segments or structure needed to accommodate the Contractor’s construction methods.

452-13.3 Precast Segments -Reinforcement: Payment for reinforcement in precast

segments, closure pours, wet joints and other cast -in-place concrete joints and details will be at the Contract bid price per pound for reinforcing steel (superstructure) and for reinforcing steel (substructure). No additional payment will be made for ex tra reinforcement necessitated by approved modifications to the segments or structure for the purposes of the Contractor’s construction methods.

452-13.4 Precast Segments -Post-Tensioning: Payment for permanent post -tensioning

will be in accordance with Se ction 462. No additional payment will be made for extra permanent or temporary post - tensioning necessitated by approved modifications to the segments or structure for the purposes of the Contractor’s construction methods, nor will payment be made for tem porary tendons which are approved to be left in the structure, either stressed or unstressed, for the convenience of the Contractor’s operations.

452-13.5 Precast Segments -Partial Payment: Partial payment for precast segments will

be made at 65% of the bi d price per cubic yard of concrete and per pound of reinforcement when the segment has been cast and accepted. Remaining payment will be made when the segment has been erected and accepted for incorporation into the structure. Payment for post -tensioning w ill be in accordance with Section 462.

452-13.6 Precast Segment -Non-Compliance: Any penalties or deductions for non -

compliance with regard to concrete, reinforcement or post -tensioning will be applied to the work affected in accordance with the requiremen ts of the respective specifications. FY 2023-24 Return to Table of Contents

452-13.7 Precast Segment Production: Preparatory operations for superstructure

segment casting will be paid for separately at the Contract Lump Sum price for precast segment production. This item consists of the work n ecessary for establishing and putting into operation segment casting facilities. It includes preparatory work, operations, acquisition or lease of real property, acquisition or lease of segment manufacturing equipment, acquisition or lease of equipment for the handling, transport and storage of the segments, and all other work or operations which must be performed or costs incurred prior to the manufacture of the concrete segments, including engineering services such as shop drawings. Partial payments wil l be made as indicated below:

452-13.8 Epoxy Jointing: No separate payment will be made for the work of epoxy

jointing of precast concrete segments. The cost of this work will be included in payment for the various precast concrete items.

452-13.9 Payment Items:

Payment will be made under: Item No. 400 - 4- 39- Class IV Concrete (Precast Superstructure Segments) - per cubic yard. Item No. 400 - 4- 40- Class IV Concrete (Precast Substructure Segments) - per cubic yard. Item No. 400 - 8- 40- Class V Concrete (Precast Substructure Segments) - per cubic yard. Item No. 415 - 1- 4- Reinforcing Steel (Superstructure) - per pound. Item No. 415 - 1- 5- Reinforcing steel (Substructure) - per pound. Item No. 452 - 70- Precast Segment Production - lump sum. FY 2023-24 Return to Table of Contents SECTION 455 STRUCTURES FOUNDATIONS Index

455-1 General.

The Contractor may examine available soil samples and rock cores obtained during the soil boring operations at the appropriate District Materials Office.

455-1.1 Monitor Existing Structures: Monitor existing structures in accordance with

Section 108.

455-1.2 Excavation: Complete all excavation of the foundations prior to installing piles

or shafts unless otherwise authorized by the Engineer. After completing pile/ shaft installation, remove all loose and displaced materials from around the piles/shafts, leaving a clean, solid surface. Compact the soil surface on which concrete is to be placed or which will support the forming system for the concrete to support the l oad of the plastic concrete without settling or causing the concrete to crack, or as shown in the Contract Documents.

455-1.2 1 Abutment (End Bent) Fill : Place and compact the fill before installing

end-bent piling/shafts, except when driving specified t est piling in end bents or the Plans show uncased piles through proprietary retaining wall fills. When installing piles/shafts or casing prior to placing fill, take necessary precautions to prevent displacement of piles/shafts during placing and compact ing fill materials within 15 feet of the piles/shafts or casing. Reference and check the position of the piles/shafts or casing at three approximately equal intervals during construction of the embankment. Place embankment material in 6 inch compacted lifts in the 15 foot area around the piles/shafts or casing. Compact embankment material within the 15 foot area adjacent to the piles/shafts or casing to the required density with compaction equipment weighing less than 1,000 pounds. When installing piles/ shafts prior to the completion of the surrounding fills, do not cap them until placing the fills as near to final grade as possible, leaving only the necessary working room for construction of the caps. When shown in the Plans, p rovide permanent casings installed prior to placement of the fill, for all drilled shafts through mechanically stabilized fills (for example, behind proprietary retaining walls) for shafts installed after fill placement. Install temporary casings through the completed conventiona l fill when permanent casings are not required. Provide permanent casings, if required, before the fill is placed extending a sufficient distance into the existing ground to provide stability to the casings during construction of the abutment fill. FY 2023-24 Return to Table of Contents