502.02 Forms , Falsework, and Temporary Works
302 SECTION 502
502.01 Description
This work consists of designing, constructing, and removing temporary structures used for highway bridge structure s. The Department defines formwork, falsework, and temporary structures as follows: Temporary Structures. Falsework, formwork, temporary retaining structures, temporary water control systems, and detour bridges. Falsework. Temporary construction used to su pport a permanent structure until it becomes self-supporting. Formwork. Temporary structure or mold used to contain plastic or fluid concrete in the shape shown on the Plans until the concrete reaches the compressive strength required by the Contract. Temporary Retaining Structure. A temporary structure that holds the surrounding earth and water out of an excavation and protects adjacent property during construction of the permanent work. Temporary Water Control System. A system to divert water from and prevent it from entering an excavation. Detour Bridge. A conveyance for traffic during construction of permanent work.
502.02 Materials
A.Falsework
1.General The Department will allow the use of new or used manufactured components, or both in falsework construction. Provide materials in accordance with the following sections: Material: Section: Structural Steel 506 Structural Concrete (Class A) 509 Reinforcing Steel for Structures 511 If the Contract requires, provide certification for new materials. Perform concrete tests in accordance with Section 701, “Portland Cement Concrete. ”
2.Salvaged Steel Provide steel meeting ASTM A 6 criteria for surface imperfections at the allowable working stresses for new steel of the same grade . Provide salvaged steel in good condition with an FORMS, FALSEWORK, AND TEMPORARY WORKS 502.02 303 identifiable grade in accordance wit h Section 506, “Structural Steel.” for salvaged steel with an unidentifiable grade.
3.Timber All wood species assigned allowable stresses in the National Design Specification for Wood Construction (NDS) Supplement, as published by the National Forest Products Association are acceptable for use in falsework construction.
4.Used Lumber For used lumber in good condition with an unidentifiable grade, provide lumber with stress es that do not exceed those for new lumber of the same grade. For used lumber with an unidentifiable grade, provide lumber with the lowest NDS allowable stresses for the species, with appropriate reductions for condition.
5.Manufactured Components The Department will allow manufactured components of the following classes: Vertical shoring systems, including tubular welded frame shoring, tube and coupler shoring, and related components; and Assemblies manufactured for commercial use, including single -post shores, brackets, jacks, joists, clamps, and simila r devices.
B.Forms
1.General Provide mortar -tight concrete forms with sufficient strength to resist deflection during concrete placement.
2.Sheathing Provide U.S. Product Standard PS 1 for Exterior B -B (Concrete Form) Class I Plywood for exposed concr ete surfaces, or another material that produces a smooth, uniform concrete surface, as approved by the Engineer. Provide form panels in good condition with no surface defects. Ensure the properties are equal to or exceed the properties for the type of pl ywood required by the Contract if using a form panel material other than plywood.
3.Structural Support Provide materials for structural form support in accordance with Subsection 502.02.A, “Falsework.” The Departme nt considers vertical side forms, wall forms, column forms, and related studs, walers, and other form features to be formwork or structural support for formwork.
502.04 Forms , Falsework, and Temporary Works
304 (4) Prefabricated Formwork If providing prefabricated formwork, submit the following to the Engineer: Shop drawings in accordance with Subsection 105.02, “Plans and Working Drawings,” and Technical data substantiating the load -carrying capacity, detailing the application instructions, and describing the limita tions of use. Provide prefabricated formwork in accordance with the manufacturer recommendations.
5.Stay -in-Place Steel Deck Forms Provide stay -in-place steel deck forms only if allowed by the Contract or approved by the Engineer. Ensure stay -in-place st eel deck forms meet the requirements for prefabricated formwork in accordance with Subsection 502.02.B(4), "Prefabricated Formwork." Submit shop drawings to the Engineer, including related deck design calculations. Fabricate stay -in-place steel deck forms and supports using steel in accordance with ASTM A653, Grade 40(275), and Grade 50(340) with a coating class of G 165 in accordance with ASTM A 525.
6.Stay -in-Place Prestressed Concrete Deck Forms Provide stay -in-place prestressed concrete deck forms only if allowed by the Contract or approved by the Engineer. Ensure stay -in-place prestressed concrete deck forms meets the requirements for prefabricated formwork in accordance with Subsection 502.02.B(4), "Prefabricated Formwork." Submit shop drawings to the Engineer, including related deck design calculations. Fabricate stay -in-place deck forms in accordance with Section 503, “Prestressed Concre te Bridge Members.”
502.03 Equipment — Vacant
502.04 Construction Methods
A.Falsework If the falsework is taller than 14 ft [4.3 m] or traffic will travel under the falsework, ensure a professional engineer registered in Oklahoma designs the falsework.
1.Working Drawings Submit falsework drawings in accordance with Subsection 105.02, “Plans and Working Drawings.” Submit separate falsework drawings for each structure. The Department will allow one set of drawings for i dentical structures with identical falsework design and details. Begin falsework construction only after the Engineer approves of the working drawings. Ensure the working drawings include the following: FORMS, FALSEWORK, AND TEMPORARY WORKS 502.04 305 (a) General Design the falsework and provide desi gn details showing the following characteristics: Provides the necessary rigidity, Supports the imposed loads, and Produces a finished structure to the lines and grades shown on the Plans. Ensure the design calculations show the stresses and deflections i n load -supporting members.
b.Submission Sets Submit three sets of falsework drawings and one set of design calculations.
c.Design Details Include the information and details necessary to enable falsework construction without reference to source documen ts. Provide design -controlling dimensions, including those that control falsework design and erection.
d.Foundation Loads Show the maximum applied structural load on the foundation material. Include a drainage plan or a description of the plan to prote ct foundations from saturation, erosion, and scour.
e.Materials Specifications Describe proposed falsework material. Use manufacturer’s tests and recommended working loads to describe materials that standard nomenclature cannot define (such as AASHTO or ASTM). Determine whether the physical properties and conditions of the falsework material can support the assumed design loads.
f.Concrete Placement Provide a plan for the proposed concrete placement operation, including details of the equipment, labor , and procedures. For each concrete pour, include placement rates and design pressures. Include a superstructure placing diagram showing the concrete placing sequence and construction joint locations.
g.Settlements Show anticipated total settlements of falsework and forms, including falsework footing settlement and joint take -up. Design falsework and forms so anticipated settlement does not exceed 1 in [25 mm]. Design and construct the falsework to elevations that anticipate settlement during concrete placement and allow for camber needed to compensate for falsework member deflections during construction.
h.Traffic Show the locations of openings in the falsework intended for traffic. Provide details showing horizontal and vertical clearances and locations of temporary railing. Describe the sequence of falsework erection and removal.
502.04 Forms , Falsework, and Temporary Works
306 (2) Design Limitations The allowable maximum design stresses and loads listed in this section are based on the use of undamaged, high -quality material. If using less er quality material , reduce the allowable stresses and loads. Ensure design limitations are in accordance with the current edition of the AASHTO Guide Design Specifications for Bridge Temporary Works .
3.Falsework Foundations Field -verify ground elevations at proposed foundation locations before design. Determine the soil -bearing capacity if using spread footing foundations. The maximum allowable bearing capacity for foundation material, with the exception of rock, is 2 ton/ft² [200 kPa]. Do not place the edge of footings closer than 12 in [300 mm] to the intersection of the bench and the top of the slope. If the excavation is not supported by shoring, place the footing edge no closer to the edge of the excavation than the greater of a distance o f 4 ft [1.2 m] or a distance equal to the excavation depth. Construct pile type foundations in accordance with Section 514, “Driven Foundation Piles.” For falsework supported by footings placed on paved slopes, do not strut the falsework to columns unless the columns are founded on rock or supported by piling. Size spread footings to support the footing design load at the soil bearing capacity without exceeding anticipated settlements. Provide steel reinforcement in concrete foo tings. Provide a design that allows for uniform settlement under all legs or each tower under all loading conditions if steel towers have maximum leg loads greater than 30 kips [130 kN]. Inform the Engineer of foundation protection plans.
4.Proprietary Shoring Systems Submit to the Engineer a letter of certification from the proprietary shoring manufacturer indicating that the shoring system is being used in accordance with the manufacturer recommendations for loads and conditions of use , if using propri etary shoring systems .
5.Falsework Over or Adjacent to Roadways and Railroads Design and construct falsework to protect it from vehicle impact. Provide protection for the following: Falsework supports for members crossing over a roadway or railroad, and Falsework supports where the horizontal distance, from the traffic side of the falsework to either the pavement edge or a point 10 ft [3 m] from the centerline of track, is less than the total height of the falsework. Increase vertical design loads by 150 percent for falsework supports including posts, columns, and towers, but not footings. Install temporary concrete traffic barriers before erecting falsework towers or columns adjacent to an open public roadway. Place barriers so falsework footings or pil e FORMS, FALSEWORK, AND TEMPORARY WORKS 502.04 307 caps clear concrete traffic barriers by at least 3 in [75 mm], and all other falsework members clear the barriers by at least 12 in [300 mm]. Do not remove barriers until approved by the Engineer. Use steel falsework columns with a minimum section modul us of 10 in³ [150,000 mm³] around every axis, or sound timbers with a section modulus of at least 250 in³ [4,000,000 mm³] around every axis. Mechanically connect the base of each column or tower frame that supports falsework over or adjacent to a public ro ad to its supporting footing. Alternatively, apply other lateral restraints capable of withstanding a horizontal force of at least 2,000 lb [9 kN] applied to the base of the column in any direction. Mechanically connect columns or frames to the falsework cap or stringer to resist a horizontal force of at least 1,000 lb [4.5 kN] in any direction. Neglect the effects of frictional resistance. Mechanically connect the following to the falsework cap or framing: Exterior falsework stringers, Stringers adjacen t to the end of discontinuous caps, Stringers over points of minimum vertical clearance, and Every fifth remaining stringer. Ensure these mechanical connections are capable of resisting a load of at least 500 lb [2.2 kN] in any direction, including uplift on the stringer. Install connections before allowing traffic to pass beneath the span. Use bolts at least ⅝ in [16 mm] in diameter to connect timber members to brace falsework bents adjacent to roadways or railroads. Solid sheath falsework bents within 2 0 ft [6 m] of the centerline of a railroad track in the area from 3 ft to 16 ft [1 m to 5 m] above and on the side facing the track. Construct sheathing using plywood at least ⅝ in [16 mm] thick or lumber at least 1 in [25 mm] thick. Provide bracing so t he bent resists the required assumed horizontal load or 5,000 lb [22 kN], whichever is greater, without sheathing. Provide the minimum vertical and horizontal clearances as required by the Contract.
6.Falsework for Steel and Precast Concrete Beams and Gi rders Do not erect beams over traffic. Use falsework design loads consisting of all loads supported by the falsework. Do not apply loads to existing, new, or partially completed structures that exceed the load carrying capacity of any part of the structu re in accordance with the AASHTO LRFD Bridge Design Specifications . Build supporting falsework to accommodate the erection method without overstressing the beams and girders. Ensure the supporting falsework produces the final structural geometry, intended continuity, and structural action. Block and brace beams and girders to ensure lateral stability. Brace or tie exterior girders that support overhanging bridge deck falsework brackets to adjacent interior girders to prevent exterior girder rotation and o verstressing of the girder web. Alternatively, use needle beams clamped to the bottom flanges of the exterior girder and the
502.04 Forms , Falsework, and Temporary Works
308 adjacent interior girder to prevent exterior girder rotation and overstressing of the girder web. The Department will not allow w elding forms or falsework to structural steel. Design falsework and forms for concrete supported on steel structures to apply loads to girder webs within 6 in [150 mm] of a flange or stiffener. Distribute the loads to prevent local distortion of the web. Space bracing and supports no more than 8 ft [2.5 m] apart.
7.Falsework Construction Build camber into the falsework to compensate for falsework and structure deflection. Camber shown on the Plans is only for structure deflection. Attach tell -tales to the soffit of concrete forms that will allow a determination, from the ground, of the total structure settlement during concrete placement. Do not apply dead loads to falsework, other than forms and reinforcing steel, until approved by the Engineer. Dis continue concrete placement and make corrections if deviations occur that are greater than ⅜ in [10 mm] from the falsework drawings. If corrections are not made before initial set, remove unacceptable concrete.
8.Inspection and Certification After insta lling the falsework and before placing or removing concrete, have a registered professional engineer, proficient in structural design, and inspect the falsework. Submit to the Engineer before concrete placement, written certification that the installation complies with the Contract.
B.Forms
1.General Make concrete forms mortar -tight and strong enough to prevent deflection during concrete placement. Unless otherwise required by the Contract, comply with the tolerance requirements in Table 502:1. Table 502: 1 Maximum Dimensional Tolerances for Cast -in-Place Formed Concrete a Item Tolerance, in [mm] Deviation from plan line b ±1 [±25] Cross -sectional dimensions of columns, piers and beams, slabs, and walls +1 , −½ [+25, −12] Bridge deck thickness +½ , −1/2 [+12, −12] a Compare variations with the dimensions as shown on the Plans or as directed by the Engineer. b Tolerance measurements include alignment, plumb, grade, and level, and are perpendicular to the plan line or surface. The Engineer will inspect plumb of retaining walls before and after backfilling. FORMS, FALSEWORK, AND TEMPORARY WORKS 502.04 309 Place embeds before concrete placement. Clean the inside surfaces of forms. Remove loose material before completing forms for deck slab of cast -in-place box girders or cells, or voids of other members. Do not place concrete until inspection and approval of the forms.
2.Removable Formwork Coat forms with form oil to allow easy release. Use form oil that will not discolor the concrete. Except where the formed member is less than 3 ft [1 m] wide, provide and place form panels for exposed surfaces, in uniform widths of at least 3 ft [1 m] and in uniform lengths of at least 6 ft [2 m]. Arrange panels in symmetrical patterns co nforming to the general lines of the structure. For vertical surfaces, place panels with the longer dimension horizontal. Make the horizontal joints level and continuous. Alternatively, for walls with sloping footings that do not abut other walls, place panels with the longer dimension parallel to the footing. Align form panels on each side of the panel joint with supports or fasteners common to both panels. Provide ¾ in [20 mm] triangular fillets at sharp edges of the concrete. The Department will allo w devices cast into the concrete to support forms or to lift precast members, but will not allow devices driven into the concrete for fastening forms or form supports. Use form ties to prevent the forms from spreading during concrete placement. Do not use twisted wire loop form ties. Use form ties and anchors that will not damage the concrete surface when removed. Construct metal ties or anchors within the forms to allow removal to a depth of at least 1 in [25 mm] from the face without damaging the concr ete. Fill cavities with cement mortar and finish. Make forms rigid so the formed concrete surface does not vary more than ⅜ in [9 mm] using a 5 ft [1.5 m] straightedge or template, or vary more than 1/360 of the center to center distance between studs, jo ists, form stiffeners, form fasteners, or wales. The Department considers interior surfaces of underground drainage structures as enclosed surfaces. Form exposed surfaces for each element of a concrete structure with the same forming material or with mat erial that produces similar surface textures, color, and appearance. Support roadway slab forms of box girder type structures on wales or similar supports fastened to the top of the web walls.
3.Stay -in-Place Steel Deck Forms
a.General Do not rest form sheets directly on top of girder, stringer, or floor beam flanges. Fasten sheets to form supports with a bearing length of at least 1 in [25 mm] at each end. Place form supports in contact with the girder, stringer, or floor beam flange and attach with bolts, clips, or other methods approved by the Engineer. Do not weld forms to girder, stringer, or floor beam flanges or reinforcing steel. Clean, wire brush, and paint exposed form metal where the galvanized coating is damaged. Paint with at least 5 mil [130 µm] of zinc rich paint containing at least 90 percent zinc. The
502.04 Forms , Falsework, and Temporary Works
310 Department does not require touch -ups for minor heat discoloration in areas of welds. Replace forms damaged by bending or crimping. Locate transverse slab construction joints at the bo ttom of a flute. Field drill ¼ in [6 mm] diameter weep holes at least 12 in [300 mm] on center along the line of the joint. Lap adjacent forms and connect form sheets without welding at a maximum of 18 in [450 mm] centers along the lap. At the lap, plac e the first panel to be loaded during concrete placement on top. Use epoxy -coated reinforcing steel in bridge decks (including any reinforcing that extends into the bridge deck) that use stay -in-place forms. If epoxy -coated reinforcing steel is not shown on the Plans, provide epoxy coated steel at no additional cost to the Department. The Department will not allow the use of reinforcing steel placed on the forms as support chairs. Provide means for inspection of the underside of forms after concrete plac ement. At least 48 hr later, test for soundness and bonding of the forms by sounding with a hammer. If soundness testing reveals noncompliant concrete, remove forms as directed by the Engineer. Do not use a cutting torch to remove forms. Repair or repl ace concrete as required by the Contract.
b.Design Requirements
1.Design Load Use a design load consisting of the weight of the forms, reinforcement, and plastic concrete plus 50 lb/ft² [2,400 Pa] for construction loads.
2.Allowable Bending Stress Limit the unit working stress in the steel form sheet to a maximum of 0.725 times the minimum yield strength of the provided material as required by the Contract, to no greater than 36 ksi [250 MPa].
3.Allowable Deflection Limit the deflection of form she ets to a maximum of 1/240 of the form span, no greater than ¾ in [20 mm]. Use the calculated design load, less 50 lb/ft² [2,400 Pa] for construction loads, or 120 lb/ft² [5760 Pa], whichever is higher, to calculate the deflection.
4.Maximum Camber Limit the form camber to not exceed the deflection under actual load. Do not use camber to compensate for deflection exceeding the limits required by the Contract.
5.Design Span Length The Department defines the span length of form sheets as the distance betwe en the flanges of the supporting beams minus 2 in [50 mm], measured parallel to the form flutes.
6.Design Properties Calculate physical design properties in accordance with the American Iron and Steel Institute North American Specification for the Design of Cold -Formed Steel Structural Members . FORMS, FALSEWORK, AND TEMPORARY WORKS 502.04 311 7) Weight Limitation Limit the combined load of the forms and additional concrete necessitated by use of stay-in-place forms to a maximum of 5 lb/ft² [0.24 kN/m²] greater than the design dead load of the bridge deck . The Department will not allow the use of plywood sheeting on steel stay-in-place deck forms.
8.Deck Reinforcement Maintain the dimensions of deck reinforcement shown on the Plans from the top surface of the concrete deck, including cover.
9.Flange Bra cing The Department does not consider stay -in-place forms as lateral bracing for compression flanges of supporting structural members.
c.Shop Drawings Prepare shop drawing for stay -in-place steel forms showing the following: The layout of the form sheets on the bridge floor, identifying form sheets by piece marks; The steel grade, dimensional, and section properties for form sheets and supports; The type and spacing of chairs; Lap details and planned direction of concrete placement; Views of all connectio ns; A bill of materials; and Installation instructions.
C.Removal of Forms and Falsework Remove all forms, except stay -in-place forms. Unless otherwise required by the Contract, remove forms and falsework in accordance with the time periods in Table 502:2. Release falsework for cast-in-place post -tensioned portions of structures after tensioning prestressing steel. Table 502:2 Form and Falsework Release Criteria Forms and Falsework Time Supporting spans: >14 ft [>4.3 m] (i.e. slab spans, pan girders, RCB decks, pier caps) 14 days ≤14 ft [≤4.3 m] (i.e. bridge decks on girders, RCB decks, diaphragms, pile bent pier caps) 10 days Not supporting dead concrete weight (i.e. columns, walls, side forms for abutments and pier caps) 24 hr For railings and barriers 12 hr
502.04 Forms , Falsework, An D Temporary Works
312 After removing the forms for the structure, cure in accordance with Section 509, “Structural Concrete. ” Refer to Section 509, “Structural Concrete, ” for sequence of placement and application of load requirements. The time periods in Table 502:2 assume a concrete cure temperature of 50 ºF [10 ºC] or higher. For each day temperatures are below 50 ºF [10 ºC], add a day to the original curing time for form and falsework release period . If the concrete attains 80 percent of the strength required by the Contract, the Engineer may shorten the time period for falsework release. Determine strengths from test cylinders cured at the work site under similar environmental conditions in accorda nce with Section 701, “Portland Cement Concrete.” If the Contractor proposes to prematurely apply loads to an element, it may be necessary to leave the forms and falsework in place until such time that 100 percent of the strengt h is obtained and a minimum time has elapsed in accordance with 509.04.I, “Application of Loads Including Bridge Decks and Approach Slabs .” Completely remove falsework. Remove falsework piling at least 2 ft [0.6 m] below the surface of the original ground line or stream bed. If falsework piling is driven within the limits of ditch or channel excavation, remove the piling to at least 2 ft [0.6 m] below the bottom and side slopes of the excavated areas.
D.Temporary Reta ining Structures
1.General Excavate in accordance with Section 501, “Excavation and Backfill for Structures,” and the OSHA Standard outlined in 29CFR 1926, Subpart P.
2.Vertical -Sided Excavations Sheet and brace vertical -sided excavations to keep the earth and water pressure and surcharges, and to protect adjacent property and facilities during construction. Employ a registered geotechnical engineer to identify unknown soils. Employ a registered structural engineer to design temporary retaining structures and prepare working drawings. Submit calculations and drawings for the temporary retaining structure to the Engineer before beginning work.
3.Cofferdams and Shoring Size cofferdams to allow pumping outside the concrete for ms and concrete placement in dry conditions. If water cannot be controlled enough to produce dry conditions, use a cofferdam with a Class A-concrete seal placed underwater below the elevation of the footing. Control the water level within the cofferdam du ring concrete seal placement to prevent water flow through the seal. Construct cofferdams to protect green concrete from a sudden rise of the stream and erosion. Do not leave bracing inside the permanent concrete structural members. Before constructing, o btain approval from the Engineer to substitute round pier bases of equal stability for square or rectangular bases as shown on the Plans. FORMS, FALSEWORK, AND TEMPORARY WORKS 502.04 313 Unless otherwise required by the Contract, remove cofferdams and shoring with all sheeting and bracing after completing the footing.
E.Temporary Water Control Systems
1.General Temporary water control systems consist of dikes, bypass channels, flumes, other surface water diversion works, cutoff walls, and pumping systems, including wellpoint and deep well systems , used to prevent water from entering excavations for structures.
2.Working Drawings When shown on the Plans, submit working drawings for temporary water control systems in accordance with Subsection 105.02, “Plans an d Working Drawings.” Include details of the design and equipment, operating procedures, and the discharge locations. Design and operate the system in accordance with water pollution control and environmental requirements.
3.Operations Pump from the int erior of foundation excavation using a method that will prevent the possibility of water moving through fresh concrete. Stop pumping ground water from an excavation during and at least 12 hr after concrete placement, unless using a sump separated from the concrete work by a watertight wall or other means. Before pumping to dewater a sealed cofferdam, allow the seal to set to withstand the hydrostatic pressure. Regulate pumping from wellpoints or deep wells to avoid damage by subsidence to adjacent propert y.
F.Detour Bridges Construct and maintain the detour bridge as required by the Contract or an alternative design approved by the Engineer. Use a registered professional engineer to design the alternative detour bridge. Submit signed and sealed working draw ings and calculations for approval of the alternative design in accordance with Subsection 105.02, “Plans and Working Drawings.” Ensure the alternative design is equivalent to the design shown on the Plans. Use the ro adway width and traffic rail shown on the Plans. In the submittal, show the design parameters required by the Contract. Design in accordance with AASHTO LRFD Bridge Design Specifications . Use an HL -93 live load, unless otherwise required by the Contract . Verify that used beams satisfy the minimum section modulus required by the approved design. Account for section loss due to corrosion, fatigue life, or bent, cracked, or damaged flanges or webs. Replace unsatisfactory beams at no additional cost to the Department. Remove detour bridges as required by the Contract or directed by the Engineer. Beams become the Contractor’s property at the end of the project.
503.01 Prestressed Concrete Bridge Members
314 502.05 METHOD OF MEASUREMEN T — VACANT
502.06 Basis of Payment
The Department will pay for each pay item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit:
A.ENGINEERED FALSEWORK Lump Sum
B.FALSEWORK ENGINEERING SERVICES Lump Sum
C.DETOUR BRIDGE Lump Sum Unless specified in the Contract as pay items, include the cost of forms and falsework, Engineered Falsework and Falsework Engineering Services , in the Contract unit price for the relevant concrete pay item. If the Contractor chooses to use stay -in-place f orms, the Department will not pay for additional quantities of concrete and reinforcing steel in excess of the quantities shown on the Plans. Include the cost of temporary retaining structures and temporary water control systems in the Contract unit price for the relevant excavation pay item. The Department will pay for piling and drilled shafts for detour bridges in accordance with Section 514, "Driven Foundation Piles," and Section 516, "Drilled Shaft Foundations." SECTION 503 PRESTRESSED CONCRETE BRIDGE MEMBERS
503.01 Description
This work consists of providing and placing precast, prestressed beams and other precast concrete bridge component s in the bridge structure. Post -tensioned concrete bridge members are not covered by Section 503. Prestressing. The stressing of bridge members in which the stressing forces are placed in the steel strand before the concrete is placed. Detensioning. The transfer of stress from the steel strand tendons into the hardened concrete. Sweep. Horizontal deviation from a straight line parallel to the centerline of the member. Camber. Upward deflection of the member caused by prestressing forces.
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 316–327 of 935.