468 THREE -SIDED REINFORCED CONCRETE BRIDGE/CULVERT
620.1 -DESCRIPTION : This work shall consist of furnishing the design, construction plans, materials, and construction of single piece precast or cast -in-place reinforced concrete three -sided flat -topped bridge/culverts or single piece precast reinforced concrete three -sided arch -topped bridge/culverts or a two -piece precast reinforced concrete continuous arch bridge/culverts, with headwalls and wingwalls, in accordance with these specifications and in reaso nably close conformity with the lines, grades, design, and dimensions shown in the plans.
620.2 -GENERAL : The bridge/culvert design and detail plans for construction shall be submitted t o the Engineer for approval. The time required for preparation and review of these submittals shall be charged to the allowable contract time. Delays caused by untimely submittals or insufficient data will not be considered justification for time extensio ns. No additional compensation will be made for any additional material, equipment, or other items found necessary to comply with the project specifications as a result of the Engineer's review. The proposed bridge/culvert design shall be compatible with the Contractor's proposed method of construction, and shall be compatible with any method of construction shown in the plans. The Division does not assume nor warrant any bridge/culvert system's compatibility with any particular construction methods.
620.3-DESIGN CRITERIA : 620.3.1 -General: The following data will be provided on the contract plans:
box i n addition to the bearing capacity and roadway profile.
The size of all structural elements shall be determined such that the design load stresses do not exceed the allowable stresses found in the AASHTO LRFD Bridge Design Specifications, latest editio n. The structural design of the two -piece precast reinforced concrete arch bridge/culverts shall provide for a structurally reinforced section at the crown/closure section such that the completed arch bridge/culvert is structurally continuous. If parape ts are used on any portion of the headwalls and wingwalls as shown in the plans, they shall be designed to resist traffic loads in accordance with the AASHTO LRFD Bridge Design Specifications, latest edition. The load shall be a HL -93 (HS25) test level 3. The length and height of the wingwalls and headwalls must be designed to accommodate the specified fill slope without fill encroaching on the underlying streambed, waterway or edge
469 of roadway template . Wingwalls with a tapered bottom surface shall not be used due to compaction difficulties beneath the wingwall. Wingwall options other than cast -in-place shall only be systems that have been evaluated by HITEC. Except those on roads with a design year ADT less than 500 and where the product of the desig n year percent trucks times the ADT is less than 100, all flat -topped structures with less than two feet of cover shall have approach slabs per the Divisions Structural Design Manual.
620.3.2 -Precast Three -Sided Bridge/Culvert: The bridge/culvert unit dimension and reinforcement details shall be as prescribed in the plan and the shop drawings provided by the manufacturer. The minimum concrete compressive strength shall be 4000 psi. The minimum steel yield strength shall be 60 ksi. The minimum require d strength for form removal and handling shall be 70% of Design Strength unless otherwise specified by the Designer. The precast three -sided bridge/culvert unit shall also conform to MP 604.02.40. The top exterior surface shall ha ve positive drainage with a minimum slope of 2% from the centerline of the span to the exterior corner of the structure. Unless noted otherwise on the shop drawings and designed accordingly, a minimum of one foot of cover above the crown of the bridge/c ulvert unit is required in the installed condition.
620.3.2.1 -Placement of Reinforcement: The cover of concrete over the outside reinforcement shall be two ( 2) inches minimum. The cover of concrete over the inside reinforcement shall be 1 -1/2 inches m inimum. The clear distance of the end shall not be less than one (1) inch nor more than two (2) inches from the ends of the bridge/culvert unit. Reinforcement shall be assembled utilizing single or multiple layers of welded wire fabric, or utilizing a sin gle layer of deformed billet -steel bars. The welded wire fabric shall be composed of circumferential and longitudinal wires meeting the spacing requirements of 620.3.2.3 and shall contain sufficient longitudinal wires extending through the unit to maintain the shape and position of the reinforcement. Longitudinal distribution reinforcement may be welded wire fabric or deformed billet -steel bars and shall meet the spacing requirements of subsection 620.3.2.3. The ends of the longitudinal distribution reinfor cement shall be not more than three ( 3) inches from the ends of the unit.
620.3.2.2 -Bending of Reinforcement: The outside and inside circumferential reinforcing steel for the corners of the bridge/culvert unit shall be bent to such an angle that is appr oximately equal to the configuration of the unit's outside corner.
620.3.2.3 -Laps, Welds, and Spacing: Tension splices in the circumferential reinforcement shall be made by lapping. Laps may be tack welded together for assembly purposes. For smooth we lded wire fabric, the overlap shall meet the requirements of ACI 12.8 and 12.19. For deformed welded wire fabric, the overlap shall meet the requirements of ACI 12.7 and 12.18. For deformed billet -steel bars, the overlap shall meet the requirements of ACI 12.2. For splices other than tension splices, the overlap shall be a minimum of twelve ( 12) inches for welded wire fabric or deformed billet -steel bars. The spacing center -to-center of the circumferential wires in a wire fabric sheet shall be not less than two ( 2) inches nor more than four ( 4) inches. For the wire fabric, the spacing center - to-center of the longitudinal wires shall not be more than eight ( 8) inches. The spacing center -to-center of the longitudinal distribution steel for either line of reinf orcing in the top slab shall be not more than sixteen ( 16) inches.
470 620.3.3 -Cast -In-Place Three -Sided Bridge/Culvert: Cast-in-place structures shall be constructed per section 601.
620.4 -SUBMITTALS : 620.4.1 -General: The Contractor shall submit complete design calculations, explanatory notes, and detail plans for the proposed bridge/culvert system. The detail plans shall include all details, dimensions, quantities, and cross sections necessary to construct the bridge/culvert and shall include but not be limited to the following items:
edition, to determine the headwater elevation and velocity of flow for the proposed culvert, plus all supporting hydraulic calculations on separate sheets.
requirements.
with bar s ize, length, and spacing indicated. Footing plan and section views shall be provided. The soil bearing pressure used in the design shall be noted on the footing detail sheets.
reinforcing steel and anchorage details. Wingwall plan, elevation, and section views shall be provided.
details. Headwall elevation and section views shall be provided.
At the time the detail plans are submitted for review, they shall be accompanied by design calculations and explanatory notes. These do cuments shall be legible and shall demonstrate that the design criteria have been met. The plans shall be prepared on reproducible sheets eleven ( 11) x seventeen ( 17) inches including borders. Each sheet shall have a title block in the lower right hand corner. The title block shall include the sheet number of the drawing, name or designation of the structural unit detailed on the sheet, the state and federal project designation, project name, fabricator and Contractor name. Design calculations and notes shall be prepared on sheets 8½ x 11 inches, and shall contain the project designation, structural unit designation, date of preparation, initials of designer and checker, and page number at the top of the page. The Detail Plans, Design Calculations, and E xplanatory Notes shall be signed and stamped by a Professional Engineer registered in West Virginia and knowledgeable in the proposed bridge/culvert system. The initial submission shall include three sets of the detail plans, calculations, and notes. One set of notes and plans will be returned to the Contractor with any indicated corrections. When the plans and notes are stamped approved by the Engineer, the Contractor shall furnish the Engineer with the requested number of sets of prints and a Mylarse t of the plans for distribution by the Division. The Contractor shall perform no work or ordering of materials for the structures until the Engineer has approved the submittal.
471 620.4.2 -Precast Three -Sided Bridge/Culvert: The details and material specifications for the bridge/ culvert system elements and incidental accessories shall be included with the detail plans for approval by the Engineer.
620.4.3 -Cast -in-Place Three Sided Bridge/Culvert: The plans for the cast -in-place bridge/cu lvert shall contain a complete reinforcing bar schedule showing all bending details and bar marks. The plans shall also show the location of all construction joints, expansion joints, or other joints in the bridge/culvert.
620.5 -MATERIALS : 620.5.1 -Concrete: The concrete for the bridge/culvert units shall be air -entrained composed of Portland cement, fine and coarse aggregates, admixtures and water. Concrete shall contain 7 ± 2 percent (7±2%) air. The air entraining admixture shall conform to section 707.1.
620.5.1.1 -Portland Cement: Shall conform to the requirements of sections 701.1 and 701.3.
620.5.1.2 -Coarse Aggregate: Shall consist of stone having a maximum size of one
620.5.1.3 -Water Reducing Admixture: The manufacturer may submit for approval by the Engineer, a water -reducing admixture, per section 707.3, for the purpose of increasing workability and reducing the water requirement for the concrete.
620.5.14-Calcium Chloride: The addition to the mix of calcium chloride or
admixtures containing calcium chloride will not be permitted.
620.5.1.5 -Fine Aggregates: Shall conform to section 702.1. Only siliceous sand shall be used when the top of the structure is to be the driving surface.
620.5.1.6 -Mixing Water: Shall conform to section 715.7.
620.5.1.7 -Water Reducers / Retarding Admixtures: Shall conform to section 707.2.
620.5.1.8 -Joint Material: Shall conform to Section 708.7.
620.5.1.9 -Supplementary Cementitious Materials (SCMs): Shall conform to
620.5.2 -Reinforcing Steel: All reinforcing steel for the bridge/culvert units shall be fabricated and placed in accordance with the detailed shop drawings submitted by the manufacturer. Reinforcement shall be grade 60 or as specified in the plans, and shall comply with sections 709.1, 709.4 or 709.6. Longitudinal distribution reinforcement may consist of welded wire fabric or deformed billet -steel bars.
472 Steel reinforcing shall be epoxy coated per AASHTO M -284 or galvanized per AASHTO M-111 for structures installed at an elevation such that the top or crown of the structure is above the bottom of the subgrade in the pavement section.
620.5.3 -Permissible Variations: 620.5.3.1 -Internal Dimensions: The internal dimensions shall not vary from the design dimensions by more tha n 1 percent (1%) or 1-1/2 inches, whichever is less. The haunch dimensions shall vary not more than 3/4 inch from the design dimension.
620.5.3.2 -Slab and Wall Thickness: The slab and wall thickness not be less than that shown in the design by more th an 1/4 inch. A thickness more than that required in the design shall not be cause for rejection.
620.5.3.3 -Length of Opposite Surfaces: Variations in laying lengths of the two opposite surfaces of the culvert shall not be more than 5/8 inch in any bridge/culvert unit, except where beveled ends for laying of curves are specified by the purchaser.
620.5.3.4 -Length of Unit: The underrun i n length of a unit shall not be more than 1/2 inch in any unit.
620.5.3.5 -Position of Reinforcement: The maximum variation in position of the reinforcement shall be + 1/2 inch. In no case shall the cover over the reinforcement be less than 1 -1/2 inch for the outside circumferential steel or be less than one (1) inch for the inside circumferential steel as measured to the external or internal surface of the bridge/culvert unit. These tolerances or cover requirements do not apply to mating surfaces of the joints.
620.5.3.6 -Area of Reinforcement: The areas of steel reinforcement shall be the design steel areas as shown in the manufacturer's shop drawings. Steel areas greater than those required shall not be cause for rejection. The permissible variation in diameter of any reinforcement shall conform to the tolerances prescribed in the ASTM Specification for that type of reinforcement.
620.5.4 -Curing: All Bridge/Culvert units shall be cured in accordance with Section
601.12except that curing may be discontinued once 70% of the design Strength is achieved
620.5.5 -Testing and Inspection: 620.5.5.1 -Precast Three -Sided Bridge/Culvert Units: 620.5.5.1.1 -Type of Test Specimen: Concrete compressive strength shall be determined from compression te sts made on cylinders or cores. For cylinder testing a minimum of 5 cylinders shall be fabricated during each production day. For core testing, one core shall be cut from a unit selected at random from each group of 15 units or less of a particular size a nd production run. For each continuous production run, each group of 15 units of a single size or fraction thereof shall be considered separately for the purpose of testing and acceptance. A production run shall be considered continuous if not interrupted for more than 3 consecutive days.