CONCRETE BOX CULVERT (AMENDED SPECIFICATION AS PART OF ADDENDUM NO. 2)

Transcription

1 SECTION CONCRETE BOX CULVERT (AMENDED SPECIFICATION AS PART OF ADDENDUM NO. 2) PART 1 GENERAL 1.1 SECTION INCLUDES A. Concrete Box Culvert 1. Concrete Box Culvert is bid with the alternative of Cast-in-Place Methods, or Pre-Cast Methods. Refer to Document , Document and Document for more information. 1.2 RELATED SECTIONS A. Section Concrete Forming B. Section Concrete Reinforcing C. Section Concrete D. Section Concrete Placement E. Section Concrete Finishing F. Section Concrete Curing G. Section Water Repellant H. Section Common Fill I. Section Excavation J. Section Backfilling for Structures K. Section Ornamental Picket Fence 1.3 REFERENCES A. AASHTO M 198: Joints for Circular Concrete Sewer and Culvert Pipe Using Flexible Watertight Gaskets B. AASHTO LRFD Bridge Design Specifications C. ASTM C 877: Standard Specification for External Sealing Bands for Concrete Pipe, Manholes, and Precast Box Sections Page 1 of 8

2 D. ASTM C 1577: Standard Specification for Precast Reinforced Concrete Box Sections for Culverts, Storm Drains, and Sewers Designed According to AASHTO LRFD. 1.4 SUBMITTALS Cast-in-Place Concrete Box Culvert A. Provide Submittals for each RELATED SECTION from part 1.2. B. Traffic Control Plan C. Ornamental Fence Information D. Submit construction phasing, staging and water diversion plan Precast Concrete Box Culvert A. Provide Submittals for each RELATED SECTION from part 1.2. B. Traffic Control Plan C. Ornamental Fence Information D. Submit construction phasing, staging and water diversion plan. E. Furnish to the Engineer: 1. Shop drawings for all fabricated materials: a. Submit five copies on 11 inch by 17 inch sheets with a 1½ inch blank margin on the left-hand edge. b. Detail all phases of construction including layout, joint details, lifting devices, casting methods, construction placement and details of any castin-place sections. Note proposed transportation methods. c. Include the project designation data and structure number in the lower right-hand corner of each sheet. d. Prepare shop drawings under the stamp of a Utah PE. 2. Design calculations signed and sealed by a Professional Engineer (PE) licensed in the State of Utah. a. Not required for ASTM C 1577 standard designs. b. Certify that precast products comply with the project design loading criteria. 3. The Engineer reserves the right to retain these drawings and calculations up to 14 calendar days without granting an increase in the number of working days for the project. This is reduced to 7 days when drawings are submitted electronically. This right applies each time the drawings are submitted. Page 2 of 8

3 1.5 ACCEPTANCE Cast-in-Place Concrete Box Culvert A. Acceptance criteria from each of the related sections will be followed Precast Concrete Box Culvert A. Acceptance criteria from each of the related sections will be followed. B. Units fabricated before written approval of the fabricator's shop drawings will be rejected. PART 2 PRODUCTS 2.1 MATERIALS Cast-in-Place Concrete Box Culvert A. Portland Cement Concrete: Class AA(AE); days minimum compressive strength. Submit Mix Design. B. Steel Reinforcement 60,000 psi non-coated bar will be accepted. Install reinforcing Steel per Section C. Granular Backfill Borrow Per Section D. Ornamental Picket Fence Per detail on sheet STR-04 and Section Precast Concrete Box Culvert A. Concrete a. Wet Cast Concrete: Class 3A(AE). 4,000 psi design strength. Submit Mix Design. b. Dry Cast Concrete: 1. Minimum cement content: 470 lb/yd3 of concrete 2. Maximum water/cement ratio: Mix design: Submit for approval B. Steel Reinforcement 60,000 psi non-coated bar will be accepted. Install reinforcing Steel per Section C. Granular Backfill Borrow Per Section D. Ornamental Picket Fence Per detail on sheet STR-04 and Section Page 3 of 8

4 E. Joint Sealant a. Meet AASHTO M 198. b. Use a flexible butyl-blend material with a minimum cross-section of 1½ square inches as a joint sealant for box culverts. c. Maintain the joint material at 70 degrees F or greater during placement. 2.2 QUALITY ASSURANCE Precast Concrete Box Culvert A. Permanently mark each precast unit with date of casting and supplier identification. B. Prevent cracking or damage during handling and storage of precast units. C. Replace cracked or damaged precast units at no additional cost to the owner. Page 4 of 8

5 PART 3 EXECUTION 3.1 PREPARATION A. Riter Canal Diversion a. The canal MAY NOT be shut down for any reason during construction. b. It is anticipated that the normal volume of water to be bypassed will be 40 cfs, but would not be unusual to have 60 cfs at times, with storm surges in excess of 130 fs to 150 cfs Below is the Kennecott Process Water Call History and Projections for This is information provided to aid the contractor in making decisions on sizing the temporary canal diversion. The information in this table shows only process water through the canal, and does not include storm flows or other irrigation inflows into the canal. North Jordan Process Water Call: Diversions Passing the Gardner Mill. All flows in CFS. 1 to to 30 1 to to 31 Jan Feb Mar April April May June July Aug Sept Oct Oct Nov Dec 2011 Estimated c. CONTRACTOR will be responsible to size the temporary bypass, and accepts the risk for damage to the concrete box culvert should the flows overtop the diversion and flood the work area. Canal bypass plan must be presented to ENGINEER for review, and must be prepared by a Professional Engineer. d. Form placement and grades shall be checked by the contractor and notify OWNER for inspection prior to placement of concrete. e. If box is to be cast-in-place, CONTRACTOR will be responsible for concrete testing to verify strength prior to backfilling, or placing a load on the concrete. f. If box is cast-in-place, provide certification of compliance with the specification for the quantity of box placed. Provide access to owner to inspect manufacturing processes. Box must be manufactured in a certified pre-cast plant. B. Form Construction: Place forms per Section Obtain ENGINEER s review of forms before placing concrete. C. Excavating, Trenching, Bedding, and Backfill: Refer to Sections and Page 5 of 8

6 3.2 CAST-IN-PLACE CONCRETE BOX CULVERT A. Allow the base slab and footing to cure for 24 hours before constructing the remainder of culvert. B. Construct the side walls and top slab monolithically. Keep construction joints vertical at right angles to the axis of the culvert. C. Do not backfill until the concrete has been placed at least 7 days and has attained the specified strength. D. Do not transfer traffic loads to the culvert until the concrete has reached the design strength. E. Construct wingwalls monolithically. F. Construct shear keys in the top of the side walls to anchor the top slab when the side walls and top slab are not placed monolithically. 3.3 PRE-CAST CONCRETE BOX CULVERT A. Precast Concrete Box Culverts: a. Meet ASTM C b. Provide minimum reinforcing steel spacing 4 inches around circumference and 8 inches longitudinal. c. Provide 1 inch minimum concrete cover to reinforcing steel for box sections covered with 2 ft of fill or greater. d. Provide 2 inch minimum concrete cover for steel in top slab for box sections covered with less than 2 ft of fill. e. Ancillary precast appurtenances such as footings, cutoff walls, aprons, wing walls and headwalls are acceptable. B. Bedding and Backfill a. Level and compact bedding material to provide uniform support of the structure along its entire supported width and length. b. Use a loose sand leveling course no greater than 2 inch in depth if needed in addition to the granular backfill borrow bedding. 1. Excavate the area to the appropriate depth to accommodate the backfill and leveling course if loose sand is added. c. Backfill structure with granular backfill borrow as specified in Section Page 6 of 8

7 C. Installation a. Inspect precast elements for defects before lowering into trench. b. Repair or replace any defective, damaged or unsound precast elements. Repair must be approved by ENGINEER. c. Use a trench width adequate to place and compact bedding material. Minimum outside width of trench is the outside width of structure plus 2 feet. d. Lay precast elements starting at the downstream end. e. Use proper equipment that is capable of safely lifting and lowering precast sections into place without damaging sections. f. Remove all dirt and foreign material from joints. Prevent dirt and material from re-entering joints. g. Apply joint sealant furnished by culvert manufacturer to box culvert. 1. Place the joint material on the bottom half of the groove (bell) of the box last placed. 2. Place the balance of the joint material on the top half of the tongue (spigot) of the box to be set. 3. Place the material about 1 inch from the leading edge of the groove and tongue. h. Disassemble joint, check position of joint sealant, repair alignment, and re-install when adjoining elements cannot be pulled together to meet minimum joint requirements. i. Close the joints tightly. j. Do not disturb previously completed joints during laying operation. k. Do not lay precast elements when water is in the trench. l. Clean top and sides of concrete surface at joints before placing joint wrap. m. Use appropriate pulling devices to avoid misalignment and damage to box sections. n. Apply joint wrap when specified in the plans. D. Joints a. Make joint opening between box sections less than 1 inch measured face to face of adjoining concrete surfaces. 1. Reject box sections when the installation tolerance cannot be met due to casting variations. 2. Prevent soil from being forced into the joint as the box sections are placed. b. Provide shear transfer devices for box culvert sections with less than 2 ft of cover. 1. Device or method must be capable of transferring a minimum shear load of 3,000 lb/ft of joint width through top slab of adjacent units. 2. Space closer than 2.5 ft center to center with at least two per joint when using individual devices. E. Lifting Holes a. Provide a maximum of four lifting holes in the top slab. F. Connection to Cast-in-Place Concrete a. Project the reinforcing steel at least 12 inches out of the precast box section and square off the concrete face where precast box sections join cast-in-place concrete. Page 7 of 8

8 G. Repairs a. Box sections may be repaired as allowed in the referenced specification only when approved in advance by the ENGINEER. b. Repairs made before approval will be cause for rejection. H. Minimum Length a. Do not use precast segments less than 5 ft in lay length. 3.4 CONCRETE PLACEMENT A. Place concrete per Section CURING A. Cure concrete per Section END OF SECTION Page 8 of 8