SECTION PRECAST CONCRETE STRUCTURES

Transcription

1 SECTION PRECAST CONCRETE STRUCTURES PART 1 GENERAL 1.01 DESCRIPTION A. CONTRACTOR shall provide all professional services, labor, materials, equipment and incidentals as shown, specified and required to design, furnish, and install all precast concrete structures. B. Structures shall conform in shape, size, dimensions, material, and other respects to the details shown or as ordered by ENGINEER. Minimum thickness sizes for slabs and walls are provided on the Drawings. C. The sodium hypochlorite injection vault shall be governed by this specification. All stormwater inlet structures shall be governed by Section Site Drainage RELATED SECTIONS A. Section Excavating, Backfilling, and Grading for Structures B. Section Aluminum Access Hatches 1.03 QUALITY ASSURANCE A. Standards referenced in this Section are: 1. American Association of State Highway and Transportation Officials (AASHTO). 2. ASTM C 478, Standard Specification for Circular Precast Reinforced Concrete Manhole Sections. 3. AWWA C 302, Reinforced Concrete Pressure Pipe, Non-Cylinder Type for Water and Other Liquids. 4. Precast/Prestressed Concrete Institute (PCI) MNL-116, Manual for Quality Control for Plants and Production of Structural Precast Concrete Products. B. Fabrication Tolerances: 1. General: Fabricate precast concrete units complying with manufacturing and testing procedures, quality control recommendations, and dimensional tolerances of PCI MNL-116, unless otherwise indicated. Keep bar sizes small, even where this will reduce the spacing of the bars. 2. Units shall be true to dimensions. Unit bow, as fabricated and installed, shall not exceed 1/8-inch per unit in the short dimension and 1/4 inch per unit in the long dimension. Step in alignment face and jog in alignment shall not exceed 1/4-inch. Provide a 3/4-inch chamfer or 1 x 2-inch radius on all exposed edges and corners PN:

2 SECTION PRECAST CONCRETE STRUCTURES 3. Imperfections such as air bubbles, ripples, joint lines, warpage, stains, projections, honeycombs, uneven matrix plate, and other defects will not be acceptable. C. Qualifications and Responsibilities of CONTRACTOR s Design Professional: 1. Professional Engineer a. Engage a registered professional engineer qualified to practice in the State of Florida and experienced in providing engineering services of the kind indicated. b. Responsibilities include but are not necessarily limited to: 1) Carefully reviewing precast concrete structural performance and design criteria stated in the Contract Documents. 2) Preparing written requests for clarifications or interpretations of performance or design criteria for submittal to ENGINEER by CONTRACTOR. 3) Preparing or supervising the preparation of design calculations and related drawings, shop drawings, testing plan development, test result interpretation and a comprehensive engineering analysis verifying compliance of the precast concrete structure with the requirements of the Contract Documents. 4) Signing and sealing all calculations and design drawings, and shop drawings. 5) Certifying that: i. It has performed the design of the precast concrete structure in accordance with the performance and design criteria stated in the Contract Documents, and ii. The said design conforms to all applicable local, state and federal codes, rules and regulations, and to the prevailing standards of practice. D. Qualifications of Fabricator: A firm that complies with the following requirements and is experienced in producing structural precast concrete units similar to those indicated for this Project and with a record of successful in-service performance. 1. Participates in PCI s Plant Certification program at the time of bidding and is designated a PCI-certified plant for Group C, Category C1 Precast Concrete Products (no pre-stressed reinforcement). 2. Certification shall be maintained throughout the production of the precast concrete units. Production shall immediately stop if at any time the fabricator s certification is revoked, regardless of the status of completion of contracted work. Production will not be allowed to re-start until the necessary corrections are made and certification has been re-established. In the event certification(s) cannot be re-established in a timely manner, causing project delays, the PN:

3 1.04 SUBMITTALS SECTION PRECAST CONCRETE STRUCTURES fabricator, at no additional cost, will contract out the remainder of the units to be manufactured at a PCI certified plant. A. Submit for approval the following: 1. Qualifications a. Submit qualifications data for the CONTRACTOR s Design Professional. 2. Precast Structures a. Drawing showing design and construction of all precast concrete, as well as the location and details of all items that are to be embedded in the precast units. b. Provide manhole drawings showing the elevations and all piping to and from each structure. c. Design calculations and shop drawings, signed and stamped with a seal of a Registered Professional Engineer licensed to practice in the State of Florida and PE certification provided in Section d. Test result from concrete cylinder strength tests. B. Shop Tests 1. Submit description of proposed testing methods, procedures, and apparatus. Prepare and submit report for each test DELIVERY, STORAGE, AND HANDLING A. Delivery of Materials 1. Deliver precast concrete units to project site in such quantities and at such times to assure continuity of installation. B. Storage of Materials 1. Store units at project site in a manner that will prevent cracking, distortion, warping, staining, or other physical damage and so that precast copings are without damage at time of installation. C. Handling of Materials 1. Lift and support units only at designated lifting or supporting points as shown on final Shop Drawings. PART 2 PRODUCTS 2.01 PRECAST CONCRETE STRUCTURES A. Layout and details shall be as shown and specified. Design shall be adequate to withstand live loads, lateral earth pressure loading, and uplift case PN:

4 SECTION PRECAST CONCRETE STRUCTURES 1. Design Criteria a. Top slab live load: 300 psf. b. Maximum ground water table = assume at existing ground surface c. Vertical surcharge on soil of 300 psf. d. Safety factor for uplift normal ground water > 1.5. e. Safety factor for uplift 100 year storm ground water > Design shall meet the requirements of ACI 350 and the current Florida Building Code. B. Concrete Mix: Standard-weight concrete consisting of specified Portland cement, pigments, aggregates, admixtures, and water to produce the following properties: 1. Compressive Strength: 5,000 psi minimum at 28 days. 2. Total Air Content: not less than 4 percent nor more than 6 percent. C. Where precast structures are made up of various precast components such as base sections, riser sections and top sections, the joint between sections shall be watertight and be the tongue and groove type complying with AWWA C302. D. Walls shall be precast with wall pipes or with pipe sleeves with water stop suitable for application or as shown on Drawings. E. Precast structure shall be designed and constructed to accept access hatches or castings as shown and specified. F. Precast structures shall be designed to support the weight of equipment lifted from the station to the top slab as necessary. G. Underground precast units shall have a shop-applied exterior coating. The units shall be given two coats of bitumastic coating with a total dry film thickness of 12 mils. Each coat shall be applied at a rate not to exceed one gallon per 100 square feet. Time shall be allowed between coats to permit sufficient drying. Field application of coating is unacceptable except for coating repairs. H. Lifting holes, if used, shall be tapered. Tapered, solid rubber plugs shall be furnished to seal the lifting holes. The lifting holes shall be made to be sealed by plugs driven from the outside face only. I. Mark date of manufacture and name of trademark of manufacturer on inside of barrel ACCESS HATCHES AND CASTINGS A. All necessary access hatches as shown and specified shall be cast into concrete as necessary, refer to the civil details and/or Section for additional requirements PN:

5 SECTION PRECAST CONCRETE STRUCTURES B. The CONTRACTOR shall provide built-up type brick risers to place castings at grade where shown on the Drawings SHOP TESTING A. At a minimum, conduct the following shop test: 1. Conduct concrete cylinder strength tests. Cylinders shall be cured in the same manner as the precast structures. Collect a minimum of 1 test cylinder from every 10 cubic yards of concrete poured. PART 3 EXECUTION 3.01 INSPECTION A. CONTRACTOR and his installer shall examine the substrate and the conditions under which Work is to be performed and notify OWNER of unsatisfactory conditions. Do not proceed with the Work until unsatisfactory conditions have been corrected in a manner acceptable to OWNER INSTALLATION A. Set units in true alignment. All joints shall be sealed with cement mortar inside and out and troweled smooth to the contour of the wall surface. Raised or rough joint finishes will not be accepted. B. Precast structures shall be set on a crushed stone, crushed gravel, or concrete foundation as shown on drawings and in accordance with geotechnical recommendations. Precast units shall be set at the proper grade and carefully leveled and aligned. C. Install units in accordance with manufacturer s recommendations. D. Replace precast concrete units damaged for any reason or which fail to perform as specified. E. Each structure shall be watertightness tested and the ENGINEER shall observe each test. 1. Lower groundwater table below bottom of the manhole, wet well, or structure for the duration of the test. Plug all pipes and other openings into the structure and brace to prevent blow out. Fill structure with water to the top of the section. If the excavation has not been backfilled and no water is observed moving down the surface of the structure, the structure is satisfactorily watertight. If the test, as described above is unsatisfactory as determined by the ENGINEER, PN:

6 SECTION PRECAST CONCRETE STRUCTURES or if the structure excavation has been backfilled, continue the test. A period of time may be permitted to allow for absorption. Following this period, refill manhole to the top of the cone, if necessary and allow at least 8 hours to pass. The requirement shall be zero leakage over the time period. Uncover the rejected structure as necessary and to disassemble, reconstruct or replace it as directed by the ENGINEER. Retest the structure and, if satisfactory, fill and paint the interior joints. 2. No adjustment in the leakage allowance will be made for unknown causes such as leaking plugs, absorptions, etc. It will be assumed that all loss of water during the test is a result of leaks through the joints or through the concrete. 3. Testing shall be completed prior to any interior coating (if required) being applied. END OF SECTION PN:

7 SECTION ALUMINUM ACCESS HATCHES PART 1 GENERAL 1.01 SCOPE OF WORK A. CONTRACTOR shall provide all labor, materials, equipment, and incidentals as shown, specified, and required to furnish and install access hatches. B. The Work includes providing openings in and attachments to the access hatch to accommodate the Work under this and other Sections, and required accessory items such as anchorage devices for which provision is not specifically included under other Sections. C. Review installation procedures under this and other Sections and coordinate the installation of items to be installed with or before the access hatches QUALITY ASSURANCE A. MANUFACTURER shall have not less than five years experience producing products substantially like those specified and, upon ENGINEER s request, shall submit documentation of not less than five satisfactory installations in place for not less than five years each. B. Obtain all products included in this Section regardless of the component MANUFACTURER from a single access hatch MANUFACTURER. Furnishing hatches from more than one MANUFACTURER is not acceptable. C. The access hatch MANUFACTURER shall prepare, or shall review and approve, all shop drawings and other submittals for all components furnished under this Section. D. Components shall be suitable for specified service conditions and shall be integrated into the overall assembly by the access hatch MANUFACTURER SUBMITTALS A. Submit the following in accordance with Section Detailed plans and other drawings showing location of products and direction of door swing; access hatch schedules indicating cover location, material, type, loading capacity, and other information; and fabrication details for the access hatch covers Work, including materials, thickness of metals, finishes, latching or locking provisions, type of anchorages, and accessory items. 2. Copies of MANUFACTURER s literature and specifications for each type of access hatch incorporated in the Work. 3. Installation data, including setting drawings and templates PN:

8 SECTION ALUMINUM ACCESS HATCHES 1.04 DELIVERY, STORAGE, AND HANDLING A. Packing and Shipping: 1. Protect mill finish and other finish during shipping and installation by an attached, adhesive-backed vinyl material that is removable during and after installation of the access hatch. B. Storage and Protection: 1. Protect aluminum members and packaged materials from corrosion and deterioration. 2. Refer to Section for additional information. PART 2 PRODUCTS 2.01 GENERAL A. Provide MANUFACTURER s standard fabricated access hatch units, modified when necessary to comply with the Contract Documents. Where standard units are not available for the sizes and types required, provide custom-fabricated units of the same quality as MANUFACTURER s similar standard-sized units. B. Fabricate each access hatch unit in the shop, complete with anchors, gaskets, hardware, and accessory items, as required. C. Galvanizing Repair Paint: For repairing damaged galvanized surfaces, provide high zinc-dust content paint complying with MIL-P-21035B. D. Provide access hatches in accordance with Table A, Access Hatch Schedule: TABLE A ACCESS HATCH SCHEDULE Size Hatch Material Leaf Type Frame Type Location No. Width (clear opng), inches Length (clear opng), inches Aluminum Single See 2.02A Chemical Injection Vault 2.02 ANGLE-FRAME TYPE ACCESS HATCH A. Aluminum Access Hatch 1. Design Live Load: 300 pounds per square foot. 2. Products and MANUFACTURERS: a. Single-Leaf Door Aluminum Access Hatch Cover 1. TPS by USF Fabrication. 2. Or ENGINEER approved equal. b. Double-Leaf Door Aluminum Access Hatch Cover PN:

9 SECTION ALUMINUM ACCESS HATCHES 1. TPD by USF Fabrication. 2. Or ENGINEER approved equal. 3. Cover: 1/4-inch thick, aluminum diamond-pattern plate reinforced for 300 psf live load. Cover shall be equipped with a lifting handle and 316 stainless steel hold-open arm with red vinyl grip that automatically locks the cover in the 90- degree open position. 4. Frame: Frame shall be 3/8-inch aluminum angle with integral anchor flange on all four sides. The frame shall include an EPDM odor reduction gasket that reduces the amount of odor that escapes from below the door. A 1.5-inch drain coupling shall be provided for a pipe connection to the wet/clear well below. 5. Gasket: A U-shaped EPDM gasket mechanically attached or riveted to the channel frame. 6. Hinges: Type 316 stainless steel, heavy-duty butt hinges with Type 316 stainless steel pin fastened to door with Type 316 stainless steel tamperresistant bolts. 7. Latch: Latches shall be 316 stainless steel pressure locks with exterior staple for padlock. 8. Lift Assistance: Compression spring operators enclosed in telescopic tubes. Automatic hold-open arm with release handle automatically locks cover(s) in the open position. 9. Fall-Through Prevention System: Provide access hatch cover MANUFACTURER s standard safety grating of FRP or aluminum, constructed for live load capacity of not less than 300 psf. Provide hinges and lift-assist to allow grating sections to automatically lock in place in fullopen 90-degree position. Provide hold-open arm and release assembly of aluminum or Type 316 stainless steel. Grating shall be colored OSHA Safety Yellow or Safety Orange. 10. Finish: Mill finish aluminum with SS hardware. 11. Bituminous coating shall be applied to surfaces in contact with concrete. PART 3 EXECUTION 3.01 INSPECTION A. Examine areas and conditions under which roof access hatch cover Work will be performed and notify ENGINEER in writing of conditions detrimental to proper and timely completion of the Work. Do not proceed with the Work until unsatisfactory conditions are corrected INSTALLATION A. Install access hatches in accordance with approved shop drawings and other approved submittals, the Contract Documents, and MANUFACTURER s instructions. B. Set each access hatch level and true to line or grade, without warp or rack. C. Protection of aluminum from dissimilar materials: Coat surfaces of aluminum in PN:

10 SECTION ALUMINUM ACCESS HATCHES contact with dissimilar materials such as concrete, masonry, steel, and other metals in accordance with Section or as described above. D. Galvanized covers: Where zinc coating is damaged, touch-up abraded surfaces with galvanizing repair paint applied in accordance with the paint MANUFACTURER s instructions and recommendations ADJUSTING AND CLEANING A. Adjust leaves of roof access hatch covers as necessary to provide proper operations. B. Remove stains, concrete splatter, oils, grease, and other foreign materials necessary and provide clean, finished surfaces. END OF SECTION PN:

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