SECTION STRUCTURAL STEEL

Transcription

1 SECTION STRUCTURAL STEEL PART 1 - GENERAL 1.01 DESCRIPTION A. The Contractor shall provide structural steel beams, columns, bracings, galvanizing, and appurtenances, complete, in accordance with the Contract Documents RELATED SECTIONS A. The Work of the following Sections apply to the Work of this Section. Other Sections, not referenced below, shall also apply to the extent required for proper performance of the Work. B. Related Work Specified in Other Sections: 1. Section Reinforcement Steel. 2. Steel supports, hangars, brackets and other miscellaneous items accessory to the mechanical and electrical installations REFERENCE SPECIFICATIONS, CODES AND STANDARDS A. The current edition of the California Building Code (CBC) of International Conference of Building Officials (ICBO). B. Commercial Standards (Current Edition): 1. AISC M 011 Manual of Steel Construction for Shop and Field Welding. 2. AISC S 326 Design, Fabrication and Erection of Structural Steel for Buildings. 3. AWS B 3.0 Welding Procedures and Performance Qualifications. 4. AWS D 1.1 Structural Welding Code - Steel. 5. AWS W 1 Welding Metallurgy C. ASTM Standards in Building Code (Current Edition): 1. ASTM A 6 General Requirements for Rolled Steel Plates, Shapes, Sheet Piling, and Bars for Structural Use 2. ASTM A 36 Structural Steel (Except W rolled shapes) 3. ASTM A 283 Low and Intermediate Tensile Strength Carbon Steel Plates, Shapes and Bars 4. ASTM A 325 High Strength Bolts for Structural Steel Joints 5. ASTM A 490 Heat-Treated Structural Steel Bolts 6. ASTM A 992 High Strength Structural Steel ( W rolled shapes) STRUCTURAL STEEL AERATION UPGRADE PROJECT

2 7. ASTM A 500 Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes 1.04 CONTRACTOR SUBMITTALS A. The Contractor shall furnish submittals to the Engineer for review in accordance with the Specification Section Contractor Submittals. B. Shop Drawings and Erection Drawings: The shop drawings shall provide a materials and specification list, construction and fabrication details, layout and erect diagrams, and the method of anchorage to adjacent construction. The shop drawings shall give the location, type, size and extent of welding and bolted connections, and clearly distinguish between shop and field connections. Before submittal of the shop drawings, the Contractor shall coordinate the shop drawings and related trades to ensure proper mating of assemblies. All work shall conform to the approved shop drawings. C. Test Reports: The Contractor shall furnish certified physical and chemical mill test reports for material used for structural members. All tests shall be performed in accordance with applicable ASTM Standards DELIVERY A. The Fabricator shall deliver the fabricated material to the job site in the sequence as approved by the Engineer. B. All shipped material to be piece-marked for erection with metal tags or other appropriate method approved by the Engineer. C. All material shipments shall include sufficient bolts for erection, plus at least the following extra bolts: 1. Add a minimum of 5% for unfinished bolts. D. The Engineer reserves the right to inspect fabricated material at Fabricator s shop. The Engineer s expenses for shop inspections shall be borne by the Contractor. In the event the Engineer identifies faulty materials or workmanship in fabricated material at the Fabricator s shop, the materials shall be re-fabricated at no cost to the Owner. The Engineer shall be notified at least 7 days before the shipment of material. Shipments of material shall not be delayed if the Engineer does not require inspection. E. Material damaged in shipment shall be replaced or repaired at the Contractor s expense at no additional cost to the Owner QUALITY ASSURANCE A. The Contractor shall fabricate and erect structural steel work in accordance with the latest edition of AISC Specification for the Design, Fabrication and Erection of Steel for Buildings, and Code of Standard Practice for Steel Buildings and Bridges, except whenever there is a discrepancy between the Plans and this Section, the Plans will govern. B. Continuous Inspections: 1. The Contractor shall perform all welding and high strength bolting of structural steel assemblies under continuous inspection of the Engineer. Should such fabrication be performed in the shop of a licensed Fabricator approved by the Engineer, only the field welding and high strength bolting of structural steel STRUCTURAL STEEL AERATION UPGRADE PROJECT

3 1.07 WARRANTY assemblies will be required to be performed under continuous inspection of the Engineer. 2. The Contractor shall notify the Engineer at least 48 hours in advance of the needed inspection. 3. The Contractor shall provide copies of inspection reports to the Engineer and Building Department, if applicable. A. The Fabricator shall furnish a warranty to the Owner to replace or repair all defective material and workmanship within 18 months of shipment, or 12 months of plant startup, whichever occurs first, excluding defects due to normal usage. PART 2 - PRODUCTS 2.01 MATERIALS A. General: All materials shall be new, sound and conform to the requirements herein. Unless otherwise indicated, structural steel shall be coated per Technical Specification - Division 9 requirements. B. Structural Steel: Rolled shapes, plates and bars shall conform to the latest edition of the AISC Manual of Steel Construction, and shall also conform to current ASTM Designation A 36. All W rolled shapes shall conform to A 992. C. Pipe: Pipe shall conform to ASTM A 53, Grade B seamless galvanized as required, Schedule 40, except as otherwise shown on the Plans. D. Tubes: Tubes shall conform to ASTM A 500 Grade B. E. Welding Electrodes: The Contractor shall use steel electrodes conforming with AWS D 1.1, except that E7024 rods or electrodes shall not be used FABRICATION A. Fabrication shall be in accordance with AISC S 326 and indicated requirements. All structural steel welding in off-site fabrication shops shall be continuously inspected by the Engineer with the inspection cost of the Engineer to be borne by the Contractor. The continuous inspection will be waived if the work is done in a shop certified by the Council of American Building Officials (CABO), or listed by the International Conference of Building Officials (ICBO) Evaluation Services, Inc. PART 3 - EXECUTION 3.01 INSTALLATION A. General: 1. Structural assemblies and shop and field welding shall meet the requirements of AISC M 011 and AISC S Measurements and dimensions shall be verified by the Contractor at the site. STRUCTURAL STEEL AERATION UPGRADE PROJECT

4 3. Bolt holes shall be 1/16 inch larger than the nominal size of bolts. Where thick metals are indicated, holes shall be sub-punched and drilled, or reamed. 4. Dissimilar metals shall be protected from galvanic corrosion by means of pressure tapes, coatings or isolators. 5. Bolts shall not be permitted to drift, and holes shall not be enlarged to correct misalignment. In the event of mismatching of holes, new materials shall be provided. 6. Structural steel completely encased in concrete shall not be galvanized or painted, and shall have a clean surface for bonding to concrete. 7. Damaged structural steel shall be replaced. Use of salvaged, reprocessed, or scrap materials shall not be permitted. B. Welding: Welding shall be performed by operators who have been qualified by tests as prescribed by AWS-W1 Section 7, to perform the type of welding indicated. Welding shall comply with AWS Code for Arc Welding in Building Construction, Section 4, Workmanship. Electrodes shall be matching per AWS. C. Coating: The Contractor shall coat structural steel in accordance with Technical Specification - Division 9 requirements INSPECTION A. The Engineer reserves the right to inspect all materials and workmanship covered in this Specification. However, such inspection shall not relieve the Contractor of his responsibility to furnish materials and workmanship in accordance with the Contract requirements. If inspection indicates a weld or part of the material is defective, the Contractor shall remove and replace it at the Contractor s expense. B. Shop inspection may include, but not be limited to, the following: 1. Verification of conformance of materials with this Specification and the Plans. The limits of acceptability and repair of surface imperfections for structural steel shall be in accordance with ASTM A Visual and dimensional inspection of shop-fabricated structural steel members and assemblies shall be in conformance with this Specification and the Plans. 3. Verification of welding procedures, welding operations and welder and tacker certificates of qualification shall be in accordance with this Specification and AWS D END OF SECTION STRUCTURAL STEEL AERATION UPGRADE PROJECT

5 SECTION STRUCTURAL ALUMINUM PART 1 - GENERAL 1.01 SUMMARY: A. Section Includes: Requirements for providing structural aluminum products, including sheet, pipe, extrusions, and associated accessories REFERENCES: A. American Society for Testing and Materials (ASTM): 1. B Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate 2. B 221 Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Shapes, and Tubes. 3. B 308/ B 308M Standard Specification for Aluminum-Alloy 6061-T6 Standard Structural Shapes. B. American Welding Society (AWS): 1. A 5.10 Specification for Bare Aluminum and Aluminum-Alloy Welding Electrodes and Rods. 2. D 1.2 Structural Welding Code- Aluminum SUBMITTALS: A. Quality Control Submittals: 1. Design Data: a. Test Reports: Certified copies of mill tests or reports from a recognized commercial laboratory including chemical and tensile properties of each shipment of structural metal or part thereof having common properties. Tests and analysis shall be done in accordance with applicable ASTM standards. QUALITY ASSURANCE: A. Qualifications: 1. Perform welding of structural metals with welders who have current American Welding Society (AWS) certificate for the type of welding to be performed. 2. Notify the engineer 24 hour minimum before starting shop or field welding. 3. Engineer may check materials, equipment, and qualifications of welders. 4. Remove welders performing unsatisfactory work, or require to re-qualify. 5. Engineer may use gamma ray, magnetic particle, dye penetrant, or other aids to visual inspection to examine any part of welds or all welds. 6. Contractor shall bear costs of retests on defective welds. 7. Contractor shall also bear costs in connection with qualifying welders. PART 2 - PRODUCTS 2.01 MATERIALS: A. Structural Sheet Aluminum: ASTM B 209, Alloy 6061-T06 B. Structural Aluminum: ASTM B 308 Alloy 6061-T6 C. Extruded Aluminum: ASTM B 221, Alloy 6063-T42 STRUCTURAL ALUMINUM AERATION UPGRADE PROJECT

6 D. Miscellaneous Materials: 1. Furnish supplementary parts necessary to complete each item even where such work is neither definitely indicated on the Drawings nor specified. 2. Size, form, attachment, and location shall conform to the best of current practice. 3. Conform to applicable ASTM Standards for materials not otherwise specified FABRICATION: A. Aluminum Layout: 1. Center punch hole centers, and punch or scribe cutoff lines, except where marks would remain on fabricated material. 2. Apply temperature correction where necessary in layout of critical dimensions. Use a coefficient of expansion of per degree of Fahrenheit. B. Cutting Aluminum: 1. Material ½ inch thick or less: Shear, saw, or cut with a router. 2. Material more than ½ inch thick: Saw or rout. 3. Make cut edges true and smooth, free from excessive burrs or ragged breaks. 4. Avoid reentrant cuts wherever possible. Where used, fillet by drilling prior to cutting. 5. Do not flame cut aluminum alloys. 6. Punch or drill river or bolt holes to finished size before assembly. a. Make finished diameter of holes for bolts 1/16 maximum larger than nominal bolt diameter. b. Make holes cylindrical and perpendicular to principal surface. c. Do not permit holes to drift in a manner to distort metal. C. Aluminum Forming and Assembly: 1. Do not heat structural aluminum, except as follows: a. Heat aluminum to 400 degrees Fahrenheit for 30 minutes maximum, to facilitate bending or welding. 2. b. Heat only when proper temperature controls and supervision can ensure that limitations on temperature and time are observed. D. Before assembly, remove chips lodged between contacting surfaces. E. Welding Aluminum: 1. Perform welding of aluminum in accordance with AWS D1.2, Structural Welding Code-Aluminum. 2. Weld aluminum in accordance with the following: a. Preparation: 1) Remove dirt, grease, forming or machining lubricants, and organic materials, from areas to be welded by cleaning with a suitable solvent or by vapor degreasing. 2) Additionally, etch or scratch brush to remove oxide coating just prior to welding when inert gas tungsten arc welding method is used. 3) Oxide coating may not need to be removed if welding is performed by automatic or semi-automatic inert gas shielded metal arc. 4) Suitably prepare edges to assure 100 percent penetration in butt welds by sawing, chipping, machining, or shearing. Do not cut with oxygen. b. Filler Metal: Aluminum alloys conforming to the requirements of AWS A5. 10 and AWS classification ER 4043, ER 5654, ER 5554, ER 5183, ER 5356, or ER 556. STRUCTURAL ALUMINUM AERATION UPGRADE PROJECT

7 c. Perform welding of structures which are to be anodized using filer alloys which will not discolor. When anodized, AWS ER 5654, ER 5554, ER 5183, ER 5356, or ER d. Perform welding by using a non-consumable tungsten electrode with filler material in an inert gas atmosphere (TIG) or using a consumable filler metal electrode in an inert gas atmosphere (MIG). e. Do not use welding processes that require use of a welding flux. f. Neatly make welded closures. g. Where weld material interferes with fit or is unsightly in appearance, grind it smooth. h. Make welds full penetration welds unless otherwise indicated on the drawings. PART 3 - EXECUTION 3.01 EXAMINATION: A. Verification of Conditions: Examine Work in place to verify that it is satisfactory to receive the Work of this Section. If unsatisfactory conditions exist, do not begin this Work until such conditions have been corrected INSTALLATION: A. Install structural aluminum products as indicated on the Drawings and specified. B. Install structural aluminum products accurately and securely, true to level, plumb, in correct alignment and grade, with all parts bearing or fitting structure or equipment for which intended. C. Do not cock out of alignment, re-drill, reshape, or force fit fabricated items. D. Place anchor bolts or other anchoring devices accurately and make surfaces which bear against structural items smooth and true to level. E. Rigidly support and brace structural products needing special alignment to preserve straight, level, even, smooth lines, and keep braced until concrete, grout, or dry pack mortar has hardened for a minimum 48 hour period. F. Interface with Other products: See specification section END OF SECTION STRUCTURAL ALUMINUM AERATION UPGRADE PROJECT

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9 SECTION MISCELLANEOUS METALWORK PART 1 - GENERAL 1.01 THE REQUIREMENT: A. The Contractor shall furnish, fabricate and install miscellaneous metalwork and appurtenances, complete and in accordance with the requirements of the Contract Documents RELATED WORK SPECIFIED ELSEWHERE: A. Aluminum Railings. Section REFERENCE SPECIFICATIONS, CODES AND STANDARDS: A. All work specified herein shall conform to or exceed the requirements of the Building Code and the applicable requirements of the following documents to the extent that the provisions of such documents are not in conflict with the requirements of this Section. B. Products and their delivery, handling and installation shall be in accordance with the following trade standards, codes or specifications. C. Commercial Standards: Aluminum Assn. AA-M32 AISC AISI ASTM A 36/A36M ASTM A 48 ASTM A 53 ASTM A 123 ASTM A 153 ASTM A 307 ASTM A 563 C22A41 Specifications and Commentary Specifications and Commentary Specification for Structural Steel Specification for Gray Iron Castings Specification for Pipe, Steel, Black and Hot-Dipped Zinc- Coated, Welded and Seamless Specification for Zinc (Hot-Galvanized) Coatings on Products Fabricated from Rolled, Pressed and Forged Steel Shapes, Plates, Bars and Strip Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware Specification for Carbon Steel Externally Threaded Standard Fasteners Specification for Carbon and Alloy Steel Nuts ASTM A 575 Specifications for Steel Bars, Carbon, Merchant Quality, M- Grades ANSI/AWS D1.1 Structural Welding Code - Steel MISCELLANEOUS METAL WORK AERATION UPGRADE PROJECT

10 NFPA 101 NAAMM Life Safety Code Metal Stairs Manual 1.04 CONTRACTOR SUBMITTALS: A. Shop Drawings: Shop drawings of all miscellaneous metalwork shall be submitted to the Engineer for review in accordance with Section entitled, "Contractor Submittals". B. Welders Qualifications: Welders shall submit certified qualifications for the type of welding being performed. PART 2 - PRODUCTS 2.01 GENERAL REQUIREMENTS: A. Standard: All structural steel shapes, plates, bars and their products shall conform to the requirements of ASTM A 36. B. Corrosion Protection: Unless otherwise shown, miscellaneous metalwork of fabricated steel, which will be used in a corrosive environment and/or will be submerged in water/wastewater shall be coated in accordance with Section entitled, "Architectural Paint Finishes", and shall not be galvanized prior to coating. All other miscellaneous steel metalwork shall be hotdip galvanized after fabrication as specified herein. C. Stainless Steel: Stainless steel metalwork shall by of Type 316 stainless steel unless otherwise indicated in the drawings STEEL PIPE HANDRAILS: A. Steel pipe handrails which may be partially or wholly submerged or which are located inside a hydraulic structure shall be entirely of Type 316 stainless steel. All other steel pipe handrails shall be standard 1-1/2 inch black steel pipe made up by welding and hot-dip galvanized after fabrication. B. Steel Pipe handrails shall be TUFrail, as supplied by Thompson Fabricating LLC (NO EQUAL) to match existing handrail style at the site STEEL STAIRS AND ALUMINUM SAFETY TREADS: A. Steel Stairs: Steel stairs shall be fabricated in accordance with standard practice of the National Association of Ornamental Metal Manufacturers, and as shown. Steel stairs shall be hot-dip galvanized after fabrication. B. Safety Treads: Safety stair treads shall be provided on all stairs and elsewhere where shown. The safety treads shall be 4-inches wide, shall be of aluminum and shall be American Metals Company, Style A; American Mason Safety Tread Company; or equal LADDERS: A. Ladders which may be partially or wholly submerged or which are located inside a hydraulic structure shall be entirely of Type 316 stainless steel. All other ladders shall be of carbon steel, hot-dip galvanized after fabrication. MISCELLANEOUS METAL WORK AERATION UPGRADE PROJECT

11 2.05 METAL GRATING AND FLOOR HATCHES: A. General: Metal grating and floor hatches shall be of the design, sizes and types shown. Aluminum in contact with other metal or concrete shall have the contact surface shop-painted per Section entitled, "Protective Coatings". B. Metal Grating: Metal grating shall be of aluminum or stainless steel as shown. No single piece of grating shall weigh more than 40-lbs. unless specifically detailed otherwise. Aluminum shall be 6061T6 Alloy Bearing Bars and 6063T5 Alloy Cross Bars. All grating shall be completely banded. Grating shall be rated at 150 lb/sq. ft. C. Floor Hatches: Floor hatches shall be aluminum as shown. Hatches that are single-swing or double-swing shall be furnished with stay bars designed to hold the covers in an open position. The hatch shall be designed to provide storage for the stay bars when the hatch is closed. The hatch shall have flush handles and a gutter or moat-type edge drain complete with drain connection. Hatches shall be supplied by USF Fabrication Inc., Halliday Products, Thompson Fabrication, or equal SEAT ANGLES AND SUPPORTS: A. Seat angles for grating shall be stainless steel or aluminum. All support angles buried, submerged or below top of hydraulic structures shall be stainless steel BOLTS AND ANCHORS: A. Stainless Steel Bolts: Unless otherwise shown or approved, all bolts, anchor bolts, washers and nuts shall be of Type 316 stainless steel POWER-DRIVEN PINS: A. Power-driven pins shall not be used unless specifically approved by the Engineer. PART 3 - EXECUTION 3.01 FABRICATION AND INSTALLATION REQUIREMENTS: A. Fabrication and Erection: Except as otherwise shown, the fabrication and erection of structural steel shall conform to the requirements of the American Institute of Steel Construction "Manual of Steel Construction" B. Aluminum Railings: Aluminum railing is specified in Section C. Steel Railings: Field welding of steel pipe handrail joints will be permitted only if approved by the Engineer WELDING: A. Method: All welding shall be by the metal-arc method or gas-shielded arc method as described in the American Welding Society's "Welding Handbook" as supplemented by other pertinent standards of the AWS. Qualification of welders shall be in accordance with the AWS Standards governing same. B. Quality: In assembly and during welding, the component parts shall be adequately clamped, supported and restrained to minimize distortion and for control of dimensions. Weld MISCELLANEOUS METAL WORK AERATION UPGRADE PROJECT

12 3.03 GALVANIZING: reinforcement shall be as specified for the AWS Code. Upon completion of welding, all weld splatter, flux, slag and burrs left by attachments shall be removed. Welds shall be repaired to produce a workmanlike appearance with uniform weld contours and dimensions. All burrs, spatter and sharp corners of material shall be ground smooth prior to coating. A. All structural steel plates, shapes, bars and fabricated assemblies required to be galvanized shall, after the steel has been thoroughly cleaned of rust and scale, be galvanized in accordance with the requirements of ASTM A 123. Any galvanized part that becomes warped during the galvanizing operation shall be straightened. Bolts, anchor bolts, nuts and similar threaded fasteners, after being properly cleaned, shall be galvanized in accordance with the requirements of ASTM A 153. Field repairs to galvanizing shall be made using "Galvinox", "Galvo-Weld", or approved equal. END OF SECTION MISCELLANEOUS METAL WORK AERATION UPGRADE PROJECT

13 SECTION ALUMINUM RAILINGS PART 1 - GENERAL 1.01 THE REQUIREMENT: A. The Contractor shall furnish and install all aluminum railings complete and in accordance the requirements of the Contract Documents RELATED WORK SPECIFIED ELSEWHERE: A. Cast-In-Place Concrete. Section B. Miscellaneous Metalwork. Section C. Protective Coatings. Section REFERENCE SPECIFICATIONS, CODES AND STANDARDS: A. Codes: The Building Code, as referenced herein, shall be the California Building Code (CBC), as specified in Section entitled, "Reference Standards". B. Commercial Standards: Aluminum Assn. (AA) publications as cited herein CONTRACTOR SUBMITTALS: A. The railing manufacturer's shop drawings, technical data and engineering calculations shall be submitted for review in accordance with Section entitled, "Contractor Submittals". Engineering calculations shall include, but not be limited to, railings, brackets, support flanges and fasteners or anchors. PART 2 - PRODUCTS 2.01 SUPPLIERS: A. Pipe railings and pipe handrails shall match existing handrail style at the site STRUCTURAL PERFORMANCE OF RAILING COMPONENTS: A. Railings and handrail brackets shall be capable of withstanding either of the following loading conditions without exceeding the allowable working stress of the material and without permanent deformation: 1. A 200-lb. concentrated load applied to any point in any direction. 2. A 50-lb. per linear foot loading applied perpendicular to the top rail. ALUMINUM RAILINGS AERATION UPGRADE PROJECT

14 2.03 MATERIALS: A. Rail, Post and Toeboard Materials: Railings and handrails shall be round pipe design railing system unless specified or shown otherwise. Aluminum shall be U.S. Alloy 6061 or 6063, T-5 or T-6. Aluminum pipe rail and posts shall be not less than 1-1/2 inch diameter, Schedule 40 pipe. B. Welding Rods: Aluminum welding rods shall be of type recommended by the aluminum manufacturer for anodized finished products. C. Fasteners: Fasteners, screws and bolts shall be concealed and shall be of stainless steel. D. Support Brackets: Handrail support brackets shall be aluminum with a finish that matches the handrail or railing of which they are a part. E. Toeboards: Toeboard for pipe railing shall be as shown on the Drawings. F. Socket Grout: Non-shrink grout for handrail post sockets shall consist of an inorganic, nonmetallic, pre-mixed grout with a minimum 28-day compressive strength of 4,000 psi FINISHES: A. Pipe Railing System: Pipe railing system including posts, railings, tube caps, support brackets and other miscellaneous parts shall be provided with a 0.7-mil clear anodized finish, AA-M32 C22A ASSEMBLIES: A. Height and Spacing Requirements: Railing shall be a three (3) rail system with equal open spaces between rails (and toeboard when required). Whenever the CBC requirements are not specified and only California OSHA requirements are specified the open spaces between rails need only conform to California OSHA requirements and may be spaced 21-inches apart. Top of upper railing shall be 42-inches above the working surface. Toeboards shall be not less than 4-inches in height nor more than 1/4-inch off the working surface and shall be provided where indicated and/or required. Railings shall be mounted as shown on the Drawings. The posts shall be evenly spaced at not less than 4-feet nor more than 6-feet on centers. Field conditions may require some adjustment of spacing. The top railings shall be as long as possible and the post shall not project through the top rails. PART 3 - EXECUTION 3.01 GENERAL: A. Unless specified or shown otherwise, all handrails and railings shall be component systems, installed complete and ready for use with all anchors, attachments, balusters, brackets, caps, fasteners, gates, posts, sleeves, trim and all other related items required or necessary for the complete installation. B. All installation work hereunder shall be performed by craftsmen experienced in the fabrication or architectural metal work. Exposed surfaces shall be free from defects or other surface blemishes. All dimensions and conditions shall be verified in the field in advance. All joints, junctions, miters and butting sections shall be precision-fitted with no gaps occurring between sections and all surfaces shall be flush and aligned. ALUMINUM RAILINGS AERATION UPGRADE PROJECT

15 3.02 WELD FINISH: A. All exposed welds shall be ground smooth and flush and shall be polished and anodized. Discoloration of exposed aluminum surfaces, whether or not due to welding, shall constitute a basis for rejection of the entire assembly EXPANSION/CONTRACTION: A. Exterior railing systems shall provide for 1/4-inch expansion and contraction per 20 linear feet of railing. Interior railing systems shall provide for 1/8-inch expansion or contraction per 20 linear feet of railing RAILING CONTINUITY AND END TREATMENT: A. Handrails and railings shall be designed to form a continuous run system with elbow turns and bends that do not have interferences with hand movement. Handrails shall be continuous for the full length of the stairs and landings. The handrails shall extend not less than 6-inches beyond the top and bottom risers. Whenever possible, the extension shall be at least 18-inches for the possible use by handicapped people. The ends of handrails shall be returned to wall or shall be terminated in newel posts or safety terminals. Newel posts and safety terminals may be used only when approved by the Engineer INSTALLATIONS WITH DISSIMILAR MATERIALS IN CONTACT WITH ALUMINUM: A. Special care shall be exercised to prevent aluminum components from coming in contact with steel, galvanized steel and concrete or dissimilar metals or materials. Proper coatings shall be applied to protect the aluminum surface in contact with dissimilar materials. See Section Only stainless steel bolts or components shall be used to connect isolated dissimilar materials. END OF SECTION ALUMINUM RAILINGS AERATION UPGRADE PROJECT