512FORMS AND FALSEWORK

512-1.01 DESCRIPTION . Design, construct, maintain and remove forms and falsework used to

form or temporarily support structural concrete until the structure is self supporting.

512-1.02 Definitions .

COMPRESSIVE STRENGTH . See definitions in Subsection 501- 1.02. FALSEWORK. A temporary structure erected to support the permanent structure, in the process of construc tion, until the permanent structure attains adequate strength to become self -supporting and capable of supporting other imposed loads. FORMS. Also known as formwork, are a temporary structure or mold used to retain the plastic concrete in its designated shape while the concrete is curing and gaining sufficient strength to maintain its designated shape. HAUNCH. A thickened portion of a concrete deck filling the space between the top of the girder and the bottom of the roadway slab. INFORMATIONAL FIELD TEST. See definitions in Section 501- 1.02.

512-2.01 MATERIALS. As specified or approved.

DESIGN AND CONSTRUCTION REQUIREMENTS

512-3.01 Submittals.

512-3.03 FALSEWORK C ONSTRUCTION. Construct falsework to conform to the approved

falsework plan. Do not begin falsework construction without an approved falsework plan. Do not modify or alter the structure to accommodate falsework unless otherwise noted or authorized by the Engineer. When welding falsework, meet the welding requirements of Section 504. Build camber into the falsework to compensate for falsework deflection and anticipated structure deflection. Camber shown on the Plans or specified by the Engineer is for anticipated structure deflection only. Do not use driven devices to attach falsework to concrete. Do not modify or alter the structure to attach falsework unless otherwise noted or authorized by the Engineer .

512-3.04 FORMS. For surfaces that are exposed in the completed work, use plywood forms

meeting the requirements of the American Plywood Association (APA) grade High Density Overlaid (HDO) Plyform Class I or other approved material that will produce an eq uivalent smooth and uniform concrete surface. For other surfaces, use plywood forms meeting the requirements of the American Plywood Association (APA) grade B -B Plyform Class I. Use only form panels in good condition free of defects on surfaces in contact with concrete. Furnish and place form panels for exposed surfaces in uniform widths of not less than 3 feet and in uniform lengths of not less than 6 feet except where the width of the member formed is less than 3 feet. Arrange form panels in symmetrical patterns conforming to the general lines of the structure. Place panels for vertical surfaces with the long dimension horizontal and with horizontal joints level and continuous. For walls with sloping footings that do not abut other walls, placement of pane ls with the long dimension parallel to the footing is permitted. Follow the manufacturer’s written recommendations when using form liners. Increase the thickness of concrete members that receive an architectural finish to maintain the specified cover to reinforcing steel. Bevel exposed corners and edges with 3/4 inch chamfers built into the forms. Do not modify or alter the structure to attach forms unless otherwise noted or authorized by the Engineer. Form ties, anchors, and other devices may be cast into the concrete for supporting 246 ALASKA 2020 forms or for lifting precast members. Ensure form ties and anchors can be removed without damaging the concrete surface. Do not use driven devices to attach forms to concrete. Do not use anchors coated with materials that will stain the concrete for supporting forms. Construct metal ties or anchorages within the forms to permit their removal to a depth of at least 1 inch from the concrete surface without damage to the concrete. Construct concrete forms mortar -tight. Clean the i nside surfaces of forms free of contaminants that affect the concrete finish. When forms are supported by existing concrete, ensure the forms fit tightly against the existing concrete and mortar will not pass through the joint. Forms may be omitted when the sides of a footing excavation is in rock. If the excavation is larger than the plan dimensions, any additional concrete placed will be at the Contractor’s expense. Coat forms to be removed with form release agent prior to use. Use a commercial quality pr oduct, designed specifically to release forms, and that will not discolor the concrete surfaces.

512-3.05 FORMS AND F ALSEWORK FOR CONCRET E DECKS. Use forms and falsework that

span between adjacent girders without altering or damaging the supporting girder s. Hangers may be cast into the concrete for supporting deck falsework. Do not use driven devices to attach forms or falsework to concrete. Do not use materials that will stain the concrete to support the falsework. Construct hangers to permit their removal to a depth of at least 1 inch from the concrete surface without damage to the concrete. Adjust the falsework haunch dimensions to accommodate the camber and elevation of the installed girders. Measure the installed girder elevations along the centerline of the girders at locations shown on the Plans after erection but before installing falsework, forms, reinforcing steel, or applying other loads. Determine the required haunch dimensions accounting for the variations in the girder elevations and anticipated deflection due to additional dead loads. Prestressed concrete girder elevations shown on the Plans are based on estimated girder deflections at 40 and 120 days after release of the prestressing strands. The girder elevations shown in the Plans are intend ed to advise the Contractor as to the expected range of girder deflection at the time of deck forming. Construct falsework supporting concrete work on steel structures so that loads applied to girder webs are applied within 6 inch of the flange or stiffener. Construct Falsework to distribute loads so that local distortion of the web is not produced.

512-3.07 C LEANUP. Upon completion of the structure and before final acceptance, leave the

structure and entire site in a clean and orderly condition. Remove temporary structures, equipment, unused materials, debris, forms, and falsework. Remove falsework piling at l east 2 feet below the finished ground line, unless noted otherwise.

512-4.01 METHOD OF M EASUREMENT. Forms and Falsework will not be measured for

payment.

512-5.01 BASIS OF PA YMENT. When either Item 512.0001.____ or 512.0002.____ does not

appear in the bi d schedule, the work required for that item is subsidiary. Payment will be made under: PAY ITEM Item Number Item Description Unit 512.0001.____ Forms LS 512.0002.____ Falsework LS 248 ALASKA 2020 SECTION 513 FIELD PAINTING OF ST EEL STRUCTURES

513-1.01 DESCRIPTION . Clean and paint the structural steel on existing bridges. Contain,

collect, and dispose of waste materials and protect existing facilities, vehicles, the environment, and the public from damage due to this work.

513-2.01 MATERIALS. Use materials that confor m to the following:

513-2.02 COMPONENT O RIGIN. Use only components that are the standard, regularly produced

product of a single manufacturer and meet or exceed the requirements in this Section. Paint systems must be the same generic type, be field applicable under the environmental constrictions of the site and structure, and have been used successfully in the field for at least 2 years on similar structures in a similar environment as this project. Submit the following information on paint systems for approval:

513-3.01 SYSTEM DURA BILITY AND CERTIFICA TION. Require the coating manufacturer to

review the project and the proposed service environment and issue written recommendations and instructions to the applicator to ensure maximum durability, proper surface preparation, and proper coating application. Make these documents available at the prepainting conference. Require the coating system manufacturer to have a technical representative on the job site during the prepainting conference and also be available and on- call during construction.