GAIL (India) Limited

415.8 REUSE OF FORMSImmediately after the forms are removed, they shall be cleaned with jet of water and a soft brush beforethey are reused.The contractor shall not be permitted reuse of any forms which in the opinion of the Consultant has wornout and has become unfit for formwork.The Consultant/Engineer-in-charge may in his absolute discretion, order rejection of any forms heconsiders unfit for use in the works, and order their removal from the site.5.9 FORM WORK FOR SLOPED SURFACESForms for sloped surfaces shall be built so that the formwork can be placed board-by-board immediatelyahead of concrete placement so as to enable ready access for placement, vibration, inspection and repair ofthe concrete.The form work shall also be built so that the boards can be removed one by one from the bottom up assoon as the concrete has attained sufficient stiffness to prevent sagging. Surfaces of construction jointsand finished surfaces with slopes steeper than 4 horizontal: 1 vertical shall be formed as required herein5.10 FORM WORK FOR CURVED SURFACESThe contractor shall interpolate intermediate sections as necessary and shall construct the forms so that thecurvature will be continuous between sections. Where necessary to meet requirements for curvature, theform lumber shall be built up of laminated splines cut to make tight, smooth form surfaces.After the forms have been constructed, all surface imperfections shall be corrected and all surfacesirregularities at matching faces of form material shall be dressed for the specified curvature.5.11 FORM WORK FOR EXPOSED CONCRETE SURFACESWhere it is desired, directed or shown on the drawings to have original fair finish of concrete surfacewithout any rendering or plastering, formwork shall be carried out by using wood planks, plywood orsteel plates of approved quality and as per direction of the Consultant.The Contractor shall use one type of material for all exposed concrete surfaces and the forms shall beconstructed so as to produce a uniform and consistent texture and pattern on the face of the concrete.Patches on forms for these surfaces will not be permitted. The formwork shall be placed so that allhorizontal formworks are continuous across the entire surface If forms are constructed of lumber and arenot paneled the formwork shall be staggered.To achieve finish which shall be free of board marks, the formwork shall be faced with plywood orequivalent material in large sheets The sheets shall be arranged in an approved pattern. Whereverpossible, joints between sheets shall be arra.To achieve a finish which shall give the rough in appearance of concrete cast against swan boards,formwork boards unless otherwise stated shall be in an average be 150 mm wide, securely jointed withtongued and grooved joints if required to prevent grout loss with tie rod positions and direction of boardscarefully controlled Sawn boards shall be set horizontally, vertically or at an inclination as shown in thedrawings. All bolts holes shall be accurately aligned horizontally and vertically and shall be filled withmatching mortar recessed 5 mm back from the surroundings concrete face.Forms for exposed concrete surfaces shall be constructed with grade strips (the underside of whichindicates top of pour) at horizontal construction joints, unless the use of groove strips is specified on thedrawings Such forms shall be removed and reset from lift to lift. Sheathing of reset forms shall betightened against the concrete so that the forms will not spread and permit abrupt irregularities or loss ofmortar Supplementary from ties shall be used as necessary to hold the reset forms tight against theconcrete.