Arch (dome) roofs repairing of RPD, MATD And ESD Building at CSIR-CRRI, New Delhi - 110025

Chipping of unsound/cement mortar/ concrete material from slabs, beams, columns etc. including removing of fibre cloth with manual Chisel and/ or by standard power driven percussion type or of approved make including tapering of all edges, making square shoulders of cavities including cleaning the exposed concrete surface and reinforcement with wire brushes etc. and disposal of debris for all lead and lifts all complete as per direction of Engineer-In-Charge. 25 mm average thickness

Providing, mixing and applying bonding coat of approved adhesive on chipped portion of RCC as per specifications and direction of Engineer-In-charge complete in all respect.SBR Polymer (@10% of cement weight) modified cementitious bond coat @ 2.2 kg cement per sqm of surface area mixed with specified proportion of approved polymer.

Providing, mixing and applying SBR polymer of approved make modified Cement mortar in proportion of 1:4 (1 cement: 4 graded coarse sand with polymer minimum 2% by wt. of cement used) as per specifications . as directions of Engineer-in-charge. 20 mm average thickness. Note: Measurement and payment: The pre-measurement of thickness shall be done just after the surface preparation is completed and Payment under this item shall be made only after proper wet curing has been done and surface has been satisfactorily evaluated by sounding / tapping with a blunt metal instrument and/or the 75mm size cube crushing strength at the end of 28 days to be not less than 30 N/Sqmm2).

Making hole up to 20x20 cm and embedding pipes up to 150 mm diameter in masonry and filling with cement concrete 1:3:6 (1 cement : 3 coarse sand: 6 graded stone aggregate 20 mm nominal size) including disposal of malba.

Providing and laying in position specified grade of reinforced cement concrete, excluding the cost of centering, shuttering, finishing and reinforcement - All work up to plinth level :1:1.5:3 (1 cement : 1.5 coarse sand (zone-III) derived from natural sources : 3 graded stone aggregate 20 mm nominal size derived from natural sources)

Centering and shuttering including strutting, propping etc. and removal of form for Edges of slabs and breaks in floors and walls Under 20 cm wide.

Steel reinforcement for R.C.C. work including straightening, cutting, bending, placing in position and binding all complete above plinth level. Thermo-Mechanically Treated bars of grade Fe-500D or more.

Smooth finishing of the exposed surface of R.C.C. work with 6 mm thick cement mortar 1:3 (1 Cement : 3 fine sand).

Providing and fixing double scaffolding system (cup lock type) on the exterior side, up to seven story height made with 40 mm dia M.S. tube 1.5 m centre to centre, horizontal & vertical tubes joining with cup & lock system with M.S. tubes, M.S. tube challies, M.S. clamps and M.S. staircase system in the scaffolding for working platform etc. and maintaining it in a serviceable condition for the required duration as approved and removing it there after .The scaffolding system shall be stiffened with bracings, runners, connection with the building etc wherever required for inspection of work at required locations with essential safety features for the workmen etc. complete as per directions and approval of Engineer-in-charge .The elevational area of the scaffolding shall be measured for payment purpose.The payment will be made once irrespective of duration of scaffolding. Note : This item to be used for maintenance work judicially, necessary deduction for scaffolding in the existing item to be done.

Providing and laying broken tiles ( size note more than 75 mm x100 mm) over the roofs of slab consisting of following steps (a) Cleaning the exposed concrete surface of sticking materials including loose and foreign materials by chiseling and brooming (b) Providing, mixing and applying bonding coat of approved adhesive on chipped portion of RCC as per specifications and direction of Engineer-In-charge complete in all respect.SBR Polymer (@10% of cement weight) modified cementitious bond coat @ 2.2 kg cement per sqm of surface area mixed with specified proportion of approved polymer. Note Payment to be made separately of part b) (c) Providing, mixing and applying SBR polymer (of approved make) modified Cement mortar in proportion of 1:4 (1 cement: 4 graded coarse sand with polymer minimum 2% by wt. of cement used) as per specifications Note Payment to be made separately of part C) d) Providing and laying layer of Fibre glass tissue reinforcement Type IIGrade I when the first layer is still green, Overlaps of joints of fibre cloth should not be less than 10 cm (e) Providing and Fixing ceremic glazed broken tiles over 15 mm thick bed of Cement Mortar 1:3 ( 1 cement :3 coarse sand) and jointing with grey cement slurray @ 3.3 kg per sqm/ as required site including finishing the gap with polymer modified SBR Polymer @ 2% of cement mortar 1:3 Cement Mortar 1:3 ( 1 cement :3 coarse sand) to ensure the gaps between the broken tiles is not more than 15 mm. The whole Terrace so finished shall be covered with wet Jute cloths for a minimum period of two weeks for curing All the above operation to be done in order and as directed and specified by the Engineer-in-Charge.