COMPREHENSIVE REPAIR/ MAINT OF SINGLE LIVING AREA AND CONNECTED BLDGS OF HQ EC INSIDE VIJAY DURG UNDER GE (FW) KOLKATA

M&L Examining concrete by tapping with light hammer and marking of the loose concrete areas of structural elements in straight line geometrical forms, grooving the edges same with grinder upto 5-10 mm depth without damaging existing rebars, carefully removing unsound weak/ loose concrete/ cover & concrete around the rebars upto 10 mm depth by low impact high frequency hammer/ chipper without damaging the sound concrete, daily cleaning and stacking of debris at prescribed location in polypropylene/ paper bags, disposing off the debris so generated on weekly basis outside the premises. etc, complete with necessary scaffolding complete all as specified and directed.

Cleaning as directed & specified all rust/ scales/corrosion from reinforcement bars using rust remover Reebaklens RR or equivalent - Rust remover, cleaning and etching agent, having Specific Gravity 1.16 - 1.22 @ 25°C. Reebaklens RR cleaning agent is a combination of acid based material, corrosion inhibitors and dispersing agents and is supplied as a clear green solution. Application of Reebaklens RR with brush for complete wetting of rusted metal surface and allowed to react it for 16-24 hours followed by cleaning the surface with wire brush and washing surface with fresh water as required to exposed reinforcement bars complete as specified. Item rate is inclusive of materials all labour, tools and tackles, and transportation etc. complete as per specification and as directed by Engg.-incharge.

M&L for drilling and fixing 12mm dia upto 50-75 mm long injection packer in structural members at the interval of 300mm in staggered manner in reinforced concrete (RC) structural element including cleaning of the holes by air blower and inserting 12mm dia NRV (Non Return Valve) nozzle compatible with epoxy injector and having machined external end to receive outlet of grouting gun fix inside the hole by using Epoxy chemical anchoring Lokfix E77 or approved equivalent to ensure complete sealing and allow curing system for minimum of 40 Mins before grouting including nozzle projections, excess putty, if any over concrete element by grinding, levelling and finishing the external surface , after completion of work etc. complete with necessary scaffolding, all as specified and as directed by EIC.

Providing and executing injection/pressure grouting in cracks in the parent concrete by fixing PVC nipples at 150 mm to 200 mm distance or specified distances as per design and detailed specifications. Pressure grouting using low viscous epoxy grout Conbextra EP 10(M) of Fosroc or equivalent having mix density 1060 kg/m3,Compressive Strength(ASTM D695)-60 N/mm2,Tensile Strength(ASTM C 304-97)-20 N/mm2,Flexural strength(BS 6319 Part 4)-45 N/mm2.Pressure grouting shall be done at required pressure etc. shall complete as directed by EIC.

Providing & applying inhibition coats/system to exposed reinforcement bars after drying & also new bars after cleaning & removing scales and rust completely as specified. Nitozinc Primer or equivalent - Two component epoxy zincrich primer based on metallic zinc and epoxy resin which on mixing gives a grey coloured liquid. An Anti corrosive coat contents Active 'Zinc-rich' system which combats corrosion by electro chemical means. having specific gravity of 1.75, Adhesive bond strength > 1.5 N/mm2 Zinc content >84 % by weight, 40 microns DFT, Fully dry/ Recoatable - 45 minutes to 1 hour. Typical application includes surface preparations by cleaning steel surface to a bright condition paying particular attention to the back of exposed steel bars, mixed two components slow speed heavy duty drill fitted with a paddle, applying unbroken coat with suitable brush and allow to dry, after 30 mins apply second coat to ensure complete cover to exposed steel/ rebar etc complete. Total Dry film thickness is 40 microns. Item rate is inclusive of materials all labour, tools and tackles, and transportation etc. complete as per specification and as directed by Engg.-in-charge.

Providing and applying Epoxy bonding agent on the prepared surface to receive polymer modified mortar/polymer modified micro concrete, with two component epoxy based bonding coat Nitobond EP Std of Fosroc make or equivalent, having Compressive strength(BS 6319 Pt.2)- 40 Mpa at 7 days, Flexural strength strength(BS 6319 Pt.3)- 25 Mpa at 7 days, Tensile strength (BS 6319 Pt.7)- 15 Mpa at 7 days, Bond Strength (ASTM C881)- 11 Mpa at 7 days, having an over lay time of 3 Hrs at 35 °C. Laying of reinstatement polymer modified mortar or micro concrete shall be completed within the overlay time of bonding coat. The bond coat act as a bonding coat between old and new concrete. Item rate is inclusive of materials all labour, tools and tackles, Shuttering Supporting material and transportation etc. complete as per specification and as directed by Engg.-incharge

Providing and laying of polymer modified single component fibre reinforced,thixotropic, dual shrinkage compensate cementitious patch repair mortar Renderoc HSxtra of Fosroc make or equivalent that achieves compressive strength (BS 6319 Pt. 2)-50 Mpa at 7 day & 70 Mpa at 28 days, Tensile Strength(BS 6319 Pt.7) > 4 Mpa at 28 Days, Flexural Strength(BS 6319 Pt.3)>9 Mpa at 28 days, Fire resistance (EN1504-3 cl 5.5)- Class A1. Finishing the same withtrowel carefully compacting the same around the rebars and finishing to bring it in line with existing concrete surface on the beams, slabs, piles etc.,where the thickness of application is less than 50 mm in patches as per specification after applying of epoxy bonding coat. Item rate is inclusive of materials all labour, tools and tackles, and transportation etc. complete as per specification and as directed by Engg.-in-charge Note Work to be executed by the authorized applicator of manufacturer only

Demolition of Brick work / stone masonry built in cement mortar and removing the debris from MD land complete all as specified and directed.

Dismantling wrought iron or mild steel work of any description not other wise provided for complete all as specified and directed.

Dismantling old/unserviceable Asbestos cement (corrugated, semicorrugated, etc.) sheets in roof coverings or any description all as specified and directed