ADDN/ALTN TO BLDG NO P-06 AND P-07 MD ACCN AT MES COLONY UNDER GE (UTILITIES) UDHAMPUR

Identify the cracks and joints, shall be chased open into ‘U’ groove shape. Prepared suitable surface as require to apply the mortar. Apply a bond coat of Fosroc Nitobond SBR Latex and sealed with Shrinkage controlled, polymer modified, fiber reinforced cementitious repair mortar, Fosroc Renderoc SP40. Fixing pvc nozzle, injection grouting to be done with cement slurry admixed with expanding grout admixture Cebex 100 to be mixed @225 gm per bag of cement and Bore packing to be done at pipe entries by forming proper formwork and filling the gap with non-shrinkable cementitious grout Conbextra GP2 and sealed with epoxy/polyester sealant.

Supplying, cutting, bending to shape, fabricating, fixing in position TMT Reinforcement 10 mm dia and above Steel of Fe 500 grade. The reinforcement shall be of an approved brand. Including, cost of providing & tying with 18 gauge GI binding wire/ welding shall be included in the reinforcement rate. Rate of reinforcement shall also include cost of all related operations, inputs of labour, materials, tools and plants etc complete.

Surface Preparation and removal of Loose Concrete : Removing & Hacking of existing concrete Carefully by low impact high frequency hammer OR by manual chipping without damaging the existing concrete or control sand blasting including cleaning the surfaces by air jet etc. complete.(Mode of measurement- per sqmt of breaking area of concrete).

Cleaning of Rebar : For rusted metal (iron base) apply Reebaklens RR or Equivalent with brush for complete wetting of rusted metal surface and allowed to react it for 16-24 hours. After 24 hours, a white layer will appear which will protect further corrosion of metal / steel for about 5-7 days. Before applying protective coating, the surface should be wire brushed and thoroughly cleaned for dust with dry cloth.

Anticorrosive treatment : Providing and applying two coats of Nitozinc Primer or Equivalent a two component epoxy zinc rich Primer or equivalent product on the properly cleaned and prepared steel bars after the required chipping and cleaning of the concrete surface as per the manufactures specification.

Re-Bar Anchor: Providing and fixing shear connectors of 10 mm dia by drilling 12 mm diaholes on the concrete surface to a depth of 100 mm using a rotary cumhammering drilling machine as per specification and throughly cleaning thehole using compressed air and water jet and anchoring with pure resinbased grout solution like Fosroc Lokfix E77 or other equivalent approved make chemicals.

Crack Sealing : Identify the cracks and joints, honeycomb areas, shall be chased open into ‘U’ groove shape and sealed with High strength, abrasion - resistance epoxy reinstatement mortar, Fosroc Nitomortar S or Equivalent, Providing and fixing 6-8mm dia nozzle along the joints and honeycomb areas after proper surface preparation. The injection of Conbextra EP10 or Equivalent through the nozzle till the refusal of the grouting materials.

Bonding Agent: Supply and applying a bond of Fosroc Nitobond SBR Latex, or Equivalent SBR Latex based bonding agent admix with cement as per manufacturer recommended ratio.

Patch Repair Work : Guniting concrete surface with single component, fibre reinforced shrinkage compensated, polymer modified structural grade repair mortar like Fosroc Renderoc SP 40 or equivalent at a thickness of 25 mm. The repair mortar should have a compressive strength 45 N/mm², flexural strength 7 N/mm² and tensile strength 2.5 N/mm² at 28 days.

Micro Concrete : Providing and laying micro concrete up to the required thickness on the designated area to the prepared slurry tight shuttering with proper shear connector and bonding agent where ever necessary, The fluid micro-concrete repair material shall be a single component, cement based, Renderoc RG or equivalent micro-concrete to which only the site-addition of clean water (and approved graded coarse aggregates where specified) shall be permitted. The micro concrete shall contain no metallic aggregates, or chlorides and shall be shrinkage compensated in the plastic state. The micro concrete in the flow able consistency should achieve a compressive strength of 50 N/mm2 after 28 days at 30C as per BS 4551-80. The unrestrained expansion shall be between 1 - 4% as per ASTM C827-1987. Again as per BS 4551-80 the flexural strength shall not be less than 5 N/mm2 @ 28 days. The micro concrete shall have a coefficient of thermal expansion 10-12 X 10¯6/°C & Thermal conductivity 1.5 W/m°C The mixed density of micro concrete shall exceed 2100-2200 kg/m3 at 27ºC