West Bengal Electronics Industry Development Corporation Limited Tender

Treatments of Columns: - Removing all existing damaged/ loose materials and loose layers, all dust, dirt particles to prepare clean Columns substrate. (debris from the working location to the ground floor.) Removing the rust from reinforcement of columns by applying “Fosroc Reebaklens / Sika Rustoff 100 or equivalent” and providing “Fosroc Nitozinc Primer / Sika Friazinc R or equivalent” epoxy based high pigmented, zinc rich primer anticorrosive coating over the reinforcement. Cleaning concrete surface properly and then coating the surface with Fosroc Nitobond SBR Latex or equivalent mixing with cement and water @ 1:3:5 to provide good adhesion in between old concrete to new concrete. After the above application for finishing the entire column surface area is covered with column shuttering. Shall be protected using M-25 normal concrete using with Recron 3s (6mm) or equivalent @ 125gram/50kg cement shall be mixed with concrete. The screed concrete shall be admixed with Sika plastocrete super or equivalent @150 gram by weight of cement. Admixture dilution & mixing with concrete shall be done. After removing shuttering then protect the vertical surface 12-15mm thick 1:4 plaster admixed with Fosroc Nittobond SBR or equivalent @150 gram by weight of cement. The protective screed & plaster shall be cured for min 7days.

Surface Preparation : - Clean all concrete surfaces free of laitance, dust, dirt, cavities, projecting nibs etc.by wire brush. Remove all protrusions from concrete surfaces using a fine hair broom finish. Remove moss and lichen manually. Wash the surface thoroughly with clean water and allow it to dry. Standing water must be removed to prevent subsequent compromise of waterproof properties. Surface should be absolutely dry before application of coating. Chamfering & Coving: - At all the junctions to be done for a size of 30mm X 30mm with cement mortar admix with Fosroc Nittobond SBR or equivalent at the rate of 3% by weight of cement.

Injection Grouting: - All damp areas to be treated with pressure grouting with cement slurry admixed with non-shrink additives Fosroc Cebex 100 Additive or equivalent in the ratio of 5% by weight of cement through the nozzle at low pressure of max up to 2 to 2.5 kg/sqm. with grout pump machine.