REPAIR/REHABILITATION OF RCC STRUCTURE, COLUMN, BEAMS, PARAPET, RCC CHAJJA, CI PIPE, SUNKEN TREATMENT, REPAIR OF RCC TANK AND MISC B/R NATURE WORK IN CARIAPPA VIHAR, TARUS SAINIK ARAMGRAH IN THE AREA OF AGE B/R-II UNDER GE (WEST) DELHI CANTT-10

M&L for impregnating cream for injection into masonry or concrete wall 230mm thick against capillary rising humidity. Rising bar super strong Injection No. 306 of chowgule building chemicals or equivalent in Pidilite/Dr Fixit/Sika/Fosroc complete all as specified and directed.

Method of Application. Methodology:- (a) The surface must be sound, absorbent, clean, free of dust, oil, paint, curing agents, loose cement or lime plaster & concrete, debris or any separation layer. (b) The plaster must be knocked off at least 50 cm beyond the visibly penetrated area. (c) Damaged mortar joints are to be scraped out to a depth of approximately 2-3 cm. All sharp edges/Joints need to be levelled. Loose concrete shall be removed. (d) Drill boreholes at ground level horizontally. The bore holes are drilled horizontally into the masonry. (e) The holes should be drilled until a depth of approx 5 cm (for a 6mm thick wall) before the end of the wall is reached. The boreholes should have a diameter of 12mm upto a maximum of 15mm and should be spaced approx 100 to 120mm apart and the vertical offset is 6cm max. (f) Before inserting Rising bar super strong or equivalent the boreholes must be cleaned from boring dust by using air pressure. It is not necessary to pre-wet the boreholes. (g) For applying the rising bar super strong or equivalent the dosing system inserted as far as possible into the boreholes. While dosing the product uniformly, the injection nozzle is pulled out leading to a completely filled boreholes. (h) Treatment of highly absorbent masonry might require repeated filling of the boreholes, depending upon extent of damage, rising Bar super strong or equivalent can be re-injected in the same hole after 24 hours. Depending on absorbency, application or masonry thickness 0.1 to 0.15 litre/m with 10cm wall thickness.

25-30 mm average thickness ( in 2 layers) up to 8th floor level

50-60 mm average thickness ( in 3 layers ) up to 8th floor level

PMM repairs at 3.01 and 3.02 above shall be done as per following methodology :-

Chipping of plaster and unsound/weak concrete material till reinforcement bars are exposed, which enable their rust removal vide item below, from slabs, beams, and columns etc. with standard power driven percussion type or pneumatic chisel of standard make as directed by Engineer-in charge including tapering all edges, making square shoulders of cavities etc complete and disposal of debris up for all lifts and leads .

Rust removal by Providing and applying Fosroc Reebaklens RR or equivalent from SIKA/ BASF, a combination of acid based material, corrosion inhibitors and dispersing agents, rust remover, for removal of all rust/ scales/corrosion from reinforcement bars before micro concreting or patch repair. It Shall be applied with brush for complete wetting of rusted metal surface at coverage of 2- 2.5 Sqm/ltr. & allowed it to react 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 any protective coating, the surface should be wire brushed and thoroughly cleaned for dust with dry cloth.

Anticorrosive treatment by Providing and applying Nitozinc Primer an epoxy based zinc rich anti corrosive primer having adhesive bond strength ≥ 1.5 MPa as per ASTM D4541, & shall comply to per ASTM B-117 to be applied on well cleaned, fully exposed and all loose scale , rust free rust free surface obtained by grit blasting or suitable means , to be done with coverage @4.5sqm/litres to achieve a minimum thickness of 40microns DFT or complete all as specified and directed.