Structural Concrete Repair and Maintenance Works in New Campus, Indian Institute of Management Ahmedabad.

Amount

Repair of Structural & Non-structural Cracks:

Repair of Structural & Non-structural Cracks:- (By Chemical Grouting technique) - Open the crack completely in the form of V-notch shape with top width of minimum 10mm and depth of atleast 10mm. Concrete, if found weak immediately next to cracks to be removed completely. The surface should be cleaned with air blower/soft brush and washed throughly with water and dried before the application of bonding agent. -Apply bonding agent by brush on prepared dry surface (NITBOND EP by Fosrock or equivalent) within scheduled pot life. -Lay Polymer modified mortar (Renderoc SP 40 or equivalent) in V-notch (matching with existing surface) and as directed by Engineer In-charge including mixing, transporting, placing and all labour, tools, equipments, etc., complete. -Treated cracks to be cured for minimum 3days. Mixing tray, Curing pipe and hessian cloth for curing will be in the scope of contractor. -Install nozzles (with valve type-photo attached) at an interval of 150 to 300mm compatible with pressure pump around the cracks upto a depth of 50mm (+/-10mm) within concrete surface. Periphery of nozzles sealed with micro-concrete or epoxy putty suitable and is left for a day to become firmly tight. - Grouting can be done by gravity pouring / flooding or pressure grouting High Molecular Weight Polymer Grout (MONOPOL of Krishna Conchem or equivalent) within scheduled pot life. The injection process shall be started from the widest part if it is a horizontal surface or from the lowest point if it is a vertical surface. The pressure to be maintain shall be 5-10Psi. The nozzles shall be removed by cutting it at the line of concrete and finishing as existing surface. - Curing in air for 24 hours. (Refer Annexure-C for manufacture specification). - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Record of the material consumed during grouting to be done. Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-1,1A,2,2A&2B

Repair of Structural & Non-structural Cracks:- (By filling it with Polymer modified mortar) - Open the crack completely in the form of V-notch shape with top width of minimum 10mm and depth of atleast 10mm. Concrete, if found weak immediately next to cracks to be removed completely. The surface should be cleaned with air blower/soft brush and washed throughly with water and dried before the application of bonding agent. -Apply bonding agent by brush on prepared dry surface (NITBOND EP by Fosrock or equivalent) within scheduled pot life. -Lay micro concrete (Renderoc RG or equivalent) in V-notch (matching with existing surface) and as directed by Engineer In-charge including mixing, transporting, placing and all labour, tools, equipments, etc., complete. -Treated cracks to be cured for minimum 3days. Mixing tray, Curing pipe and hessian cloth for curing will be in the scope of contractor. - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-1,1A,2,2A&2B

Spalling of Concrete:

For Damaged area - Upto 100 mm:- (Specification as per 201.00 to 201.03) - First, existing loose concrete is to be chipped off to a sound substrate surface. The surface should be cleaned with air blower/soft brush and washed throughly with water and dried. - Remove loose rust from steel bars by wire brush and hammering, etc. - Apply rust remover (RUSTICIDE by Sunanda Speciality Coatings Pvt. Ltd. or equivalent) on the affected metal surface by using cotton waste swab or brush. -Leave it in contact with the surface till the red color of the corroded surface has changed to original black. After a minimum of 24 hours, remove the freed rust particles by wire brush. -Sometimes, after the detachment of loose scales, reddish rusted surface is still left exposed. In such a case, repeat the above mentioned procedure of applying rust remover till original black surface is observed. -Now apply a passivating coating of Polyalk Fixoprime by Sunanda Speciality Coatings Pvt. Ltd. in slurry form to the steel surface by brush. Allow this coat to set for 6hours and then apply a second coat and let it to set. (Refer Annexure-C for manufacture specification). Refer Photo-3&4

Apply bonding agent by brush (NITBOND EP by Fosrock or equivalent) on prepared dry surface of old concrete within scheduled pot life. -If any steel/metal projecting outside the concrete surface, should be embedded within micro-concrete. It also includes binding wire for tying if necessary. - Within 6 hrs of applying bonding agent, lay micro concrete for formwork area (Renderoc RG or equivalent) OR Polymer modified mortar for area where forwork could not be done (Renderoc SP 40 or equivalent) matching with existing surface and as directed by Engineer In-charge including centering, shuttering, mixing, transporting, placing, vibrating, including all labour, tools, equipments, etc., complete. - Treated surface to be cured for 7days. Mixing tray, curing pipe and hessain cloth for curing will be in the scope of contractor. It include disposal of the waste outside the campus at unobjectionable place. (Refer Annexure-C for manufacture specification). - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-3&4

By using Micro concrete (Renderoc RG or equivalent)

By using Polymer modified mortar (Renderoc SP 40 or equivalent)

For Damaged area - Above 100 mm: (Specification as per 202.00 and 202.01) - First, existing loose concrete is to be chipped off to a sound substrate surface. The surface should be cleaned with air blower/soft brush and washed throughly with water and dried. - Remove loose rust from steel bars by wire brush and hammering, etc. - Apply rust remover (RUSTICIDE by Sunanda Speciality Coatings Pvt. Ltd. or equivalent) on the affected metal surface by using cotton waste swab or brush. -Leave it in contact with the surface till the red color of the corroded surface has changed to original black. - After a minimum of 24 hours, remove the freed rust particles by wire brush. -Sometimes, after the detachment of loose scales, reddish rusted surface is still left exposed. In such a case, repeat the above mentioned procedure of applying rust remover till original black surface is observed. -Now apply a passivating coating of Polyalk Fixoprime by Sunanda Speciality Coatings Pvt. Ltd. in slurry form to the steel surface by brush as per manufacturer specifications. Allow this coat to set for 6hours and then apply a second coat and let it to set.

Apply bonding agent by brush (NITBOND EP by Fosrock or equivalent) on prepared dry surface of old concrete as per Manufacturer’s specifications & Instructions within scheduled pot life. -If any metal projecting outside the concrete surface, should be embedded within micro-concrete. It also includes binding wire for tying if necessary. - Within 6 hrs of applying bonding agent, lay micro concrete (Renderoc RG or equivalent) in mix 1:0.75 by weight basis (1 Renderoc RG or Renderoc SP 40: 0.75 stone aggregate (hard granite) 12mm graded down to 6mm size) matching with existing surface and as directed by Engineer In-charge including centering, shuttering, mixing, transporting, placing, vibrating, including all labour, tools, equipments, etc., complete. - Treated surface to be cured for 7days. Mixing tray, curing pipe and hessain cloth for curing will be in the scope of contractor. It include disposal of the waste outside the campus at unobjectionable place. (Refer Annexure-C for manufacture specification). - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered.

Treating the Exposed Steel at Concrete Surface (Steel exposed for a minimum length of 100mm and above): - Remove all loose material with wire brush and Clean the concrete surface. - Cutting extra length of steel which is projecting outside the concrete surface if not required. - Repeat the procedure for treatment of steel by rust remover, apply bonding agent & cover it by Ploymer modified mortar as per Spalling of concrete item specifications. - Wherever upto possible height the Ladder will be in the scope of contractor. - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-5,6&7

Miscellaneous Problem

Weather effect / Efflorescence: - Affected surface should be cleaned by wire brushing, so that it should be totally removed. It it washed with water to remove completely. - After cleaning and drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Wherever upto possible height the Ladder will be in the scope of contractor. - After drying the surface, colourless silicone water repellent (NITOCOTE SN522 by Fosrock or equivalent) should be applied by spraying or brushing. Make sure that whole surface is covered. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-14

Shuttering (Tie rod of all diameters) rod projecting outside the face of concrete: - First, remove surrounding concrete of the rod by chipping off up to 50 mm deep. - Then cut or grind the rod up to 40 to 50 mm inside the hole. - Clean the surface thoroughly with wire brush and apply bonding agent and then apply micro concrete. - Wherever upto possible height the Ladder will be in the scope of contractor. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-8

Providing and Fixing zinc based Sacrificial Anodes Providing and fixing zinc based sacrificial anodes (SUNANODE of M/s. Sunanda Speciality Coatings Pvt. Ltd.) of size-50mm in diameter & height-18mm or equivalent at 1.0 mtr c/c along the embedded reinforcement bars in the structural members. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills.

Providing and fixing double scaffolding system (cup lock type) -Providing and fixing double scaffolding system (cup lock type) on the exterior side, up to 5 (five) story height made with 40mm 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 (Fall arrester, safety belt, helmet, safety shoes, safety jacket) for the workmen etc. complete as per directions and approval of Engineer In-charge. -The elevation area of the scaffolding shall be measured for payment purpose. The payment will be made once irrespective of duration of scaffolding at any location. Only one time will be paid for same location. -Safety board designating "Work is in Progress" around scaffolding system to be installed. Safety barricades & tapes to be placed aroud the area of work.

Removing MS brackets supporting water lines on Dorm terrace in Dorm 19 to 25 - Removing MS brackets (length-300mm) and its fasteners/nails supporting water lines. And shifting to the location inside the campus shown by Engineer In-charge. - Clean the holes thoroughly with wire brush and apply bonding agent and fill the same with Polymer modified mortar. Finishing to be done with white cement to match with existing surface. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-9

Casting & Placing Concrete Pedestral for supporting water lines in Dorm 19 to 25 -Casting concrete pedestral by using nominal mix of 1:1.5:3 proportion (size-150mm*300mm*150mm (+/-50mm)) and placing below water lines in dormitories (Top terrace) at the location of old brackets. -Concrete pedestral should be solid from all sides and it should be cured for 7days in drum/tank i.e. completely under water before shifting to dormitories. -If any pipe fixtures (CPVC material-Pipe/bend/T junction) get damaged during removing MS brackets and placing concrete pedestral to be rectified. It inludes all miscellaneous materials required for doing that. - It also includes necessary reinforcement of 8mm diamter as per details attached. Refer Drawing

China Mosaic Work

Removal of loose & major cracked China Mosaic patch in Dorms, Academic block & IMDC terraces -Carefully removal of loose & major cracked china mosaic flooring upto sound or firm china mosaic. It include disposal of the waste outside the campus at unobjectionable place. It includes all tools for removing loose layer. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-10&11

Providing and laying China Mosaic patch in Dorms, Academic block & IMDC terraces -Providing & laying of China Mosaic Patch work / touching in the existing flooring from approved broken glazed tile pieces of white colour laid in cement mortar 1:4 (1cement:4coarse sand) finished with white cement brought to approved existing finish complete. -Surface preparation before laying china mosaic- Clean the surface thoroughly with wire brush & air blower. -Apply a cement slurry over entire area & lay cement mortar to fill up any depressions or undulations etc. complete to facilitate easy drain of rainwater. Slope of the china mosaic to be matched with the existing flooring. -Curing to be done for 03days by covering the treated surface with Hessain cloth. -No extra will be paid for wastages. -Actual plan area will be consider for measurement. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-10&11

Providing and laying China Mosaic patch (At edges of terraces) in Academic block & IMDC terraces -Providing & laying of China Mosaic Patch work / touching in the existing flooring from approved broken glazed tile pieces of white colour laid in cement mortar 1:4 (1cement:4coarse sand) finished with white cement brought to approved existing finish complete. China mosaic edges to be sealed in cement mortar 1:4 (1cement:4coarse sand) as per existing. -Surface preparation includes removing the loose edges of china mosaic & clean the surface thoroughly with wire brush -Apply a cement slurry and seal the edge of china mosaic flooring with cement mortar (1:4) as shown in photo . -Curing to be done for 03days by covering the treated surface with Hessain cloth. -No extra will be paid for wastages. -Actual length will be consider for measurement. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-12

Providing and applying Splash waterproofing chemical over hair cracks in China Mosaic flooring in Dorm, Academic block & IMDC terraces -Providing & applying Splash waterproofing chemical over laid China Mosaic Patch work in two coats. Minimum 01hour gap should be there between two coats of splash. Clean the existing china mosaic surface with wire brush and wash it with water before applying splash. -Chemical to be applied through paint brush covering the 75mm wide area over crack portion. -No extra will be paid for wastages. -Actual length will be consider for measurement. - Photographic record of old and repaired surface to be done and submit to IIMA alongwith bills. Refer Photo-13

Bracket repairing at IMDC, Academic block & CIIE building at Expansion joint locations -Adequate temporary supporting system to be provided to the slab / beam of that area to avoid transfer of load to the affected bracket. -The bracket to be chipped off / dismantled carefully-Without cutting the existing reinforcement & without damaging any other structural element. -Bottom surface of the bracket also to be exposed. -All reinforcement shall be cleaned from any loose materials. -Gap of expansion joint and space between sliding mechanism shall also be cleaned from all concrete / mortar. -Apply anti rust spray/rust remover over the plates and provide grease over the sliding surfaces. -Apply a passivating coating to reinforcement. -Apply bonding agent to the exposed surface of existing RCC bracket. -Re-barring shall be done in existing bracket to hold the new concrete with Fischer grout. -Fix 8mm Dia rings and arrange the shuttering work as per the original size. -Pour non-shrink grout material (in place of concrete chipped off / removed from the bracket) to build the bracket as per original size. It includes shuttering too. -Curing to be done upto 28days and de-shuttering of bottom support to be done after 28days. -Water repellent coating to be done to the area to re-establish the aesthetic look as existing one. -Treat the expansion joint by applying primer, fixing backer rod & filling it with PU sealant as per existing. -Remove temporary supporting system after achieving full strength i.e. 28 days. The temporary support shall be removed step by step starting from bracket side. Work area to be separated by covering the work area with green net. Bracket size- 210 X 250 X 450mm (+/-50mm) (Refer Annexure-C for manufacture specification). Refer Photo-15, 16 & Drawing

Providing and fixing double scaffolding system (cup lock type) upto 9.5 mt height

Entire Work Methodology of bracket repairing

karm construction

kaushik c suthar