RC Jacketing

• Remove broken concrete cover if any around the piles/piers.
• Cleaning and roughening of all concrete surfaces around the piles/piers.
• Vertical reinforcement and helical reinforcement should be according to the drawing shall be fixed. Where required overlaps in helical will not be less than 780mm.
• In order to achieve the required bond between old and new concrete, just before concreting, the piles/piers surface will be coated with a bonding agent Chemdur 32 (or equivalent).
• Place steel formwork around the piles/piers. The height of the formwork in each stage of concreting should not be more than one meter height. Repeat it in succession on subsequent days.
• Concrete used for RC Jacketing will be Class A3 with minimum cylinder strength of 280 kg/cm2 at 28 days with concrete cover of 50mm using concrete spacers.
• Concreting should be done in steps of one meter height at one time and second lift to be carried out after one day.
• After removal of steel formwork, concrete wet curing is must be at least for 14 day using wet hessian cloth warped around the fresh concrete. The hessian cloth should remain wet throughout day and night. Wet curing is very essential to achieve the desired strength of 280kg/cm2.

The PDF Drawings of Proposed Rehabilitation of Existing Bridge using RC Jacketing is as follows: