ILLUSTRATIONS

REPAIRING OF STRUCTURES AVINASH KUMAR GUPTA

TRAINING INSTITUTE

CCW AIR

APRIL 2017

Strengthening Of columns

• Section Enlargement by jacketing.• Apply specified bond coat on existing column.• Bond coat of sunepoxy 368• M-25 or higher grade of concrete.

Strengthening of Beams• Section enlargement with micro concrete• Shotcrete self compaction concrete• Increased flexure strength by enlarging

compression zone and additional reinforcement in tension.

• Increased shear strength by fixing of stirrup with epoxy and quartz sand mortar as specified.

• MS Plate bonding• High strength fiber fabric wrap technique.

Strengthening Of Slab

• Provide overlays in case of negative moment deficiency.

• Provide underlay in case of positive moment deficiency.

• Increase in stiffness and control of deflection.• Slabs are safe in shear.

STICHING of walls/slab cracks

• Concrete and masonry weak in tension.• Crack indicate tensile failure of material• Insert U shaped MS bars in the holes and span

across the crack.• Grouting the holes with either epoxy or non

shrink grout.(non moving cracks)• Active cracks are to be filled with flexible

materials like poly- sulphides, bituminous fillers.

BEAM AND COLUMN REPAIR BYGUNITE/SHOTCRETE

TREATMENT OF DEPRESSED FLOOR IN TOILET/KITCHEN

• Remove all materials and expose the pipes.• Test the water supply pipes and drainage pipes

for leakages using pressure applying methods.• Provide 40 mm dia GI spout and CC sloped

flooring with water proofing compound. • Provide 12 mm thick cement plaster (1:3) with

water proofing on the vertical walls • Provide two coats of bitumen(85/25)in the

sunken portion.

Column Beam Junction

Repairs at Beam column junction

Beam Column Junction

COOROSION IN BARS .RCC STRUCTURE

CORODED BARS REPAIR• Remove all defective concrete and expose

corroded reinforcing bars to their full circumference.

• Remove the corrosion from the bars until the shine.

• Apply anti corrosive protective passivating coat to protect re –bars.

• Patch with repair mortar or concrete and resurface to required thickness.

• Apply protective coating and follow up with decorative painting.

JACKETING

Column repairs

GROUTING

Beam Strengthening

REPAIR STRATEGY

• Remove all unsound concrete at spalled ,cracked and hollow sounding areas.

• Expose the full corroded rebars to further depth.• Remove corrosion by approved manual method

or by sand blasting.• Treat rebars by a passivating material.• Shotcreting, microconcreting• Curing and top coat of alkyd to prevent ingress of

deleterious gases.

Beam Repairs

CRACK FORMATION, IDENTIFY THE CAUSE

Brick wall Column Junction

Jacketing upto foundation level

Over Head Tank repair

Bridge Repair

Roof Repair

Water proofing of roofs

• Remove existing treatment.• Number of rain water pipes to be increased.• Mark surface cracks. Inject polymer modified cement

slurry through nipples along crack lines.• Regarding.• Apply two coats of polymer modified cement slurry

with 20% polymer.• Apply 20 mm thick polymer modified non shrink

cement plaster with 300 X300 square thread identation.

• Curing and ponding to check adequacy.

FILLING CRACKS

Filling Cracks

Basement Repair

Leak Reapair , Rubber based polymer

DOME REPAIR

DOME REPAIR, External surface

• Remove old plaster.• Fix grouting nipples and inject cement based

non shrink slurry.• Provide first layer of Ferrocement.• Lay second layer and level upto required level.• Cure for 14 days.• Apply anti carbonation treatment in two

layers.

Dome repair , Internal surface

• Remove old plaster and clean joints wth brushes.• Remove corroded steel and replace it.• Pack with non shrink concrete.• Repack all exposed masonry joints with non

shrink cement sand mortar. Pressure grout with nozzles at the dome junction with bottom drum.

• Provide specified layer of ferrocement.• Cure for 10 days • Apply two coats of polymer cement water

proofing.