Repairs & Strengthening

01
Durability Repairs

Durability Repairs are Carried out to structures which show deterioration to non-structural area of concrete. Some of the findings of structure signifying requirement of durability repairs are:

  • Cover Concrete is spalled in Columns, Beams, Slabs, other elements
  • Chajjas / Pardi’s and other non-structural members exhibit damages
  • Core Concrete (concrete inside rebar) is sound and intact.
  • Façade needs to be replaced – New plasters and coating
  • Tiles & other Finishes need replacement / repairs
  • Cover concrete is rebuilt using PMM / Shotcrete
  • Chajjas / Pardi’s are replaced with new members or are repaired using variety of materials
02
Structural Repairs

Structural Repairs are Carried-out to structures which exhibit structural damage in the core section of the concrete. Some of the findings of structure signifying requirement of Structural repairs are:

  • Reduction in rebar > 20% Loss
  • Spalling/damage/buckling of core concrete
  • Main structural members such as columns, beams and slabs which form an integral part of the framework are damaged in core zone
  • Core Concrete needs replacement including addition of new rebars
  • Jacketing of foundations/Columns/Beams and Slabs
  • Micro-concrete / Self-compacting concrete / Polymer modified Concrete/ FRP’s / Structural Steel / Ground Improvement / Micro Piles etc.
03
Structural Strengthening

Structural Strengthening is carried out in situations wherein there is a change in user requirements e.g. residential structure getting converted to commercial premise. New vertical loads being added, such as addition of floors, new loads such as chillers, cooling towers, Antenna's being added on top of existing premises

  • Usual strengthening practices involve strengthening by section enlargement using micro-concrete, Polymer modified Concrete, SCC, Steel plates / Sections and FRP’s
  • Involves detailed redesign of the existing framework using strength of various elements.
04
Siesmic Retrofitting

Buildings designed prior to 2002 may-not comply to Codal provisions of revised IS codes. To protect the old structures, from the effect of seismic forces, Specialized retrofitting process for to counter seismic forces involves:

  • Addition of Shear Walls
  • Introduction of Lateral Ties
  • Jacketing of Columns / Beams
  • Strengthening of Column / Beam junctions
05
Waterproofing & Protective Coatings

The most important role of waterproofing is to protect a building’s visual and structural integrity by forming an impervious envelop around the building which will prevent water entry into the building areas.


Requirement of an ideal W/P System

  • mpermeable/ prevent passage of water
  • Flexible/ Crack bridging ability
  • Durable / long life
  • Breathable
  • Compatible/ good bond
  • Weatherability/ resistance to UV attack
  • User-Friendly
06
Coatings

A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. Various Kinds of Coatings Exist in the market which provide functionality and aesthetic end results. Few of them commonly used are:

  • Acrylic / OBD / Lime Wash
  • Anti-Carbonation Coatings
  • Corrosion Inhibitors
  • Abrasion Resistant Coatings
  • Chemical resistant coatings
  • Temperature resistant Coatings
07
Corrosion mitigation

The major cause of concrete deterioration (cracking, delamination, and spalling), is the corrosion of embedded steel reinforcing bars as a result of chloride ions (permeating through the concrete cover) in combination with moisture and oxygen. The extent of concrete degradation and corrosion of reinforcement over a period of time, impairing both serviceability and structural safety is a matter of great practical concern in view of economic consequences for assessment, maintenance and repair.

Typical Causes for corrosion of rebar:
  • Chemically active soil
  • Pollution
  • Industrial abuse (chemicals)
  • High relative humidity
  • Environmental attack
  • Cast in Chlorides
  • Chloride & Co2 induced
Solutions
  • Replacement of concrete after treating the rebars and passivation of steel
  • Coating of Concrete surface by penetrating Corrosion mitigating Impregnators
  • Insertion of Sacrificial Anodes
  • Impressed Current Cathodic Protection