2. CONTENTS
MATERIALS FOR REPAIR
Types
Applications
SURFACE COATING
What is surface coating?
Essential parameters for coatings
Types of surface coatings
Various types of coatings & their performance
characteristics
POLYESTER RESINS
What is polyester resins ?
Properties of polyester resins
3. MATERIALS FOR REPAIR
TYPES APPLICATIONS
Premixed Cement
concrete/mortars
Polymers/latex
modified cement
additives for
mortars/concrete/ceme
nt slurry
Epoxy resins
Chemicals for
corrosion inhibitor,
removal of rust
Materials for Surface Preparation
Chemical Rust removers for
corroded reinforcement
Passivators for reinforcement
protection
Bonding Agents
Structural Repair Materials
Non-structural Repair Materials
Injection grouts
Joint sealants
Surface coatings for protection of
RCC
4. WHAT IS SURFACE COATING?
Surface coating are referred as resurfacing
materials and toppings. Protective coatings
can greatly reduce the effect of deteriorate
conditions, and significantly improve the
durability characteristics of the concrete. A
variety of coatings are available and some are
tailored for greater chemical resistance, while
others are to resist wear and erosion.
5. ESSENTIAL PARAMETERS FOR
COATINGS
Protective coatings over structural concrete should
necessarily possess following properties:
Posses excellent bond to substrate
Be durable with a long useful life normally 5
years.
Little or no colour change with time.
Little or no chalking.
Should have maximum permeability to allow
water vapour escape from concrete substrate.
Should have sufficient impermeability against the
passage of oxygen and carbon dioxide from air
to concrete.
Should be available in a reasonable range of
attractive colours.
6. TYPES OF SURFACE COATINGS
The surface coating could be classified as :
Solvent based coatings
Solvent free coatings
Water borne coatings
Reinforced coatings (preferred for repairing
Badly damaged liquid Retaining structures)
SOLVENT
BASED
SOLVENT
FREE
WATER
BASED
REINFORCED
7. VARIOUS TYPES OF COATINGS & THEIR
PERFORMANCE CHARACTERISTICS
COATING
TYPE
CHARACTERISTIC
Chlorinated
rubber coatings
Resistant to heat, sunlight and weather, moderately
resistant to acids, alkalis. Not recommended for
immersed conditions. Adhesion to concrete is good.
Acrylic coatings Higher permeability, a life of three years may be
possible
Polyurethane
coatings
Excellent UV resistances abrasion and cracking
resistance, has high elasticity and resistance to
biological department.
Bitumen or tar
products
Provide excellent protection; however aesthetics is
affected
Polyvinyl butyrol Outstanding abrasion, resistance, toughness, flexibility,
water and heat resistance
Neoprene Excellent weather resistant
8. POLYESTER RESINS
First let us understand Resin Mortars:
For relatively smaller repair areas, cover less
than 12mm Resin Mortars are used.
In this case protection to steel reinforcement
depends on total impermeability.
Resin Mortar = Reactive Resin + Graded
aggregate.
Commonly used Resins: Epoxy, Polyester,
Acrylic.
These are Thermosetting Resins (they do not
melt or flow like thermoplastics when heated, but
lose strength gradually).
Resin mortars are supplied as 2/3 component
systems: Resin, Hardener & Filler.
9. WHAT IS POLYESTER RESINS ?
Polyester resins are unsaturated synthetic resins
formed by the reaction of dibasic organic acids
and polyhydric alcohols.
Unsaturated polyester resin is a thermoset,
capable of being cured from a liquid or solid state
when subject to the right conditions.
There are two principle types of polyester resin
used as standard laminating systems in the
composites industry.
Orthophthalic polyester resin is the standard
economic resin used by many people.
Isophthalic polyester resin is now becoming the
preferred material in industries such as marine where
its superior water resistance is desirable.
10. PROPERTIES OF POLYESTER
RESINS
Most polyester resins are viscous, pale coloured
liquids consisting of a solution of a polyester in a
monomer which is usually styrene.
Polyester resins can be moulded without the use
of pressure and are called 'contact' or 'low
pressure' resins.
Polyester resins have a limited storage life as
they will set or 'gel' on their own over a long
period of time.
Polyester resin requires the addition of several
ancillary products like Catalyst, Accelerator &
Additives .
11. PROPERTIES OF POLYESTER
RESINS
Polyesters offer ease of handling, low cost,
dimensional stability, as well as good
mechanical, chemical-resistance and electrical
properties.
Polyester resins are the least expensive of the
resin options, providing the most economical way
to incorporate resin, filler and reinforcement.