Binding materials, properties, types and uses

2. Binders are substances that are
used to bind inorganic and
organic particles and fibers to
form strong, hard and/or flexible
components.

3. The binding action is generally
due to chemical reactions
which take place when the
binder is heated, mixed with
water and/or other materials, or
just exposed to air.
just exposed to air.

5. There are three main groups of binders: -
1. Mineral binders
2. Bituminous (Asphalt)binders
3. Synthetic binder

7. Non-hydraulic binders are only harden in
the presence of air
The most common non-hydraulic binder is:-
A. Lime. B. Gypsum
Hardening of non-hydraulic binder/lime
Hardening of non-hydraulic binder/lime
depends on its combination with carbon
dioxide from the air (carbonation), by
which it again becomes calcium
carbonate (limestone).

8. By gentle heating up to about the boiling
point of water, calcium sulphate hemi-
hydrate (CaSO4 .1/2H2O) is produced,
more commonly known as "Plaster of Paris",
more commonly known as "Plaster of Paris",
which when mixed with water sets in 10
minutes.
The common name for calcium sulphate
hemihydrates is known as Plaster of Paris

9. Hydraulic binders require water to
harden and develop strength.
The most common hydraulic binder
is Portland cement.
is Portland cement.
Hydraulic binders are usually
available in the form of a fine
powder. Why?

10. On account of their affinity to
water, hydraulic binders must be
stored in absolutely dry conditions.
Why?
Answer:- to avoid premature
setting and hardening (pre-
setting and hardening (pre-
hydration and carbonation).
Even humid air can cause
hydration

11. "Asphalt" is a dark brown to black,
highly viscous, hydrocarbon
produced from petroleum
distillation residue.
This distillation can occur naturally,
This distillation can occur naturally,
resulting in asphalt lakes, or occur
in a petroleum refinery.

13. Synthetic binders are generally
produced by industrial
processes.
They can either be used as
They can either be used as
adhesives or as surface
coatings and are either
applied hot, or as an emulsion,
or with a solvent.

14. Synthetic admixtures which
bind loose particles together
are mainly resins derived from
plant materials or mineral oil.
Adhesives are used to stick
Adhesives are used to stick
larger particles, components,
membranes, sheets, boards,
tiles, etc. on another surface.