2. R.C.C. (Reinforced Cement Concrete) : Concrete is good in resisting compression but is very
weak in resisting tension. Hence reinforcement is provided in the concrete wherever tensile stress
is expected.
The best reinforcement is steel, since tensile strength of steel is quite high and the bond between
steel and concrete is good. As the elastic modulus of steel is high, for the same extension the
force resisted by steel is high compared to concrete.
3.
4. Cement - A cement is a binder, a finely powdered mixtures of inorganic compounds that sets and
hardens and can bind other materials together when combined with water.
Cements used in construction can be characterized as being either hydraulic or non-hydraulic,
depending upon the ability of the cement to be used in the presence of water.
Non-hydraulic cement, referred to as mortar, is a lime based paste that will not set in wet
conditions or underwater, it sets as the cement dries and reacts with carbon dioxide in the air.
5. Hydraulic cement is made by replacing some of the cement in a mix with activated aluminium
silicates, pozzolanas, such as fly ash, Blast-furnace slag etc. This allows setting in wet condition
or underwater.
All Portland cements are hydraulic cements. Hydraulic cements are sometimes referred to as
being “water resistant” because they can cure in wet or submerged environments and do not
deteriorate with contact with water.
6. Portland Cement - is the most common type of cement in general use around the world, used as
a basic ingredient of concrete, mortar, stucco, and most non-specialty grout.
Typical constituents of Portland clinker plus gypsum:
Clinker Notation Mass %
Tricalcium silicate (CaO)3 · SiO2 C3S 45–75%
Dicalcium silicate (CaO)2 · SiO2 C2S 7–32%
Tricalcium aluminate (CaO)3 · Al2O3 C3A 0–13%
Tetracalcium alumino ferrite
(CaO)4 · Al2O3 · Fe2O3 C4AF 0–18%
Gypsum CaSO4 · 2 H2O 2–10%