Shortnotes of PCC and RCC

Plain concrete and reinforced concrete

In this article we discuss some basic not points of plain concrete and reinforced concrete

Plain Concrete

Plain concrete is a combination  of sand, gravel, cement, and 
water which results in a solid mass. 
Concrete is strong in compression but weak 
in tension. Its tensile strength is approx, 
one tenth of compressive strength. Plain 
concrete is mostly used in mass concrete 
work. (As in dams)

REINFORCED CONCRETE

1) It is a concrete with reinforcement
embedded in it. The embedded
reinforcement makes it capable of
resisting tension also.
2) Steel bars embedded in the tension
zone of concrete, relieves concrete of
any tension and takes all tension
without separating from concrete.
3) The bond between steel and
surrounding concrete ensures strain
compatibility i.e., the strain at any point
in the reinforcement bars  is equal to  the
adjoining concrete.
4) Reinforcing steel imparts ductility to
concrete which is otherwise brittle
material.
(5) Here ductility means large deflection 
owing to yielding of steel, thereby 
giving ample warning of impending 
collapse.
6) Tensile stress in concrete arises on
account of direct tension, flexural
tension, diagonal tension (due to shear),
temperature and shrinkage effect,
restraint to deformation.
7) Under these conditions, reinforcements
must be provided across potential
tensile crack.