reinforced concrete

area of bar 

Ab

Dead Load

D

diameter of aggregates

dagg

diameter of bar

db

Earthquake Load

E

modulus elasticity of steel

Es

specified compressive stress of concrete

fc’

specified yield strength of steel

fy

Live Load

L

Wind Load

W

Concrete

is a mixture of sand, gravel, crushed rock, or other aggregates held together with a paste of cement and water.

sand, gravel, crushed rock, or other aggregates held together with a paste of cement and water

mixtures of a concrete

mud

impurity on gravel

silt

impurity on sand

oil

impurity on water

impirical

 formulas derived from experimentation

math and physics, high compressive strength, weak in tension, not exact science

about concrete

3000 psi

strength of concrete

1:2:4 CSG

3000 psi mixture

20KG

40 KG OF CEMENT = ____ OF WATER

RETARDER

DELAY SETTING OF CONCRETE

CONCRETE ADDITIVES

HIGH EARLY STRENGTH

PLASTICIZER

INCREASE WORKABILITY OF CONCRETE

UNIVERSAL TESTING MACHINE

USE TO CHECK CONCRETE CYLINDER

Reinforced concrete

is a combination of concrete and steel wherein the steel reinforcement provides the tensile strength lacking in the concrete.

concrete and steel

reinforced concrete combination

3/4

aggregate occupies ____ of concrete volume

sand

fine aggregates

gravel

coarse aggregates

Aggregates

used in concrete occupy about three-fourths of the concrete volume

Aggregates

less expensive than the cement, it is desirable to use as much of them as possible

Fine aggregates

aggregates that passes on no. 4 sieve (6mm size)

greater than 6mm or no.4 sieve

size of coarse aggregate

water

used in mixing concrete shall be clean and free from injurious amount of substances

oils, acids, alkalis, salts, organic materials

injurious amount of substances such as:

strong in compression, great resistance on fire and water, very rigid, low maintenance, long service life, widely available, can be cast into variety of shapes

advantages of reinforced concrete

very low tensile strength, mixing and proportions, relatively low strength per unit weight

disadvantages of reinforced concrete

THE NATIONAL STRUCTURAL CODE OF THE PHILIPPINES

NSCP MEANS