hardened_concrete

Hardened Concrete
Properties

Hardened Concrete
Properties

 It is important for the engineer to
understand the basic properties of hardened
concrete and be able to evaluate these
properties.

 The main properties of hardened concrete
are compression strength, tensile/bending
strength, durability strength, permeability,
Resistant to weather and chemical reaction,
deformation, shrinkage, creeping and fire
resistant

1)Compressive Strength

 Compressive strength is the capacity of a
material or structure to withstand axially
directed pushing forces

 Measured in Mega Pascal(Mpa) or kn/mm²
 Compressive strength is one of the main

structural design requirement to ensure the
concrete structure will able to carry the
intended load

Compressive strength test

Tensile and flexural strength

 It is the ability of a concrete to resist failure
in tensile and flexural

 Also measured in Mega Pascal(Mpa) or
kn/mm²

 Concrete are weak in tensile strength
 Tensile strength of a concrete usually is

1/10 from its compressive strength

flexural strength test

Durability Strength

 Resistance to weathering, chemical,
freezing and fire attack.

 Depends a lot on the density of concrete
 Concrete cover thickness affect the

durability properties.
 Resulting crack and rebar Corrosion

Permeability

 Permeability is an important factor that
largely affects the durability of hardened
concrete.

 Permeable concrete allows water and
chemical to penetrate and attacks the
concrete and reinforcement steel.

Resistant to weather and
chemical reaction

 Concrete can be exposed to weather and
chemical attacks within time.

 Concrete structure especially located at food
process industries such as vinegar factories
are exposed to chemical attack.

 Dense concrete have high ability to
withstand chemical and weather attack

Deformation ( ubah bentuk)

 Concrete like the other material is exposed to expansion
and contraction due to weather changes

 Concrete will expand when it is wet or the temperature is
in cold and high humidity

 Concrete will shrink/contract when it dries or the
temperature is high

 Concrete is also exposed to warping due to weather
changes.

Creep ( keterikan)

 Creep is defined as the gradual increases in
strain within time under sustained load

 Creep of concrete is a long term process and
it takes places over many years.

Creep in Concrete

Creep in Concrete

water

Creep

Consequences of creep

 Loss in pre-stress
 possibility of excessive deflection
 stressing of non load bearing members

Fire Resistant

 Concrete has a high degree of fire resistance and,
in the majority of applications, can be described as

 fireproof when properly designed. Concrete is a
very effective fire shield. The mass of concrete
confers

 a high heat storage capacity. Also its porous
structure provides a low rate of temperature rise
across a section.

 These properties result in a low rate of
temperature rise that enables concrete to act as an
effective fire shield.

Fire Resistant