shanke-1314是什么意思啊
The durability
of concrete
In civil engineering,
concrete is the most widely used and the amount of
one
of
the
largest
building
materials.
Over
the
past
century,
the
concrete
strength
to
continuously
improve
its
main
development
trends.
China's
large
population,
the
urgent need for ural Design not only to
meet the requirements of safe
and
reliable indicators, but also consider the
durability requirements.
The durability of concrete
issues,
refers to the structure in the
environment
and cause long-term
evolution of the structure due to internal or
external reasons, the
concrete
has
to
lose
the
ability
to
use.
That
for
durability
failure,
the
durability
of
many reasons, have antifreeze failure,
failure of alkali - aggregate reaction, chemical
corrosion
failure.
Part
of
the
concrete
structure
in
the
environment
below
freezing,
water in the pores
will freeze, resulting in volume expansion of cold
water migration,
the formation of
various pressures, when the pressure reaches a
certain level, resulting
in
the
destruction
of
the
-
aggregate
reaction
of
concrete
chemical
reactions that occur by the active
component of the alkali in the concrete
aggregates,
causing the expansion of
the concrete, cracking, or even destroy. Response
factors in
the concrete, and its
harmful effects are often not the root of the rule
is a big hidden in
the concrete works.
Concrete structures in aggressive media
environment, will cause
the cement
paste to a series of chemical, physical, and
materialized change gradually
been
eroded,
cement
strength
to
reduce
serious,
as
well
as
destruction.
In
concrete
engineering in
order to meet the requirements of concrete
construction work, that is,
water
consumption,
water-cement
ratio
is
high,
resulting
in
high
porosity
of
the
concrete, durability reduce. Also, the
lack of hydrate stability in the cement paste will
have
an
impact
on
the
durability.