What is meant by curing of concrete,
what is mean by curing?
what is mean by curing?
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| Curing |
The
maintaining of an adequate amount of moisture content and temperature in
concrete at early ages so that it can provide or give the properties the
mixture was design to achieve. Curing begins immediately after RCC or PCC
work and finishing so that the concrete may develop the desired
strength and durability. It is very important step in building a structure. Because
without curing the concrete doesn’t achieve its full strength. So the strength
of concrete is decreased without curing.
Curing period is generally having minimum seven days for
all member.
all member.
Curing Time of
Concrete
Concrete
Curing of cement concrete is defined as the
process of maintaining the moisture and temperature conditions of concrete for
hydration reaction to normally so that concrete develops hardened properties
over time. The main components which needs to be taken care are moisture, heat
and time during curing process.
process of maintaining the moisture and temperature conditions of concrete for
hydration reaction to normally so that concrete develops hardened properties
over time. The main components which needs to be taken care are moisture, heat
and time during curing process.
Purpose
of curing/Curing of cement concrete is required for the following reasons:
of curing/Curing of cement concrete is required for the following reasons:
- When most people think of curing, they think only of
maintaining moisture on the surface of the concrete. But curing is more
than that—it is giving the concrete what it needs to gain strength
properly. - To prevent the concrete to dry out prematurely due
to solar radiation and wind. This prevents plastic shrinkage of concrete. - It helps to maintain the concrete temperature by
allowing the hydration process. Hydration process requires water to carry
on and releases heat. - Curing helps the concrete to harden and bond with
internal materials and reinforcement. This helps to prevent damage to bond
between concrete and reinforcement due to vibration and impact. - This helps development of
impermeable, crack free and durable concrete.
Time
of concrete curing
of concrete curing
The time to start curing of concrete depends
upon the environmental condition on the evaporation rate of moisture from the
concrete. The evaporation rate is influenced by wind, radiant energy from
sunshine, concrete temperature, climatic conditions, relative humidity. Curing
may start 5 hrs after casting concrete on site.
upon the environmental condition on the evaporation rate of moisture from the
concrete. The evaporation rate is influenced by wind, radiant energy from
sunshine, concrete temperature, climatic conditions, relative humidity. Curing
may start 5 hrs after casting concrete on site.
The evaporation of moisture is driven by the
difference in vapor pressure on concrete surface and the in surrounding air.
When the difference is high, evaporation rate is high.
difference in vapor pressure on concrete surface and the in surrounding air.
When the difference is high, evaporation rate is high.
Bleeding
of Concrete:
of Concrete:
When the concrete placed on the site and compacted
on its line and level, after some time bleeding occur. Bleeding means water
rises above the surface of the concrete due to many reasons but the main reason
is settlement of concrete. But the rate and duration of bleeding depends upon
the many factors which is mix proportion, thickness, workmanship, water cement
ratio, height of free fall of concrete etc.
on its line and level, after some time bleeding occur. Bleeding means water
rises above the surface of the concrete due to many reasons but the main reason
is settlement of concrete. But the rate and duration of bleeding depends upon
the many factors which is mix proportion, thickness, workmanship, water cement
ratio, height of free fall of concrete etc.
After getting bleed and sun light fall on
that bleeding its evaporate form the surface, when all the bleeding water are
evaporate form the surface and the concrete getting start drying, that time we
provide fresh water to prevent from plastic shrinkage cracks this the initial curing
that bleeding its evaporate form the surface, when all the bleeding water are
evaporate form the surface and the concrete getting start drying, that time we
provide fresh water to prevent from plastic shrinkage cracks this the initial curing
The initial curing of concrete is done by
many method that is to provide sunshades, fogging etc.
many method that is to provide sunshades, fogging etc.
Concrete
curing depends upon:
curing depends upon:
- It depends
upon to prevent plastic shrinkage, temperature control, strength and
durability of concrete, - It depends
upon the size of structural member, - It depends upon the type of concrete grade, type of
cement and rate of hardening of concrete, - It depends
upon the exposure conditions of the concrete surface during and after
curing, - It depends
upon temperature and moisture on surrounding environment,
Method of Curing:
There are various method of curing some of them are given
below but the main concern of curing is to reduce the heat of hydration and the
temperature should kept minimum and the water loss should be prevented.
below but the main concern of curing is to reduce the heat of hydration and the
temperature should kept minimum and the water loss should be prevented.
1. Ponding with water
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| Curing on slab |
2. Covering with wet jute bag
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| Curing with Jute in Column |
3. Continuous sprinkling/spraying
of water
of water
4. Chemical curing : It is
for desert where water is not available
for desert where water is not available
The Indian Standard IS 456 – 2000 says
that curing duration of concrete must be at least
that curing duration of concrete must be at least
7 days -in case of ordinary Portland cement,
at least
at least
10 days -for concrete with mineral admixtures
or blended cements
or blended cements
It also recommends that the
curing duration should not be less than 10 days for concrete exposed to dry and
hot weather conditions and 14 days for concrete with mineral admixtures or
blended cement in hot and dry weather.
curing duration should not be less than 10 days for concrete exposed to dry and
hot weather conditions and 14 days for concrete with mineral admixtures or
blended cement in hot and dry weather.
References:
- IS 456 – 2000 : Indian Standard
Code of Practice for Plain and Reinforced Concrete
tags : What is meant by curing of concrete?
What is meant by curing of concrete, what is mean by curing?
Method of Curing