CERTIFICATE
This is to certify that ________________ a student of class
_____________ has successfully completed the research on the
below mentioned project under the guidance of
__________________(subject teacher) during the session
_____________ in partial fulfilment of chemistry practical
examination conducted by AISSCE, New Delhi.
Signature of external examiner Signature of chemistry teacher
(PGT chemistry) (PGT chemistry)
Signature of the Principal
(PHD chemistry)
ACKNOWLEDGEMENT
In accomplishment of this project successfully,
many people have best owned upon me their
blessings and the heart pledged support, this
time I am utilizing to thank all the people who
have been concerned with the project.
Primarily i would thank God for being able to
complete this project with success. Then i would
like to thank my Principal _________________and
chemistry _________________(PGT chemistry)
whose valuable guidance has been the ones that
helped me patch this project and make it full
proof. Her suggestions and instructions has
served as the major contributor towards the
completion of the project.
AIM OF THE
EXPERIMENT
To study the setting of
mixture of cement with
sand, time and fly ash with
respect to time and strength.
1.
CERTIFICATE OF EXCELLENCE
2. ACKNOWLEDGEMENT
3. AIM OF PROJECT
4. INTRODUCTION
5. THEORY
6. APPARATUS REQUIRED
7.PROCEDURE FOLLOWED
8. OBSERVATION
9. CONCLUSION
10. PRECAUTIONS
INTRODUCTION
In the most general sense of the word, cement
is a binder, a substance that sets and hardens
independently and can bind other materials
together. The word cement traces to the
Romans who used the word opus
caementicium to describe masonry resembling
modern concrete that was made from crushed
rock with burnt lime as binder. The volcanic
ash and a pulverised brick additive that were
added to the burnt lime to obtain a hydraulic
binder were later referred to as cementum
cimentum, cament and cement.
The most important use of cement is the
production of mortar and concrete.
The bonding of natural and artificial
aggregates to form a strong building material
that is durable in the face of normal
environmental effects.
Portland cement
Cement is made by heating limestone (calcium
carbonate), with small quantities of other material,
like clay, to 1450 degree celcius in a kiln in a process
known as calcination, whereby a molecule of carbon
dioxide is liberated from calcium carbonate to form
calcium oxide or quicklime which is then blended
with other material that have been included in the
mix. The resulting hard mixture called clinker is then
ground with a small amount of gypsum into a powder
to make ordinary Portland cement(POC), the most
commonly used type. It is a basic ingredient of
concrete, mortar and non speciality grout. The most
common use of POC is in production of concrete.
Concrete is a composite material consisting of
aggregate (gravel and sand) cement and water.
Portland cement maybe grey or white.
CONSTRUCTION OF
BUILDINGS USING CEMENT
Cement used in constructions is categorised
as hydraulic or non-hydraulic .
Hydraulic cements harden because of
hydration reactions that take place
independently of the mixture’s water content;
they can harden even underwater or when
constantly exposed to wet weather. The
chemical reaction that results when the
anhydrous cement powder is mixed with water
produces hydrates that are non water soluble.
Non-hydraulic cements(lime and gypsum)
must b kept dry in order to retain their
strengths.
EFFECT OF QUALITY OF SAND ON
SETTING OF CEMENT MORTAR
Sand obtained from different sources has different
qualities. For example sea sand obtained from sea
contains unwanted sea salts and retards setting of cement
and is nor suitable for making mortar.
On the other hand, pit sand is obtained from pits in soil
and river sand is obtained from riverbeds is considered
excellent for preparing mortar and concrete.
EFFECT OF TIME ON SETTING OF
CEMENT MORTAR
Time has an important role on strength of
developed mortar. When a cement paste in
ratio 1:3 in water is allowed to dry, the
strength of solid mass keeps on increasing
with increase in time given for setting. It
acquires a nearly full strength in 28 days.
APPARATUS REQUIRED
PROCEDURE
1. Prepare mixtures of various compositions as
given in observation table.
2. Take each of the given mixtures in different
beakers and prepare their paste by adding
minimum amount of water.
3. Take 9 cases of empty boxes and mark them 1-9.
4. Fill three cases with paste of each composition.
5. Spray water time to time so that they remain
moist all the time.
6. After 3 days take out one slab of each
composition and test their strengths.
7. Similarly take out a set of 3 slabs after 7 days
and then after 30 days respectively and test
their strengths.
8. Record your readings in an observation table.
OBSERVATIONS
By seeing the observations we can estimate
the hardness of the slab.
CONCLUSION
The strength of slab increases with increase in setting time
allowed.
PRECAUTIONS
● Handle the glass wares carefully.
● Prepare the mixture in proper
ratios.
● Allow the time required to set.
● Spray only required amount of
water.
● Record your observations carefully.
RESOURCES
1. Internet
2. Information from library
3. Help from teachers
