Super plasticizers are high range water reducing admixtures that can reduce the water content of concrete by 30% or more. They allow for production of highly workable, self-leveling, and self-compacting concrete while also increasing strength. Super plasticizers are chemically different than normal plasticizers and make it possible to use water-cement ratios as low as 0.25. They disperse cement particles better than normal plasticizers, producing more fluid concrete at lower water-cement ratios and strengths. Compatibility between super plasticizers and cement can vary, and field tests are needed to determine the optimum dosage.

1. Super Plasticizers
B.Joy Dason 19PA1A0107
Ch.Manikanta 19PA1A0115
K.jagadeesh 19PA1A0122
K.V.N.S.Vamsi 19PA1A0128
P.Vinod Kumar 19PA1A0142
V.Tarun Satya Kumar 19PA1A0151
P.M.S.N.Srinivas 20PA5A0105
II-II Civil
Vishnu Institute Of Techonology

2. Super plasticizers
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Super Plasricizers are high Water range reducing
Agents are additives used in making high strenght to
Concrete
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Super Plasticizers allow reduction of water content
by 30% or More
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It is improved version of Plastizers which was
developed in Japan and Germeny in 1960 to 1970

3. ●
It gives Production of flowing,self levelling,and
self compacting .
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Production of high strength and high
performance of Concrete.
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They are Chemically different from normal
Plasticizers .

4. ●
With Super plasticizers It is possible to use w/c
as low as 0.25 or even lower .
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Use of Super Plasticizer – fly ash, slag and
particularly Silica fume to make high
performence Concrete .
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Super Plasticizers are more powerful as
despersing agents and they are high range
water reducers .

5. Super Plasticizers can produce
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At the w/c Ratio much more workable concrete
than the plane ones .
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For the same worability,it permits the use of lower w/c
ratio .
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As a consequence of incresed strength with lower w/c
ratio ,it permits reduction of cement
content .

6. Classification of superplasticizer
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Sulphonated melamine – formaldhyde condensates
( S M F ) .
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Sulphonated naphthalene – formaldehyde condensates
(S N F )
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Modified lignosulphonates ( M L S )

7. Effects
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No dramatic improvement in workability-zero
slump .
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Initial slump of about 20 mm to 30 mm fludized
by super plastizers at normal dosages .
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High dosage is required to fluidify no slump
concrete .

8. Compatibility of superplasticizers
and cement
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It has been noticed that all superplastizers are not
showing the some extent of improvements in fluditity
with all types of cements .
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Some of the superplastizers may show higher
fludising effect on the some type of cement than
other cement .
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Compatibility problem looks like very complex .

9. Field tests to determine optimum
dosage of the superplastizer
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Marsh cone test
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Mini slump test
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Flow table test

10. Marsh cone test
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Marsh cone is a coniacal brass vessel,which has a smooth aperture at
the bottom of diameter 5 mm.
Procedure :
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Take 2kg cement,proposed to be used at the project.
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Take 1 liter of water (w/c = 0.5 ) and say 0.1% of plasticizer .
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Mix them thoroughly in a mechanical mixer for 2 min .
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If hand mixing is done, the slurry sholud be sieved throgh 1.18
sieve to exlude lumps.

11. ●
Take 1 liter slurry and pour it into marsh cone duly closing the
aperture with a finger.
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Start a stop and simultanesusly remove the finger .
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Find out the time taken in seconds,for complete flow out the slurry.
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The time in seconds is called the “Marsh cone” .
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Repeat the test with different dosages of plasticizers.
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The dose at which the marsh cone of time is lowest is called the
“saturation point ” .

12. Effect of superplasticizer on the
properties of hardened concrete
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Since plasticizers and super plasticizers improve the workability and
facilitate reduction on w/c ratio,and thereby increase the strength of
concrete .
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Hence the use of superplasricizers is a pragmatic step to improve all
round properties of hardened concrete.
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No bad effect upto only 3% by weight of cement .
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Only if the bad quality lignosulphonate based plasticizers .

13. Factors effecting the workbility
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Type of superplasticizers
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Dosage
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Mix composition
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Mixing procedure
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Equipments
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Others

14. Site problems in the use of
superplasticizers
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Slump of reference mix .
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Problem with crusher dust and dust .
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Compatibility with cement .
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Slump loss .
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Finishing .
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Removal of form work.