marsh cone test concrete technology

1. DETERMINATION OF
ADMIXTURE DOSAGE BY –
MARSH CONE TEST

2. Admixture
What is an admixture ?
A material other than
cement
water
aggregate

3. HISTORY
 History of admixtures is as old as the history of
concrete it embraces a very vast field .
 Specially developed in Japan and Germany
around 1970
 Later on they were made popular in USA and
Europe
 Unfortunately the use of plasticizer and super
plasticizer have not become popular in India till
recently (1985)

4. Recent advances and
challenges in concrete
technology
High quality concrete : HSC and HPC
chemical admixture : Super plasticizer
to provide the desired properties.
However, variations in the
characteristics of Cement and type and
dosage of admixture compromises
benefits of super plasticizer due to
incompatibility problems.

5. TYPES OF ADMIXTURES
Admixture
Chemical
admixture
Plasticizer
Super plasticizer
Accelerators
Set retarders
Mineral
admixture
Blast furnace slag
Flyash
Silica fume
Rice husk

6. OUR INTERSET OF STUDY
Super plasticizer

7. STUDYOFTHECOMPATIBALITY
OPTIMUMSUPERPLASTICIZERDOSAGE
COST-BENEFITCONSIDERATION
SELECTION OF THE SUPER
PLASTICIZER

8. Factors affecting cement
-superplasticizer intereaction
Direct effect :
Rate of hydration reaction
Solubility of calcium sulphate
Absorption of superplasticizer

9. HOW MUCH QUANTITY OF
SUPER PLASTICIZER TO USE
?

10. MARSH CONE TEST :EVALUATION
OF THE OPTIMUM DOSAGE

11. i. 70% of mixing water is
added with cement
ii. Superplactisizer and
remaining water added after
one minute
iii. Mix for two minutes at same
speed
iv. Then pass cement slurry
through the funnel
simultaneously note time
MIXING
SEQUENCE

12. CASE STUDY
 Different types of cement
 OPC
 PPC
 Super plasticizer -
POLYTANCRETE
 Different dosage
 0.1 to 0.5

13. Procedure
i. As per IS code 2kg of cement- Marsh cone test
and w/c ratio is 0.4
i.e Cement = 2kg
Water quantity = 2000X 0.4 = 800 g = 800ml
ii. Super plasticizer dosage is varied from 0.1 to
0.5
iii. Slurry is prepared
iv. The prepared slurry is passed by the marsh
cone test and the time passing the cone is
noted as t sec.
v. A graph is plotted dosage in % versus Marsh
time (sec)

14. LAB TRIALS

15. OBSERVATION TABLE 1
TYPE OF
CEMENT
W/C
RATIO
QTY. OF
CEMENT
DOSAGE
OF
SUPERPLASTI
CIZER
IN “ %”
MARSH
TIME
OPC 0.4 2 KG 0.2 3’46”
OPC 0.4 2 KG 0.25 3’10”
OPC 0.4 2 KG 0.3 1’ 39”
OPC 0.4 2 KG 0.35 1’ 30”
OPC 0.4 2 KG 0.4 1’ 16”
OPC 0.4 2 KG 0.425 1’1”
OPC 0.4 2 KG 0.45 1’0”

16. OBSERVATION TABLE 2
TYPE OF
CEMENT
W/C
RATIO
QTY. OF
CEMENT
DOSAGE
OF
SUPERPLA
STICIZER
IN “ %”
MARSH
TIME
PPC 0.4 2 KG 0.2 2’ 16”
PPC 0.4 2 KG 0.25 1’ 48”
PPC 0.4 2 KG 0.3 1’09”
PPC 0.4 2 KG 0.35 1’ 09”
PPC 0.4 2 KG 0.4 14”
PPC 0.4 2KG 0.425 8”

17. OBSERVATION
 From Graph - zone of
saturation dosage of
0.425%and 0.35% for
OPC and PPC
respectively.
 After a sudden change
in the time and the
constant value of time
shows optimum
dosage of super-
plasticizer
0
20
40
60
80
100
120
140
160
180
200
220
240
0 0.1 0.2 0.3 0.4 0.5
TIMEINSEC
DOSAGE in %
OPC
PPC

18. RESULT
i. The optimum dosage of
polytancrete SPR Superplasticizer
for OPC cement is between 0.425
to 0.45%
ii. The dosage of polytancrete for
PPC cement is between 0.3 to
0.35%

19. CONCLUSION
From this case
study it is
concluded that
the % of dosage
of same
plasticizer for
different type of
cement having
same w/c ratio
is
DIFFERENT.
%
dosage
MARSH
TIME
OPC
MARSH TIME
PPC
0.2 3’46” 2’ 16”
0.25 3’10” 1’ 48”
0.3 1’39” 1’ 09”
0.35 1’25” 1’ 09”
0.4 1’16” 14”
0.425 1’01” 8”