study on improving the weathering resistance of concrete by using rice husk ash

1. BY
AHMED ALI FAWAZ.K
ARAVINDRAJ .C.M
MAHESHWARAMOORTHI.M
PAVITHRAN.P
GUIDED BY
MR.SAKTHIVEL M ,
ASSISTANT PROFESSOR,
DEPARTMENT OF CIVIL ENGINEERING
KCG COLLEGE OF TECHNOLOGY

2. INTRODUCTION
Due to seasonal changes in concrete there will be alternate
shrinkage and swelling results in tensile crack followed by
strength reduction.
Generally pozzolanic materials are used to improve the
Weathering resistance.
List of Pozzolanas (Fly ash, Silica fume, Rice husk ash,
Metakaoline, Ground Granulated blast furnace slag) and its
properties are mentioned in IS456:2000 ( clause 5.2)
Problem description

3. ADVANTAGES OF USING RHA
 RHA makes a role to increased resistance to chemical attack
 Show better durability of concrete.
 Improves resistance to sulphate attack.
 Enhances workability of concrete.
 Reduces shrinkage due to particle packing, making concrete denser.
 Decreases permeability due to the filler and pozzolanic effect.
 Increases compressive strength.

4. FINALISATION OF ADMIXTURE
This pozzolana possess high impermeability factor.
Due to this the water absorption of concrete decreases
considerably.
60kg (approx) of waste Rice husk ash obtained while burning
250kg of rice husk obtained from 1ton of rice.
Risk husk ash is dumped in land in large amount as a waste
produced from rice mill, which is cheap and eco-friendly compared
to other admixtures, therefore we have used it as admixture.

5. OBJECTIVE
 To establish a eco-friendly and weather resisting concrete by
using Rice husk ash.
 To minimize the strength reduction of the concrete due to
weathering action.
 To decrease the permeability property of concrete
 To eliminate the tensile cracks due to weathering action

6. SCOPE OF THE PROJECT
The scope of the project can be summarized as:
 The final outcome of the project have an overall beneficial effect
on the utility of rice husk ash concrete in the field of civil
engineering.
 Reducing amount of cement, which in turn will reduces material
cost and emission of 𝑐𝑜2.
 Elimination of structural failure due to weathering action, thereby
saving the lives of people.

7. LITERATURE REVIEW
 In (1996) Ismail, M.S ; Waliuddin,A.M. has studied the effect of
rice husk ash on high strength concrete and they observed that
optimum replacement of cement by RHA was 10-20% maintaining
same value of workability
 In (1984) Dharam Paul has been studied in weathering of hardened
concrete causes and suggested remedies. Their experimental results
confirmed that the concrete suffer damages and consequently loses its
compressive strength to the extent of 30% to 40%. A richer concrete
with lower water-cement ratio and replacement of 20% cement by
weight with fly ash is shown to enhance the resistance of weathering.

8. LITERATURE CONCLUSION
 In (2006) D.V. Reddy has worked in research for replacement of
cement with RHA in part proportions. Their research has shown that
concrete made with RHA as a partial cement substitute to levels of
10% to 20% by weight of cement has superior performance
characteristics compared to normal concrete
 In (2009, 2010) A.A. Ramezanianpour, P.pourbiek,
M.Mahdikhani and F.Moodi has concluded that burning rice husk
at temperature below 700˚C produces rice husk ashes with high
pozzolanic activity.
Considering the above notes from literature review along with
advantages of Rice husk ash, we have decided to do a replacement
(in 10%, 20%, 30%) of cement to study the resistance of concrete
subjected to weathering action

9. Literature
review
Selection of
material
Mix design
Curing & weathering
comparison of strength
reduction
Results &
Documentation
METHODOLOGY
Casting of concrete
Testing on concrete
specimens
Problem
Identification

10. EXPERIMENTAL DETAILS
Physical properties
Rice husk ash
 Colour Grey
 Particle size 45micron
 Specific gravity 2.3
Cement
 Grade OPC 53 grade
 Fineness value 225m2/kg
 Setting time
 Initial 30min
 FINAL 600min
 Compressive strength 53N/mm2 in 28days
Concrete
 Grade M20

11. EXPERIMENTAL DETAILS
CASTING
CURING
RICE HUSK ASH

12. SPECIMEN DETAILS
Type of specimen Dimension in mm No. of specimen
Cube 150x150x150 42
Prism 100x100x500 24
Cylinder Dia.-150 height-300 24

13. COMPRESSION TESTING MACHINE

14. COMPRESSIVE STRENGTH
Curing 28days
Admixture
Compressive Strength (Mpa)
0cycle 15cycle 30cycle
0% 22.1 24.152 24.25
10% 20.885 29.662 35.77
20% 17.77 18.85 19.77
30% 15.44 14.94 14.44
0
5
10
15
20
25
30
35
40
0 15 30
compreessivestrength(Mpa)
No of cycles (days)
Compressive strength after 28days curing
0%
10%
20%
30%

15. SPLIT TENSILE TEST OF CRACK PATTERN
CYLINDER AS PER BIS OF CYLINDRICAL
NORMS SPECIMEN

16. SPLIT TENSILE STRENGTH
Curing 28days
Admixture
Tensile Strength (Mpa)
0cycle 15cycle 30cycle
0% 2.7 2.57 2.2
10% 2.96 2.91 2.82
20% 2.37 2.34 2.29
30% 1.92 1.81 1.73
0
0.5
1
1.5
2
2.5
3
3.5
0 cycle 15 cycle 30 cycle
Mpa
No of cycles
split tensile strength after 28days curing
0%
10%
20%
30%

17. FLEXURAL TESTING MACHINE

18. FLEXURAL STRENGTH
Curing 28days
Admixture
Flexural Strength (Mpa)
0cycle 15cycle 30cycle
0% 6.22 6.26 6.3
10% 5.04 5.68 6.2
20% 4.8 5.76 6.66
30% 4 4.3 4.6
0
1
2
3
4
5
6
7
0 15 30
Flexuralstrength(Mpa)
No of cycles (days)
flexural strength after 28days curing
0%
10%
20%
30%

19. RESULTS AND DISCUSSION
Curing Days
Percentage admixture
0% 10% 20% 30%
7 days 7.69 98.11 22.07 0
28 days 9.72 71.27 11.25 0
7.69
98.11
22.07
0
9.72
71.27
11.25
0
0
20
40
60
80
100
120
0% 10% 20% 30%
%increaseincompressivestrength
% Admixture
Compressive strength results after weathering
7 days
28days
COMPRESSIVE STRENGTH RESULTS AFTER WEATHERING

20. DISCUSSION ON COMPRESSION STRENGTH
RESULTS
The chart indicates the percentage increase in compressive
strength of the concrete containing 10%, 20%, 30% of RHA as part
replacement of cement. As per the reference journal Dharam paul
(1984) indicates that the compressive strength will increases upto 50
cycles of weathering period. The chart clearly shows that concrete
with 10% RHA has higher percentage (61%) of increase in strength
over the weathering period, when compared to the conventional
concrete. For 20% replaced RHA the increase in strength is 11%, so
for nominal and environmental usage 15% replacement of RHA can
be used to obtain the optimum compressive strength due to
weathering process.

21. RESULTS AND DISCUSSION
Curing Days
Percentage admixture
0% 10% 20% 30%
7 days 6.7 0.7 0.44 0.67
28 days 18.5 3.09 2.13 4.41
SPLIT TENSILE STRENGTH RESULTS AFTER WEATHERING
6.7
0.7 0.44 0.67
18.5
3.09
2:13
4.41
0
2
4
6
8
10
12
14
16
18
20
0% 10% 20% 30%
Percentage
Admixture
Percentage decrease in split tensile
strength
7 days
28days

22. DISCUSSION ON SPLIT TENSILE
STRENGTH RESULTS
The chart indicates the percentage decrease in the split tensile
strength. concrete cylinders with 20% replaced RHA shows least
percentage decrease (2.3%) and 10% RHA shows 4% reduction in
strength . when compared to the conventional concrete , the
reduction in split tensile strength decrease with the replacement of
RHA from 10%- 20% . This is due to the least formation of tensile
cracks in the concrete over the weathering period. We suggest to use
15% RHA as replacement of cement to restrict the reduction in
strength due to weathering.

23. RESULTS AND DISCUSSION
Curing Days
Percentage admixture
0% 10% 20% 30%
7 days 1.66 17.6 126 85
28 days 1.28 23.01 38.75 15
FLEXURAL STRENGTH RESULTS AFTER WEATHERING
1.66
17.6
126
85
1.28
23.01
38.75
15
0
20
40
60
80
100
120
140
0% 10% 20% 30%
%increaseinflexuralstrength
% Admixture
flexural strength results after weathering
7 days
28days

24. DISCUSSION ON FLEXURAL STRENGTH
RESULTS
The chart shows the percent increase in flexural strength
increase with the addition of RHA upto 20% replacement of cement.
The maximum flexural strength(39%) has obtained by the addition
of 20 % of RHA . The flexural strength normally increases by
addition of reinforcement bars in the structure. concrete structure
with 15% replacement of cement with RHA will promotes better
increase in flexural strength and the abrasion of concrete will
gradually decreases due to weathering.

25. CONCLUSION
On the basis of the results obtained, its is indicated that the
rice husk ash shows good weathering resistance at the replacement
of 20% and the reduction in tensile strength of concrete is decreased
up to 15%, whereas compressive and flexural strength increases up
to 71% and 39% respectively with the replacement between 10% to
20%. Therefore optimum weathering resistance can be obtained by
replacing 10% to 20% of cement by the Rice husk ash.

26. THANK YOU