This study investigated the effects of partially replacing cement with fly ash and coarse aggregate with rubber chips in concrete. Concrete mixtures were prepared with 0%, 10%, and 20% fly ash replacement of cement and 5% rubber chip replacement of coarse aggregate. Fresh and hardened properties were tested. Test results found that 5% rubber replacement slightly reduced compressive strength compared to normal concrete. However, increasing fly ash content from 10% to 20% improved mechanical properties of the rubberized concrete. Therefore, partial replacement of cement with fly ash and coarse aggregate with rubber chips has potential to produce concrete with comparable strength to normal concrete while utilizing waste materials.

1. BY (BATCH-7)
ABHISHEK.K(11241A0132)
REDDY PRASHANTH(12245A0117)
BHARADWAJ.S(11241A01A9)
MD.FAISAL FARZAN(11241A0195)
NITHIN REDDY.B(11241A0166)
PROJECT GUIDE:
Mr. V.MALLIKARJUNA REDDY
DEPARTMENT OF CIVIL ENGINEERING

2. The results of an experimental investigation to study the effects of partial
replacement of cement with flay ash in rubberized concrete. The
percentage of rubber used in this study was 5% replaced with coarse
aggregate and fly ash varies from 0-20% were replaced with cement in
conventional concrete. One size of tire rubber chips are used of about
10mm.The mix design was targeted to be M20 grade of concrete. The
mix proportion of concrete was 1:1.5:3 with water cement ratio of
0.45.The fresh and hardened properties of rubberized concrete produced
at two different replacements ratios of fly ash compared to the
conventional concrete without rubber and fly ash .The test result indicate
that there was a small reduction in the strength with the 5% replacement
in rubber content as compared with the conventional concrete. However,
the increase of fly ash from 10% to 20% improved the mechanical
properties of rubberized concrete. This study explores the effects of
rubber particles on some properties of concrete.
Key words: Fly ash, rubber, coarse aggregate, fine aggregate, cement

3.  Concrete is one of the main component in any concrete
masonry construction
 Concrete composes of cement ,fine aggregate, coarse
aggregate
 Researches have shown that these components can be
replaced to some extent by fly ash, rubber, plastic,
stone dust etc..,

4.  Waste or worn out rubber can be used as replacement
to the coarse aggregate to about 5% instead of
disposing it out as waste material (from "influence of
fly ash on mechanical properties of rubberized
concrete” by M.Mishra,K.C.Panda)
 Fly ash to be replaced to about 20% of cement.
 Studies are made on both fresh as well as hardened
properties of rubberized concrete and compare with
normal concrete.

5.  Growth of cement usage leads to the greater
production of CO gas which is one of the major cause
for GLOBAL WARMING
2

6. Excavation of sand and stones from river banks is one of
the main cause for disasters caused due to FLOODS

7.  Materials like rubber, fly ash, stone dust, waste
materials, etc.., Can be used to replace aggregates and
cement
 But these materials cannot be replaced fully but they
are partially replaced to about 5% to 20%(by “influence
of fly ash on mechanical properties of rubberised
concrete” by M.Mishra,K.C.Panda).
 Their strength would not be as high as the traditional
concrete but this can be used for domestic concrete
works.

8.  The disposal of waste or worn out tyres have become a
global problem
 It is a potential fire hazard and as well as health risks
due to growth of mosquitoes breed in stagnant water
which accumulates in tyres
 Rubber from scrap tyres is one of the most recent waste
materials investigated for its potential use in
construction industry

10. FLY ASH
 Fly ash is finely divided residue obtained from the
combustion of powdered coal
 CLASS F fly ash from thermal power plants collected
and is used for about 5%to 20%to replace cement.
 10% and 20% replacement of cement specimens have
been prepared.

11. WASTE TYRE RUBBER
 Bike tyre is trimmed into pieces of about 10 mm size by
means of wood cutter and by using knifes.
 This rubber would be used to replace for about 5% with
course aggregate(as per “influence of fly ash on
mechanical properties of rubberized concrete” by
M.Mishra,K.C.Panda.)
 Two waste bike tyres from nearby puncher shop has been
collected for the project

13. CEMENT
 Ordinary Portland cement (53 grade) Ultratech cement
is used
COARSE AGGREGATE
 Normal coarse aggregate of 20 mm size is used

14. FINE AGGREGATE
 River sand which is available locally is used as fine
aggregate for entire process

15. GRADE OF CONCRETE
 The mix is targeted for M20 grade(Nominal mix).
WATER-CEMENT RATIO
 Water-cement ratio is be taken as 0.45.

16. CONCRETE
MIX
PROPORTION
MIX IDENTITY NO. OF
SPECIMENS
Concrete mix with
100%NCA+100%ce
ment+0%rubber+
0%fly ash
CR0F0 6
95%NCA+90%cem
ent+5%rubber+10%
fly ash
CR5F10 6
95%NCA+80%cem
ent+5%rubber+20%
fly ash
CR5F20 6

17. MIX
IDENT
ITY
(kg)
NO.
OF
BLOC
KS
CEMENT
(kg)
SAND
(kg)
NORMAL
COARSE
AGGREGA
TE(NCA)
(kg)
RUBBER
CHIPS
(kg)
FLY
ASH
(kg)
WATER
(ml) (w/c
ratio
=0.45)
CR0F0 6 10 15 30 -- -- 4500
CR5F10 6 9 15 28.5 1.5(5%
replacem
ent of
NCA)
1(10%r
eplace
ment to
cement)
4500
CR5F20 6 8 15 28.5 1.5(5%
replacem
ent of
NCA)
2(20%
replace
ment to
cement)
4500

18.  FRESH CONCRETE TEST
Slump cone test
 HARDENED CONCRETE TEST
Compressive strength test

19. Slump cone test

20. S.NO MIX IDENTITY SLUMP
VALUE(mm)
1 CR0F0 45
2 CR5F10 40
3 CR5F20 43.5
Slump cone test values

21. Slump chart
3.6 3.8 4 4.2 4.4 4.6
CR0F0
CR5F10
CR5F20
SLUMP
SLUMP

22. Compressive strength test

24. MIX PROPORTION MIX
IDENTITY
AVERAGE COMPRESSIVE
STRENGTH
7 DAYS 28 DAYS
Concrete mix with 100% NCA
+ 100% Cement + 0% Rubber
chips + 0% FA
CR0F0 17.96 23.70
Concrete mix with 95% NCA
+ 90% Cement + 5% Rubber chips
+ 10% FA
CR5F10 15.23 19.04
Concrete mix with 95% NCA
+ 80% Cement + 5% Rubber chips
+ 20% FA
CR5F20 18.09 23.80
Compressive strength test results

25. 7 days
28 days
0
5
10
15
20
25
CR0F0 CR5F10 CR5F20
Compressive strength variation for 7 &28
days
(N/mm^2)

26.  The workability decreases when we replace coarse
aggregate with 5% rubber and cement by 10% fly
ash
 Again the workability increases as greater
percentage of fly ash increases the workability
 The strength of concrete decreases with increase in
percentage of fly ash first and again increases as
the percentage of fly ash increases.

27.  “Influence of fly ash on mechanical properties of
rubberized concrete” by M.Mishra,K.C.Panda.
 “Rubber tyre particles as coarse aggregate” by
N.N.Eldin ,A.B.Senouci ,journal of materials in
civil engineering,vol-5,pp.478-96.
 I.B.Topcu,(1995),”The properties of rubberized
concrete", cement concrete
research,vol.25(2),pp.304-310.
 A.Yilmaz&N.Degirmenci,(2009),”Possibility of
using waste tyre rubber and fly ash with Portland
cement concrete as construction materials", waste
managements,vol29(5),pp.1541-1546.