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Characteristics of self- compacting concretes with tire rubber
wastes
Prepared by: NAHLA N. HILAL
Supervisor:Assoc.Prof.Dr.Erhan
GÜNEYISI
January 2016
1987

Self-compacting concrete (SCC) can be placed and consolidating
under its own-weight without any mechanical vibration.
Advantages of (SCC)
Greater strength,
 rapid construction,
 better quality and stability,
 reduced problems related with vibration and
 low noise-level in the construction sites and plants.
Introduction
Rubberized concrete
When a portion of the fine or coarse aggregate is replaced with
rubber scraps, we are gain the rubberized concrete, comparison
with traditional concrete, the rubberized concrete is found to
be cheap and resists more temperature.

Rubber tyre recycled carbon
black feedstock
industrial floorings
Fuel for cement kilns

In marine environments as reefsRubber scraps in parks
Recycled tire rubber as partial aggregate in concrete

AIM OF THE THESIS
 The main objective of the thesis is to investigate ‘The properties of the
self compacting concretes made with fly ash and tire waste’. For this
purpose, an experimental program was conducted in two stages
 The first part covered the sieving of scrap tire rubber to three sizes
(FCR, CCR,MCR and Tire chip) and found specific gravity for each
type.
 The second part of the thesis included the production of the self-
compacting rubberized concretes (SCRC), and testing of fresh and
hardened properties.

MATERIALS
 CEM I 42.5 R ordinary Portland cement.
 Class F type fly ash
 Superplasticizer(Glenium 51).
 A mixture of natural sand and crushed sand was incoporated in
the concrete production as well as natural coarse aggregate.
 Two types of scrap tire rubber, crumb rubber (CR) and tire chips
(TC) came from used truck tires castaway after a second
recapping were utilized.
 Steel bar with 16 mm and length 500 mm.

The photographic views of No.18 and No.5 crumb rubbers and tire chips

Mixes Cement Fly Ash Water SP NS CS NG FCR CCR TC
Control 364 156 182 3.38 573.57 245.81 819.38 0.00 0.00 0.00
FCR5 364 156 182 3.64 544.89 233.52 819.06 7.94 0.00 0.00
FCR10 364 156 182 3.90 516.21 221.23 818.74 15.88 0.00 0.00
FCR15 364 156 182 4.16 487.53 208.94 818.42 23.82 0.00 0.00
FCR20 364 156 182 4.42 458.85 196.65 818.10 31.76 0.00 0.00
FCR25 364 156 182 4.68 430.17 184.36 817.77 39.70 0.00 0.00
CCR5 364 156 182 3.64 544.89 233.52 819.06 0.00 10.64 0.00
CCR10 364 156 182 3.90 516.21 221.23 818.74 0.00 21.28 0.00
CCR15 364 156 182 4.16 487.53 208.94 818.42 0.00 31.92 0.00
CCR20 364 156 182 4.42 458.85 196.65 818.10 0.00 42.56 0.00
CCR25 364 156 182 4.68 430.17 184.36 817.77 0.00 53.20 0.00
MCR5 364 156 182 3.64 544.89 233.52 819.06 3.75 5.62 0.00
MCR10 364 156 182 3.90 516.21 221.23 818.74 7.49 11.24 0.00
MCR15 364 156 182 4.16 487.53 208.94 818.42 11.24 16.86 0.00
MCR20 364 156 182 4.42 458.85 196.65 818.10 14.99 22.48 0.00
MCR25 364 156 182 4.68 430.17 184.36 817.77 18.73 28.10 0.00
TC5 364 156 182 3.64 573.57 245.81 778.41 0.00 0.00 15.42
TC10 364 156 182 3.90 573.57 245.81 737.44 0.00 0.00 30.84
TC15 364 156 182 4.16 573.57 245.81 696.47 0.00 0.00 46.26
TC20 364 156 182 4.42 573.57 245.81 655.50 0.00 0.00 61.68
TC25 364 156 182 4.68 573.57 245.81 614.53 0.00 0.00 77.10
Mix proportions for self-compacting rubberized concrete (kg/m3)

Concrete Mixing
The crumb rubber, fine and coarse aggregates in a power-driven
revolving pan mixer were mixed homogeneously for 30 seconds,
half of the mixing water was added into the mixer and it was allowed
to continue the mixing for one more minute.
After that, the crumb rubber and aggregates were left to absorb the
water in the mixer for 1 min. Thereafter, the cement and fly ash was
added to the mixture for mixing another minute.
 Finally, the SP with remaining water was poured into mixer, and the
concrete was mixed for 3 min and then left for a 2 min rest.
 At the end, to complete the production, the concrete was mixed for
additional 2 min.
According to this mixing procedure by Khayat et al. (2000)

•To measure the slump flow, an ordinary slump flow cone is filled with SCC without
any compaction and leveled. The cone is lifted and average diameter of the resulting
concrete spread is measured as seen.
slump flow
TESTS ON SCRC
A-Fresh Properties

• To measure the V-funnel flow time filling the V-shaped funnel with fresh concrete,
thereafter, the hinged trapdoor is released and the flow time measured until it
completely becomes empty.
V-funnel flow time test

•To measure L-box height ratio and T20and T40 flow time the test procedure is
pouring fresh concrete in the vertical section and then the gate is opened and let the
concrete flows to horizontal section through the gaps between the obstructing bars.
L-box test

ICAR rheometer was used to characterize the rheology of SCRCs fresh self-compacting
concrete was poured up to a height of 300 mm in to 300 mm diameter container in
which a 125 mm diameter and 125 mm height four-bladed vane was placed in the
centre of the container with a 87.5 mm spacing above and below the vane. Flow curves
for every fresh concrete mixture was obtained representing shear stress and shear rate.
Views of rheometer and detailed schematic
representation

The number of casting samples for each mix

B- Mechanical Properties SCRCs
Compressive strength Splitting tensile strength

In order to obtain the fracture energy (GF) of SCRCs, the test was
carried out coinciding with of RILEM 50-FMC (1985). The
measurement of displacement was observed simultaneously via a
linear variable displacement transducer (LVDT) at midpoint of
span. A testing machine (Instron 5590R) The beams having length
of 500 mm and cross-section of 100x100 mm were cast for the
fracture energy test. The opening notch was achieved through
reducing the effective cross section to 60x100 mm via a saw .
Fracture energy

Net Flexural Strength
fflex =
𝟑𝐏 𝐦𝐚𝐱 𝐒
𝟐𝐁(𝐖−𝐚) 𝟐
The notched beams were used to calculate the net flexural
strength using the following equation on the assumption that
there is no notch sensitivity.
Characteristic Length
By the following expression, the brittleness of materials can
be determined in terms of characteristic length .
lch =
𝐄𝒙𝐆 𝐅
𝒇 𝒔𝒕
𝟐

Bond Strength: The stress acting parallel to the bar along the
interface is called bond stress
τ =
𝑭
𝝅 𝒙 𝒅 𝒙 𝑳

An adequate concrete cover is necessary in order to properly transfer
bond stresses between steel and concrete
Detail of the bond strength test specimen

550
650
750
850
0 5 10 15 20 25 30
Slumpflowdiameter(mm)
Rubber content (%)
No.18 crumb rubber
No.5 crumb rubber
Mixed crumb rubber
Tire chips
SF2SF3
Slumpflowclasses
SF1
TC25 smallest flow diameter 560 mm
765 mm
Slump Flow Diameter of SCRCs
The longitudinal particles blocked the rolling of other ingredients in the mixtures, which
adversely affect the self-compatibility of concrete.

0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
0 5 10 15 20 25 30
T50slumpflowtime(s)
Rubber content (%)
No.18 crumb rubber No.5 crumb rubber Mixed crumb rubber Tire chips
VS2VS1
Viscosityclassses
Slump Flow Time of SCRCs
8.14 s
1.5 s

V-funnel Flow Time of SCRCs
0
4
8
12
16
20
24
28
0 5 10 15 20 25 30
V-funnelflowtime(s)
Rubber content (%)
No.18 crumb rubber
No.5 crumb rubber
Mixed crumb rubber
Tire chips
VF1VF2
Viscosityclassses
6.84 s
27.73 s
an increase in the TC content is accompanied with segregation.

0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
0 5 10 15 20 25 30
L-boxheightratio
Rubber content (%)
No.18 crumb rubber
No.5 crumb rubber
Mixed crumb rubber
Tire chips
PA2
Passingabilityclass
0.55
0.942
This is due to the roughness particles of tire chip.
L-box Height Ratio of SCRCs

2
3
4
5
6
7
8
9
10
11
12
0 5 10 15 20 25 30
T20L-boxflowtime(s)
Rubber content (%)
11.89 s
2.84s

6
10
14
18
22
26
30
0 5 10 15 20 25 30
T40L-boxflowtime(s)
Rubber content (%)
7.04 s
29.68 s

0
0.2
0.4
0.6
0.8
1
0 0.1 0.2 0.3 0.4 0.5 0.6
Torque,N.m
Speed, rps
Control No.18 CR5 No.18 CR10 No.18 CR15 No.18 CR20 No.18 CR25
Torque versus rotational speed obtained from rheometer for SCRC produced with: a)
No.18
utilization of rubbers, which are not spherical as much as natural aggregate, increased
the applied torque. Aggregate shape and texture are strongly effective on the rheology
of self-compacting concretes.

0
0.2
0.4
0.6
0.8
1
0 0.1 0.2 0.3 0.4 0.5 0.6
Torque,N.m
Speed, rps
b) No.5 CR

0
0.2
0.4
0.6
0.8
1
0 0.1 0.2 0.3 0.4 0.5 0.6
Torque,N.m
Speed, rps
Control Mixed CR5 Mixed CR10 Mixed CR15 Mixed CR20 Mixed CR25
c) Mixed crumb rubbers

0
0.2
0.4
0.6
0.8
1
0 0.1 0.2 0.3 0.4 0.5 0.6
Torque,N.m
Speed, rps
Control TC5 TC10 TC15 TC20 TC25
d) Tire chips

y = 4.300 + 10.998x1.135
y = 8.824 + 16.434x1.175
y = 10.865 + 19.350x1.167
y = 14.194 + 19.213x1.185
y = 20.969 + 19.828x1.199
y = 28.258 + 20.168x1.205
0
10
20
30
40
50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
Application of the Herschel-Bulkley model on the rheological data
for the SCRC produced with: a) No.18
Use of 25% of No.18 resulted in 6.2% increase ‘n’

y = 4.300 + 10.998x1.135
y = 14.308 + 12.546x1.339
y = 19.804 + 13.002x1.365
y = 28.567 + 13.581x1.378
y = 32.560 + 14.467x1.386
y = 36.714 + 14.850x1.410
0
10
20
30
40
50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shearrate, 1/s
b) No.5
25 %NO.5CR increased the exponent ‘n’ values as much as 24.2%

y = 4.300 + 10.998x1.135
y = 12.938 + 12.971x1.289
y = 17.124 + 14.612x1.308
y = 22.627 + 14.487x1.330
y = 27.064 + 16.017x1.355
y = 32.967 + 16.017x1.363
0
10
20
30
40
50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
25 %MCR increased the exponent ‘n’ values as much as 20.2%.

y = 4.300 + 10.998x1.135
y = 17.594 + 10.880x1.470
y = 28.061 + 11.160x1.484
y = 38.655 + 11.422x1.490
y = 45.116 + 12.008x1.527
y = 49.279 + 12.339x1.543
0
10
20
30
40
50
60
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
d) Tire chips
25% of TC resulted in 36.0% increment ‘n’ value .

y = 4.4287 + 71.859x + 18.194x2
y = 8.6563 + 112.2x + 31.792x2
y = 11.215 + 129.47x + 38.112x2
y = 15.009 + 130.08x + 41.559x2
y = 23.306 + 133.62x + 48.454x2
y = 32.409 + 134.86x + 52.667x2
0
20
40
60
80
100
120
140
160
180
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
Application of the modified Bingham model on the rheological
data for the SCC produced with:
a) No.18
‘c/µ=0.362 ’
c/µ=0.253

y = 4.4287 + 71.859x + 18.194x2
y = 15.195 + 83.984x + 63.775x2
y = 21.97 + 85.2x + 75.457x2
y = 32.624 + 89.115x + 82.352x2
y = 37.367 + 94.613x + 90.587x2
y = 42.336 + 96.305x + 101.5x2
0
20
40
60
80
100
120
140
160
180
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
b) No.5
‘c/µ=’ 1.054

y = 4.4287 + 71.859x + 18.194x2
y = 13.79 + 86.621x + 53.816x2
y = 18.666 + 96.761x + 66.839x2
y = 25.227 + 96.842x + 71.436x2
y = 30.336 + 103.24x + 84.076x2
y = 37.713 + 105.16x + 92.119x2
0
20
40
60
80
100
120
140
160
180
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shear rate, 1/s
moderate ‘c/µ= 0.814’

y = 18.194x2 + 71.859x + 4.4287
y = 91.928x2 + 68.304x + 19.292
y = 98.631x2 + 69.616x + 32.172
y = 103.23x2 + 70.676x + 45.332
y = 122.38x2 + 71.995x + 53.195
y = 131.38x2 + 73.469x + 58.185
0
20
40
60
80
100
120
140
160
180
200
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Shearstress,Pa
Shearrate, 1/s
d) Tire chips
highest ‘c/µ ’
The replacing the spherical grains, natural aggregate, with longitudinal grains, rubber,
needed the higher torque values at the same rotational speed.

R² = 0.967
0.0
0.4
0.8
1.2
1.6
2.0
1 1.1 1.2 1.3 1.4 1.5 1.6
c/µ(modifiedBingham)
n (Herschel-Bulkley)
650
750
850
0 5 10 15 20 25 30
Slumpflowdiameter(mm)
Rubber content (%)
Control No.18 crumb rubber No.5 crumb rubber Mixed crumb rubber Tire chips
There is a strong relationship between ‘c/µ’ coefficients and
exponent ‘n’ values.

2050
2100
2150
2200
2250
2300
2350
2400
0% 5% 10% 15% 20% 25%
Freshconcretedensity(kg/m3)
Rubber content %
control
FCR
CCR
MCR
TC
Fresh Density of SCRCs
Higher reduction with FCR
Lower reduction with TC

30
35
40
45
50
55
60
65
0 5 10 15 20 25
Compressivestrength,fc(MPa)
Rubber content (%)
No. 18 crumb rubber No.5 crumb rubber Mixed crumb rubber Tire chips
Compressive Strength of SCRCs at 28 days
62.8Control
58.3 FCR5
31.0 TC25

35
40
45
50
55
60
65
70
75
0 5 10 15 20 25
Compressivestrength,fc(MPa)
Rubber content (%)
Compressive Strength of SCRCs at 90days
72.4 Control
68.0 FCR5
35.5 TC25
Rubber is a soft material and the adhesion between rubber particles and cement paste is
low.

2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 5 10 15 20 25
Splittingtensilestrength,fst(MPa)
Rubber content (%)
Splitting Tensile Strength of SCRCs 90 days
4.36 Control
2.24 CCR25

25
30
35
40
45
50
55
0 5 10 15 20 25
Modulusofelasticity,E(GPa)
Rubber content (%)
50.71 Control
48.68 FCR5
29.96 TC25

Net Flexural Strength of SCRCs at 90 days
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0 5 10 15 20 25
Netflexuralstrength,fflex(MPa)
Rubber content (%)
3.2
5.6
This behavior may be related to the very low adhesion between the chipped
rubber and the cement paste.

Fracture Energy of SCRCs at 90 days
100
110
120
130
140
150
160
0 5 10 15 20 25
Fractureenergy,GF(N/m)
Rubber content (%)
110.2
155. 8
FCR5 143.5
TC5 141.2

Typical loads versus displacement curves ofNo.18CRwith respect to control mix

Typical loads versus displacement curves ofNo.5CRwith respect to control mix

Typical loads versus displacement curves of MCR with respect to control mix

Typical loads versus displacement curves of tire chip with respect to control mix

400
450
500
550
600
650
700
750
800
0 5 10 15 20 25
Characteristiclength,lch(N/m)
Rubber content (%)
717.91
415.6
Characteristic Length of SCRCs at 90 days

7
8
9
10
11
12
13
14
15
0 5 10 15 20 25
Bondstrength,(MPa)
Rubber content (%)
7.21
14.6
poor bonding characteristic around rubber tires and cement paste and .
There are a lot of micro - cracks near the ITZ in the rubberized concrete.

CONCLUSIONS
 It is very clear from the test results that all most the mixes
satisfy the requirements of SCC with respect to EFNARC
(2005).
 Densities in the range of 2344 - 2192 kg/m3 were produced.
 The slump flow diameters ranging from 560 to 750 mm were
obtained for the self-compacting rubberized concretes.
 Replacing the crumb rubber with fine aggregate increased
both T50 slump flow and V-funnel flow times while replacing
the tire chip with coarse aggregate decreased both T50 slump
flow and V-funnel flow times.

using the crumb rubber caused increasing of the L-box T20 and T40
flow times. And replacement of coarse aggregates with the TC
caused increasing of T20 and T40 flow times and decreasing of the L-
box.
The highest exponent ‘n’ values and ‘c/µ’coefficients were obtained
when the natural coarse aggregate was substituted with tire chips,
while the lowest values were achieved when the natural fine
aggregate was replaced with FCR crumb rubber at each
replacement level.
The compressive strength of self-compacting rubberized concrete
having more than 30 MPa could be produced easily.
The self-compacting concretes produced with FCR gave the
highest splitting tensile strength those produced with CCR gave the
lowest splitting tensile strength.

The self-compacting concretes produced with (TC) gave the
lowest static elastic modulus while the control mix gave the
highest static elastic modulus.
The control mix had greater net flexural strength compared
to other mixture.
The lowest reduction of fracture energy with 5FCR where it
was 9%.
The best value for ductility was obtained with MCR.
It was observed decreasing of bond strength with
increasing the crumb rubber and tire chip size and
content.

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