*Green Recycled Aggregate Concrete (GRAC) *Effect of mineral addition on the performance of GRAC *Silica fume,Metakaolin,Fly Ash,GGBFS

1. INFLUENCE OF MINERALADDITIONS ON
THE PERFORMANCE OF GREEN
RECYCLED AGGREGATE CONCRETE
DAYAL KURIAN VARGHESE
1
24-Dec-16

2. OVERVIEW
Introduction
Green recycled aggregate concrete (GRAC)
Recycled concrete aggregate (RCA)
Case study-1
Case study-2
Conclusion
References
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Mobile Recycling Unit

3. INTRODUCTION
 By the end of the 20th century, sustainable
development and environmental protection became
key goals of modern society
 Main problems that industry of construction
materials faces were:
 natural aggregate depletion
high consumption of Portland cement and
associated high emission of carbon dioxide
large amount of generated construction and
demolition (C&D) waste
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4. GREEN RECYCLED AGGREGATE
CONCRETE (GRAC)
 GRAC made with recycled concrete aggregate, low
cement content and high content of different mineral
supplements
 Such concretes belong to ‘‘green’’ or ‘‘eco’’ concretes
 Here GRAC produced with
fine river aggregate
coarse recycled aggregate
Portland Cement
Silica fume (SF), fly ash (FA), Metakaolin (MK),
GGBS
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Enterprise Park

5. RECYCLED CONCRETE
AGGREGATE (RCA)
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Collection of
C&D wastes
Screening
Vibrating
feeder
Plant
crusher
Jaw
crusher
Magnetic separatorcone crusher
vibratory
screens
storage
compartment
Recycled
aggregate
Sampling & Testing

6. CASE STUDY-1
“Comparisons of natural and recycled aggregates
concretes prepared with the addition of different
mineral admixtures”
 Kou et al. (2011) conducted studies on GRAC
prepared with different mineral admixtures such
as SF (10%),MK (15%),FA (35%), GGBS (55%)
 The coarse aggregates were replaced with 50%
and 100% of RCA
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7. MATERIALS USED
 Portland cement (PC)
 Metakaolin (MK)
 Silica fume (SF)
 Fly ash (FA)
 Ground granulated blast slag (GGBS)
 Natural fine aggregate
 Recycled coarse aggregate
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GGBS
Fly ash
Recycled concrete material
Silica fume Metakaolin

8. 24-Dec-16
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Contents Cement Fly ash Silica
fume
Metakaolin GGBS
SiO2 21 56.79 85-86 53.2 44.6
Al2O3 5.9 28.21 - 43.9 13.3
Fe2O3 3.4 5.31 - 0.38 0.9
CaO 64.7 <3 - 0.02 33.8
MgO 0.9 5.21 - 0.05 4.8
Na2O - - - 0.17 1.0
K2O - - - 0.10 -
TiO2 - - - 1.68 -
SO3 2.6 0.68 0.3-.7 - 1.3
Specific gravity (g/cm3) 3.15 2.31 2.22 2.62 2.98
Specific surface (cm2/g) 3520 3960 18650 12680 5350
Physical and chemical properties of cement, fly ash, silica
fume, GGBS and metakaolin
(Source: Shi-cong Kou et al. (2011))

9. SPECIMEN PREPARATION AND CURING
 Three series of concrete mixtures were prepared in
the laboratory using a Pan mixer
 SF, MK, FA and GGBS were used as cement
replacements on a weight basis
 A constant water/binder ratio at 0.50 was used
 Series I concrete mixtures used natural aggregate
as the coarse aggregate
C (control, natural aggregate with 100% OPC),
C-SF10 (natural aggregate with 10% SF),C-
MK15,C-FA35,C-GGBS55
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10. Contd…….
 In Series II mixes, recycled aggregates were used to
replace 50% of natural coarse aggregate
 R50,R50-SF10,R50-MK15,R50-FA35,R50-
GGBS55
 In Series III mixes, recycled aggregates were used
to replace 100% of natural coarse aggregate
 R100,R100-SF10,R100-MK15,R100-
FA35,R100-GGBS55
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11. 24-Dec-16
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Constitution (kg/m3)
Composite of binder
Sand
Series I Series II Series III
Water Cement Mineral
admixtures
Coarse
natural
agg.
Coarse
natural
agg.
Coarse
recycle
d agg.
Coarse
recycled
agg.
Control 195 390 0 678 1107 527 539 1078
SF10 195 351 39 664 1107 527 539 1078
MK15 195 331.5 58.5 669 1107 527 539 1078
FA35 195 253.5 136.5 640 1107 527 539 1078
GGBS55 195 175.5 214.5 658 1107 527 539 1078
Concrete mix proportion
(Source: Shi-cong Kou et al. (2011))

12. Contd…….
 Workability measured using the slump cone test
 Concrete cubes of size 100 mm casted for
determining compressive strength
 100mm x 200mm concrete cylinders casted to
determine the tensile splitting strength
 100mm x 50mm concrete cylinders casted to
determine the chloride ion penetration
 75mm x 75mm x 285mm prisms were casted for
determining drying shrinkage
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13. RESULTS13
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Slump of concrete mixtures
Slump value
(Source: Shi-cong Kou et al. (2011))

14. Compressive strength14
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Development of compressive strength of concrete mixtures in Series I
C-FA35 : 66.2%
C-GGBS55 : 66.5%
C-SF10 : 41.7%
C-MK15 : 43.3%
Compressive
strength gain
(Source: Shi-cong Kou et al. (2011))

15. Compressive strength
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Development of compressive strength of concrete mixtures in Series II
RA50-FA35 : 68.6%
RA50-GGBS55 : 67.2%
RA50-SF10 : 49.8%
RA50-MK15 : 52.2%
Compressive
strength gain
(Source: Shi-cong Kou et al. (2011))

16. Compressive strength
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Development of compressive strength of concrete mixtures in Series III
RA-FA35 : 70.9%
RA-GGBS55 : 69.1%
RA-SF10 : 55.7%
RA-MK15 : 56.8%
Compressive
strength gain
(Source: Shi-cong Kou et al. (2011))

17. Tensile strength
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Tensile splitting strength of concrete mixtures
Tensile strength
gain
C:17.2%,C-SF10:23.1,C-MK15:26.4,C-FA35:35.3,C-GGBS55:33
R50:23.9%,R50-SF10:34.9,R50-MK15:36.9,R50-FA35:40.5,R50-GGBS55:38.8
R100:24.6%,R100-SF10:46.2,R100-MK15:40.8,R100-FA35:48,R100-GGBS55:44.9
(Source: Shi-cong Kou et al. (2011))

18. Drying shrinkage
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Drying shrinkage of concrete mixtures at 112 days
(Source: Shi-cong Kou et al. (2011))

19. Chloride ion penetration
 The total charge passed increased with the use of RA.
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Total charge passed in coulombs of concrete mixtures
(Source: Shi-cong Kou et al. (2011))

20. DISCUSSION
 The compressive strength of RAC was lower than
that of the control specimen, but could be
compensated by the use of 10% SF or 15% MK
 However 35% FA or 55% GGBS lowered the
compressive strength
 The tensile strength of natural and RAC made
with SF and MK was higher than that of the
corresponding control concrete at all test ages
 FA and GGBS decreased the tensile strength
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21. Contd…….
 The drying shrinkage values of the natural and RAC
made with SF and MK was higher than that of control
 The chloride ion penetration test indicated that the
concrete containing recycled aggregate had a more
open pore structure, compared to the control concrete
 The test results show that SF and MK can improve
both strength and durability properties of RAC
 FA and GGBS significantly improved the durability
performance of the recycled aggregate concrete
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22. CASE STUDY-2
“Experimental analysis of properties of recycled coarse
aggregate (RCA) concrete with mineral additives”
 Ö. Çakır (2014) observed compressive strength and
splitting tensile strength of GRAC prepared with
incorporation of SF and GGBFS
 The RAC was prepared by using 5%, 10% of SF and
30% ,60% of GGBFS whereas coarse aggregates
were replaced with 50% and 100% of RCA
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23. MATERIALS USED
 Portland cement (PC)
 Silica fume (SF)
 Ground granulated blast slag (GGBS)
 Natural fine aggregate
 Recycled coarse aggregate
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GGBS
Recycled concrete material
Silica fume

24. SPECIMEN PREPARATION AND CURING
 Three series of concrete mixtures were prepared
in the laboratory using a Pan mixer
 SF, GGBFS were used as cement replacements
on a weight basis
 A constant water/binder ratio at 0.50 was used
 Series I concrete mixtures used natural aggregate
as the coarse aggregate
NA (control, natural aggregate with 100%
OPC), NA-SF5 (natural aggregate with 5%
SF),NA-SF10,NA-GGBS30,NA-GGBS60
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25. Contd…….
 In Series II mixes, recycled aggregates were used to replace
50% of natural coarse aggregate
 RA50,RA50-SF5,R50-SF10,RA50-GGBS30,RA50
GGBS60
 In Series III mixes, recycled aggregates were used to
replace 100% of natural coarse aggregate
 RA100,RA100-SF5,RA100-SF10,RA100
GGBS30,RA100-GGBS60
 100mm x 200mm concrete cylinders casted to determine
the tensile splitting strength
 150 mm concrete cubes casted for the determination of the
compressive strength
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26. RESULTS
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Notation Compressive strength(Mpa) Splitting tensile strength(Mpa)
NA 42.40 3.30
NA-SF5 42.90 3.30
NA-SF10 46.10 3.50
NA-GGBS30 34.50 3.20
NA-GGBS60 32.10 3.20
RA50 34.70 3.20
RA50-SF5 35.50 3.30
RA50-SF10 35.80 3.30
RA50-GGBS30 30.10 2.90
RA50-GGBS60 26.60 2.70
RA100 32.10 3.00
RA100-SF5 32.00 3.20
RA100-SF10 35.60 3.30
RA100-GGBS30 25.30 2.60
RA100-GGBS60 21.90 2.50
Compressive and splitting tensile strength at 28 day
(Source: Ö. Çakır (2014))

27. DISCUSSION
 The compressive strength of the GRAC gradually decreases
as the amount of RCA increases.
 At 100% of the replacement level, the compressive strength
decreases about 24% at 28 days. At over 50% of the
replacement level, the strength reduction is more significant.
 GRAC containing 5% and 10% SF increases the
compressive strength. However, the use of 30% and 60%
GGBFS lowered the compressive strength.
 GRAC containing 5% and 10% SF increases the tensile
strength. However, the use of 30% and 60% GGBFS
lowered the tensile strength.
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28. 24-Dec-16
28 Examples of Structural Application of
GRAC
BRE Office
Building
Enter prise
park

29. CONCLUDING REMARKS
 SF and MK improve both strength and durability
properties of green recycled aggregate concrete.
 Use of FA and GGBS improved the durability
performance of the recycled aggregate concrete.
 Stricter quality control of recycled concrete aggregate
is required.
 The resistance to chloride penetration decreases as the
percentage of recycled aggregate in concrete increases.
 Use of mineral admixtures enhances the resistance to
chloride attack .
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30. Contd…….
 Mineral admixtures contribute more to the strength
properties RAC than that of natural aggregate concrete.
 In GRAC, it was finally concluded that the recycled
aggregates may be used up to 50% and silica fume
may be used up to 10% for obtaining best results.
 Overall economy of GRAC is comparable with that of
natural aggregate concrete.
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31. REFERENCES
 Kou S.C, Poon C.S, Agrela F (2011), “Comparisons of natural
and recycled aggregates concretes prepared with the addition of
different mineral admixtures.” Cement and Concrete Composites,
Vol. 33, pp. 788-795.
 Ö. Çakır (2014), “Experimental analysis of properties of recycled
coarse aggregate (RCA) concrete with mineral additives.”
Construction and Building Materials Vol. 68, pp 17–25.
 Marinkovic´ S, Radonjanin V, Malešev M, Ignjatovic´ I (2010),
“Comparative environmental assessment of natural and recycled
aggregate concrete.” Waste Manage Vol. 30, pp 2255–2264.
 Radonjanin V, Malesev M, Marinkovic S, Al Malty A.E.S (2013),
“Green recycled aggregate concrete.” Construction and Building
Materials Vol. 47, pp 1503-1511.
 Corinaldesi V, Moriconi G. (2009), “Influence of mineral
additions on the performance of 100% recycled aggregate
concrete.” Constr Build Mater Vol. 23, pp 2869–2876.
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THANK YOU FOR YOUR KIND ATTENTION!!!
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