the presentation covers the history of SCC, its composition and its comparision with conventionally vibrared concrete.
The presentation was made for ultratech rising star competion and won the third prize in the zone.
1. Self Compacting
Concrete
L D College of Engineering Ahmedabad
A presentation for UltraTech – Rising Star
A presentation by:-
Het Modi
Drashti Shah
Garima Lodha
Under the guidance of :
Prof P I Modi
Prof Tarachandani
Prof D K Oza
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2. Table of content:
• Genesis
• Introduction to Self Compacting Concrete (SCC)
• Modifications in constituents for concreting
• Site visit
• Application of SCC
• Comparative study b/w normally vibrated concrete and SCC
• Why has SCC not been standardized?
• Future Scope
• References 2
3. Introduction
The need for very fluid concrete has been existing for a long time. In
earlier times, this always had to be done with a high increase of the
water content.
The results were poor stability of the concrete because of insufficient
cohesion. Segregation and bleeding caused very low concrete quality.
Hence SCC – Self compacting concrete is revolutionary development in
Concrete World.
3
4. Genesis
1983
• Labor crisis in Japan and concern for durability of concrete
structures
1986
• Basic concept of SCC by Prof H. Okamura of Tokyo
University
1988
• First prototype for field experiments and implementation
2002
• EFNARC published 1st European Guideline for SCC
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5. Dr. (prof.) Hajime Okamura
• Hailed as Father of SCC
Technology
• Currently President of Kochi
University of Technology
• CAMET/ACI award for
outstanding contribution in
development of self compacting
high performance concrete,
1995
5
7. Self Compacting Concrete
• According to European guidelines by EFNARC :
“Concrete that is able to flow and consolidate under its own weight,
completely fill the formwork even in the presence of dense
reinforcement, whilst maintaining homogeneity and without the need
for any additional compaction”
• According to Japan Society for Civil Engineers (JSCE):
“Self-compacting high-performance concrete is a high performance
concrete that can be compacted into every corner of a formwork,
purely by means of its own weight and without the need for vibrating
compaction”
NOTE: SCC has not been mentioned in IS codes
7
8. SCC and conventional concrete along the common
scale for workability
Source: Self compacting Concrete in Japan by Masahiro OUCHI Associate Professor, Kochi University of Technology, Japan.8
9. A concrete mix may be classified as self compacting if it has the
following characteristics :
• Filling ability
• Passing ability
• Segregation Resistance
Aspects of SCC:
9
12. • Mixing Water:
• Water quality must be established on the same line as that for
using reinforced concrete or prestressed concrete.
• Cement:
• All cements conforming to standards can be used
• C₃A content is the main factor in the control of the fluidity of
cement pastes
• Portland cement with a C₃A content of less than 5%, such as low
heat Portland cement and moderate heat Portland cement, is very
useful for the production of self compacting concrete.
12
13. • Aggregates:
Aggregates should be from the same source such that all their
properties (water absorption, moisture content etc.) are same.
Coarse Aggregates
Size<20mm
Desirable 10-12 mm
Should be cubical or
rounded
Fine Aggregates
Affect the properties of SCC
more potently as opposed to
Coarse
Fine aggregates should be well
graded (preferably blended
sands)
Moisture content should be
closely monitored (bulking)
13
14. • Additions:
Additions are used to improve and maintain the cohesion and
segregation resistance. Also, the addition will regulate the cement
content in order to reduce the heat of hydration and thermal
shrinkage.
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15. • Mineral fillers:
• Mineral fillers are widely used specially ground limestone (CaCo₃)
Limestone powder is regarded as a non-binder however it improves
the fluidity of concrete and prevents the segregation of high
flowable concrete
15
16. • Fly ash :
• Increases cohesion
• Reduces sensitivity to changes in water content (hence prevents
bleeding and segregation)
• Makes the concrete dense and impervious
• Reduces the cement content in concrete
16
17. • Silica fumes:
• high fineness and spherical shape of silica fume results in good
cohesion and improved resistance to segregation
• Contributes to strength by creating dense packing and acting as
pore filler
• Vulnerable to plastic shrinkage cracking
Used at Palais Royal, Shri Ram Mills, Mumbai 17
18. • Ground Granulated Blast Furnace Slag :
• Reduces Heat of hydration
• Pore filler
• Reduces W/C ratio
Source: Concrete Technology by M.S. Shetty
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20. Concrete viscosity can be reduced
Reduces water content up to 30%
Good dispersing agents and hence
allow the usage of silica, fly ash etc
Workability characteristics such as
pumpability, compactability,
finishibility is improved
Changes in concrete performance
by pumping are small
SUPERPLASTICIZER
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22. • Viscosity Modifying Agent:
• Makes SCC more robust
• Reduces sensitivity towards variations in proportions
Note: they should not be regarded as a way of avoiding the need of a
good mix design
22
24. • Limited aggregate
content
• Low water to powder
(cement) ratio
• Use of superplasticizer
(HRWRA: High Range
Water Reducing
Admixture)
Methods of
achieving SCC
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27. Step1-Batching and Proportioning:
• During Storage of aggregates, following precautions should be taken:
• Cross-contamination of different type and size of aggregate should be
prevented
• Protected from weather to minimize surface moisture fluctuation and
fine movement
• Adequate storage capacity should be available
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28. Step-2 Mixing
• Longer time is needed to achieve complete mixing of SCC
• ‘ball’ formation of constituent material(due to free fall) should be
prevented
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30. Step 4- Placing
• SCC gives a mirror copy of the formwork. Hence, if care is not taken,
SCC shows up any deficiencies in the formwork material
• Limit of vertical free fall distance to 5 meter
• Limit of permissible distance of horizontal flow from point of
discharge
• SCC allows novel methods of placing concrete including pumping
bottom up
30
31. Step 5&6 – Compacting and
Finishing
• SCC is capable of achieving both self compacting and self finishing
• Use of vibrators will affect the balance of SCC and will usually lead to
significant segregation
• Light vibration can be used if the need arises
• If air is trapped
• If there is break in placing process
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32. Step 7 - Curing
• SCC tends to dry faster, and is vulnerable to plastic shrinkage
cracking.
• Hence early curing should be commenced as early as possible.
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33. Site Visit : Nuvoco Vistas’ (Lafarge)
RMC Plant
• Location: Nuvoco Vistas operating RMC plant, B/H Sanghi
Cement Godown, Sarkhej Sanathal Road, Ahmedabad
• Date of visit: 7/02/2018
• Objective: To analyze various properties of SCC and making of
mix design
• Quality Control Incharge: Mr. Dhiren Patel
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34. • Can retain it’s workability
for 4 hours without any
change.
• w/c ratio : 0.3
• Admixture used: HWRA
and VMA (.6% weight of
binder)
• Cement – OPC 53
• Concrete – M 25
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52. ensures absolutely no joints
(monolithic) between the
elements with great surface
finish
all the elements are cast
together
52
What is RMD
Technology??
53. Rajiv Gandhi Housing
Corporation, Karnataka
Project completion time: 7 days
Technology Support: UltraTech Cement
Limited, Unit -UltraTech Concrete
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56. COMPARISON OF COST ANALYSIS BETWEEN SELF COMPACTING CONCRETE AND
NORMAL VIBRATED CONCRETE by Krishna Murthy
(as published in IJCIET in 2014)
Cost Comparison
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57. Cost reduction factors:
• Higher speed of placing
• Reduced machine/ equipment cost
• Possible higher concrete quality and durability
• Reduced manpower
• Reduced finishing/ repair work
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58. Why has SCC not been standardized
yet?
• It is a fairly new concept (1983) in the concrete domain, with it’s
entry happening in India in the year 2004 only
• No specific mix design exists for SCC, with each mix being designed
differently to cater to the construction needs.
• There is no particular limit at which we can differentiate between
NVC and SCC
• However, with the ongoing research we do expect the
standardization of SCC
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59. Future Scope
• The use of SCC has been gaining momentum and the SCC market is expected
to grow by 5.7% annually ( for UK as estimated by designbuilding.org).
• Use of rice husk, and similar additives in SCC is being experimented in order
to reduce the concrete manufacturing cost.
• SCC gives flexibility to both the engineers as well as the architects to design
and construct complicated structures, without having to compromise on
quality and durability.
• With the increasing population, the need for high rise buildings would be
inevitable which in turn would make SCC a necessity.
• ACI has already published journals regarding SCC and we expect both, BIS
and ACI to standardize SCC in near future.
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60. References
• Papers and Guidelines:
• Japan Society of Civil Engineers “Recommendation for Mix Design of Fresh
Concrete and Construction Placement related Performance of Evaluation” 2007
• The European Guidelines for Self-Compacting Concrete in accordance with BIBM,
CEMBUREA, ERMCO, EFCA and EFNARC
• Okamura, H. and Ouchi, M. “Self-compacting high performance concrete” Journal
of Advanced Concrete Technology of Japan Concrete Institute
• “Self-compacting concrete: modern concrete and admixture technology” by R
Beissel, Sika AG, Switzerland H Lim, Sika Pte. Ltd. , Singapore
• Masahiro OUCHI Associate Professor, Kochi University of Technology, Japan “Self-
compacting concrete in japan”
• EN codes
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62. “ 25 years ago no one in concrete construction industry
could ever imagine creating and placing concrete mixes
that would achieve in place compressive strengths as
high as 120 MPa….
…. however structures today have attained strength as
high as 130 MPa – are testaments to the benefits of
Sillica Fume technology in Concrete construction”
-- Michael Shydlowski, President, Master Builder
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