This slide includes some test conducted in self compacting concrete and basic definitions.

1. PRESENTED BY
SREE

3.  Self compacting concrete is a flowing concrete mixture
that is able to consolidate under it own weight
 The highly fluid nature of scc makes it suitable for
placing in difficult conditions and in section with
congested reinforcement

4.  By the early 1990’s, Japan has developed and used scc
that does not require vibration to achieve full
compaction.
 As the year 2000, scc used for prefabricated products
(precast members) and ready mixed concrete(cast-in-
situ) in Japan, USA and later on India etc.

5.  In 1983,the problem of durability of the concrete
structures was a major topic of interest in Japan.
 The creation of durable concrete structures requires
adequate compaction by skilled workers.
 Solution for the achievement of durable concrete
structures independent of the quality construction work
is the use of scc.
 The necessity of this type of concrete was proposed by
Okamura in 1986.
 Present-day scc can be classified as an advanced
construction material.

6.  With regard to its composition,scc consists of the same
components as conventionally vibrated concrete, which
are
 Cement(OPC 43 OR 53 grade can be used)
 Aggregates
 Water
 Chemical Admixtures i.e., Super plasticizers and
Viscosity Modifying Agents.
 Mineral Admixtures i.e., Fly ash, Silica Fume,GGBFS
etc.

8.  Give dimensional stability to concrete
 The important properties of aggregates is shape and
gradation.
 Self- compactability is achievable at lower cement (or
fines)content when rounded aggregates are used. Rounded
aggregates would provide a better flowability and less
blocking potential for a given ware-to-powder ratio.
 The presence of flaky and elongated particles may give rise
to blocking problems in confined areas, and also increase
the minimum yield stress
 Fillers can be used with aggregates having poor gradation

9.  The most important admixtures are the super plasticizers
(high range water reducers),used with a water reduction
greater than 20%.
 HRWRAs that work on ‘steric hindrance’require low
dosage as compared to those based on ‘electrostatic
repulsion’.
 Acrylic copolymers(AC) and polycarboxylated ethers(PCE)
are effective at lower dosages.

10.  Use to improve the stability
 Used for underwater concreting in the past.
 VMA should be added after the superplasticizers.

11.  Fly ash: It reduces free drying shrinkage and restrains
the shrinkage cracking width.
 Silica fume: It gives good cohesion, improved
resistance to segregation, also very effective in
reducing or eliminating bleeding.

13.  Filling ability:
Slump Flow test & T₅₀ slump flow test.
 Passing ability:
L-box , U- box ,J-ring test
 Segregation Resistance:
V-funnel test & V funnel at T₅ minutes

14.  Slump flow test is used to find the filling ability of the scc.
 The scc sample is poured into the slump cone then the
slump flow diameter is measured.
 The flow time is measured & that is known as T₅₀ slump
time.
 The higher the slump flow value , the greater its ability to
fill formwork under its own weight.

16.  The L-Box test is used to find the passing ability of scc.
 The scc sample is poured into the L-Box apparatus,
now the plate is removed to allow flow.
 The L-Box ratio is calculated as H2/H1.
 According to EFNARC , when the ratio of h2 to h1 is
larger than 0.8,self compacting concrete has good
passing ability.

18.  The V-Funnel test is used to find the segregation
resistance of scc.
 The scc sample is poured into the V-Funnel apparatus
now its allowed to flow by its weight.
 The emptying time of V-Funnel is noted.
 This test measured the ease of flow of the concrete,
shorter flow times indicate greater flow ability. After 5
minutes of setting, segregation of concrete will show a
less continuous flow with an increase in flow time.

21.  Faster costruction
 Reduction in site manpower
 Better surface finish
 Easier placing
 Improved durability
 Greater freedom in design
 Thinner concrete sections
 Reduced noise level
 Safer working environment

22.  More precise measurement and monitoring of the
constituent materials.
 Requires more trial batches at laboratory as well as at
ready-mixed concrete plants.
 Costlier than conventional concrete based on concrete
material cost (exception to placement cost).
 Lack of globally accepted test standards and mix
designs.

23.  Self-compacting concrete has been used in bridges and
pre-cast sections.
 One of the most remarkable projects built using self-
compacting concrete is the Akashi-Kaikyo Suspension
Bridge, Japan.
 The highest use of scc in India was done at Delhi metro
project. About 10000 m³ of scc has been used.
 At Kaiga nuclear power plant,scc of characteristic
strength 30MPa was used.

26. THANK YOU