Advanced Construction material.

1. SELF -COMPACTING CONCRETE
(SCC)
&
LIGHT-WEIGHT CONCRETE
(LWG)
Group Members:
-Ayushi Mehrotra
-Richa Shukla
-Warepam Bishworjit Mangang

2. SELF
COMPACTING/CONSOLIDATI
NG CONCRETE Self-compacting concrete (SCC) has been described as
"the most revolutionary development in concrete
construction for several decades“.
Properties, Benefits & Advantages over conventional
concrete
• Faster construction
• Reduction in site manpower, equipments and
onsite repairs.
• Improved quality of concrete and its durability ,
reliability of structure .
• Greater freedom in design
• Thinner concrete sections
• Reduced noise levels, absence of voids.
• Safer working environment.
• Lower overall cost.
• Possibilities for utilization of “dusts“ which are
currently waste products and costly to dispose.
Concrete that is able to flow under its
own weight and completely fill the
formwork, even in the presence of
dense reinforcement, without the need
of any vibration, whilst maintaining
homogeneity.

3. • Segregation resistance (stability)
• The ability of SCC to remain homogeneous in
composition during transport and placing.
• Moderate viscosity.
• Mixture self compacting ability allow the elimination
of macro-defects , air bubbles & honey combs
responsible for penalizing mechanical performance
and structure durability.
• Workability: A measure of the ease by which fresh
concrete can be placed and compacted: it is a
complex combination of aspects of fluidity,
cohesiveness, transportability, compactability and
stickiness.
• Unconfined flow ability (Filling ability, extremely
flowing material).
• Passing ability , close to self-levelling & Low yield
stress.
• High deformability .
• Better surface finishes.
• Easier placing .
• Contains less water than standard concrete .
Instead SCC gains its fluid properties
from an unusually high proportion of
fine aggregate , such as sand (
typically 50%) combined with
superplasticizers & viscosity-
enhancing-admixtures (VEA).

4. DISADVANTAGES
• SCC requires high fluidity in tight joints formworks ,
which slow downs the casting rate.
• Due to low water cement ratio , plastic shrinkage
cracks may 0ccur , but this can be avoided by curing
properly .
• Highly skilled and experienced workers are required
for the production.
• More costly than other conventional concrete.
Selection of Mix Proportions
1. Air content (by volume)
2. Coarse aggregate content (by volume)
3. Paste content (by volume)
4. Binder (cementitious) content (by
weight)
5. Replacement of mineral admixture by
percentage binder weight
6.Water/ binder ratio (by weight)
7.Volume of fine aggregate/ volume of
mortar
8. SP dosage by percentage cementitious
(binder) weight
9.VMA dosage by percentage cementitious
(binder) weight
Picture showing Slump test of SCC v/s Conventional
Concrete

5. REQUIREMENTS FOR CONSTITUENT
MATERIALS
Cement
• General suitability is established for cement 43
grade ordinary Portland cement (OPC)
conforming to IS :383-1970(6) .
• Selection of the type of cement depends on the
overall requirements for the concrete such as
strength , durability etc.
• It should be fresh and without any lumps.
Constituents of SCC
Sand and fine aggregates
• confirms to grading Zone II as per IS: 383-1970
(Reaffirmed 1997).
• The sand passing through 4.75 mm size sieve is used in
the preparation of concrete mix.
• The properties of sand such as fineness modulus and
specific gravity as per IS: 2386-1963.
• water absorption is 1.5%.
• bulk density of fine aggregate :- 1768 kg/m3.
• All normal concreting sand are suitable for SCC (either
crushed or rounded) .
• Particles smaller than 0.125 mm contribute to the
powder content.
• A min amount of fines must be achieved to avoid
segregation .

6. Aggregate
• The coarse aggregate 12.5 mm down size graded
confirm to IS 383-1970 (Reaffirmed 1997) locally
available crushed stone obtained from local quarries.
• specific gravity of coarse aggregate is found to be 2.65.
• The water absorption is 0.3%.
• The bulk density of coarse aggregate in compact state is
1584kg/m3.
• Well all type of aggregate are suitable. Size varies 16 mm
to 20 mm .however particle size up to 40 mm more have
been used in SCC.
• Consistency of grading is of vital importance .
• Gap graded aggregates better than those continuously
graded , which might experience greater internal friction
and give reduced flow.
• The moisture content should be closely
monitored and must be taken into
account in order to produce SCC of
constant quality .
• Crushed aggregates tend to improve the
strength because of the angular
particles , whilst rounded aggregates
improve the flow because of lower
internal friction .
Aggregates: Rounded & Angular
Water
• Potable water and it should be
free from organic content ,
turbidity and salts confirms to
IS 456-2000 .

7. Admixtures
• Superplasticizers are an essential component of SCC to
provide the necessary workability.
• Super plasticizer- PCE ,
• AUROMIX 400 Commercially available polycarboxylic
ether based super plasticizer. It is an admixture of a new
generation based on modified polycarboxylic ether. Its use
enhances the workability of the mix and strength aspect,
helps in producing a better compaction and finishing. It
also permits reduction in water content .
• Air entraining admixtures (AEA) to improve freeze-thaw
resistance, retarders for control of setting, etc.
• • High range water reducing admixtures -
HRWRA Application of HRWRA provides fluidity of
fresh concrete and reduces the required water
quantity.
• •Viscosity modifying admixtures-VMA increase
the cohesion of fresh concrete and can replace a
part of mineral additions.They have the effect of
cement paste densifying and keeping fine particles
within the matrix.
• • Special admixtures for SCC –combined HRWRA
+VMA:The majority of admixture manufacturers
produce special admixtures for SCC which include
both HRWRA andVMA within them. By application
of these special admixtures, possible
incompatibility inapplication of separate
admixtures is avoided and desired viscosity of fluid
mix is obtained.

8. Additions (including mineral fillers and pigments)
• Cement is replaced by 35% of fly ash by weight of
cementitious material.
The specific gravity of fly ash is 2.12.
• Filler ( Fly ash)- Filler Materials such as fly ash, blast
furnace slag, etc.
• An extremely important aspect of the durability of
concrete is its permeability.
• Fly ash concrete is less permeable because fly ash
reduces the amount of water needed to produce a given
slump, and through pozzolanic activity, creates more
durable CSH as it fills capillaries and bleed water
channels occupied by water Soluble lime.
• Improves corrosion protection by decreasing concrete
permeability.
• It can reduce corrosive chemicals and oxygen
• Increase sulfate resistance and reduces alkali-silica
reactivity .
Blast furnace slag
Constituents of Fly Ash concrete

9. Typical additions are:
Stone powder.
• Finely crushed limestone, dolomite or granite may be used to
increase the amount of powder: the fraction less than 0.125 mm will
be of most benefit.
Note: dolomite may present a durability risk due to alkali-
carbonate reaction
Silica Fume:
• Silica fume gives very good improvement of the rheological as well
as the mechanical and chemical properties.
• Improves also the durability of the concrete.
Ground (Granulated) Blast Furnace Slag:
• GGBS is a fine granular mostly latent hydraulic binding material,
which can also be added to SCC to improve the rheological
properties.
Ground Glass Filler:
• usually obtained by finely grinding recycled glass.
• The particle size should be less than 0,1 mm and the specific surface
area should be > 2500 cm2/g.
• Larger particle sizes may cause Alkali-Silica reaction.
Pigments
Silica Fume
Ground Granulated blast furnace slag

10. Fibers
• Commonly used types of fibers are steel or polymer.
• Fibers may be used to enhance the properties of
SCC in the same way as for normal concrete.
• Steel fibers are used normally to enhance the
mechanical characteristics of the concrete such as
flexural strength and toughness.
• Polymer fibers may be used to reduce segregation
and plastic shrinkage, or to increase the fire
resistance.
• Ease of mixing and the placing processes proposed,
shall be demonstrated by site trials to the approval
of the engineer.
Steel fibers
Polymer fibers

11. REQUIREMENTS FOR SELF-COMPACTING CONCRETE
Application area
• SCC may be used in pre-cast applications or for concrete placed on site.
• It can be manufactured in a site batching plant or in a ready mix concrete plant and
delivered to site by truck.
• It can then be placed either by pumping or pouring into horizontal or vertical
structures.
• In designing the mix, the size and the form of the structure, the dimension and density
of reinforcement and cover should be taken in consideration.
• Due to the flowing characteristics of SCC it may be difficult to cast to a fall unless
contained in a form.
• SCC has made it possible to cast concrete structures of a quality that was not possible
with the existing concrete technology.

12. EXAMPLES OF STRUCTURES BUILT
OF SELF-COMPACTING CONCRET
Burj Dubai
Arlanda Airport ControlTower, Stockholm,
Sweden.
National Museum of 21st Century Arts
(MAXXI) in Rome, Italy
Burj, Dubai
Arlanda airport control tower,
Sweden
National museum of 21st century art, Rome

13. LIGHT- WEIGHT CONCRETE
(LWC)

14. LIGHT WEIGHT
CONCRETE
• Lightweight concrete is concrete with a dense
microstructure containing porous aggregates
bonded any room temperature.
• Can be defined as a type of concrete which
includes an expanding agent that increases the
volume of the mixture while giving additional
qualities.
• considered to be lightweight if the density is not
more than 2200kg/m3 (the density of normal
weight concrete is assumed to be between
2300kg/m3 and 2400kg/m3) and a proportion of
the aggregate should have a density of less than
2000kg/m3.
• Bulk density 5-18 KN/M3.
• -Light weight Aggregate Concrete
-No Fines Concrete
-Foamed Concrete
-AAC (Autoclaved Aerated Concrete)

15. LIGHT WEIGHT
AGGREGATE
CONCRETE Lightweight aggregate concrete can be produced using
a variety of lightweight aggregates.
Lightweight aggregates originate from either:
• Natural materials, like volcanic pumice.
• The thermal treatment of natural raw materials like
clay, slate or shale i.e. Leca.
• Manufacture from industrial by-products such as fly
ash, i.e. Lytag.
• Processing of industrial by-products such as
pelletised expanded slab, i.e. Pellite.
• The required properties of the lightweight concrete
will have a bearing on the best type of lightweight
aggregate to use. If little structural requirement,
but high thermal insulation properties, are needed
then a light, weak aggregate can be used.This will
result in relatively low strength concrete.
Pumice stone
Leca block

16. FOAMED CONCRETE
• Foamed concrete is a highly workable, low-
density material in which air contained is
maintained up to 40% - 80% of the total
volume.
• The size of air bubbles: 0.1mm- 1.5mm.
• The main raw material for Foaming is Genfil &
its organic substance.
• It is generally self-levelling, self-compacting
and may be pumped.
• Foamed concrete is ideal for filling redundant
voids such as disused fuel tanks, sewer
systems, pipelines, and culverts - particularly
where access is difficult.
• It is a recognised medium for the reinstatement
of temporary road trenches.
• Good thermal insulation properties make
foamed concrete also suitable for sub-screeds
and filling under-floor voids.

17. NO FINES CONCRETE
• By omitting the fine aggregate from the mix so that a
large number of internal voids are present; normal
weight coarse aggregate is generally used.This
concrete is no-fines concrete.
• There exist, therefore, large pores within the body of
the concrete which are responsible for its low
strength, but their large size means that no capillary
movement of water can take place.
• Although the strength of no-fines concrete is
considerably lower than that of normal-weight
concrete, this strength, coupled with the lower dead
load of the structure, is sufficient in buildings up to
about 20 storeys high and in many other
applications.
Typical Roof deck detail of Light weight concrete

18. AAC (AUTOCLAVED
AERATED CONCRETE)
• AAC is well suited for high rise buildings and those with
high temperature variations.
• AAC construction systems such as masonry units,
reinforced floor/roof and wall panels and lintels are
being used.
• It can also be sculpted and penetrated by nails, screws
and fixings.
• It is a highly thermally insulating concrete-based
material used for both internal and external
construction & has lower environmental compact.
• AAC products include blocks, wall panels, floor and roof
panels, cladding (facade) panels and lintels.
• Improved thermal efficiency reduces the heating and
cooling load in buildings.
• Porous structure allows for superior fire resistance.
• Larger size blocks leads to faster masonry work.
• Workability allows accurate cutting, which minimizes
the generation of solid waste during use.
• Light weight saves cost & energy in transportation,
labour expenses, and increases chances of survival
during seismic activity.

19. Advantages
• Rapid and relatively simple construction.
• Economical in terms of transportation as well as
reduction in manpower.
• Significant reduction of overall weight results in
saving structural frames, footing or piles.
• Most of lightweight concrete have better nailing
and sawing properties than heavier.
• Stronger conventional concrete.
Disadvantages
• The mixtures are very sensitive to water content.
• Difficult to place and finish because of the porosity
and angularity of the aggregate. I
• In some mixes, the cement mortar may separate
the aggregate and float towards the surface.
• Mixing time is longer than conventional concrete to
assure proper mixing.
ADVANTAGES &
DISADVANTAGES
OF
LIGHT WEIGHT
CONCRETE

20. AGGREGATES
USED TO PRODUCE
LIGHT WEIGHT
CONCRETE
• Natural aggregates:
• Inorganic Natural Aggregates: Diatomite, pumice,
scoria and volcanic cinders are natural, porous
volcanic rocks with a bulk density of 500 – 800
kg/m3 which make a good insulating concrete.
• Organic Natural Aggregates: Wood chips and
straw can be mixed with a binder to provide a
lightweight natural aggregate.These are cellular
materials which have air trapped within their
structures once they have low moisture content.
• Manufactured aggregates:
1. Bloated clay, sintered fly ash and foamed blast
furnace slag.
2. Lightweight expanded clay aggregate:This is
produced by heating clay to a temperature of 1000
– 1200 oC, which causes it to expand due to the
internal generation of gases that are trapped inside.
The porous structure which forms is retained on
cooling so that the specific gravity is much lower
than what was before heating it.
Shale Slate
Fly Ash

21. Thank you.