ravi.pate

1. Aggregate
Pic.. In aggregate working
 introduction
 Aggregate can be defined as a material
that is used as filler for filling up the
voids during construction. It comprises
of a broad category of coarse material
that is used in construction. Aggregates
are the most mined category of
minerals in the world. They have been
in use for thousands of years with
significant use taking place back during
the Roman Empire. The invention of
concrete resulted in demand for
aggregate since it is a crucial material
for preparation of concrete.

2. principale
 Working Principle of Aggregate
 Aggregates impart strength by reinforcing
the composite material, that is to say,
they fill up the voids to form a substance
that has more compressive strength. By
filling up the space that is available,
aggregate ensures that the structure
doesn’t fail when load is applied to the
structure.

3. Main Types of aggregate
 Types of Aggregate
 Sand
 Gravel
 Slag
 Geo-synthetic Aggregates and
 Crushed stone
 Granular material
 Recycled concrete

4. Conti…

5. Application
 Applications of Aggregate
 Foundations
 French Drains
 Septic Drain Fields
 Retaining Wall Drains
 Foundations
 Roads
 Railroads
 Concrete Constituent

6. Measures of aggregate size
 Precautionary
Measures
 Make sure that
segregation of aggregate
does not occur.
 Depending upon its
usage, it should be
dry/wet.
 Make sure that it has
passed the sieve size test
and is correctly graded.
 Different applications
require different
standards of aggregates;
be wary of that.

7. Aggregate
Aggregate
Based on Unit
weight
Normal
Sand, gravel,
crushed rocks,
granite, basalt
Light weight
Broken bricks, air
cooled slag,
bloated clay
Hevy weight
Barite,
Magenetite ,
limonite,
hematite
Based on size
Fine
coarse
Based on shape
Rounded,
irreguler, angular
falky, elongated
Based on texure
Glassy, smooth,
grannuler,
crystaline etc..

8. Types of aggegates
o Classification of aggregate based on unit
weight
1. Normal weight aggregates
2. Light weight aggregates
3.Hevy weight aggregates
o Classification of based on size
1. fine aggregate
2. coarse aggregate

9. Conti..
o Classification based on shape
1.Rounded aggregate
2.irreguler aggregate
3.Flaky aggregate
4.Elongated aggregate
o Classification based on texure
 Glassy : black , fint
 smooth: chert , slaet , marble , some
rhyolite
 Granular: sandstone , oolites
 crystalline: fine ,midiume , coarse
 Honeycombed and prous: scoria , pumice
trass

10. Classification of aggregate based
on unit weight
1. Normal aggregates
 Normal weight aggregate can be used in all
types of works.
 The specific grevity of these aggregate is about
1.5 to 2.7.
 The density of concrete produce using is about
2300kg/m3 to 2600kg/m3 .
 Natural aggregates
Sand
Gravel
crushed rock as grenite
Basalt
Quartzilt
Sandston

11. Conti….
 Artificial aggregates
Broken bricks
Air cooled slag
sintered fly-ash
Bloated clay

12. Conti….
2. Light weight aggregate
Natural agg.
pumiee
scoria
rise husk
saw dust

13. Conti…
 Aetificial aggregate
foamed slag
bloated clay
expanded shale
sintered fly ash

14. Conti…
3. Hevy weight aggregate
 barite
 magnetite
 limonite
 hematite

15. Classification based on size
1.Fine aggregate (F.A)
 The size of aggregate 4.75mm and
smaller is called fine aggregate
2. Coarse aggregate (C.A)
 The size of aggregate bigger then 4.75
mm is called coarse aggregate

16. Conti..
Fine
aggregate
•Size <4.75 mm
• Bulking is more (up to
40%)
•F.A fills voids between
C.A
•Eg. Natural sand,
stone
Coarse
aggregate
•Size >4.75 mm
•Bulking is very small &
neglected.
•C.A gives strength to
concrete
•Eg. Gravel , crushed
stone