This document is a study on recycled aggregate concrete conducted by Neelanjan Sarkar from Murshidabad College of Engineering & Technology. It discusses what recycled aggregate concrete is, its characteristics, classification, production process, uses, applications, and benefits. Recycled aggregate concrete is produced using crushed waste concrete as a substitute for natural aggregates. It has properties like lower strength, density and higher water absorption compared to normal concrete. However, using recycled materials reduces waste and saves on costs and natural resource usage, making it a more sustainable construction material.

1. A STUDY ON
“RECYCLED AGGREGATE CONCRETE”
BY- NEELANJAN SARKAR
MURSHIDABAD COLLEGE OF ENGG. & TECH.
BRANCH -- Civil engineering
Year -- 3rd
year (6th
sem)

2.  I would like to express my gratitude to all those who gave
me the possibility to complete this project.
I am deeply indebted to my my HOD (CIVIL) and the faculty
members of my department whose help, stimulating
suggestions and encouragement helped me in all the time
of research and for completing this project.
 I would also like to thank my friends for supporting me a
lot .
Neelanjan Sarkar
ACKNOWLEDEGMENT

3. CONTENTS
 INTRODUCTION
 WHAT IS RECYCLE AGGREGATE CONCRETE?
 CHARACTERISTICS OF RECYCLE AGGREGATE
CONCRETE
 CLASSIFICATION OF RECYCLE AGGREGATE
CONCRETE
 PROCESS OF RECYCLE AGGREGATE
CONCRETE
 HOW TO PRODUCED RECYCLE AGGREGATE
CONCRETE
 USE OF RECYCLE AGGREGATE CONCRETE
 APPLICATION OF RECYCLE AGGREGATE
CONCRETE
 BENEFIT OF RECYCLE AGGREGATE
CONCRETE
 CONCLUSION

4. INTRODUCTION
 To achieve sustainable issue in
construction area, researchers and
companies focus on using waste
concrete as a new construction
material. It is called recycled
aggregate which can be produced by
concrete crusher.
 The aggregates are categorized by
size as coarse and fine aggregate.
 The characteristic of recycled
aggregates could be different by its
parent concrete because the parent
concrete was designed for its
purposes such as permeable, durable
and high strength concrete

5. Its a lower density , elastic modulus, strength and a
higher water absorption capacity.
recycled aggregate has a proportional mortar which
attached to aggregate, it gives a higher porosity and a
lower strength to RAC than the normal concrete.
In addition, since recycled aggregates require a more
amount of water than natural aggregate, shrinkage
issue could be a problematic to use RAC in practically.
What Is Recycle aggregate concrete

6. Characteristics of recycle aggregate
concrete
Recycle aggregate concrete
has a Crushed sound and
clean waste concrete of at
least 95% by weight of
concrete with typical total
contamination lower than 1%
of the bulk mass
Class 1A RCA is a well graded
RCA with no more than 0.5%
brick content

7. Classification & properties of recycle
aggregate concrete
Material composition is the
basis for classification of
recycled concrete aggregate
in two main types-
1) Crushed concrete
2) Mixed material
Each of these types is
divided in a class for bound
and a class for unbound use
Crushin
g age
Bulk
specific
gravity
Bulk
density
Absorp
tion
(%)
Crushin
g
value(%
)
1 days Coarse
Mediu
m
Fine
2.59
2.35
2.23
1433
1220
1342
3.2
9.7
11.2
25.4
n/a
n/a
3 days Coarse
Mediu
m
Fine
2.60
2.38
2.25
1433
1234
1342
3.4
8.1
11.4
25.3
n/a
n/a
28 days Coarse
Mediu
m
Fine
2.55
2.32
2.23
1433
1278
1321
2.3
8.0
12.7
24.3
n/a
n/a

8. 1. crushed concrete- This materials generally resulted
in increased water demand and decreased
workability.
2. Mixed concrete- mixed concrete remain plastic for
a short time. This properties are important because
they affect the quality and in place cost of the
hardened concrete

9. Process of recycle aggregate
concrete
Process of recycle
aggregate concrete-
 crushing
 pre-sizing
 sorting
 screening
 contaminant elimination

10. How to produce recycle aggregate
concrete
 Crushing and screening systems start with
primary jaws, cones and/or large impactor
taking rubble from 30 inches to 4 feet.
 A secondary cone or impactor may or may
not need to be run, and then primary and
secondary screens may or may not be used,
depending upon the project, the equipment
used and the final product desired.
 A scalping screen will remove dirt and
foreign particles. A fine harp deck screen
will remove fine material from coarse
aggregate.
 Further cleaning is necessary to ensure the
recycled concrete product is free of dirt,
clay, wood, plastic and organic materials.
 This is done by water floatation, hand
picking, air separators, and electromagnetic
separators.

12. Uses of recycle aggregate
concrete

13. In a world that is increasingly emphasizing on
sustainable construction practices; recycled
aggregates have a major role to play.
Recycled concrete is in fact recognized by the LEED
Green Building Rating System in its point system.
Credit 4 (Materials and Resources) points out that
“specify a minimum of 25% of building materials that
contain in aggregate a minimum weighted average of
20% post-consumer recycled content material, OR, a
minimum weighted average of 40% post-industrial
recycled content material.”
Making Concrete more Green

14. ∗ Apart from the obvious benefits, there is one more
aspect that of carbonation that occurs during the
process of concrete crushing for producing concrete
aggregates. Certain areas that were earlier not
carbonated absorb carbon dioxide from the
immediate environs adding to the already high
sustainability quotient of concrete.

15. For recycled concrete to be used in greater quantities
in a country like India, there are certain aspects that
need to be taken care of initially.
∗ The setting up of a proper institutional mechanism for
taking care of all the steps, such as collection of the
construction and demolition waste, transportation,
and disposal is of key importance.
∗ Outsourcing of such functions to private enterprise is
an idea that the concerned authorities could give a
though to in this day and age of open economies.
Challenges in the Indian Context

16. ∗ Set up of the necessary processing infrastructure.
∗ Necessary infrastructure should also be available for
testing the quality of recycled aggregates.
∗ Project developers need to be educated on on-site
waste management plans.
∗ Concerned authorities need to plan an awareness
campaign, using the electronic and online media to
promote the virtues of recycled aggregates.
∗ Removing misconceptions about recycled aggregates
as being of inferior quality among the public.
STEPS TO BE TAKEN

17. Scope of application
CLASS-- H No limitation are put on the type
segment for concrete & structures
with a nominal strength of45 mpa
or less.
CLASS –M Member not subjected to drying or
freezing – and – thawing action,
such as piles ,under ground beam
and concrete fill in steel tubes.
CLASS-- l Backfill concrete, building concrete,
and leveling concrete
Application of recycle aggregate

18. There are a variety of benefits in recycling concrete
rather than dumping it or burying it in a landfill.
Keeping concrete debris out of landfills saves landfill
space.
Using recycled material as gravel reduces the need for
gravel mining
Using recycled concrete as the base material for
roadways reduces the pollution involved in trucking
material.
Benefit of recycle aggregate
concrete

19. Initial moisture states of RCA is one of the most important
variables that impact strength and shrinkage.
 When oven-dried RCA is used, strength is used to be
greatly reduced but free shrinkage as measured in this
study was low.
 The creep to free shrinkage ratio for RAC was similar to
that of normal concrete at 7 days under restrained
conditions.
 When greater volume of recycled fine aggregates and fly
ash was used, free shrinkage of the specimens was
reduced.
Conclusion

20. The use of recycled aggregate has been found to be
better than that of virgin aggregates for certain
applications. For example, the physical properties of
recycled aggregates make them ideally suited for
road base and sub-base. This is because of their
physical properties which means less cement is
required making them suited for sub-base use. This is
in addition to the cost benefits accrued by developers
in the process.

21. Recycled concRete AggRegAte
An ideA
Whose time hAs come

22. Thanking you