Download engineering seminars, projects and eBooks.

document file ppt file contact me CERTIFICATE ..........................................................................................

seminar on recycled aggregates

document file

ppt file

contact me

CERTIFICATE ...........................................................................................    II

ACKNOWLEDGEMENT ............................................................................    III

CONTENTS ..............................................................................................     1

INTRODUCTION ......................................................................................     2

HISTORICAL BACK GROUND ....................................................................    3

INTERNATIONAL STATUS .........................................................................    4

INDIAN STATUS ........................................................................................    5

RECYCLED AGGREGATES ..........................................................................    6

WHY RECYCLED AGGREGATES IN CONCRETE? .........................................    6

SOURCES  OF  RECYCLED AGGREGATES ....................................................   6

PRODUCTION OF RECYCLED AGGREGATES................................................   7

METHODS OF PRODUCING HIGH QUALITY RECYCLED AGGREGATES ........   16

COMPARISON OF RECYCLED AGGREGATES AND NATURAL AGGREGATE ...  18

APPLICATIONS OF RECYCLED AGGREGATES................................................  20

MERITS AND DEMERITS OF RECYCLED AGGREGATES.................................  24

EXAMPLES OF APPLICATION.......................................................................  26

CONCLUSION ..............................................................................................  28

RFERENCE .................................................................................................... 29

                                                                                                                                        RECYCLED AGGREGATES

Recycling is the act of processing the used material for use in creating new product.

The usage   of   natural   aggregate   is   getting   more   and   more   intense   with   the

advanced development  in  infrastructure  area.  In  order  to  reduce  the  usage  of

natural  aggregate, recycled  aggregate  can  be  used  as  the  replacement  materials.

Recycled  aggregate  are comprised of crushed, graded inorganic particles processed

from the materials that have been used in the constructions and demolition debris.

These materials are generally from buildings,  roads,  bridges,  and  sometimes  even

from  catastrophes,  such  as  wars  and earthquakes.

                                                                                                                                        RECYCLED AGGREGATES

The applications of recycled aggregate in the construction areas are wide and they had

been used long time ago.

C & D Recycling Industry, the fact file stated that from the time of the Romans, the stones

from the previous roads were reused when rebuilding their vaunted set of roads. It also

stated  that  since  the  end  of  world  war  two,  the  recycling  industry  had  been  well

established in Europe.

Wilmot and Vorobieff (1997) stated that recycled aggregate have been used in the road

industry  for  the  last  100  years  in  Australia.

The extensive research on recycled concrete aggregate and recycled aggregate concrete

(RAC) as started from year 1945 in various part of the world after second world war, but in a

fragmented manner. First effort has been made by Nixon in 1977 who complied all the work

on recycled aggregate carried out between 1945-1977 and prepared a state-of-the-art

report on it. However, a comprehensive state-of-the-art document on the recycled

aggregate concrete has been presented by Hansen & others in 1992 in which detailed

analysis of data has been made, leading towards preparation of guidelines for production

and utilization of recycled aggregate concrete.

                                                                                                                                        RECYCLED AGGREGATES

It has been estimated that approximately 180 million tones of construction & demolition

waste are produced each year in European Union.

10% of recycled aggregates in UK are RCA. 78,000 tons of RCA were used in Holland in 1994.

The Netherland produces about 14million tons of buildings and demolition wastes per

annum in which about 8 million tons are recycled mainly for unbound road base courses.

The 285 million tons of per annum construction waste produced in Germany, out of which

77 million tons are demolition waste. Approximately 70% of it is recycled and reused in new

construction work.

It has been estimated that approximately 13 million tons of concrete is demolished in

France every year.

In Japan total quantity of concrete debris is in the tune of 10-15 million tons each year.

The Hong Kong generates about 20 million tons demolition debris per year and facing

serious problem for its disposal.

USA is utilizing approximately 2.7 billion tons of aggregate annually out of which 30-40% are

used in road works and structural concrete work.

The rapid development in research on the use of RCA for the production of new concrete

has also led to the production of concrete of high strength/performance.

                                                                                                                                        RECYCLED AGGREGATES

The central pollution control board (CPCB) estimates the current quantum of solid waste

generation in India to be 48 million tonnes per annum, out of which the waste from

construction industry accounts for about 12 to 14.7 million tonnes. These waste materials

produced by demolished structures are disposed off by dumping them as land fill. Dumping

of wastes on land is causing shortage of dumping place in urban areas. Therefore, it is

necessary to start recycling and re-use of demolition concrete waste to save environment,

cost and energy.

Realising the future & national importance of recycled aggregate concrete in construction,

SERC, Ghaziabad had taken up a pilot R&D project on Recycling and Reuse of Demolition and

Construction Wastes in Concrete for Low Rise and Low Cost Buildings in mid nineties with

the aim of developing techniques/ methodologies for use recycled aggregate concrete in

construction.

The properties of RAC has been established and demonstrated through several

experimental and field projects successfully. It has been concluded that RCA can be readily

used in construction of low rise buildings, concrete paving blocks & tiles, flooring, retaining

walls, approach lanes, sewerage structures, subbase course of pavement, drainage layer in

highways, dry lean concrete(DLC) etc. in Indian scenario. Use of RCA will further ensure the

sustainable development of society with savings in natural resources, materials and energy.

                                                                                                                                        RECYCLED AGGREGATES

RECYCLED AGGREGATE

Recycled aggregates are the aggregates produced from the processing of previously used

construction materials such as concrete or masonry.

                       Recycled aggregates consists of hard, graduated fragments of inert mineral

materials, including sand, gravel, crushed stone, slag, rock dust, or powder.

WHY RECYCLED AGGREGATES ?

1. Due to rapid growth in population and urbanization, the natural resources are

depleting.

2. The construction industry is facing non availability of good quality aggregates within

reasonable distances.

3. High cost of good quality crushed aggregates, as compared to Recycled aggregates.

4. An enormous increase in the quantity of waste materials and the shortage of

dumping sites.

5. Shortage of dumping sites has resulted in sharp increase in transport and disposal

costs.

6. High dumping cost for demolished waste, because it has to be dumped away as for

as possible form construction site.

SOURCES OF RECYCLED AGGREGATES

1. Construction and demolished waste generated due to natural disasters, for future

development the old buildings are replaced by new ones, and war inflicted damages.

2. Crushing  of  Portland  concrete  pavement

3. Tested specimens from laboratory.

4. Concrete from ready mix concrete plants and precasting units.

5. Worn out rail ballast.


downlaod complete file from the link given at the top of the page