PREPARED BY :-KISHAN THAKKAR ASHISH NAGPAL

DEMOLISHED WASTE AS COARSE AGGREGATE IN

CONCRETE PRODUCTION

INTRODUCTION• AS URBANIZATION IS INCREASING OVER TIME,

THE DEMAND FOR NEW BUILDINGS AND INFRASTRUCTURE HAS SHARPLY RISEN.

• WITH THE STEEP INCREASE IN THE NEW CONSTRUCTION THE DEMAND OF NATURAL AGGREGATES HAS ALSO RISEN.THIS LEADS TO INCREASED QUARRYING AND SUBSEQUENT DEPLETION OF NATURAL AGGREGATES.

• LARGE QUANTITIES OF CONSTRUCTION AND DEMOLITION WASTES ARE CONTINUOSLY BEING GENERATED WHICH ARE JUST BEING DUMPED IN THE LANDFILLS.THIS REQUIRES LARGE AREAS OF LAND WHICH IS BECOMING DIFFICULT TO FIND.

• BEST SOLUTION WOULD BE TO RECYCLE AND RESUSE THE DEMOLISHED WASTE WHICH WOULD NOT ONLY HELP IN PROTECTING THE ENVIRONMENT BUT ALSO HELP IN DEALING WITH CONSTRUCTION WASTES.

NEED RECYCLED AGGREGATE?...BUT WHY?

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 REPLACEMENT MATERIALS

REASON FOR INCREASE OF QUANTITY OF DEMOLISHED WASTE

• MANY OLD BUILDINGS AND STRUCTURES HAVE OVERCOME THEIR AGE AND LIMIT OF USE.

• STRUCTURES NOT SERVING THE NEEDS IN PRESENT SCENARIO.

• NEW CONSTRUCTION FOR BETTER ECONOMIC GROWTH AND JOB OPPURTUNITIES.

• CREATION OF BUILDING WASTE RESULTING FROM NATURAL AS WELL AS MANMADE DISASTERS.

WHAT DOES DEMOLISHED WASTE CONSISTS OF?

• CONCRETE• BRICK• TIMBER• SANITARY

WARE• GLASS• STEEL• PLASTICS

CON-CRETE65%

BRICKS AND TILES25%

WOOD5%

METAL2%

OTHER3%

Chart Title

APPLICATIONS IN UNPROCESSED STATE:• MANY TYPES OF GENERAL BULK FILLS• BANK PROTECTION• BASE OR FILL FOR DRAINAGE STRUCTURES• ROAD CONSTRUCTION• EMBANKMENNTS• AFTER REMOVAL OF CONTAMINANTS THROUGH SELECTIVE

DEMOLITION,SCREENING, AND/OR AIR SEPERATION AND SIZE REDUCTION IN A CRUSHER TO AGGREGATE SIZESCRUSHED CONCRETE CAN BE USED AS: NEW CONCRETE FOR

PAVEMENTS,SHOULDERS,MEDIAN BARRIERS,SIDEWALKS

CURBS AND GUTTERS AND BRIDGE FOUNDATIONS.

RECYCLED AGGREGATE CONCRETE

• DEMOLISHED CONCRETE WASTE OBTAINED AFTER THE DEMOLITION OF THE STRUCTURE IS BEING PROPERLY PROCESSED BEFORE THE COARSE AGGREGATES OF IT CAN BE USED IN CONCRETE PRODUCTION.

• SO THESE PROCESSED COARSE AGGREGATES UTILIZED IN THE CONCRETE ARE CALLED RECYCLED AGGREGATE AND CONCRETE IS CALLED RECYCLED AGGREGATE CONCRETE.

PROCEDURE

• SORTING• CRUSHING• PRE-SIZING• SCREENING• CONTAMINANT ELIMINATION

BASIC PROPERTIES OF CONCRETE WITH RCA

• LOWER QUALITY OF RAC(RECYCLED AGGREGATE CONCRETE) AS COMPARED TO NA(NATURAL AGGREGATE)

• INCREASED WATER ABSOPTION• DECREASED BULK DENSITY• DECREASED SPECIFIC GRAVITY• INCREASED ABRASION LOSS• INCREASED CRUSHABILITY

METHODOLOGYA. MATERIAL PROPERTIES TEST ON FINE AGGREGATES

TEST ON CEMENT

PROPERTY RESULTSFINENESS MODULUS 2.35

SPECIFIC GRAVITY 2.492BULK DENSITY Compact state-32.2%

Loose state-36.482% MOISTURE CONTENT 0.604%

PROPERTY RESULTS

FINENESS 0.04

SPECIFIC GRAVITY 3.279

STANDARD CONSISTENCY 30.5%

SETTING TIME Initial- 80min Final- 6hr 30 min

PROPERTY NATURAL AGGREGATE RECYCLED AGGREGATE

FINENESS 6.25 5.45

SPECIFIC GRAVITY 2.657 2.469

BULK DENSITY Compact state=1.55kg/L Loose state=1.404kg/L

Compact state1.44kg/L Loose state1.31kg/L

CRUSHING VALUE 27.56% 28.1%

IMPACT VALUE 21.176% 29.66%

WATER ABSORPTION 0.311 2.24

TEST ON COARSE AGGREGATE-12.5 MM DOWN SIZE

B. MIX DESIGNMIX NO.

RCA% W/C CEMENT KG/M3

FINE AGG

KG/M3

SILICAFUMEKG/M3

NCAKG/M3

RCAKG/M3

WATERKG/M3

SP IN %

1 0 0.4 360 762.363 40 1000 0 160 3

2 10 0.4 360 758.236 40 900 100 160 3

3 20 0.4 360 751.095 40 800 200 160 3

4 30 0.4 360 743.953 40 700 300 160 3

5 40 0.4 360 736.812 40 600 400 160 3

COMPRESSION TEST% RCA 3 DAYS

N/MM27 DAYS

N/MM214 DAYSN/MM2

28 DAYSN/MM2

0 41.52 50.24 52.88 69.2

10 41.08 49.99 52.32 68.82

20 40.88 49.89 52.32 68.25

30 38.56 48.56 50.03 67.12

40 36.88 47.12 47.28 59.26

FROM ABOVE TEST RESULTS WE OBSERVE THAT WITH THE INCREASE IN THE REPLACEMENT RATIO THE STRENGTH OF THE CONCRETE REDUCES.BUT FROM GRAPHS IT CAN BE SEEN THAT UPTO 30% REPLACEMENT OF NATURAL AGGREGATES BY RECYCLED AGGREGATES IN THE CONCRETE CAN BE DONE AS 28-DAY COMPRESSIVE STRENGTH CROSSES THE TARGET STRENGTH(ie.67Mpa )

SPLIT TENSILE STRENGTH TEST RESULTSSR. NO. %

REPLACEMENTSPLIT TENSILE STRENGTH

7 DAYS 28 DAYS

LOAD STRENGTH LOAD STRENGTH

1 0 102.1 3.25 177.0 5.63

2 10 98.96 3.15 164.9 5.25

3 20 91.42 2.91 152.4 4.85

4 30 82.93 2.64 138.0 4.40

5 40 78.03 2.48 130.0 4.14

CRACKING PATTERN OF SPECIMEN

FLEXURE STRENGTH RESULTS

SR. NO.

% REPLACEMENT

FLEXURE STRENGTH

1 0 4.882 10 4.713 20 4.634 30 3.935 40 3.54

FAILURE OF SPECIMEN

INTERNATIONAL SCENARIO• EXTENSIVE RESEARCH STARTED AFTER WORLD WAR-

II BUT IN A FRAGMENTED MANNER.• NIXON IN THE YEAR OF 1977 COMPILED ALL THE

WORK CARRIED OUT BETWEEN 1945-1977.• IN 1992 HANSEN PRESENTED A COMPREHENSIVE

DOCUMENT ON RECYCLED AGGREGATE CONCRETE.• GERMANY PRODUCES AROUND 77* MILLION TONS

OF DEMOLISHED WASTE IS PRODUCED, FROM WHICH 70% (i.e. APPROX. 54 MILLION TONS) IS RECYCLED.

*ALL FIGURES MENTIONED ABOVE ARE OF THE YEAR 2007-08

• NETHERLAND PRODUCES AROUND 40* MILLION TONS OF BUILDING AND DEMOLITION WASTE, FROM WHICH 80% IS RECYLED.

• IN SCOTLAND 63% OF DEMOLISHED WASTE IS RECYCLED LEAVING ONLY 37% FOR DUMPING ON LANDFILLS.

• IN USA OF THE TOTAL WASTE, 22% IS DEMOLISHED WASTE. ALONG WITH GREEN BUILDING CONCEPT , RECYCLING OF DEMOLISHED WASTE USA ALSO PROMOTES DECONSTRUCTION IN PLACE OF DEMOLITION WHICH MEANS PLANNED BREAKING OF A BUILDING WITH REUSE BEING THE MAIN MOTIVE.

ALL FIGURES MENTIONED ABOVE ARE OF THE YEAR 2007-08

SOME INTERNATIONAL STANDARDS AND LITERATURES

1. JAPANESE STANDARD AND RILEM REPORTS.2. UNITED KINGDOM STANDARDS

– BS EN 12620:2002 + A1:2008 SPECIFIES REQUIREMENTS FOR RECYCLED AGGREGATES.

– BS 8500-2:200628 SETS OUT RECYCLED AGGREGATE MATERIAL COMPOSITION RESTRICTION.

3. AUSTRALIAN STANDARDS– HB 155:2002 (GUIDE TO THE USE OF RECYCLED CONCRETE

AND MASONRY MATERIALS) DEFINES TWO CLASSES OF RECYCLED AGGREGATE FOR USE AS AGGREGATE FOR NEW CONCRETE AND ALSO TWO GRADES OF RECYCLED AGGREGATE CONCRETE.

4. OTHER COUNTRIES SUCH AS USA, GERMANY, PORTUGAL, HONG KONG AND KOREA ARE ALSO KNOWN TO HAVE SOME QUALITATIVE CRITERIA AND LITERATURE ON PRODUCTION OF RECYCLED AGGREGATE CONCRETE.

5. SOME OTHER NGOS SUCH AS CDRA ARE ALSO PROMOTING RECYCLED AGGREGATE CONCRETE.

INDIAN SCENARIO• ACCORDING TO CPHEEO INDIAN HOUSE BUILDING INDUSTRY

ALONE IS FACING A SHORTAGE OF AGGREGATES TO THE EXTENT OF 55 BILLION M3 AND FURTHERMORE AN ADDITIONAL 750 BILLION M3 OF AGGREGATES WOULD BE REQUIRED TO ACHIEVE THE TARGETS OF THE ROAD BUILDING SECTOR.

• IN NINTIES SERC,GHAZIABAD HAS UNDERTAKEN A PROJECT ON RECYCLING AND REUSE OF DEMOLITION WASTE IN CONCRETE FOR LOW RISE AND LOW COST BUILDINGS WITH THE AIM OF DEVELOPING TECHNIQUES/ METHODOLOGIES FOR USING RECYCLED AGGREGATE CONCRETE IN CONSTRUCTION.

• BUT RAC (& RA) IS NOT WELL ADOPTED IN CONSTRUCTION PRACTICES IN INDIA.

• SO FAR IN INDIA DEMOLISHED AND RECYCLED CONSTRUCTION WASTES ARE EMPLOYED IN EMBANKMENT CONSTRUCTIONS ONLY.

• LIKE OTHER COUNTRIES, INDIA DOES NOT HAVE A STANDARDISED CODAL PROVISIONS OR LITERATURE FOR RECYCLING OF DEMOLISHED WASTE AND RECYCLED AGGREGATE CONCRETE.

• A FIRST PLANT RECYCLING CONSTRUCTION WASTE PLANT (BY IL&FS) HAS BEEN SET-UP IN DELHI OF 500 TON CAPACITY ON A DAILY BASIS.

BARRIERS IN PROMOTING USE OF RECYCLED AGGREGATE CONCRETE IN INDIA

• LACK OF APPROPRIATELY LOCATED RECYCLING FACILITIES

• LACK OF TECHNOLOGY• LACK OF AWARENESS• LACK OF GOVT. SUPPORT• LACK OF PROPER STANDARDS

ADVANTAGES OF RECYCLED AGGREGATE CONCRETE

1. COST SAVING2. ECO-FRIENDLY3. DURABILITY4. VERSATILITY5. SUSTAINABILITY6. OTHER VALUE ADDED ENGINEERING

BENEFITS.

CONCLUSION• THE USE OF RECYCLED AGGREGATES FROM

CONSTRUCTION AND DEMOLITION WASTES IS SHOWING PROSPECTIVE APPLICATION IN CONSTRUCTION AS AN ALTERNATIVE TO PRIMARY (NATURAL) AGGREGATES.

• RECYCLED AGGREGATES ARE FOUND TO POSSESS RELATIVELY LOWER BULK DENSITY, HIGHER CRUSHING AND IMPACT VALUES AND HIGHER WATER ABSORPTION AS COMPARED TO NATURAL AGGREGATE.

• THE COMPRESSIVE STRENGTH OF RECYCLED AGGREGATE CONCRETE IS RELATIVELY LOWER THAN NATURAL AGGREGATE CONCRETE. HOWEVER, THESE VARIATIONS ARE DEPENDENT ON THE ORIGINAL CONCRETE FROM WHICH THE AGGREGATES HAVE BEEN OBTAINED.

• USE OF RCA WILL FURTHER ENSURE THE SUSTAINABLE DEVELOPMENT OF SOCIETY WITH SAVINGS IN NATURAL RESOURCES, MATERIALS AND ENERGY.

• THERE ARE CERTAIN BARRIERS IN PROMOTING THE USE OF RCA (&RAC) IN INDIA LIKE LOW ECONOMIC COST OF VIRGIN AGGREGATE, LACK OF APPROPRIATELY LOCATED RECYCLING FACILITIES, ABSENCE OF APPROPRIATE TECHNOLOGY, LACK OF AWARENESS, LACK OF SPECIFICATION AND GUIDELINES, HIGH INITIAL INVESTMENT ETC.

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