Strength and Durability of RecycledStrength and Durability of Recycled Concrete … ·...

2010 International Concrete Sustainability Conference, Dubai, UAE 1

Strength and Durability of RecycledStrength and Durability of RecycledStrength and Durability of Recycled Strength and Durability of Recycled Concrete made from Recycled Aggregate Concrete made from Recycled Aggregate

and Wastewater and Wastewater

Mohamed ElchalakaniDubai Mens College

1


DMC Silicon Oasis CampusDMC Silicon Oasis Campus

International Conference on Concrete Sustainability, Dubai, 13-14 December 2010 2


Session OutlineSession Outline

C&D Waste StatisticsThe making of RC from DWThe making of RC from DWStrength ResultsDurability ResultsConclusionsFuture Research

3International conference on Concrete Sustainability, Dubai, 13013 December 2010


The The Current Material Current Material Process in the Process in the GCCGCCThe one way stream Bob Scott ,ATKINS, 2010)The one way stream Bob Scott ,ATKINS, 2010)

Extraction Construction Demolition

Manufacturing Landfill Waste


Statistics for C&D WasteStatistics for C&D Waste

Around 75% of the GCC Waste is from constructionThe caption shows a Typical Construction Landfill Site in the GCC

International conference on Concrete Sustainability, Dubai, 13-14 December 2010 5


Statistics for C&D WasteStatistics for C&D Waste

Waste EU-27High Low

USA GCC

Total Municipal and 2,900 1,228 380 120C&D Waste (million ton/year)

C&D Waste(million ton/year)

727 307 130 90(million ton/year)

% C&D /Total 25% 25% 35% 75%

Population (Millions in 2010)

501 310 40

In the USA alone 2.0 billion tons of fresh aggregate are produced every year andit will increase to 2 5 billion tons by 2020 (Fisher and Werge 2009)


it will increase to 2.5 billion tons by 2020 (Fisher and Werge 2009).

Simply it is unsustainable from both point of views: the availability of virginaggregate; and the wasted unused aggregate from demolition!!


C&D WasteC&D Waste

C&D Waste:ConcreteAsphaltB i k

EU-28 Target is to Recycle 70% of C&D Waste by 2020

BricksTilesCeramicGypsumOzone Depleting Substances

Japan using 3R philosophy (reduce, Reuse, Recycle), is targeting 0%

Waste Society by 2020

Ozone Depleting SubstancesDangerous substances such as Asbestos



What we already know!!What we already know!!Comparison between RA and NAComparison between RA and NA

When demolished concrete is crushed, a certain amount of mortar and cement paste from the original concrete remains attached to stone particles in recycled aggregate. This attached mortar and the increased water to rectify the slump are the main reasons for the lower quality ofwater to rectify the slump are the main reasons for the lower quality of Recycled Aggregate (RA) compared to Natural Aggregate (NA). The RA compared to the NA has the following properties:

increased water absorption pdecreased bulk densitydecreased specific gravityincreased abrasion lossincreased crushability yincreased quantity of dust particlespossible content of chemically harmful substancesWide variation in mechanical properties depending on the amount of pastep



What we already knowWhat we already knowComparison between RC and NCComparison between RC and NC

The inconsistent flexural and bond strength variations caused by cement paste!


The mechanical properties of hardened RC made from RA only is welldocumented, however RC made from RW or RW+RA is not yet known(Data shown from Mirjana Maelesv etal., J. Sustainability, volume 2, 1204-1225,2010)


Test ProgramTest Program

The recycled aggregate was obtained from a demolitionconstruction waste at Emirates Recycling Pty Ltd in Dubai.“Emirates Recycling” is an $18 million joint venturey g jbetween Al Rostamani Group and the Italian General Workinfrastructure development company. The averagemeasured density was 2.51 t/m3 and water absorption ofthe recycled aggregate was 5.2%. The received aggregatesthe recycled aggregate was 5.2%. The received aggregateswere sieved and the 10 and 20 mm sizes were separatedand used in the mix.

Th R l d W t W t bt i d f th MBRThe Recycled Waste Water was obtained from the MBRprocess from a newly constructed wastewater treatmentplant attached to a construction labor camp in Alquzsuburb in Dubai.



Test Program and MatrixTest Program and Matrix

% Recycle RW RW+RA Type Beams Beams

0%

RW-P0% RW/RA-P0% Plain

RW-B0% RW/RA-B0% Bottom Steel

RW T0% RW/RA T0% T St l

The test program involves the preparation of moderatestrength concrete C40 out of recycled water andrecycled aggregate. A total of 27 standard cubes150x150x150 mm and 27 standard cylinders 150 mmdiameter and 300 mm long were prepared to BS 1881-

RW-T0% RW/RA-T0% Top Steel

RW-TB0% RW/RA-TB0% Top+Bottom Steel

25%




g p p116 and 40 beams 600x150x150 mm to BS 1881-118.The control mix had 370 kg OPC, 159 kg of DEWAwater, 559 kg of 20mm crushed RAK Rock, 365 kg of10mm crushed RAK Rock, 699 kg of 5mm crushed RAKRock and 238 kg dune sand. For the aggregate, onlythe 10 mm and 20 mm were replaced (The 0-5 mm sizeRW-TB25% RW/RA-TB25% Top+Bottom Steel

50%





the 10 mm and 20 mm were replaced (The 0-5 mm sizewas not recycled) by recycled material after it wassieved.

75%







100% RW-B100% RW/RA-B100% Bottom Steel




Recycled Aggregate Plant in DubaiRecycled Aggregate Plant in Dubai

Input Material Material Cleaned and Crushed



Recycled Wastewater using Membrane Bioreactor Recycled Wastewater using Membrane Bioreactor (MBR) Process(MBR) Process



Recycled Water using Membrane Bioreactor Recycled Water using Membrane Bioreactor (MBR) Process(MBR) Process


http://www.youtube.com/watch?v=fxHmLK9u7H4&NR=1http://www.youtube.com/watch?v=xpr2IV-

eSOg&feature=related


Recycled Water using MBR ProcessRecycled Water using MBR Process



RC Project PhotosRC Project Photos



Beam Specimen Beam Specimen SchmeaticSchmeatic

Figure 2 Beam Geometry and Reinforcement



Test Results: Cube StrengthTest Results: Cube Strength

-5

0

0% 25% 50% 75% 100% 125%

25

-20

-15

-10

Cubes-RW

% S

tre

ng

th

-35

-30

-25Cubes-RWRA

%

% Recyle material

Figure 3 Effect of %recycled material on axial cube strength

% Recyle material



Test Results: Bending Strength of BeamsTest Results: Bending Strength of Beams

25.0

30.0Plain

0 0

5.0

10.0

15.0

20.0

25.0

Per

cent

age

%

0% 25% 50% 75% 100%-20.0

-15.0

-10.0

-5.0

0.0

Figure 5 Effect of % recycled material on plain beam bending strength

0% 25% 50% 75% 100%RW 0.0 25.0 10.0 -15.0 5.0RW-RA 0.0 5.0 5.0 -5.0 -5.0


g



0.0

-20.0

-15.0

-10.0

-5.0ge

%Top Reinforcement

0% 25% 50% 75% 100%-40.0

-35.0

-30.0

-25.0

Perc

enta

g

Figure 6 Effect of % recycled material on beam bending strength with top reinforcement

RW 0.0 -26.8 -24.4 -17.1 -29.3RW-RA 0.0 -14.6 -36.6 -12.2 -26.8




20.0

30.0

40.0Bottom reinforcement

20 0

-10.0

0.0

10.0

Per

cen

tag

e %

Figure 7 Effect of % recycled material on beam strength with bottom

0% 25% 50% 75% 100%RW 0.0 22.8 14.0 29.8 0.0RW-RA 0.0 22.8 36.8 31.6 -10.5

-20.0


Figure 7 Effect of % recycled material on beam strength with bottom reinforcement



-5.0

0.0

20 0

-15.0

-10.0

age

%

0% 25% 50% 75% 100%-30.0

-25.0

-20.0

Perc

enta

Top + Bottom

Figure 8 Effect of % recycled material on beam strength with bottom

RW 0.0 -13.8 -25.3 -13.8 -16.1RW-RA 0.0 -13.8 -2.3 -25.3 -17.2


reinforcement


Test Results: DurabilityTest Results: DurabilityRapid Chloride Penetration Test to ASTM C1202Rapid Chloride Penetration Test to ASTM C1202

60.00

70.00 RCP

20.00

30.00

40.00

50.00

enta

ge %

0% 25% 50% 75% 100%RW 0.00 13.37 19.00 27.27 33.10RW-RA 0.00 35.32 42.11 49.76 61.76

0.00

10.00Perc

e


Figure 9 Effect of % recycled material on durability by using RCP test


Test Results: DurabilityTest Results: DurabilityWater Permeability Test to BS EN 12390Water Permeability Test to BS EN 12390--88

200.00

250.00

W.P (MM)

50.00

100.00

150.00

Perc

enta

ge %

Figure 10 Effect of % recycled material on durability by using WP test

0% 25% 50% 75% 100%RW 0.00 33.33 50.00 66.67 83.33RW-RA 0.00 116.67 138.89 161.11 194.44

0.00

P


Figure 10 Effect of % recycled material on durability by using WP test


Test Results: DurabilityTest Results: DurabilityWater Absorption Test to BS 1881Water Absorption Test to BS 1881--122 122

120.00

40 00

60.00

80.00

100.00

age

%

W.A (%)

0% 25% 50% 75% 100%RW 0 00 24 14 44 83 58 62 65 53

0.00

20.00

40.00

Per

cen

ta


Figure 11 Effect of % recycled material on durability by using WA test

RW 0.00 24.14 44.83 58.62 65.53RW-RA 0.00 72.41 79.31 86.21 103.45


Test Results: DurabilityTest Results: DurabilityInitial Surface Absorption Test to BS 1881Initial Surface Absorption Test to BS 1881--208208

200.00

250.00

ISAT

50.00

100.00

150.00

Perc

enta

ge %

0% 25% 50% 75% 100%RW 0.00 40.00 60.00 80.00 120.00RW-RA 0.00 120.00 160.00 180.00 220.00

0.00


Figure 12 Effect of % recycled material on durability by using ISAT test


GGBS Replacement in Recycled concreteGGBS Replacement in Recycled concrete



COCO2 2 EmissionsEmissions

Material Source Co2 kg/Ton Cost/m3 Mat(kg)/m3 Cost/m3 Co2 kg /m3OPC UAE 959 240 370 88.8 354.83GGBS UAE 155 280 0Fly Ash India 93 300 0

370Water UAE 1 25 159 3 975 0 159

Total Binder

Control Mix

Binder

Case Study

Burj Khalifa has 330,000Water UAE 1 25 159 3.975 0.159W/C 0.4320 mm Aggregate RAK 7 48.5 559 27.1115 3.91310 mm Aggregate RAK 7 48.5 365 17.7025 2.5555 mm Aggregate RAK 7 51 699 35.649 4.893Dune Sand AL Ain 5 25 238 5.95 1.19

1861 0Admixture kg/m3 SP 495 508 5 5.5 27.5 2.794

Total Co2 kg/m3 370

Agg

reeg

ates

Total Aggregates

Burj Khalifa has 330,000m3 of concrete. Reductionin Carbon foot print if G80Recycled Concrete wasused =330,000x(370-

Material Source Co2 kg/Ton Cost/m3 Mat(kg)/m3 Cost/m3 Co2 kg /m3OPC UAE 959 240 56 13.44 53.704GGBS UAE 155 280 314 87.92 48.67Fly Ash India 93 300 0 0

370

G80 - 80% GGBS Replacement

BinderTotal Binder

Total Co kg/m3

Total Cost/m3 207 118)/1000=85,800 ton.

This represents:

85 800/6/100 143370Water UAE 1 25 159 3.975 0.159W/C 0.4320 mm Aggregate RAK 7 48.5 559 27.1115 3.91310 mm Aggregate RAK 7 48.5 365 17.7025 2.5555 mm Aggregate RAK 7 51 699 35.649 4.893Dune Sand AL Ain 5 25 238 5.95 1.19

1861 0Admixture kg/m3 SP 495 508 5 5.5 27.5 2.794

Total Binder

Agg

reeg

ates

Total Aggregates

85,800/6/100=143passenger cars emissionsper 100 year the designlife of the building.


g/

Total Co2 kg/m3 118Total Cost/m3 219


LEED 2009 CertificationLEED 2009 Certification-- Case StudyCase Study

MR Credit 4: Recycled Content

IntentTo increase demand for building products that incorporate recycled content materials, g ythereby reducing impacts resulting from extraction and processing of virgin materials.

RequirementsUse materials with recycled content1 such that the sum of post-consumer recycled content (such as C&D waste) plus 1/2 of the pre-consumer content (such as scrap metal) constitutes at least 10% or 20%, based on cost, of the total value of the ) , ,materials in the project. The minimum percentage materials recycled for each point threshold is as follows:

Recycled Content Points Comments

10% 1 Based on cost

Case StudyAssuming that the concrete represents 40% of the total building cost:

20% 2 Based on cost

- For 25% Recycled Agg Concrete 0.25x0.40 = 10% Recycled content 1 Point

- For 50% Recycled Agg Concrete 0.50x0.40 = 20% Recycled content 2PointsInternational conference on Concrete Sustainability, Dubai, 13-14 December 2010 30


LEED 2009 CertificationLEED 2009 Certification-- Case StudyCase Study

WE Credit 2: Innovative Wastewater TechnologiesIntent

To reduce wastewater generation and potable water demand while increasing the local aquifer recharge.

RequirementsOption 1: Reduce potable water use for building sewage conveyance by 50%through the use of water-conserving fixtures (eg. Water closets, urinals) or non-potable water (eg. Captured rain water, recycled grey water, onsite ormunicipality treated water).

Option 2: Treat 50% of wastewater onsite to tertiary standards Recycled Content Points Comments

Reduce potable water by 50% 2 Option 1

Case Study

Treat wastewater on site 50% 2 Option 2

y- Treat 50% waste water using MBR System on Site 2 Points

- Treat 25% waste water using MBR System on Site 1 PointInternational conference on Concrete Sustainability, Dubai, 13-14 December 2010 31


ConclusionsConclusions

The effect of recycled aggregate and water on axial and bendingstrength was found moderate and less than 40% but had asignificant effect on durability which was of the order of 200%.The effect of increasing the percent of the recycled water andrecycled aggregate RW+RA on axial strength of cubes andcylinders is more pronounced compared to recycled water RWonly.The beams with bottom reinforcement had the most severe effecton bending strength which was in the order of 24% for RW and36% for RWRA.The deterioration in the durability for RWRA was almost doublethe one for RW only. To enhance the durability of recycled concrete and to reduce Co2 emissions , GGBS and or Fly Ash should be used for any future building construction in the Gulf.

32International conference on Concrete Sustainability, Dubai, 13013 December 2010


Future ResearchFuture Research

Recycled Concrete Reinforced with GFRP RebarsThe mechanical properties of Recycled concrete reinforced with GFRP rebars is not welldocumented as there is little experimental testing of such concrete. Recent experimental testingof GFRP showed excellent tensile strength as well as superior durability. It is proposed toperform similar experiments to the one presented in this paper for the reinforced concrete beamsperform similar experiments to the one presented in this paper for the reinforced concrete beams.The results of these future tests will be compared with those obtained for carbon steel reinforcingbars.



AcknowledgmentsAcknowledgments

DMC StudentsAhmed Badir AlnajjarAhmed Abdurrahman ShabaanAbdulla Mohammed GribanAhmed Khalid AljaziriAbdulaziz Alali

Industry PartnersEmirates Recycling Hi Star water Solutions (Dubai)( )MB MixUni Mix (Dubai)Dubai Central Laboratory (DM)G i T ti L b tGeoscience Testing Laboratory


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