WEBINAR 2: SUSTAINABILITY OF RECYCLED AGGREGATES

WEBINAR 2: SUSTAINABILITY OF RECYCLED AGGREGATESUNIVERSITI MALAYSIA PERLIS

WEBINAR 2: SUSTAINABILITY OF RECYCLED AGGREGATES

RECYCLED AGGREGATE CONCRETE IN SOUTH EAST ASIA –

FUNDED BY THE ROYAL ACADEMY OF ENGINEERING’S [FRONTIERS CHAMPION PROJECT]

PROFESSOR DR MOHD

MUSTAFA AL BAKRI ABDULLAH

DR RAFIZA BINTI

ABD RAZAK

DR WARID WAZIEN

AHMAD ZAILANI

LOCATION OF UNIVERSITI MALAYSIA PERLIS

INF

RA

ST

RU

CT

UR

E &

FA

CIL

ITIE

S

UniMAP CampusLocation Campus

Pauh Putra (Main

Campus)Engineering Campus

UNICITI, Sungai ChuchuhEngineering Technology

Campus

City Campus, Kangar Business Campus

6 (SIX) FACULTIES

1. Faculty of Electronic Engineering Technology

2. Faculty of Electrical Engineering Technology

3. Faculty of Mechanical Engineering Technology

4. Faculty of Chemical Engineering Technology

5. Faculty of Civil Engineering Technology

6. Faculty of Applied and Human Sciences

3 (THREE) INSTITUTES

1. Institute Of Engineering Mathematics

2. Institute of Nano Electronic Engineering

3. Institute of Sustainable Agrotechnology

12 (TWELVE) CENTRE OF EXCELLENCE

1. Advance Sensor Technology (CEASTech)

2. Unmanned Aerial Systems (UAS)

3. Geopolymer & Green Technology (CEGeoGTech)

4. Renewable Energy (CERE)

5. Advanced Communication Engineering Centre (ACE)

6. Frontier Materials Research (FRONTMAT)

7. Biomass Utilization (COEBU)

8. Centre of Automotive & Motorsport (MOTECH)

9. Sport Engineering Research Centre (SERC)

10. Social Innovation & Sustainability (CoESIS)

11. Water Research and Environmental Sustainability Growth

(WAREG)

12. Advanced Computing Centre of Excellence (ADCOMP)

QS Asian University Rankings# Year 2021

# TOP 207

QS World University Rankings# Year 2021

#801-1000

QS Star Ratings# Year 2020

5 STARS

Engineering – Electrical & ElectronicQS WUR by Subject 2020

# Year 2020

#451-500

https://cegeogtech.unimap.edu.my/

CONCRETE CERAMIC WASTE SLAB (CCWS)

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1. INTRODUCTION

2. PROPERTIES OF RA : FRESH STATE, PHYSICAL AND MECHANICAL PROPERTIES

3. TECHNIQUES TO IMPROVE RAC PROPERTIES

4. DURABILITY PROPERTIES OF RAC

5. CASE STUDY

6. SUMMARY

7. QUESTION AND ANSWER

WHAT IS RECYCLED AGGREGATES?• Recycled aggregates are developed from the reprocessing of materials that have been originally used in construction.

• Recycled aggregates are develop from waste materials (fly ash, bottom ash, and any pozzolanic materials)

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Waste from

construction

and

demolition

Returned

concrete from

ready mix trucks

Waste from

masonry

Waste from

plastic

Waste from

ceramic

Waste from

coal

combustion

WHAT IS RECLAIMED ASPHALT PAVEMENT (RAP) AGGREGATES?

Potential uses for RAP products include:

• RAP Fines:

• sealing grit alternative ideal as a surface void filler or for

blinding off fresh tacky bitumen surfaces

• RAP Aggregates:

• source of recycled aggregates ideal for asphalt

production.

• alternative recycled aggregates option for membrane

bitumen seals

• RAP Base:

• excellent for sub-base and basecourse materials. Suitable

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BENEFITS OF USING RECYCLED AGGREGATES1. Cost Saving

Making use of recycled aggregates over virgin materials can save money as they are less expensive to produce.

If recycled materials are available locally then this can reduce the cost of transporting the aggregates

Producing recycled aggregate for resale is more cost-effective than sending un-wanted materials to landfill and incurring landfill tax.

2. Eco-Friendly

Recycled Aggregate is regarded to be a ‘green’ construction material

Using recycled aggregate reduces the amount of virgin aggregates which are created and therefore means less use of natural resources

There is increasing pressure on landfill capacity, and pressure on construction sites to divert waste away from landfill to meet UK and sustainability targets

3. Versatile and Durable

4. Tax Incentives For Green Buildings

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MAIN ISSUES FOR RECYCLED AGGREGATE

Main Issues for Recycled Aggregate

Use

Limiting Standards/Specificati

ons

Low Quality

Customer Perception

Low Supply and

Demand

Distance of C&D

Waste Recycling Facility

Insufficient Financial Incentives

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MAIN ISSUES FOR RECYCLED AGGREGATESust

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SIGNIFICANCE OF RECYCLED AGGREGATE

The rapid industrialization and urbanization

have led to increased demolition of old

structures and construction of new ones.

Conventionally, these waste products would be

dumped in the landfill sites or used in

pavement construction. But, as the land for

landfill becomes scarce e.g., Hong Kong and

the world demand of aggregate reaches as

high as 48.3 billion tonnes annually after

2010, ways to use the C&D waste is becoming

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RA PROCESSSust

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1. IMPACT CRUSHER

2. LARGE JAW

CRUSHING


FRESH STATE, PHYSICAL AND MECHANICAL PROPERTIES

PROPERTIES OF RECYCLED

AGGREGATE

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PROPERTIES OF RECYCLED AGGREGATE

Water Absorption

Water absorption capacity of RA is higher than that of virgin aggregates and this is because of porosity of adhered mortar.

Water absorption was observed to increase with increase in size of aggregate

Codes restrict the use of RA with water absorption capacity greater than 7–10% to be used in structural concrete

(Spanish Structural Concrete Code), 2008

RILEM, I2I-DRG guidance for demolition and reuse of concrete and masonry, Mater. Struct. 27 (1994) 557-559S

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FRESH STATE PROPERTIES

Workability

Since, the porosity of RA is higher than the virgin aggregate, theworkability of the RAC mix is lower for the same water content than that ofNAC.

The initial slump and slump loss depend on the initial free water content ofaggregates. It was evident from the findings that the oven dried aggregatesled to a higher initial slump and quicker slump loss, while air dried andsurface saturated dried aggregates had normal initial slumps and slumplosses.

Usage of super-plasticizer leads to considerable increase in workability

The slump of the RAC can also be increased by using water repellentagents such as silane

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MECHANICAL PROPERTIES

Compressive Strength

Increase in RA amount at the same w/c ratio leads to decrease incompressive strength, generally up to 10% lower than that of virginaggregate concrete.

Compressive strength of RAC decreases with increase in water-binderratio similar to that of NAC – weaker ITZ Zone

With the increase in water absorption, the strength of RAC decreasedwhen compared to that of normal concrete

RAC prepared with higher grade concrete shows significantly lessdifference in compressive strength than compressive strength of NAC.

It was concluded that RAC is not fit for high performance concrete due tounreliability.S

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Compressive Strength – How to improve?

1. Usage of admixtures, superplasticizer

2. W/C ratio needs to be lowered up to 10% and cement content needs tobe increased by 10%

3. Pozzolanic materials – fly ash, silica fume,

4. Recommended 10–15% glass powder of cement weight

5. Surface Modification Technology - coating of aggregates with an inorganicpaste and it was observed to cause an increase of about 26% increase incompressive strengthS

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MECHANICAL PROPERTIES Split Tensile Strength

Split tensile strength decreases with increase in RA replacement ratio

Many studies show that the tensile strength of RAC for replacement ratioof up to 30% is same or even exceeds the tensile strength of virginaggregate concrete

The split tensile strength of RAC has also been correlated to w/c ratioand dry mixing method

Open environment and water immersed curing exhibits higher tensilestrength than laboratory conditions

The split tensile strength of RAC also depends on the strength of concretefrom which the RA was derived

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Flexural Strength

The flexural strength of RAC has been observed to decrease withincrease in RA replacement ratio

Increase in water-binder ratio has been observed to have affirmativeeffect on flexural strength of RAC

The use of RA with lower water absorption capacity leads to betterflexural strength in RAC

Addition of glass fibers, fly ash improves the flexural strength

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TECHNIQUES TO IMPROVE RAC PROPERTIES

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1. IMPREGNATION IN ACID SOLUTION

Impregnation in the solution of silica fume (increase of 23%–33%) and an ultra-sonic cleaning (increase of 3% and 7%) – increase compressive strength, filling up the micro cracks, thus good ITZ obtained

Two stage mixing approach (TSMA) gives better compressive strength.

optimum amount of

RA to be used in RAC

is 25%–40% by using

TSMA

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2. COATING POZZOLANIC MATERIALS

RAs surface were coated with pozzolanic powder (fly-ash, silica fume and blast furnace slag) which results in better quality of RA

WATER +

POZZOLANIC

POWDER

SLURRYRECYCLED

AGGREGATE

(RA)ADD

COATED RA

IMPROVED

COMPRESSIVE

STRENGTH,

FLEXURAL

STRENGTH AND

WORKABILITY

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2. SURFACE-MODIFICATION TECHNOLOGY

Covering the surface of RA with coarse paste consisting of inorganic admixtures.

This led to increase of 15% and 30% in compressive strength and shear strength, respectively

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DURABILITY PROPERTIES OF RAC

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1. CARBONATION DEPTH

Carbonation depth of RAC increases with the increase in replacement ratio of NA with RA – due to high porosity

Excessive curing and contact with water has an adverse effect on the carbonation resistance. The depth of carbonation was reported to be increased to almost twice when it is cured in water- due to the high internal humidity of the concrete produced by using cured RAC

Water binder ratio has also been observed to affect the carbonation depth

The increase in Recycled Fine Aggregate (RFA) content leads to increase in carbonation depth.

The use of fly ash as partial replacement of cement increases the carbonation depth of the concrete

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1. CARBONATION DEPTH – HOW TO REDUCE?

Use silane-based water repellent - HE 328 and HP 800 which consist of siloxane as active ingredient

Incorporation of extra crushing stages during the RA’s recycling process - gives proper aggregates size, better packing and reduction in content of porous adhered mortar resulting reduction of carbonation depth

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2. DEFORMATION

DRYING SHRINKAGE

Drying shrinkage of RAC increases with increase in percentage incorporation of recycled coarse aggregates in RAC - due to the increase in old adhered mortar and new paste volume in recycle aggregate concrete.

The additions of different percentage super plasticizers in RAC lead to increase in the shrinkage due to increase in the entrapped air.

Moisture condition of RA also influences shrinkage. Presoaking of RA for 24 h leads to increase in shrinkage as it leads to increase in entrapped air in RAC.

Addition of mineral admixture (fly ash) and silane in RAC, use two stage mixing approach may reduces the shrinkage.

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2. DEFORMATION

CREEP

The creep increases with the increase in RA content

The creep strain in RAC and NAC can be reduced by using fly ash as a partial replacement or addition of cement

TSMA effectively reduces the creep for RAC and Normal Concrete alike

Shrinkage does not become any issue for using recycled concrete aggregate

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3. PERMEABILITY

Permeability of the RAC made with fully and partial replacement of NA by RA is higher than that of NAC - RA contains more amount of porosity and cracks on the adhered mortar, formed in the RA during preparation

The water permeability in RAC increases with increase of substitution level of RA, w/c ratio and age due to increase in porosity in ITZ

Similar trends were observed for the capillary water absorption and oxygen permeability in RAC

Permeability is observed to be decreased with increase in time and has been observed to be dependent on source and quality of aggregate used

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3. PERMEABILITY – HOW TO IMPROVE?

Using lower water-binder ratio

TSMA was observed to produce concrete with betterresistance to permeability as it reduces the waterpermeability to about 5%

Using silane-based water repellent. It led to a reduction of63–81% in water permeability and 61–96% reduction incapillary water absorption coefficient

Surface coating gives better results than using it as anintegral part of the mix (micro silica, fly ash, baggase)

Some admixtures that help in improving other properties ofRAC have been found to be counterproductive in reducing thepermeability of RAC

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4. CHLORIDE ATTACK

Chloride penetration increases in RAC with the increase in NA replacement as well as the increase in w/c ratio.

The depth of penetration is directly proportional to the w/c ratio, thus suggesting limiting the water content to a minimum value in areas of high chloride attack

The usage of TSMA was observed to reduce chloride penetration to an encouraging extent of 29.98% (for 100% replacement and 126 days)

Increase in curing time of concrete has been observed to have a positive effect on chloride ion resistance

The use of silane based water repellent, pozzolanic materials, can lead to significant decrease in chloride penetration

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RECYCLED AGGREGATE IN PAVEMENT (CASE STUDY)

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RECYCLED AGGREGATE PAVEMENT

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RECYCLED AGGREGATE PAVEMENT

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MAIN ISSUES OF RECYCLED AGGREGATE IN PAVEMENT

https://doi.org/10.1016/j.conbuildmat.2019.117444

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METHODS IMPROVING RAP PERFORMANCE

1. Pre-coating or double coating with slag cement paste (0.25mm thickness)

2. Inclusion of pozzolanic powder

3. Soaking in HCl (0.1M or 0.5M for 3 days)

4. Impregnation with polyvinyl alcohol (PVA) or silica fume solution

5. Combination treatment methods:a) Soaking in HCl and H2SO4, heating, and rubbing

https://doi.org/10.1016/j.conbuildmat.2019.117444

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CERAMIC WASTE (CW) CONCRETECASE STUDY

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CERAMIC WASTE

Production of ceramic market produces 7 million ceramic every year and it also generates approximately 24 tons of ceramic waste every year.

Ceramic wastage in concrete production causes no remarkable negative effect in the properties of concrete

No Year Author Types of ceramic Replacement

1 2013 Ehikhuenmen Ceramic from on-going construction Coarse aggregates

2 2015 García-González et al Sanitary porcelain Coarse aggregates

3 2016 Awoyera et al. Ceramic floor and wall tiles Coarse aggregates

4 2016 Shruthi & Gowtham Ceramic tile Coarse aggregates

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Concrete Ceramic Waste Slab (CCWS)

Ceramic waste coarse aggregates

Concrete Ceramic Waste Slab

(CCWS)

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Plastic waste fine aggregates

PROPERTIES OF CERAMIC WASTE CONCRETE

Replacement CW increase, Slump

value will decrease

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Properties Comparison between

Concrete Ceramic Waste Slab (CCWS) &

Conventional Concrete

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PLASTIC WASTE (PW) AGGREGATECASE STUDY

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HDPE Plastic Waste Aggregate Concrete

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Compressive Strength and Flexural Strength

of HDPE Plastic Waste Aggregate Concrete

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FA & VA AS RECYCLED MATERIAL IN LIGHTWEIGHT AGGREGATE – GEOPOLYMER TECHNIQUES

CASE STUDY

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1. PERFORMANCE OF GEOPOLYMER FA AS RAW MATERIAL LIGHTWEIGHT AGGREGATE

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1. PERFORMANCE OF GEOPOLYMER FA AS RAW MATERIAL LIGHTWEIGHT AGGREGATE

Sample for 900 ⁰C shows a lowest k value – due to increasing volume of close

pores

As the sintering temperature increased, it will convert discontinues and closed

pores to the interconnected pores – thus increase k value

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2. PERFORMANCE OF GEOPOLYMER VA AS RAW MATERIAL LIGHTWEIGHT AGGREGATE

LUSI Site, Sidoarjo, Indonesia

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2. PERFORMANCE OF GEOPOLYMER VA AS RAW MATERIAL LIGHTWEIGHT AGGREGATE

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SUMMARY AND CONCLUSION1. The study shows that fresh properties as well as mechanical properties appears to

be slightly inferior for concrete made with recycled aggregates as compared to their normal counterparts.

2. The properties can be improved by proper surface treatment to the RA, addition of suitable percentage of admixtures (Silica Fume, Fly Ash, GGBS, meta-Kaolin etc.) to the fresh RAC mix

3. Mixing methods can be further worked upon since TSMA is the only method that succeed. Proper mix design procedure has yet to be established

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REFERENCES1. https://doi.org/10.1016/j.conbuildmat.2016.11.029

2. https://doi.org/10.1016/j.conbuildmat.2018.03.240

3. https://doi.org/10.1016/j.conbuildmat.2019.117444

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THANK YOU

1 2 1

+6012-5872879 [email protected]

[email protected]

+6012-5055020

+6012-5872879

Documents

WEBINAR 2: SUSTAINABILITY OF RECYCLED AGGREGATES