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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
CONCRETE CERAMIC WASTE SLAB (CCWS)
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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MECHANICAL PROPERTIES
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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MECHANICAL PROPERTIES
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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CONCRETE CERAMIC WASTE SLAB (CCWS)
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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CONCRETE CERAMIC WASTE SLAB (CCWS)
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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CONCRETE CERAMIC WASTE SLAB (CCWS)
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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CONCRETE CERAMIC WASTE SLAB (CCWS)
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)
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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CONCRETE CERAMIC WASTE SLAB (CCWS)
Properties Comparison between
Concrete Ceramic Waste Slab (CCWS) &
Conventional Concrete
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CONCRETE CERAMIC WASTE SLAB (CCWS)
PLASTIC WASTE (PW) AGGREGATECASE STUDY
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CONCRETE CERAMIC WASTE SLAB (CCWS)
HDPE Plastic Waste Aggregate Concrete
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CONCRETE CERAMIC WASTE SLAB (CCWS)
Compressive Strength and Flexural Strength
of HDPE Plastic Waste Aggregate Concrete
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CONCRETE CERAMIC WASTE SLAB (CCWS)
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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