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STST‐‐13:Fiber13:Fiber‐‐Reinforced Concrete Reinforced Concrete STST 13:Fiber13:Fiber Reinforced Concrete Reinforced Concrete Incorporating Recycled Concrete FinesIncorporating Recycled Concrete Fines
STST‐‐14: Green Concrete Incorporating 14: Green Concrete Incorporating 4 p g4 p gLocal Waste MaterialLocal Waste Material
Recycled Concrete Fines & Engineered CementitiousgComposities
Enhanced greenness of ECC
Effect of RCF on ECC mechanical properties
ff fEffect of RCF on ECC on mirco structure aspect using Micromechanics Model
• Importance of the reuse construction and d li i demolition waste
• Property of RCFHigh water absorption
• A class of ultra ductile fiber reinforced cementitiouscomposites
Normal ECC Composites
Water, Cement, Fiber, S d Additi Sand, Additives
Mitaka Dam near Hiroshima
N l C t Engineered CementitiousNormal Concrete Engineered CementitiousComposities (ECC)
Taken from: https://www.youtube.com/watch?v=tsGfCCY4_Gw
Hi h E i t l b dHi h E i t l b dHigh Environmental burdenHigh Environmental burdenVi C Li D l f G E i d C iVictor C. Li, Development of Green Engineered CementitousComposites For Sustainable Infrasture Systems
Due to high cement content and introduction of PVA
fibfibers
S l i f CS l i f CSupplementation of Cement Supplementation of Cement
C3S + H2O C‐S‐H + CHCH + SiOSiO22 C‐S‐H
Present in Ground Granulated Blast Furnace Slag (GGBS)
GGBS content
Compressive Strength
Ductility
% I D 10 – 30% Increase Decrease
55 – 59 % Increase Decrease
> 69% Decrease Increase
Supplementation of Supplementation of AAAAggregates ggregates
Lack of aggregatesLack of aggregates
Normal ECC Composites
RCF‐ECC Composites
Water, Cement, Fiber, Sand, Additives
Water, Cement, Slag, Fiber, Recycled Concrete Fines(RCF),Additi Additives
S lfS lf i C ti C tSelfSelf‐‐sensing Concrete sensing Concrete
Obj tiObj tiObjective Objective
Enhanced the Enhanced the GreenGreenness of ECCness of ECC
Investigate the effect of RCF on GGBS‐ECC of its mechanical propertiesp p
Self‐sensing measurement setup for future research
SSScope Scope Compressive Strength Flexural Strength & Deflection
Self‐sensing measurement setup stability
Mix DesignMix DesignMix DesignMix DesignNatural aggregates
RCFCement
Cement + GGBS
RCF PVA
RCFCement + GGBS
Group 1 Cement Slag Water/B1 RCF/Bsize/mm fiber2
SP3/ B
RS‐1 1 0.8 0.25 0 0~0.6 2% 0.5%
RS‐2 1 0.8 0.25 0.2 0~0.6 2% 0.8%
RS‐3 1 0.8 0.25 0.5 0~0.6 2% 0.8%
RS‐7 1 0.8 0.25 0.2 0~0.3 2% 0.8%7 5 3
RS‐8 1 0.8 0.25 0.2 0~1.18 2% 0.8%
RS‐9 1 0.8 0.25 0.2 0~2.36 2% 0.8%
1.B=cement+slag; 2. Percentage by volume; 3.SP=superplasticizer.
Mi D iMi D iMix DesignMix Design
Group 1 RCF Content
Group 2 RCF size/µm
RS‐1 0 RS‐7 0‐300
RS‐2 0.2
RS‐3 0.5
RS‐2 0‐600
RS‐8 0‐1180
RS‐9 0‐2360
C b C i T tC b C i T t
Experimental Procedures
Cube Compression TestCube Compression Test
Load Cell
Concrete Specimen
Cylinder Compression TestCylinder Compression TestExperimental Procedures
Cylinder Compression TestCylinder Compression TestLoad Cell
10mm LVDT
Concrete Specimenp
Magnetic Stand
4 i t B di T t4 i t B di T t
Experimental Procedures
Loading Pins
4 point Bending Test4 point Bending Testoad g s
Concrete Specimen
Supporting Pins
S lf S i M tS lf S i M t
Experimental Procedures
Self Sensing Measurement Self Sensing Measurement
Pl i ShPlastic Sheet
Copper Wire
S lf S i M tS lf S i M t
Experimental Procedures
Self Sensing Measurement Self Sensing Measurement AC current source
Digital Multimeter
D itD itDensityDensity(g/cm3) (g/cm3)
The degree of compactness of a substance
CompressiveCompressiveCompressive Compressive Strength Strength (28 days)(28 days)(28 days)(28 days)The resistance of the concrete to break under compression
CompressiveCompressiveCompressive Compressive Strength Strength (90 days)(90 days)(90 days)(90 days)The resistance of the concrete to break under compression
CompressiveCompressive
Group 2- RCF sizes
Compressive Compressive Strength Strength ComparisonComparisonComparisonComparison
Fl l S h C l l iFl l S h C l l iFlexural Strength Calculation Flexural Strength Calculation
Flexural Strength V Deflection Flexural Strength V Deflection Group 1- RCF content
(28 days)(28 days)
FlexuralFlexural
Group 1- RCF content
Flexural Flexural Strength Strength & & DeflectionDeflectionDeflection Deflection (28 days)(28 days)Flexural strength is a
l' b lmaterial's ability to resist deformation under load
Flexural Strength V Deflection Flexural Strength V Deflection Group 2- RCF sizes
(28 days)(28 days)
FlexuralFlexural
Group 2- RCF sizes
Flexural Flexural Strength Strength & & DeflectionDeflectionDeflection Deflection (28 days)(28 days)
Flexural Strength V Deflection Flexural Strength V Deflection Group 2- RCF sizes
(90 days)(90 days)
FlexuralFlexural
Group 2- RCF sizes
Flexural Flexural Strength Strength & & DeflectionDeflectionDeflection Deflection (90days)(90days)
FlexuralFlexural
Group 2- RCF sizes
Flexural Flexural Strength Strength ComparisonComparisonComparison Comparison (90days)(90days)
Group 2- RCF sizes
Deflection Deflection ComparisonComparisonComparisonComparison(90days)(90days)
SelfSelf‐‐sensing sensing MeasurementMeasurementMeasurementMeasurementChange in resistivity under compression
1 2 3
1. Compressive Strength drop as RCF content increase2. A slight drop then rise in compressive strength as
RCF i iRCF size increase
D i f i i RCF d i 3. Decreasing σ for increasing RCF content and size with RS9 as exceptional
4 Decreasing deflection for increasing RCF and size4. Decreasing deflection for increasing RCF and size
Future studies on RS 9 as it display a higher flexural strength which is contract to the gtrend in flexural strength and deflection.
To develop a more accurate tensile behavior of the ECC uniaxial tensile test which pull of the ECC, uniaxial tensile test which pull the specimen could be used.
C it T il Composite Tensile Ductility
Steady‐state crack analysis
Fiber Bridging Property (σ‐δ) across cracks
crack analysis
Micromechanics
Fiber, Matrix, Interface
Aim: Achieve the tensile strain hardening behaviorAim: Achieve the tensile strain‐hardening behavior
Energy Criteria:Energy Criteria:
σ0
Jb
σss
JtipCrack Tip l
δss δ0
tipCrack Tip Toughness
Complementary Energy
ss 0
Chemical Bond Strength
Constant friction bond strengthg
Slip Hardening Coefficient
Complementary Energy
Fracture Toughness
Li, V C., On Engineered Cementitious Composites (ECC) A review of the Material and Its Applications. Journal of Advanced Concrete Technology Vol 1 No 3 2003 pp215‐230 Technology Vol 1, No 3, 2003, pp215‐230
Determine the interfacial properties and matrix toughness properties
Evaluation of the effects of RCF content and particle size on ECC tensile properties based on micromechanics model
Single Fiber Pullout Test
Matrix Toughness Test
Particle Size: 0 0 6mmParticle Size: 0‐0.6mm
Actuator
Aluminum Plate
Specimen Mount
10 N Load Cell
X‐Y table
Free Length Specimen
Thickness=1 1mmThickness 1.1mm
A t tActuator
Clip Gauge Wedging Device
Steel loading d i i h ll
Clip Gauge Wedging Device
device with roller bearings
Specimen
RCF SizeRCF Size(0(0‐‐0.60.6μμm)m)
GdGd(J/m^2)(J/m^2)
ƮƮ((MpaMpa))
ββJbJb’’
(J/m^2)(J/m^2)
RS1 RCF/B=0 1.0162 2.4300 0.5196 10.14
RS2RCF/B=0.2 0.5475 2.4041 0.2504 11.25
RS3RCF/B=0.5 0.2623 2.6177 0.1956 11.47
RCF RCF ContentContent(0.2)(0.2)
GdGd(J/m^2)(J/m^2)
ƮƮ((MpaMpa))
ββJbJb’ ’
(J/m^2)(J/m^2)
RS7RS7(0‐0.3mm) 1.4241 2.1450 0.4582 9.75
RS2(0‐0.6mm) 0.5475 2.4041 0.2504 11.25
RS80 5697 1 8858 0 1760 12 72(0‐1.18mm) 0.5697 1.8858 0.1760 12.72
RS9(0‐2.36mm) 0.2438 2.1604 0.3180 13.37
Graph of Km Graph of Km vsvs RCF ContentRCF Content
Li, V C., On Engineered Cementitious Composites (ECC) A review of the Material and Its Applications , 2003
To evaluate the effect on the RCF content
To evaluate the effect on the RCF size
1 Jtip and Jb’ increases with both RCF 1. Jtip and Jb increases with both RCF content and size.
2 Jb’/Jtip shows both decreasing trend for 2. Jb /Jtip shows both decreasing trend for increasing RCF content and size which is not desirable to achieve the strain‐not desirable to achieve the strainhardening behavior.
3 RCF is not desirable material to replace 3. RCF is not desirable material to replace sand in the ECC
1. To determine a more accurate experimental work the Young modules for every mix shouldwork, the Young modules for every mix should be determined as the RCF-ECC is different from the conventional concrete.
2. Further research could be done to determine the optimal amount of RCF content and size that achieve the maximum strain hardening effect which is beneficial to the constructioneffect which is beneficial to the construction industry.
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