ST ST ‐ 13:Fiber ST ST 13:Fiber 13:Fiber ‐ Reinforced Concrete 13:Fiber Reinforced Concrete Reinforced Concrete Reinforced Concrete Incorporating Recycled Concrete Fines Incorporating Recycled Concrete Fines ST ST ‐ 14: Green Concrete Incorporating 14: Green Concrete Incorporating 4 4 p p g g Local Waste Material Local Waste Material
� Recycled Concrete Fines & Engineered Cementitious g Composities � Enhanced greenness of ECC � Effect of RCF on ECC mechanical properties � Effect of RCF on ECC on mirco structure aspect using ff f Micromechanics Model
• Importance of the reuse construction and d demolition waste li i • Property of RCF � High water absorption
• A class of ultra ductile fiber reinforced cementitious composites Normal ECC Composites Water, Cement, Fiber, S Sand, Additives d Additi Mitaka Dam near Hiroshima
Engineered Cementitious Engineered Cementitious N Normal Concrete l C t Composities (ECC) Taken from: https://www.youtube.com/watch?v=tsGfCCY4_Gw
Hi h E Hi h E High Environmental burden High Environmental burden i i t l b t l b d d Victor C. Li, Development of Green Engineered Cementitous Vi C Li D l f G E i d C i Composites For Sustainable Infrasture Systems Due to high cement content and introduction of PVA fib fibers
S S Supplementation of Cement Supplementation of Cement l l i i f C f C C 3 S + H 2 O � C ‐ S ‐ H + CH SiO 2 � C ‐ S ‐ H CH + SiO Present in Ground Granulated Blast Furnace Slag (GGBS) GGBS Compressive Ductility content Strength 10 – 30% % I Increase D Decrease 55 – 59 % Increase Decrease > 69% Decrease Increase
Supplementation of Supplementation of A Aggregates ggregates � Lack of aggregates � Lack of aggregates � Normal ECC RCF ‐ ECC Composites Composites Water, Cement, Fiber, Water, Cement, Slag, Sand , Additives Fiber, Recycled Concrete Fines(RCF) , Additi Additives
S lf S lf Self Self ‐ sensing Concrete sensing Concrete i i C C t t
Obj Obj Objective Objective ti ti Enhanced the Enhanced the Green Greenness of ECC ness of ECC � Investigate the effect of RCF on GGBS ‐ ECC of its mechanical properties p p � Self ‐ sensing measurement setup for future research
S Scope Scope � Compressive Strength � Flexural Strength & Deflection � Self ‐ sensing measurement setup stability
Mix Design Mix Design Mix Design Mix Design Cement � Natural aggregates � Cement + GGBS Cement + GGBS RCF RCF RCF PVA Water/B 1 SP 3 / B Group 1 Cement Slag RCF/B fiber 2 size/mm 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 7 1 0.8 0.25 5 0.2 0~0.3 3 2% 0.8% 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 Mi D Mix Design Mix Design i i RCF RCF Group 2 Group 1 size/µm Content RS ‐ 1 0 RS ‐ 7 0 ‐ 300 RS ‐ 2 0.2 RS ‐ 2 0 ‐ 600 RS ‐ 3 0.5 RS ‐ 8 0 ‐ 1180 RS ‐ 9 0 ‐ 2360
Experimental Procedures C b C C b C Cube Compression Test Cube Compression Test i i T T t t Load Cell Concrete Specimen
Experimental Procedures Cylinder Compression Test Cylinder Compression Test Cylinder Compression Test Cylinder Compression Test Load Cell 10mm LVDT Concrete Specimen p Magnetic Stand
Experimental Procedures 4 4 point Bending Test 4 point Bending Test 4 i t B i t B di di T T t t Loading Pins oad g s Concrete Specimen Supporting Pins
Experimental Procedures S lf S S lf S Self Sensing Measurement Self Sensing Measurement i i M M t t Pl Plastic Sheet i Sh Copper Wire
Experimental Procedures S lf S S lf S Self Sensing Measurement Self Sensing Measurement i i M M t t AC current source Digital Multimeter
D D Density Density it it (g/cm3) (g/cm3) The degree of compactness of a substance
Compressive Compressive Compressive Compressive Strength Strength (28 days) (28 days) (28 days) (28 days) The resistance of the concrete to break under compression
Compressive Compressive Compressive Compressive Strength Strength (90 days) (90 days) (90 days) (90 days) The resistance of the concrete to break under compression
Group 2- RCF sizes Compressive Compressive Compressive Compressive Strength Strength Comparison Comparison Comparison Comparison
Fl Fl Flexural Strength Calculation Flexural Strength Calculation l S l S h C l h C l l l i i
Group 1- RCF content Flexural Strength V Deflection Flexural Strength V Deflection (28 days) (28 days)
Group 1- RCF content Flexural Flexural Flexural Flexural Strength Strength & & Deflection Deflection Deflection Deflection (28 days) (28 days) Flexural strength is a material's ability to l' b l resist deformation under load
Group 2- RCF sizes Flexural Strength V Deflection Flexural Strength V Deflection (28 days) (28 days)
Group 2- RCF sizes Flexural Flexural Flexural Flexural Strength Strength & & Deflection Deflection Deflection Deflection (28 days) (28 days)
Group 2- RCF sizes Flexural Strength V Deflection Flexural Strength V Deflection (90 days) (90 days)
Group 2- RCF sizes Flexural Flexural Flexural Flexural Strength Strength & & Deflection Deflection Deflection Deflection (90days) (90days)
Group 2- RCF sizes Flexural Flexural Flexural Flexural Strength Strength Comparison Comparison Comparison Comparison (90days) (90days)
Group 2- RCF sizes Deflection Deflection Comparison Comparison Comparison Comparison (90days) (90days)
Self Self ‐ sensing sensing Measurement Measurement Measurement Measurement Change in resistivity 1 2 3 under compression
Compressive Strength drop as RCF content increase 1. A slight drop then rise in compressive strength as 2. RCF i RCF size increase i Decreasing σ for increasing RCF content and size D i f i i RCF d i 3. with RS9 as exceptional 4 4. Decreasing deflection for increasing RCF and size Decreasing deflection for increasing RCF and size
� Future studies on RS 9 as it display a higher flexural strength which is contract to the g trend 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 Composite Tensile it T il Ductility Steady ‐ state crack analysis crack analysis Fiber Bridging Property ( σ‐δ ) across cracks Micromechanics Fiber, Matrix, Interface
Aim : Achieve the tensile strain hardening behavior Aim : Achieve the tensile strain ‐ hardening behavior Energy Criteria: Energy Criteria: J b � σ 0 σ ss J tip Crack Tip Crack Tip tip Complementary l Toughness Energy δ ss δ 0 ss 0
Chemical Bond Strength Constant friction bond strength g 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 6mm Particle Size: 0 ‐ 0.6mm
Actuator Aluminum Plate Specimen Mount 10 N Load Cell X ‐ Y table
Free Length Specimen Thickness=1 1mm Thickness 1.1mm
Actuator A t t Clip Gauge Clip Gauge Wedging Device Wedging Device Steel loading d device with roller i i h ll bearings Specimen
Jb Jb’ ’ Ʈ RCF Size RCF Size Gd Gd β (J/m^2) (J/m^2) (0 (0 ‐ 0.6 0.6 μ m) m) (J/m^2) (J/m^2) (Mpa Mpa) ) RS1 1.0162 2.4300 0.5196 10.14 RCF/B=0 RS2 0.5475 2.4041 0.2504 11.25 RCF/B=0.2 RS3 11.47 0.2623 2.6177 0.1956 RCF/B=0.5
RCF RCF Jb Jb’ ’ Ʈ Gd Gd Content Content β (J/m^2) (J/m^2) (J/m^2) (J/m^2) (Mpa Mpa) ) (0.2) (0.2) RS7 RS7 1.4241 2.1450 0.4582 9.75 (0 ‐ 0.3mm) RS2 0.5475 2.4041 0.2504 11.25 (0 ‐ 0.6mm) RS8 0.5697 0 5697 1 8858 1.8858 0.1760 0 1760 12 72 12.72 (0 ‐ 1.18mm) RS9 0.2438 2.1604 0.3180 13.37 (0 ‐ 2.36mm)
Graph of Km Graph of Km vs vs RCF Content RCF 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
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