2017 adot
- 1. Cement Based Composites as a Solution to Sustainable Infrastructure Materials Barzin Mobasher Professor School of Sustainable Engineering and the Built Environment Ira A. Fulton Schools of Engineering Arizona State University Tempe, AZ 85287-5306 Department of Civil Engineering Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)
- 2. Sustainable Construction Products Societal Challenges – Challenges we face in the next several decades? – Global warming, societal development, and energy use Sustainability – Reuse and recycle – Design for durability – Quality control, wastefulness – Structural mechanics, new materials and design systems Renewable Energy power generation – Enabling Infrastructure Technologies Composite systems- New Technological Developments – Short fiber, continuous fiber systems, TRC – Ductility based designs utilizing nonlinear material properties – Aerated Concrete, life cycle energy consumption
- 3. Outline Introduction Bilinear Moment-Curvature Relationship Moment and Curvature Distributions Closed-Form Solutions for Load-Deflection Algorithm Closed-form deflection equations Parametric Study Normalized Distance vs. Deflection Coefficient Normalized Distance vs. Normalized Curvature 2-D Deflection Contour Experimental Verifications Discussions Ductility Durability Economy FRC
- 4. Introduction Severe damages to cement-based materials due to the inherent brittleness and low tensile strength. ECC, UHPC, HPFRC are developed and applied Hybrid manner -- fibers, steel rebars, FRP rods Flexural members -- beam, slab, bridge girder, tunnel lining Modelling and design approach based on analytical equations are desired Soranakom C., Mobasher B. , “Closed-Form Solutions for Flexural Response of Fiber-Reinforced Concrete Beams”(ASCE)0733- 9399, 2007.
- 5. Globalization- American Model of Economic Development China and India have achieved fast economic growth rates by rapid industrialization Over 40% of the 1.3 billion Chinese already live in cities with sky-rocketing demand for energy and energy-intensive materials China – 50% of global cement production, followed by India and US (6% and 3%, resp.) – 40% of global steel production, followed by Japan and US (9% and 7%, resp.) – 15% of the global power generation. Projected to triple By 2030 – 80% of electric power generated from coal – Equivalent of two 500-MW coal power plants built every week for the next 20 years – China has passed the U.S. as the World’s largest emitter of CO2
- 6. Concrete Specified vs. Delivered 2000 4000 6000 Specified f'c, psi 2000 4000 6000 8000 10000 DeliveredStrength,psi All concrete classes 28 day strength Each data point = 100 cubic yards Source: ADOT Database for One ready mix supplier over a course of two years Over-strength Level
- 7. Durability, Sustainability, Energy use • The Carbon cycle in construction materials industry should be viewed in the context of high initial energy demand followed by very efficient operation. CO2 generation from Cement utilization and vehicle fuel consumption yields erroneous results • Durability, efficient performance, and raw materials conservation are essential components of sustainable designs FRC as Activation Energy for Sustainable Design
- 8. FRC Engineering Applications Ductility, Durability The type and volume fraction of fibers affect the level of energy absorption increased energy absorption, fatigue life, impact/explosive loading conditions, and seismic resistance Pavements/slabs, Pre-cast components, Shotcrete
- 9. Materials characteristics Ductility Toughening Improved tensile strength Increase level of energy absorption Fatigue life, impact/explosive loading conditions, and seismic resistance Steelwork, labor, construction time. Corrosion damage Long-term repair and maintenance. 500 m 20 m (c) 200 m (d) (a) 500 m (b)
- 10. Structural Design with FRC Materials: testing, modeling, analysis and Design Shotcrete applicationsElevated slabs Precast panels
- 12. Textile Reinforced Concrete Sandwich layers Low cost equipment set up Uniform production high performance fabric-cement composites Tension, Compression, beam members High pressure pipes
- 13. Textile Reinforced Concrete 0 0.01 0.02 0.03 0.04 Strain, mm/mm 0 4 8 12 16 20 Stress,MPa AR Glass Fabric GFRC Vf =5% PE Fabric E-Glass Fabric Mortar ECC 500 m
- 14. Uniaxial Tensile Response 0 0.02 0.04 0.06 Strain, mm/mm 0 4 8 12 16 20 Stress,MPa 0 20 40 60 CrackSpacing,mm Stress-Strain Crack Spacing Pultrusion Peled, A. and Mobasher, B., (2005), “Pultruded Fabric- Cement Composites,” ACI Materials Journal, Vol. 102 , No. 1, pp. 15-23.
- 15. Homogenization of Crack spacing –Mechanical interlock 0 10 20 30 40 Crack Spacing, mm 0 0.2 0.4 0.6 0.8 1 CumulativeDistributionFunction Zone 1 = 0.015 Zone 2 .0273 Zone 3 = 0.0387 AR-Glass Fabric 0 0.02 0.04 0.06 Strain, mm/mm 0 5 10 15 20 25 Stress,MPa Zone 3 Zone 2 Zone 1 AR-Glass Fabric AR Glass Bonded Fabric Polyethylene (PE) Woven Fabric Polypropylene (PP) Knitted Fabric
- 17. Stress-Strain for Hardening and Softening FRC Material parameters are described as a multiple of the first cracking tensile strain (cr) and tensile modulus (E) Compression model Tension model
- 18. Evolution of Stress Distribution Profile (A) (B) (C)
- 19. Specifications for Canal lining, WWF, or rebar replacement Fiber Reinforced Concrete Mix Photo Courtesy: Pima-Maricopa Irrigation Project, Sacaton, Arizona Traditional #5 rebar layout Photo Courtesy: Rick Shelly, Pulice Construction
- 20. Fiber-reinforced shotcrete for initial shaft sinking support • Deep shaft (2189 m), 9 m dia, copper mine • 400,000 tons copper per year for the next 40 years • Three geological units • A range of orthotropic stress conditions • Several modes of instability: gravity driven, rockmass shear yielding, brittle failure • The shotcrete system must achieve a high early strength and ductility within a short period (less than 24 hours).
- 21. Effect of curing age on flexural response 0 0.03 0.06 0.09 0.12 0.15 CMOD, inch 0 500 1000 1500 2000 2500 3000 Load,lbf 36 hrs - Sample 1 36 hrs - Sample 2 16 hrs - Sample 1 16 hrs - Sample 2 8 hrs - Sample 1 8 hrs - Sample 2 Three Point Bending Test Result Mix 1 10-12 lbs/yd3 of macro fibers
- 22. Strain-Softening FRC 0 0.01 0.02 0.03 0.04 0.05 Deflection, in 0 200 400 600 800 1000 FlexuralLoad,lb Experiment Present Model L-056 : 9.5 lb/yd3 FibraShield sample 1 age: 14 days 0 400 800 1200 1600 Stress (psi) -2 -1 0 1 2 SpecimenDepth,(in) ARS Method, LE material ASU Method, Elastic Softening Stress Distribution Softening Zone L056-01
- 23. Comparison with JCI Method JCI method overestimates the residual strength of – synthetic fibers by 1.4 times – steel fibers by 6.3 times Bakhshi M, Mobasher B. “Sustainable Design of Structural Concrete Materials: a Case Study of Incorporating Materials Science, Structural Mechanics, and Statistical Process Control”, A Report (SR- 633) to Arizona Department of Transportation, Tempe, AZ, 2010.
- 24. FRC for 2-way elevated slab structures Composition Amount Cement Type I 350 kg Fly ash 60 kg Aggregate (1.1:1) 1800 kg W/C < 0.5 Supper plasticizer 1.25 % by Vol. Vf = 80 - 100 kg/m3
- 25. Construction and Field Testing Cast in place SFRC Use minimum reinforcement along the column lines to prevent progressive collapse
- 26. Modeling of Failure Mechanisms Oberseite - ULS Mittellast S N West Ost Unterseite S N WestOst Durchgezogen: bis 200 kN gestrichelt: bis Brucklast
- 27. Plastic analysis approach Distributed load on a simply supported square slab. The work equations are derived as: Where the resultant NR and rotation θ (from figure 9a) are: For the four segments with an NR acting at 1/3 of δmax : θ θ q δmax L L/2 L/2 m m A A δ Yield Line Square Slab Simply Supported int extW W R( N ) ( M L ) 2 2 2 4 R L L qL N q ( ) ( ) 2 max L 2 2 4 4 4 3 max max L qL ( ) ( ) ( M ) ( L ) ( ) 2 24 ult p q L M
- 28. Round panel tests for evaluation of SFRC Test setup – displacement controlled, continuous support, center point load Dimensions – D, t= 1500, 150 mm – stroke diameter = 150 mm Vf = 80 kg/m3 Vf = 100 kg/m3
- 29. ASU- Rio Tinto Project – Magma Copper mine, Superior , Arizona ASU is evaluating the initial fiber- reinforced shotcrete support design for a 2000 m-deep shaft at Resolution Mine, Arizona.
- 30. Project Overview • Evaluate fiber-reinforced shotcrete performance • No rockbolts planned for initial support. • Deep shaft (2189 m) • Three geological units • A range of stress conditions (increased with depth) • Several modes of instability: gravity driven, rockmass shear yielding, brittle failure
- 31. 3DEC Evaluation of Shotcrete Linear-elastic shotcrete liner installed in low stress, blocky ground. Early age properties use for shotcrete and rock-shotcrete interface along full length of model shaft. Extreme fiber stress used to evaluate potential shotcrete cracking. Tensile extreme fiber stress exceeding the tensile strength combined with tensile thrust at a given liner section indicates potential for a crack to form through the liner. Large regions of connected cracks would indicate potential for a block breaking through the shotcrete. Extreme Fiber Stress 3DEC-predicted liner stresses and potential cracking in TAL unit Tensile extreme fiber stress exceeding tensile strength of shotcrete
- 32. Use of Yield Line Analysis and Design procedures int extW W 2 2 P L M P P 4 ult P P L M
- 33. Round Panel Continuous Support Specimens
- 34. ASTM C1550-Round Panel 3P-support specimen
- 35. Analysis of Precast Wall Panels Assume continuous wall, pin connection at the bottom and free at the top Lateral water pressure in ultimate and serviceability limit states
- 36. Safety, mobilization, and Cost savings due to reduced section sizes
- 37. Analysis, Design and Installation of precast water tank panels Load Case1: – Self weight + Water pressure – Moment in short span controls Load Case2: – 1.4 Self weight + 1.7 Earth pressure + 1.7 Uniform pressure due to surcharge – Moment in short span direction SM1
- 38. From Microstructure to full scale wall testing -Durable, Energy efficient, Effective R-value, 3.4/in, - Fire, Pest resistant, no autocalve -Acoustical insulation, impact resistant Easy to use LVDT-1 LVDT-2 Actuator
- 39. Precast, Cont’d (slope stabilization) Slope stabilization (FRC segments are bolted into the rock)
- 40. Precast, Cont’d (slope stabilization) Slope stabilization (FRC segments are bolted into the rock)
- 41. FRC Applications in Shotcrete One of the widespread applications of fibers is shotcrete. Short fibers is added to concrete and used in the form of shotcrete to replace or reduce the steel reinforcement. Several case studies are introduced in the following slides for applications such as: • Tunnel lining • Slope stabilization • Retrofit and strengthening Tunnel lining with light steel mesh, ready for shotcrete
- 42. Shotcrete, Cont’d (tunnel lining) Fiber-reinforced concrete can be used for shotcreting tunnel lining. Macro steel fibers and macro synthetic fibers are typically used for this application. Using fibers can reduce or even eliminate the steel rebar reinforcement which results in faster and cheaper construction. In comparison with steel mesh system, shotcreting FRC uses lesser quantities of concrete since it follows the rock contours and typically has less rebound. Enhanced durability is obtained with FRC since galvanic corrosion cells are not created with fibers. Completed Spraying FRC
- 43. Shotcrete, Cont’d (slope stabilization) Fiber-reinforced concrete can be used for shotcreting for the purpose of slope stabilization. Macro steel fibers and macro synthetic fibers are typically used for this application. Using fibers can reduce or even eliminate the steel rebar reinforcement which results in faster and cheaper construction. In comparison with steel mesh system, shotcreting FRC uses lesser quantities of concrete since it follows the rock contours and typically has less rebound. Spraying FRC on slopes
- 44. Shotcrete, slope stabilization SnFRS Soil- Nailed Slope Support Burnaby, BC SnFRS Slope Protection Cleveland Dam, Vancouver BC
- 45. Shotcrete retrofit Fiber-reinforced concrete can be used for shotcreting in retrofit and strengthening of existing structures. Macro steel fibers and macro synthetic fibers are typically used for this application. Using shotcrete with fibers is a fast and economic way to retrofit cracked surfaces and to strengthen the structures for extra load or seismic resistance. Seismic Retrofit of Littlerock Dam, California with SFRS
- 46. Structural Applications There are several more applications for FRC in special structures. Short fibers are added to concrete to increase the tensile strength and ductility of the material in order to resist explosive, cyclic, or corrosive factors. Several case studies are introduced in the following slides for applications such as: • Seismic applications • Defensive applications • Hydraulic applications • Masonry structures FRC cylinders after failure
- 47. Seismic Design, Coupling beams Researchers eliminated a substantial amount of reinforcing bars by using a highly flowable, steel fiber-reinforced concrete where the fibers are introduced during the concrete mixing process. “Instead of constructing a skyscraper in the time- consuming and labor-intensive procedures used today, we envision this new coupling design being fabricated off site and delivered ready for installation
- 48. Precast Tunnel lining for Rio de Janeiro Metro Line #4
- 49. Spillway: high density of REBARS
- 51. Special Applications, seismic Boundary reinforcement detailing in reinforced concrete and HPFRC wall specimens
- 53. Tunnel Lining Fiber-reinforced concrete can be used in tunnel lining segments. Macro steel fibers and macro synthetic fibers are mainly used for this type of application. Using fibers can reduce or even eliminate the steel rebar reinforcement which results in faster and cheaper production. Due to the curved nature of lining segments, fibers are good replacement for rebars because of their distribution in the segment. M. Moccichino et al., 2010 world tunnel conference, Italy BEKAERT
- 54. Fracture and plasticity models
- 55. Localized hinge
- 56. Multiple cracking in tension and flexure Tensile test Flexural test Moment-curvature
- 57. Modelling procedures Tension model Compression model Bond (interface) model Stress/strain distribution Moment-curvature relationship Normalized parameters Incorporations of equilibrium equations Moment and curvature distributions throughout the volume Integration, application of boundary conditions Data reduction and solutions for stress, strain, load, deflection distributions
- 58. Material Models
- 59. Derivation of Moment-Curvature Relationship Strain Stress Incrementally impose 0 < t < tu Strain Distribution Stress Distribution SF = 0, determine k Moment: M = SFciyci+ SFtiyti Curvature: φ=c/kh Simplified bilinear moment- curvature Stage : l>w, b>a
- 60. Moment-Curvature Distributions Use Static Equilibrium to get moment distribution Curvature distributions along the beam are generated based on simplified bilinear moment-curvature model
- 61. Non-linear solutions 3PB, 4PB – 3, 4 point bending SS – simply supported C - cantilever
- 62. 2D Contour – Distribution loading Normal strain distribution I IIa IIb Neutral Axis Normal stress distribution
- 63. External software for moment-curvature analysis SE::MC SAP 2000 OpenSees
- 64. Experimental Verification Three point bending tests Six full scales FRC beams Fiber content : 50kg/m3 and 75kg/m3 Beams H500 H1000 H1500 Height (mm) 500 1000 1500 Effective depth (mm) 440 940 1440 Total length (mm) 3000 5900 9000 Span(mm) 2640 5640 8640 Width(mm) 250 250 250 Reinforcement longitudinal bars 8-ϕ14 8-ϕ20 8-ϕ24 Geometry of specimens Parameters for current Model Beam Type Fiber Content kg/m3 E Simulated E εcr η MPa MPa μstr H500 50 30800 30800 146 0.24 75 32100 32000 110 0.26 H1000 50 30800 29500 125 0.22 75 32100 32100 120 0.26 H1500 50 30800 29500 128 0.23 75 32100 32100 117 0.26 Minelli F., Conforti A., Cuenca E., Plizzari G., “Are steel fibres able to mitigate or eliminate size effect in shear?”, Materials & Structures , 47:459–473, 2014
- 65. Experimental Verification – Comparison with s- model Four-point bending test 200(b) × 200(d) × 2000 (L) mm Steel fibers: 50 kg/m3 Rebar 2-ϕ12 Dupont D. “Modelling and experimental validation of the constitutive law (σ-ε) and cracking behavior of steel fiber reinforced concrete” Ph.D. Dissertation, Catholic University of Leuven, Belgium, 2003 P/2 P/2 900 200 900 2000 s- Model E =29 GPa, εcr = 130 µstr μ =0.38, βtu = 192 ω = 10, λcu = 27, γ = 0.7 Bilinear M-φ Model E =30 GPa, εcr = 130 µstr η=0.21, m = 4.88, q =20 EIg =4.0×1012 EIcr=8.4×1011 (s- Model) (s- Model) (s- Model)
- 66. Experimental Verification – RC with Steel fibers Three-point bending test Fiber content: 50 and 75 kg/m3 Beams Group #1 Group #2 Group #3 Height (mm) 500 1000 1500 Span(mm) 2640 5640 8640 Width(mm) 250 250 250 Reinforcement Longitudinal bars 8-ϕ14 8-ϕ20 8-ϕ24 Beam Type Fiber Conten t kg/m3 εcr, E η m q EIg, 1013 EIcr, 1013 10-6 GPa Group #1 50 146 30.8 0.24 6.04 22 8.02 1.93 75 120 31 0.26 9.32 33 8.07 2.10 Group #2 50 120 30 0.22 5.18 20 62.5 13.8 75 120 31 0.28 6.88 22 64.6 18.1 Group #3 50 120 29 0.24 6.04 22 204 48.9 75 120 30 0.28 7.16 23 211 59.1 Simulated Parameters Normalized curvature vs. Normalized moment Deflection at mid-span vs. Applied load Minelli F., Conforti A., Cuenca E., Plizzari G., “Are steel fibres able to mitigate or eliminate size effect in shear?”, Materials and Structures , 47:459–473, 2014 Group #1
- 67. Group #2 Group #3 Experimental Verification – RC with Steel fibers Minelli F., Conforti A., Cuenca E., Plizzari G., “Are steel fibres able to mitigate or eliminate size effect in shear?”, Materials and Structures , 47:459–473, 2014
- 68. Experimental Verification – Textile Reinforced Concrete Three-point bending test 30 (b) × 9(d) × 220 (L) mm Textile fabrics: Polypropylene Aramid ID εcr,µstr E, Gpa η m q EI, 107 EIcr, 107 100P 130 22 0.01 4.28 298 4.0 0.044 100A 130 22 0.1 17 157 4.0 0.41 25A75P 130 22 0.05 10.48 198 4.0 0.202 100P Normalized curvature vs. Normalized moment Deflection at mid-span vs. Applied load Simulated Parameters (Avg.) Mobasher, Barzin, et al. "Correlation of constitutive response of hybrid textile reinforced concrete from tensile and flexural tests." Cement and Concrete Composites 53 (2014): 148-161.
- 69. 100A 25A75P Mobasher, Barzin, et al. "Correlation of constitutive response of hybrid textile reinforced concrete from tensile and flexural tests." Cement and Concrete Composites 53 (2014): 148-161. Experimental Verification – Textile Reinforced Concrete
- 70. Experimental Verification – RC with Steel fibers Four-point bending test 200(b) × 600(d) × 4000 (L) mm Steel fibers Longitudinal and shear reinforcement Measure deflections by five LVDTs x = 750, 1500, 2000, 2500, 3250 mm Beam ID Fiber volume fraction (%) Longitudinal reinforcement Shear reinforcement Ratio Tension Top bar Ratio (%) Rebars (%) V1 0 0.262 4φ10 2φ6.3 0.104 4φ6.3 V2 0 0.262 4φ10 2φ6.3 0 0 ID m q EIg, 1014 EIcr. 1014 V1 2.56 100 1.01 0.131 V2 1.91 92 1.01 0.071 Deflection at mid-span vs. Applied load Simulated Parameters Details of beams
- 71. Experimental Verification– RC with Steel fibers 4m span Fiber volume fraction : 1.25% 2ϕ10 (Tension bars), 2 ϕ6.3(Comp. bars) Pre-cracked stiffness EIg=1.08×1014 Post-cracked stiffness EIcr=1.13×1013 LVDT
- 72. Experimental Verification – RC with GFRP bars Four-point bending test 180(b) × 250(d) × 1800 (L) Steel bar Glass fiber-reinforced polymer bars Beam ID As (mm2 ) Af (mm2 ) ρeff (%) B1 452 - 1.14 B2 - 506 0.29 B4 201 397 0.71 B5 402 142 1.08 B7 113 142 0.35 B8 1206 397 3.49 ID εcr, E, η m q EIg, 1012 EIcr,1012 10-6 GPa B1 130 25 0.21 5.41 22 5.86 1.230 B2 135 25 0.08 7.16 78 5.86 0.469 B4 130 25 0.21 3.73 14 5.86 1.230 B5 130 25 0.28 5.76 18 5.86 1.640 B7 140 26 0.03 3.94 90 5.98 0.197 B8 130 25 0.55 10.35 18 5.86 3.220 Normalized curvature vs. Normalized moment Deflection at mid-span vs. Applied load Simulated Parameters Details of beams As – Area of steel reinforcement Af – Area of GFRP reinforcement ρeff – Effective reinforcement ratio Qu, W.; Zhang, X.; and Haiqun Huang, H., “Flexural Behavior of Concrete Beams Reinforced with Hybrid GFRP and Steel Bars, Journal of Composites for Construction, Vol. 13, No. 5, October 1, 2009. 13:350-359.
- 73. Experimental Verification – RC with GFRP bars Beam ID As (mm2 ) Af (mm2 ) ρeff (%) B4 201 397 0.71 B8 1206 397 3.49 Beam ID As (mm2 ) Af (mm2 ) ρeff (%) B5 402 142 1.08 B7 113 142 0.35 B4 : EIcr=1.23 ×1012 B8 : EIcr=3.22 ×1012 As ↑ EIcr ↑ B5 : EIcr=1.64 ×1012 B7 : EIcr=1.97 ×1011 Qu, W.; Zhang, X.; and Haiqun Huang, H., “Flexural Behavior of Concrete Beams Reinforced with Hybrid GFRP and Steel Bars, Journal of Composites for Construction, Vol. 13, No. 5, October 1, 2009. 13:350-359.
- 74. Maximum Curvature vs. Span L=1000 L=1800 L=2000 L=2640 L=5640 L=8640 Span ↑ Curvature ↓ Unit: mm 1 1 1 2 3 3 1 1 1 2 3 3 3 4 5 6 3
- 75. Mechanics of Fiber and Textile Reinforced Cement Composites CRC press, 2011 E-mail: barzin@asu.edu http://enpub.fulton.asu.edu/cement/
- 76. Conclusion New technologies and directions are clearly available in our future progression in Construction industry. Use of materials science based and mechanics based approaches to obtain better ways to characterize, model, analyze, and design. Better train, communicate, and follow through – respect the construction component of the manufacturing process. Address specifications, quality, and long term performance. Fiber Reinforced Concrete can be effectively used as a technology enabler for our alternative energy generation, use and infrastructure development