View
1
Download
0
Category
Preview:
Citation preview
Behavior and Strength of Ultra-High Performance Concrete in Shear
Paolo CalviDanielle Voytko
ABC-UTC Research SeminarJuly 30th, 2021
Project Contextualization2
(a) UHPC Bridge Girder
v
(b) UHPC Panel in biaxial stress
conditions
v
(c) UW Panel Element Tester(a) RC bridge girder (b) RC Panel in biaxial stress conditions
(c) Panel Element Tester
Project Contextualization3
ππ = ππ + ππ + ππ
Project Contextualization4
Project Contextualization5
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
6
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
7
Introduction
> University of Oklahoma (OU)
β UHPC mix design
β Material tests
> University of Washington (UW)
β Pure shear tests
β Material tests
> Florida International University (FIU)
β Material tests
> Iowa State University
β Material tests
> University of Nevada-Reno
β Performance of joints between panels
Collaboration
8
Introduction
> University of Oklahoma (OU)
β UHPC mix design
β Material tests
> University of Washington (UW)
β Pure shear tests
β Material tests
> Florida International University (FIU)
β Material tests
> Iowa State University
β Material tests
> University of Nevada-Reno
β Performance of joints between panels
Collaboration
9
Introduction
> Cementitious material
β Cement
β Slag
β Silica fume
β Ground quartz
β Flay ash
> Aggregate
β Fine sand
> Water
β Water-to-cement ratio: 0.17 to 0.25
> Fiber reinforcement
β Typically steel
β Standard 2% by volume
β Length: 6 to 60 mm
β Aspect ratio (L/D): 20 to 100
> Admixtures
β High range water reducer
β Retarder
Ultra-High Performance Concrete (UHPC) Composition
10
Introduction
Steel Fibers
Spajic Machines- Steel Fibers
11
Introduction
Steel Fibers
Spajic Machines- Steel Fibers
12
13 mm long0.2 mm diameter
Introduction
UHPC
www-personal.umich.edu/~eltawil/uhpc
13
Introduction
UHPC Properties
14
UHPC and Conventional Concrete Comparison
MaterialCompressive
Strength (psi)
Flexural
Strength (psi)
Tensile
Strength (psi)
Conventional Concrete 3,000-6,000 400-700 300-700
UHPC18,000-35,000
(up to 50,000)2200-3600 900-1500
MPa = psi/145
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
15
Previous Work
> Federal Highway Administration (FHWA)
β Ben Graybeal
> Proprietary mixes with 2% fiber content
> Compressive strength: 17 to 29 ksi
> Modulus of elasticity: πΈπ = 46200 πβ²π ππ π
> Tensile strength: ππ‘ = 6.7 πβ²π π’ππ‘ππππ‘ππ (psi)
ππ‘ = 8.2 πβ²π π π‘πππ ππ’πππ (ππ π)
Material Properties
16
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
17
Research Motivation
> Rehabilitation
β Strengthening of an existing steel girder using UHPC encasement
Industry Applications
18
Graybeal, Benjamin A., et al. βProperties and Behavior of UHPC-Class Materials.β FHWA, 2018.
Research Motivation
> Girders
β Comparison of typical prestressed bridge girders composed of conventional concrete and UHPC
Industry Applications (cont.)
19
Graybeal, Benjamin A., et al. βProperties and Behavior of UHPC-Class Materials.β FHWA, 2018.
Research Motivation
> Connections
β Bridge deck
β Pier cap
Industry Applications (cont.)
20
Graybeal, Benjamin A., et al. βProperties and Behavior of UHPC-Class Materials.β FHWA, 2018.
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
21
Experimental Program
> Evaluate the shear strength of UHPC.
> Determine the effect of fiber content on the behavior of UHPC by varying the percentage of fibers in UHPC batches.
> Determine the effect of material sourcing on the behavior of UHPC.
Research Objectives
22
Experimental Program
Testing Plan
23
University of Washington Testing Plan
Test Dimension (in) Test Day Reference
Compression Cylinder 4x8 3 @ 3, 60 ASTM C39
Modulus of Elasticity 4x8 3 @ 60 ASTM C469
Direct Tension 3.5x2x12 3 @ 60
Flexural Beam 3x3x11 3 @ 60 ASTM C78
Pure Shear 35x35x2.75 1 @ 60
Experimental Program
University of Oklahoma Mix Design
24
University of Oklahoma Mix Design
Material Per yd3 Unit Supplier
Type 1 Cement 1179.6 lb Ash Grove (Chanute, KS)
Slag 589.8 lb Holcim (Chicago, IL)
Silica Fume 196.6 lb Norchem (Beverly, OH)
Fine Masonry Sand 1966 lb Metro Materials (Norman, OK)
Steel Fibers (Dramix OL 13/0.2) 255.2 lb Bekaert
Superplasticizer (Glenium 7920) 15.77 oz/cwt BASF
Water 0.2 w/cm
Experimental Program
University of Washington Mix Design
25
University of Washington Mix Design
Material Per yd3 Unit Supplier
Type 1 Cement 1179.6 lb Salmon Bay Sand & Gravel (Seattle, WA)
Slag 589.8 lb Lafarge (Seattle, WA)
Silica Fume 196.6 lb Salmon Bay Sand & Gravel (Seattle, WA)
Fine Masonry Sand 1966 lb Salmon Bay Sand & Gravel (Seattle, WA)
Steel Fibers (Dramix OL 13/0.2) 255.2 lb Bekaert
Superplasticizer (Glenium 7920) 20.7 oz/cwt BASF
Retarder (Daratard-40) 5.66 oz/cwt Grace Construction Products
Water 0.2 w/cm *Including admixture water
Experimental Program
Specimen Plan
26
University of Washington Specimen Plan
Test Series Batch Name Fiber Content (%) Material Source
0UW2A 2 UW
UW2B 2 UW
1
UW2C 2 UW
UW2D 2 UW
UW2E 2 UW
2 UW1 1 UW
3 OU2 2 OU
Experimental Program
> UW Panel Element Tester
Pure Shear
27
6 ft
Experimental Program
> UW Panel Element Tester
Pure Shear (cont.)
28
Experimental Program
> Panel specimen (3β x 3β x 2.75β)
Pure Shear (cont.)
29
Experimental Program
> Panel specimen (3β x 3β x 2.75β)
Pure Shear (cont.)
30
Experimental Program
> Instrumentation
Pure Shear (cont.)
31
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
32
Experimental Results
Summary of Results
33
UHPC Strength Results
Batch Compression (psi) EMod (ksi) Tension (psi) Flexure (psi) Shear (psi)
UW2A N/A N/A N/A N/A N/A
UW2B 124 5,279 656 2495 1,063
UW2C 18,710 N/A N/A N/A 1,289
UW2D 20,160 5,744 1,194 2,857 1,414
UW2E 19,435 5,686 709 2,437 1,437
UW1 19,290 5,308 676 1,871 1,070
OU2 19,300 6,106 969 2,640 1,347
Experimental Results
Pure Shear Test Results (UW2E)
34
Experimental Results
Pure Shear Test Results (UW2E)
35
Experimental Results
Pure Shear Test Results (UW2E)
36
Experimental Results
Pure Shear Test Results
37
0 0.05 0.1 0.15 0.2 0.25
Shea
r St
ress
(p
si)
Crack Width (in)
Shea
r St
ress
(p
si)
Crack Slip (in)
Shea
r St
ress
(p
si)
Cra
ck W
idth
(in
)
Crack Slip (in)
Experimental Results
Summary of Results based on Test Series
38
UHPC Strength Results
Test Series Compression (psi) EMod (ksi) Tension (psi) Flexure (psi) Shear (psi)
1 19,435 5,715 951 2,654 1,381
2 19,290 5,308 676 1,871 1,070
3 19,300 6,106 969 2,640 1,347
> Test Series 1: UW2C, UW2D, UW2E
> Test Series 2: UW1
> Test Series 3: OU2
Experimental Results
Material Test Results based on Fiber Content
39
1% vs. 2% FiberCompressive Strength and Modulus of Elasticity: no differenceTensile and Flexural Strength: 30% reduction
Experimental Results
Pure Shear Test Results based on Fiber Content
40
1% vs. 2% FiberShear Stress: 20% reductionCrack Width and Crack Slip: larger
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
41
Comparison of Results
Summary of Results
42
Naming Convention
Batch Days Fiber (%)Student
ResearcherInstitution
Material
Sourcing
UW 60 1, 2 Voytko UW UW
OU 60 2 Voytko UW OU
C-OU 28 0, 1, 2, 4, 6 Campos OU OU
D-OU 28 0, 1, 2, 4, 6 Dyachkova OU OU
D-FIU 28 0, 1, 2, 4, 6 Dyachkova OU FIU
Comparison of Results
Compression
43
β’ Compressive strength increases as fiber content increasesβ’ D-OU does not show a big increase from 0 to 6% fibers
Comparison of Results
Modulus of Elasticity
44
πΈπ = 46200 πβ²π (ππ π)
β’ Modulus of elasticity constant slightly increases as fiber content increases
Comparison of Results
Direct Tension
45
ππ‘ = 6.7 πβ²π π’ππ‘ππππ‘ππ (psi)
ππ‘ = 8.2 πβ²π π π‘πππ ππ’πππ (ππ π)
β’ Tensile strength constant increases as fiber content increasesβ’ C-OU constant decreased from 4 to 6% fibers
Comparison of Results
Flexural Beam
46
β’ Flexural strength increases as fiber content increasesβ’ D-OU strength decreased from 4 to 6% fibersβ’ Flexural Strength less scattered than Tensile strength
Comparison of Results
Comparison of Results
Tensile Strength (Direct Tension vs. Flexural Beam)
UHPC Tensile Strength Results
Batch Fibers (%) ππ‘π (psi) ππ‘π (psi)
UW2D 2 1,194 831
UW2E 2 709 880
OU2 2 969 811
2% Average 957 840
2% Standard Deviation 199 29
UW1 1 676 624
Comparison of Results
Pure Shear vs. Tensile Strength (Flexural Beam Test)
49
UW1
OU2
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
50
Conclusions
> Fiber Content
β Fiber content had little effect on compressive strength and modulus of elasticity.
β Fiber content had large effect on tensile strength, flexural strength, and shear strength.
> Mixing procedure
β UHPC was extremely sensitive to mixing procedure.
β Mixing UHPC requires significantly more energy than conventional concrete.
β A high energy mixer would yield more consistent results.
Conclusions
51
Conclusions
UHPC Shear Estimation
52
UHPC Proposed Equation
Shear Strength π£ = 46 ππ‘ (ππ π)
π£ = π βπππ π π‘πππππ‘β
ππ‘ = π‘πππ πππ π π‘πππππ‘β
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
53
Recommendations for Future Work
> Build on the work completed by Floyd, Azizinamini, Graybeal, and others
> Test UHPC specimens with varying fiber content
β Percentage, shape, size, material
> Optimize UHPC mix design
β Fibers, admixture
> Cost-benefit analysis of UHPC in industry
> Investigate ductility of UHPC
> Conduct more pure shear tests on UHPC to create a database of results
> Model shear response of UHPC with available software (such as Vectr)
Recommendations
54
Overview
> Introduction
> Previous Work
> Research Motivation
> Experimental Program
> Experimental Results
> Comparison of Results
> Conclusions
> Recommendations for Future Work
> Acknowledgements
55
Acknowledgements
> Funding and Collaboration
β Accelerated Bridge Construction (ABC-UTC) at Florida International University
β University of Oklahoma
> PIβs
β John Stanton
β Paolo Calvi
> Undergraduate assistants
β Ben Terry, Rueben Madewell, and Clayton Black
Thank You
56
Recommended