Use of Ultra-High Performance Concrete in Geotechnical and Substructure Applications

Transcription

1 Use of Ultra-High Performance Concrete in Geotechnical and Substructure Applications i PI: Muhannad Suleiman Co-PI: Sri Sritharan Graduate Research Assistant: Thomas L. Vande Voort January 13, 29 IOWA STATE UNIVERSITY

2 Research Funding Seed funding received from IHRB for a highrisk, high-reward project that can lead to substantive advancements in highway transportation 2

3 Objectives Demonstrate the potential use of UHPC in geotechnical applications Evaluate the behavior of UHPC piles using large-scale tests and analytical procedures

4 Motivation Grand d Challenges issued by AASHTO 25: Extending service life of bridges to 75 years with minimal maintenance Optimizing structural systems using new materials Piles made of conventional materials have suffered damage

5 Why UHPC? Property UHPC HPC Normal Concrete Compressive Strength 26-3 ksi ksi 4-8 ksi Tensile Strength 1.7 ksi.8-.9 ksi.3-.7 ksi Elastic Modulus 8 ksi ksi ksi Durability Up to 4x lower Up to 7x lower 1 arameter Re elative to Normal Con ncrete P UH HPC HPC Normal Con ncrete Chloride Ion Penetration Depth PC UH HPC Normal Con ncrete PC UH HPC Oxygen Permeabilty Water Absorption Carbonation Depth (3 years) Normal Con ncrete UHPC HPC Normal Con ncrete PC UH HPC Normal Con ncrete Reinforcement Corrosion Rate

6 Tasks Conduct a literature review on the use of UHPC in super- and any sub-structural systems related to transportation structures in the United States and abroad Design of UHPC pile section Conduct comparative driveability study for UHPC and other piles Conduct laboratory tests on UHPC pile elements Conduct dynamic tests (PDA/CAPWAP) on UHPC and steel piles Perform large-scale vertical and lateral load tests on UHPC piles

7 Pile Section Shapes Considered Simple H-Shape X-Shape Tapered H-Shape

8 Final Section Properties Parameter Steel HP 1 x 57 UHPC Tapered H-Shape Area 16.8 in in 2 Weight/ft 57.2 lb 61.1 lb Moment of Inertia 294 in in 4 Stiffness Term (E I) kip in kip in 2

9 Construction b

10 Laboratory Testing Cells Top Tilt Gauge Curvature, φ (mm -1 ) DCDTs String Deflection Gauges Moment, M (in k kip) Calculated Response Lab Test Measured Data Moment, M (kn m) Curvature, φ (in -1 )

11 Field Investigation: US63 Oskaloosa, IA

12 Site Soil Profile SPT Blow Count (blows/ft) Tip Resistance, q 2 c (ton/ft ) Friction, f 2 s (ton/ft ) Friction Ratio, F r (%) Soil Classification Undrained Shear Strength, s u (psi) % 5% 1% 15% Clay Friction Angle, φ Sensitive Fine Grained Clay Depth (ft) 2 Sand Sandy Silt to Clayey Silt 2 6 Depth (m) 25 Sand to Silty Sand Tip Resistance, q c (kpa) Friction, f s (kpa) 3 Sandy Silt to Clayey Silt Very Stiff 1 Fine Clay Grained Gravelly Sand to Sand Undrained Shear Strength, s u (kpa)

13 Field Testing Plan Reaction Pile Reaction Beam Reaction Pile Reaction Pile 6.5 ft 6.5 ft 5. ft 4. ft Unit UHPC 1 Steel Pile Reaction Pile Unit UHPC 2

14 Driving of UHPC and Steel Piles Hammer Leads Pile PDA Accelerometer PDA Strain Gauge

15 Driving Logs Cum Blows etration Depth (m) Pen Blows/.3m of Steel HP 1x57 Blows/.3 m of UHPC 1 Cum blows for steel HP 1x57 Cum blows for UHPC h (ft) Pen netration Dept Blows/ ft

16 Driving

17 Vertical Load Tests

18 Load-Displacement Relationship Load (kn) Load (kn) Extrapolation Displacement (mm) Displacement (in.) Displacement (mm) Displace ment (in.) Davi avisson Pile Capacity = 198 Kips Davisson Failure Crit Criterion Davisson son Failure Criterion 7.7 Davisson Pile Capacity = 369 Kips Load (Kips) Load (Kips) UHPC Steel Pile

19 Load Transfer Depth (m) Vertical Load (kn) Ground Surface Vertical Load (Kips) Depth (ft) Load (kn)

20 Lateral Load Test

21 UHPC Pile Lateral Load-Displacement Lateral Displacement (in.) Lateral Load (kn) UHPC 1 UHPC La ateral Load (K Kips) Shear cracks Bundle of wires (a) Bundle of wires (b) Lateral Displacement (mm)

22 UHPC Pile Lateral Load-Displacement Strain (με) De epth (m) Ground Surface 15.9 kn 27.9 kn 4.7 kn 55.9 kn 68.8 kn 77.8 kn 92.7 kn 11.2 kn epth (ft) D

23 Questions