Grouted Splice Sleeve Connection Alternativessp.bridges.transportation.org/Documents/2015...

Seismic Evaluation of Grouted Splice Sleeve Connections for Reinforced Precast Concrete Bridge Piers

Chris P. Pantelides, PhD, PE, SE

M.J. Ameli, PhD Candidate

Saratoga Springs, NY

April 2015

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1-1) Accelerated Bridge Construction (ABC)

• ABC connections acceptable performance:

1- Lateral load capacity

2- Ductility levels

3- Repairability

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• Reduced construction time and traffic disruption

• Higher level of work-zone safety

• Environmental-friendly

1-2) Grouted Splice Sleeve (GSS) Connections

• Alternatively called: - Mechanical rebar splices

- Grout-filled steel sleeves

• Components: - Rebar

- Sleeve

- Grout

• GSS in Design Codes

- ACI 550 (Type 1, Type 2)

- AASHTO (Full mechanical connection)

- Caltrans (Service and ultimate couplers)

Column-to-footing connection (NCHRP 698)

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1-3) Research Objectives

• GSS used in research:

GGSS for column-to-footing

[NMB Splice Sleeve]

FGSS for column-to-cap beam

[Lenton Interlok]

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• GSS in precast components:

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GGSS for column-to-footing

[NMB Splice Sleeve]

FGSS for column-to-cap beam

[Lenton Interlok]


• Half-Scale Test Matrix [Alternatives]:

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Test Connection Type Designation Sleeve Type Sleeve Other

ID Location

Category I

1 Column-Footing GGSS-1 NMB-8UX In Column

2 Column-Footing GGSS-2 NMB-8UX In Footing

3 Column-Footing GGSS-3 NMB-8UX In Column Unbonded Rebar

4 Column-Footing GGSS-CIP NA NA Cast-In-Place

Category II

5 Column-Cap Beam FGSS-1 LK-8 In Column

6 Column-Cap Beam FGSS-2 LK-8 In Cap beam

7 Column-Cap Beam FGSS-CIP NA NA Cast-In-Place


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1-4) Individual GSS Tests

• 6 specimens for each category

• Monotonic tests only

• Instrumentation on GSS and bars

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GGSS air test specimen 9 FGSS air test specimen

Rebar fracture

169%fy on average

Type 2 (Building)

FMC (Bridge)


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Pull-out failure

145%fy on average

Type 1 (Building)

FMC (Bridge)

[GGSS] [FGSS]

2) Design and Construction of Test Specimens • Prototype bridges in Utah considered

• Capacity-based design procedure

• AASHTO LRFD and AASHTO Seismic for detailing

• Sectional and Pushover analyses conducted

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2-1) Design of Test Specimens (Col-Footing) • Effective Height of Column is 8 ft

• Octagonal Column (1.3% longitudinal, 1.9% transverse rebar)

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• Footing dimensions 6X3X2 ft

2-1) Design of Test Specimens (Col-cap beam)

• Cap beam dimensions 9X2X2 ft

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2-2-1) Column-to-Footing Connections [GGSS-1]

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15


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2-2-1) Column-to-Footing Connections [GGSS-CIP]

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2-2-2) Column-to-Cap Beam Connections [FGSS-1]

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2-2-2) Column-to-Cap Beam Connections [FGSS-2]

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2-2-2) Column-to-Cap Beam Connections [FGSS-CIP]

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3) Experimental Setup [Col-Footing Configuration]

• 120-kip or 250-kip actuator

• 500-kip axial actuator

• Spreader Beam

• High-Strength Rods

• Bottom Plate

• 4-ft support distance

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-12-10-8-6-4-202468

1012

0 2 4 6 8 10 12 14 16 18 20 22

Drift

(%)

Cycles

(4) Test Results

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4-1) Column-to-Footing Connections [GGSS-1]

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µ∆ = 5.4


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@ 3% drift

@ 6% drift

@ 8% drift

@ 8% drift- rebar fracture


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µ∆ = 6.1


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@ 3% drift

@ 7% drift



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µ∆ = 6.8


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@ 3% drift

@ 8% drift


4-1) Column-to-Footing Connections [GGSS-CIP]

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µ∆ = 8.9

4-1) Column-to-Footing Connections [GGSS-CIP]

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@ 3% drift

@ 6% drift

@ 9% drift

4-2) Column-to-Cap Beam Connections [FGSS-1]

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µ∆ = 4.9


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@ 3% drift- Peak

@ 3% drift

@ 6% drift- Peak

@ 6% drift


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µ∆ = 5.8


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@ 3% drift

@ 7% drift

@ 7% drift

4-2) Column-to-Cap Beam Connections [FGSS-CIP]

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µ∆ = 9.9

4-2) Column-to-Cap Beam Connections [FGSS-CIP]

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@ 3% drift

@ 6% drift

@ 10% drift

Summary of Most Significant Experimental Findings: Desirable performance (ductile), rebar fracture, µ∆ equal to 8.9 for

GGSS-CIP; very good hysteretic performance, energy dissipation

capacity, and well-distributed flexural cracks.

Localized damage for GGSS-1 and GGSS-3. Smaller region of

spalling with respect to GGSS-CIP.

Similar damage states for GGSS-2 and GGSS-CIP, with no sleeves

in the column base.

Rebar fracture for GGSS-CIP and premature rebar fracture for all

precast specimens due to higher values of concentrated strains at

interface.

5-1) Column-to-Footing Connections

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Summary of Most Significant Experimental Findings,

cont’d: A more ductile response achieved by incorporating sleeves inside

footing. Displacement ductility capacity increased from 5.4 to 6.1.

A postponed rebar fracture along with better strain distribution

achieved when 8db debonded rebar zone was implemented for

GGSS-3, i.e. sleeves in column base + debonding in footing.

Compare displacement ductility of 6.8 vs. 6.1.

Different distribution of inelasticity for GGSS-1 and GGSS-3, as

sleeve connectors were in the column base. Similar inelasticity

distribution for GGSS-2 and GGSS-CIP.

Strain gauge data showed both field and factory dowel yielded for

GGSS-1 and GGSS-3. The factory dowel of GGSS-2 did not yield.

Displacement ductility for all specimens exceeded minimum

component ductility of 3 per Caltrans SDC and maximum ductility

demand of 5 per AASHTO-Seismic for single-column bents.

5-1) Column-to-Footing Connections

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Summary of Most Significant Experimental Findings: Desirable performance (ductile), rebar fracture, µ∆ equal to 9.9 for

FGSS-CIP; very good hysteretic performance, energy dissipation

capacity, and well-distributed flexural cracks.

Localized damage for FGSS-1. Smaller region of spalling with

respect to FGSS-CIP.

Similar damage states for FGSS-2 (sleeves in cap beam) and FGSS-

CIP.

Rebar fracture for FGSS-CIP and premature rebar fracture for one

FGSS-2 bar due to higher values of concentrated strains at interface.

Excessive bond-slip led to pull-out failure of east rebar in

FGSS-1 and FGSS-2.

5-2) Column-to-Cap Beam Connections

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Summary of Most Significant Experimental Findings,

cont’d: A more ductile response was achieved by incorporating sleeves

inside cap beam. One bar fractured and µ∆ increased from 4.9 to 5.8.

Different distribution of inelasticity for FGSS-1, when sleeves were in

the column base. Similar inelasticity distribution for FGSS-2 and

FGSS-CIP.

Strain gauge data showed both field and factory dowel yielded for

FGSS-1. The factory dowel of FGSS-2 did not yield.

Displacement ductility for all specimens exceeded minimum

component ductility of 3 per Caltrans SDC. µ∆ of 5.8 (FGSS-2) was

greater than maximum ductility demand of 5 per AASHTO-Seismic

for single-column bents.

5-2) Column-to-Cap Beam Connections

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For flexural-dominant precast components connected

by sleeves: Well-confined connector zone is advantageous. Transverse

reinforcement shall be used to secure the sleeves.

Spiral splice length equal to two extra turns was found satisfactory.

FG sleeve was found promising for moderate-seismic zones, if the

limitation on displacement ductility is accounted for.

Enhanced ductility capacity may be achieved when FG sleeve is

inside the cap beam.

GG sleeve was found promising for high-seismic zones, if the

limitation on displacement ductility is accounted for.

Enhanced ductility capacity may be achieved when GG sleeve is

inside the footing.

More ductile performance is achievable when GG sleeve is in the

column base and a debonded rebar zone in the top of the footing is

implemented.

5-3) Design Recommendations

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CFRP composite doughnut with headed steel bars

Repairability

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University of Utah Joel Parks

Dylan Brown

Prof. Lawrence D. Reaveley

Mark Bryant

Utah Department of Transportation Carmen Swanwick

Joshua Sletten

New York State Department of Transportation Harry White

Texas Department of Transportation

NMB Splice Sleeve

Erico

Acknowledgements

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