Strengthening of Concrete Structures. Shaun Loeding, P.E. Director Strengthening Division

Transcription

1 Strengthening of Concrete Structures Shaun Loeding, P.E. Director Strengthening Division

2 Overall Intent??? Design and implement structural solutions based on our experience and technologies. Shaun Loeding, P.E. Director - Strengthening Division

3 State of the Art Products Engineering Support Services Specialty Contracting Solutions that integrate products, engineering, and construction

4 Quick Facts Total Group Annual Revenues $400 million Offerings Products Engineering Construction Employees 2,500 + Products & Engineering $50 Million Regional Technology Centers Baltimore, Dallas, & Houston Construction Annual Revenues $350 Million ENR Ranking Largest Concrete Repair Contractor & 27 th Largest Specialty Contractor Projects 2,000-2,500 annually Typical Range $2,500 to $30 Million Labor Union & Open Shop Multiple Crafts 2,000-2,500 employees Markets Served North America & Middle East

5 Quick Facts Offices Corporate HQ: Hanover, MD North America Offices: Baltimore Baton Rouge Chicago Dallas Denver Detroit Ft. Lauderdale/Miami Hartford Kansas City Lake Charles Long Island Los Angeles New York Philadelphia Pittsburgh San Francisco Sarasota/West Florida Springfield International Offices: Abu Dhabi Dubai Qatar

6 Design-Build Construction Chimney & Stack Construction Silo & Tank Construction Pre-Engineered Structures Repair Services Concrete Repair Fireproofing Force Protection Pipe Rehabilitation Strengthening Corrosion & Cathodic Protection Refractory Linings Equipment & Pump Foundations Moisture Control & Waterproofing Building Envelope Historic Restoration Maintenance Services Industry Leading Specialty Contracting Services for New & Existing Structures

7 Repair Services Concrete Repair Fireproofing Force Protection Pipe Rehabilitation Strengthening Corrosion & Cathodic Protection Refractory Linings Equipment & Pump Foundations Moisture Control & Waterproofing Building Envelope Historic Restoration Maintenance Services Industry Leading Specialty Contracting Services

8 Products & Systems Strengthening Force Protection Pipe Repair & Upgrade Corrosion Control Moisture Control Concrete Restoration Equipment Foundations Post Tensioning Engineering Support Investigative Condition Assessment Engineering Product Customization Design Assist Specialty Full Design State of the Art Products Engineered Solutions

9 Agenda Introduction FRP (fiber reinforced polymers) - Most common uses for FRP - Design strategy (ACI 440.2R-08) - Installation techniques and QA/QC - FRP limitations & fire protection - Case Studies Conventional Techniques - Section Enlargement - External Post Tensioning New Strengthening Technologies (DUCON micro-reinforced concrete)

10 Strengthening = Upgrading Structural Capacity Why Strengthen?? Construction Defects Design Deficiencies New Loads Deterioration Seismic Upgrades Blast Upgrades

11 Direct Services Design-Development Conceptual designs and associated budgets Specification support Aid in overall engineering and strengthening analysis Site visits Solution/repair strategy Construction Final design calculations and shop drawings (PE stamped/sealed upon request) QA/QC and Safety Program project specific Trained, certified and experienced installers

12 FRP Composite what is it??? FRP = Fiber-Reinforced Polymer Composite = two or more materials that when combined create one composite behaving system (fiber + epoxy = composite, with new and distinct properties) OTHER NAMES USED: Carbon fiber Carbon FRP (CFRP) or Glass FRP (GFRP) Fiber reinforced composite (FRC) Fiber wrap Externally bonded FRP reinforcement

13 FRP Applications Strengthening Typically Carbon FRP (CFRP) Upgrade flexure and/or shear capacity of member CFRP = higher strength, higher material cost Restoration Typically Glass FRP (GFRP) Corrosion protection, spall protection GFRP = lower strength, lower material cost NOTE: CFRP and GFRP = lightweight, low profile, corrosive resistant, durable

14 FRP Applications

15 Rules of Thumb flexural strengthening with CFRP 12 CFRP strip 1 layer, 12 wide = (1)-#5 rebar (60ksi) Typical application uses CFRP strips of 8, 12 or 24 width Typical application uses 1 to 4 layers of CFRP CFRP may provide up to 40% additional capacity to an element Typical application requires 20%-25% additional capacity CFRP does not stiffen an element i.e. does not aid in reducing deflections or aid in satisfying service conditions of an element

16 FRP Design Principles & Engineering Considerations 440.2R-08

17 FRP Flexural Design Concepts b e c gf ' c c 1 c h d e s e f Strain in FRP? f s f f 1c M n As f s d 2 f A f f f h 1c 2

18 FRP Design Strain Limits Peeling de-bonding effect at ends Un-zipping de-bonding effect at flexural cracks C L

19 Stress (ksi) Design Stress/Strain Relationship Ultimate (Rupture) Flexural Design CFRP Steel GFRP Modulus, E: Steel 29,000ksi CFRP 12,000ksi GFRP 3,000ksi Strain

20 LOAD FRP Strengthening Limits ACI 440.2R Supplemental Reinforcement Member with FRP New Ultimate Loads: 1.2DL+1.6LL New 440.2R Loads: 1.1DL+0.75LL Original RC Member DEFLECTION Existing strength without FRP should be able to support demand from load case of 1.1DL+0.75LL (ACI 440.2R, Eq. 9-1)

21 LOAD FRP Strengthening Limits Fire Event Supplemental Reinforcement Member with FRP New Ultimate Loads: 1.2DL+1.6LL New Service Loads: 1.0DL+1.0LL (due to change) Original RC Member 2Hr Fire Reduced Capacity DEFLECTION Existing strength without FRP should be able to support typical service loads (1.0DL+1.0LL) after 2Hr Fire

22 Fire Protection Strategies Protect FRP for Applicable Burn Characteristics per ASTM E84 Intumescent Topcoat (Flame spread & smoke density) Intumescent (Burning- ASTM E84)

23 FRP Installation General Procedures Prepare substrate surface Provide surface primer/thickened epoxy on prepared substrate Saturate fabric sheet Install saturated fabric sheet Provide coating

24 Substrate Preparation for Bond Primer Open pores! 1.Abrasive blast 2.Dustless grinding & vacuum 3.Water blast & dry

25 Surface Preparation

26 Primer/Thickened Epoxy to Substrate

27 FRP Sheet Saturation

28 FRP Sheet Saturation

29 FRP Sheet Installation Prepared substrate Saturated fabric sheet Primed substrate

30 QC Acceptance Criteria Delamination Limits of delaminated FRP area to ensure adequate performance Tap Test Material Testing Tensile tests of laminate from field Bond Pull of tests to determine bond strength to concrete Minimum 200 psi

31 FRP Pull off Bond Test Requires Min. 200psi

32 Condo Building - multiple strengthening techniques due to design defects

33 Slab Strengthening FRP layout

34 Slab Upgrade FRP strips (positive bending)

35 Slab Strengthening (negative bending)

36 Wall removal required Slab Strengthening

37 Condo Building - multiple strengthening techniques due to design defects Shear collars Column enlargement

38 New Penetrations in Existing Slabs One direction Two direction

39 New Slab Penetrations

40 Existing Concrete Joists

41 Precast Double Tees - Stem cracks

42 Install FRP Shear U Wraps

43 Guggenheim Museum

44 Guggenheim Museum

45 Guggenheim Museum Chip Open crack

46 Guggenheim Museum Steel T-Section Rebar Discontinuous 5

47 Guggenheim Museum T-Bars

48 Guggenheim Museum and dry wall Prior to insulation

49 Guggenheim Museum Thru wall detail Bond Bond Grout

50 Guggenheim Museum Web Wall Bracket

51 MOMENT RESISTING FRAMES - Column failure Lack of plastic hinge confinement

52 Beam/Column shear strengthening (Performance of an RC Corner Beam-Column Joint by Engindeniz et al., 2007)

53 FRP Wrap Increase Axial Load Capacity

54 Column Repairs - Low Strength Concrete Enlarge FRP

55 Power Plant - Missing Seismic Steel

56 Power Plant - Missing Seismic Steel

57 Power Plant - Missing Seismic Steel

58 Power Plant - Missing Seismic Steel

59 FRP Near-Surface Mounted (NSM) Rod -

60 FRP Near-Surface Mounted (NSM) Rod - CFRP Bar Installation Finished Product

61 NSM Rod- Bridge Decks ( I-75, Florida)

62 NSM Rod- CMU Wall Application

63 I-75 Rouge Bridge, MI Column FRP Upgrade

64 Shear Upgrade with FRP

65 Completed Bridge Pier FRP Strengthening

66 FRP Strengthening NSM Anchorage of Shear Reinforcing FRP Sheet FRP rod Epoxy paste FRP reinforcement

67 Far Rockaway, Queens, NY Elevated A-Line

68 Far Rockaway, Queens, NY Elevated A-Line

69 Far Rockaway, Queens, NY Elevated A-Line

70 Far Rockaway, Queens, NY Elevated A-Line

71 Enlargement- Composite Behavior Existing New

72 Enlargement: Self-Consolidating Concrete 26-28

73 Section Enlargement

74 External Post Tensioning Upgrade NEW LOAD F Live end Dead end F Uplift at Deviator

75 External Post Tensioning Encased in Concrete PT Beam Damaged From Snow Load

76 External Post Tensioning Encased in Concrete

77 External Post Tensioning Encased in Concrete

78 DUCON Slurry-infiltrated Micro-Reinforced Ultra High Performance Concrete MicroMat Micro-Reinforcement DUCON Self Consolidating Slurry DUCON Ductile Concrete Tensile: ksi Compressive: ~ 20 ksi Compressive: ~ 22 ksi Tensile: ~ 3 ksi Shear: ~ 2 ksi

79 Bundled Wire Layers

80 Micro-reinforcement mesh Multiple layer mat (Plan View) Wire Size: 0.04 to 0.06 Wire Spacing: 0.3 to 1.0 Wire Strength: 60ksi or 80ksi meshes wire

81 Concrete Slurry Infiltration 15,000psi+ slurry

82 2 inches Micro-reinforced Concrete Slurry Diameter 0.9 inch MicroMat layers per inch

83 Bending Performance

84 Original Concept - Thin Load Bearing Elements

85 T-Beam Details 1 11'-0" 4" 16" 1 U-Shape Ducon (thickness varies) 10'-0" 10'-6" Beam BS2-D & BS5-D 36" 36" 4" 4" 12" 16 3/4" 12" 17 1/2" U-Shape Ducon (Thickness 1") 12" U-Shape Ducon (Thickness 1.75") 12" 14" 15 1/2" Beam BS2-D BS5-D

86 Surface Preparation - Roughen surface to ¼ amplitude (CSP-7) - No dowels required

87 Install Steel Mesh (specified layers)

88 Slurry Pumped into Forms (Material Flow Plexiglass Window) Slurry Pumping

89 Cured and Finished Product Test Beam

90 DUCON - Slab Overlay (structural and/or finish upgrades) Crack sealing Crack control Water-tight

91 Primary Applications - Review Precast Elements Thin and strong Column forms, walls Strengthening enlargement Beams and slabs (flexure, shear) Columns (axial, seismic) Surface Repair Crack sealing, crack control, water-tight Industrial flooring Blast Protection Energy dissipation Fragmentation and spall protection safety net

92 Spall and Breach SPALL RFC BREACH & SPALL RFC 18 inch 36 inch 18 inch

93 Stand Off & Perimeter Blast Threats (>20 standoff distance) 20 Slab, Column Or Wall 10 0 Primary Damage mode: Flexure Effects: Rotation Cracking Minimal Spalling Typical Blast Pressure Range: 4 psi - 10 psi 0ft 3ft 8ft 20ft STAND OFF CHARGE

94 Mid Range Blast Threat (>8 and < 20 ) Primary Damage mode: Flexure Secondary Damage mode: Shear Slab, Column Or Wall Typical Blast Pressure: 10 psi - 20 psi Effects: Some Spalling Small Projectiles No Breach MID RANGE CHARGE ft

95 Close Range Threat (>3 and < 8 ) 12 Slab, Column Or Wall Typical Blast Pressure: 6 0 Primary Damage mode: Shear Secondary Damage Mode: Flexure Significant Spalling Large Projectiles Possible Breach psi CLOSE RANGE CHARGE ft

96 Contact Detonation Blast Threat (< 3 ) 8 Slab, Column Or Wall Primary damage mode: Shear 4 Effects: Breach (certain) Shock wave penetrates Heavy Spalling Large projectiles CONTACT CHARGE Typical Blast Pressure: 200 psi 100K psi 0 0 3

97 DUCON Ultra High Performance Concrete Shear Strength Test

98 100 lb Close Range Detonation Testing Rear Side RFC

99 Contact Detonation Test Results Attacked Side No Breach Protected Side No Spall

100 Cast in Place Walls

101 DUCON INSITU SPALL LINERS (WALLS) 3

102 Cast in Place Walls

103 Cast in Place Walls

104 THE PARKLAWN BUILDING Department of Health and Human Services

105 The Parklawn Building 1200 Columns, 21 Column Sizes, 8 Different Conditions PHASE 2 PHASE 1 PHASE 3

106 Column Blast Shields Install wire mesh

107 Column Blast Shields Form and pump cement

108 Column Blast Shields Partial height column jacket Full height column jacket

109 DUCON - Precast Wall Panels

110 Blast Mitigation for Columns for Truck Sized Bomb at Curbside No FRP

111 Blast Mitigation for Columns with FRP No FRP

112 Blast Mitigation for Columns with FRP With FRP

113 Overall Intent??? Design and implement structural solutions based on our experience and technologies. Shaun Loeding, P.E. Director - Strengthening Division

114 Concluding remarks THANK YOU! Please visit and Technical design support Budgetary estimate support Repair and QA/QC specs Contracting services Technical Lunch-Box training seminars available: - Strengthening - Corrosion Protection - Concrete Repair - Building Envelope - Waterproofing - Force protection Current projects? Local contact: Shaun Loeding, P.E sloeding@structural.net