nace concrete composite
TRANSCRIPT
Repairing Concrete Structures with Coatings and Composites
Michael P. Yee
NACE Coating Inspector Level 3 #50795
Richard Taraborelli [email protected]
RT Consults PLLC NACE Conference: June 29-July 1, 2015
• The issues with corrosion of concrete structures.• Remediation Options and Repair Requirements.• Best practices for applying FRP and Coatings on
Repaired Concrete.• The value of knowing what you are receiving.
Table of Contents
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Coating and Linings
In the realistic world:
·Surface Preparation Issues (+50% failures easily)
·Ambient Conditions/Application
·Wrong specification for environment
50%
20%
30%
Failures
Surface Prep. Wrong Spec. Bad Application
Sources: API 652, Corrosion Resistance of Linings and Coatings, SSPC Good Painting Practice Manual 4th Edition, etc.
• Corrosion of Rebar in concrete expansion.
• Atmosphere or chemical attack on concrete matrix.
• Neglected Maintenance.
• Cracks from improper installation.
Issues with Concrete Corrosion
RT Consults PLLC NACE Conference: June 29-July 1, 2015
•
The Typical Composite Filament Winding or Laminate
(Ex. Pipe, Tank, Ducting, etc.)
Interior
Corrosion FRP Barrier
Veil andMat layer
Exterior
Structural FRP (Provides the Strength)
Different ratios of resin/glass depending on design
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Realistic Considerations
Cost ·Higher than average material cost ·Unfamiliarity can rise cost/bids
Durability ·There are debatable positions ·Uncertainty affects the potential for lower long-term cost
Repair and Inspection ·Reduced experience and available methods ·Lack of Qualified/Experienced Applicators*
Education ·More complex than conventional materials ·Still lacking at the technical and professional level
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Wet-Layup Systems
·Multi/Uni-directional
fiber sheets
·Strengthening Wraps
Precured Systems
·FRP Tendons
·Multi/Uni-directional grids
·Shell elements
Typical FRP Strengthening Systems
RT Consults PLLC NACE Conference: June 29-July 1, 2015
• Removal of corroded rebar and compromised concrete.
• Proper surface preparation.• Selection of method
(physical, chemical, both)• Help correct existing cracks
and delay formation of new cracks.
• Moisture Control
Repair Requirements
RT Consults PLLC NACE Conference: June 29-July 1, 2015
What Inspections Find
• ASTM D 4258- Solvent/Detergent Cleaning• ASTM D 4259- Removing Laitance• ICRI No. 310.1R-2008 Rebar Corrosion Repair• ICRI No. 310.2R-2013 Concrete Surface Prep.• ACI 311.1R Concrete Inspection• SSPC SP13/ NACE 6 Surface Preparation of
Concrete
General Cleaning Requirements
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Issues Affecting Laminate Performance
Examples:
·Poor curing (initial)·Diffusion ·Applied stress ·Embrittlement ·Micro-cracking ·Swelling ·Impact ·Environmental cycling ·Aging (Time) Lack of Fusion and Poor Fit
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Laminate CrackingStress FailureMatrix shrinkageDry Spots and bad cure
Examples
Compliance
• Drawings
• Design Specifications
• Materials (lot numbers)
• Ambient Conditions
• Standards
• Verify Quality Control
• Pass/Fail Criteria
Quality Assurance Through Inspections
RT Consults PLLC NACE Conference: June 29-July 1, 2015
Specifications
·Documents Review
·Non Conformance Reports
·Design of System
·Resin Cure
·Peel Adhesion Test (picture)
·Dimensions and thickness
·Physical properties
Quality is What Will Last
RT Consults PLLC NACE Conference: June 29-July 1, 2015
• Proper Material Selection for Service• Comprehensive and descriptive specifications• Qualify experienced applicators• Quality assurance throughout the process• Budget for Inspection on Coating/nonmetallic
projects
Lessons Learned Keys to a Successful Project
RT Consults PLLC NACE Conference: June 29-July 1, 2015
“You can expect what you inspect- nothing more.”
- John H. Mallinson
“I prefer a composite bike to a steel one. “
- Michael Yee