NACE Concrete Composite

Repairing Concrete Structures with Coatings and Composites

Michael P. Yee

mike@rtconsults.com

NACE Coating Inspector Level 3 #50795

Richard Taraborelli P.E.Rich@rtconsults.com

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