Concrete Repair and Waterproofing for Parking Structures

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CONCRETE PRESERVATION ALLIANCE

The Concrete Preservation Alliance is a growing coalition of organizations committed to advancing best practices in the field of concrete preservation and infrastructure renewal.

Working together to promote education and awareness of concrete repair industry standards, new and innovative corrosion prevention technologies and sustainable construction practices.

WeSaveStructures.info

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OUR MEMBERS

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WESAVESTRUCTURES.INFO

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Jeff Jezzard

Jeff Jezzard is Vice President of Business Development for Vector Construction a company specializing in the restoration and corrosion protection of reinforced concrete structures.

Jeff has 30 years of experience in the construction business, 25 of those years serving in many different roles at Vector Construction.

Jeff’s education background is in management which has helped him lead and develop the U.S. Construction Divisions and now the Business Development Team.

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Concrete Repair and Waterproofing

• Concrete Repair Methods and Materials

• Crack & Joint Repair

• Waterproofing and Other Protection Systems

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Safety Considerations

• Follow OSHA standards • Review SDS

• Portland cement is highly alkaline

• Silica exposure considerations• Wear Appropriate PPE

• Hand, skin and eye protection• Respirators • Hearing protection

• Use equipment in good working order with all guards

Gravity Support System for Overhead Concrete Removal

Maintenance Program

Parking structures are exposed to extreme conditions, temperature swings, dynamic loads, moisture and chlorides which can cause accelerated deteriorationcompared to an enclosed structure.

A routine preventative maintenance plan will help extend the service life of a structure and minimize unexpected maintenance costs.

An effective asset management plan for a parking structure includes an optimal interval for repairs and maintenance to minimize the overall life-cycle cost of the parking structure.

Routine – Scheduled - Budgeted Example of Inspection and Maintenance Checklist

Parking Structure Maintenance Program References

ICRI - EFFECTIVE REPAIR AND MAINTENANCE STRATEGIES FOR PARKING STRUCTUREShttps://cdn.ymaws.com/www.icri.org/resource/resmgr/crb/2014julaug/CRBJulAug14_Gupta-Shiu.pdf

National Parking AssociationParking Facility Maintenance Manual (5th edition)

ACI - Guide for Structural Maintenance of Parking StructuresACI PRC-362.2-00: Guide for Structural Maintenance of Parking Structures (Reapproved 2013) (concrete.org)

Concrete Preservation Process

International Concrete Repair Institute www.icri.org

ACI Repair Application Procedures www.concrete.org

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Concrete Repair and Protection

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Reinforced Concrete

Reinforcing Steel

Concrete

Definition: concrete containing adequate reinforcement and designed on the assumption that the two materials act together in resisting forces.

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Ideal Concrete Repair

Bond Line

Concrete Substrate

Repair Material must be Compatible with Substrate- e.g. shrinkage, modulus, thermal, electrochemical, etc.

Repair Material

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Material Selection Considerations

• Vertical• Overhead• Horizontal• Underwater• Structural• Cosmetic

• Form and Pour• Trowel Applied• Spray Applied• Dry Packing• Conventional

Placement

Location Placement Method

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Relevant Concrete Properties

•New Construction• Strength (Compressive & Tensile)• Thermal Expansion Coefficient• Creep / Shrinkage• Bond

•Concrete Repair• Bond• Thermal Expansion Coefficient• Shrinkage / Creep• Compressive Strength (match the existing concrete)• Abrasion Resistance (if horizontal repair with traffic)

The selection of repair materials is a balancing act

OverheadCostDurabilityAdhesion/bondEase of InstallationAesthetics

CompatibleBudgetEnvironmentLow ShrinkageAvailabilitySustainability

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Edge Conditioning

•Sawcut edges ½” to 1” deep to prevent featheredge

•Repair should be square or rectangular in shape

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Concrete Removal

• Remove loose concrete• Use lightweight chipping

hammer (15 lb.)• Chip around exposed steel.

Minimum ¾” or ¼” greater than the top-sized aggregate

• Continue concrete removal until clean steel is encountered

• Create a rough surface for proper bonding

• approx. 1/8” to ¼”+ amplitude (ICRI CSP 6 or Greater)

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Surface Preparation Practices

Critical For:- Long-term Durability- Bond & Minimizing Cracking

ICRI No. 310.1R–2008 Guideline for Surface Preparation for Repair of Concrete Deterioration Resulting from Reinforcing Steel Corrosion

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ICRI Surface Preparation Guideline 310.2R

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ICRI Surface Preparation Guidelines

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Surface Preparation Practices

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Preparation and Cleaning

• Clean Concrete Surface(Dust, micro-fractured concrete, etc)

• Abrasive blasting or pressure washing (min. 5000 psi)

• Clean Steel Surface(Rust, chlorides and cement paste)

• Blast clean full circumference

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Reinforcement Protection in the Repair Area

Options• No Additional Protection

• Alkalinity of the repair material protects the steel

• Reinforcement Coating• Barrier coating

• Type 1 Embedded Galvanic Anodes

• Cathodic protection

• Reinforcement Coating and Type 1 Embedded Anodes

• Barrier coating and cathodic protection

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Concrete Repair Methods

• Small / Thin Repairs• Trowel-Applied Mortar • Appropriate for vertical and

overhead surfaces • Large / Structural Repairs

• Form and pour• Form and pump• Shotcrete• Grouted pre-placed

aggregate

• Low Shrinkage and Proper Curing is Critical for Durability

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Concrete Placement Methods

Overhead Trowel Applied Dry Packing

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Concrete Placement Methods

Form and Pour Preplaced Aggregate

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Concrete Placement Methods

Low Velocity Wet Spray Dry Shotcrete

Concrete Removals

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Cleaned Repair Area

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Form and Pour

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Mixing Material and Placement

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Completed Repair

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Quality Control

• Inspect concrete surface profile and cleanliness prior to application

• Material testing by qualified laboratory

• Before and after photos• Sounding for delaminations• Bond testing (on-site)

• ICRI Technical Guideline No. 210.3• ASTM C1583

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Parking Structure, Vancouver, BC

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Concrete Removal by Milling

• 16,000 sq.ft. (~1,500 m2) of top surface removed with milling machine

• 1” (25 mm) +/- of controlled milling to allow for consistency in topping thickness

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Concrete Surface Preparation

• 5000 psi (35 MPa) power wash of milled concrete to remove any microfractures

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Concrete Surface Preparation

• Installation of a breathable hybrid bonding agent with long open time to allow for topping installation

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Concrete Topping Placement

• Installation of a high quality, low permeability repair concrete to 16,000 sq.ft. (~1500 m2) of slab on grade (SOG)

• Roller screed utilized over standard screeding method

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Concrete Curing

• Utilization of 7-day wet curing blankets for optimum curing

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Concrete Testing

• QC/QA requirements of this project required both testing of concrete for compressive strength and bond strength to existing substrate

• Compressive strengths averaged 60 MPa (8,700 psi)

• Bond strength tests averaged 2.5 MPa (360 psi)

Bond test

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Parking Structure, Vancouver, BC Finished

• Project completed successfully within a tight schedule and is performing well

Cracks in concrete can lead to major structural issues for a structure. Cracks can affect the structural integrity of a structure or leak water, both creating long term damage to the concrete. Repairing cracks before they are a major problem can:

• Restore structural and/or design strength to the cracked concrete structure (restoring the concrete to its original monolithic integrity)

• Eliminate concrete spalling initiated by cracking and aggravated by freeze thaw cycling,

• Prevent corrosion of reinforcing steel and pre-stress tendons by encapsulating them against moisture

• Stop water and fluids leakage through concrete structures (including concrete foundations walls),

• Repair delaminations of topping slabs on floors.

Concrete Crack Repair

• Epoxy Injection – structural crack repair• Injecting an epoxy into a crack to fill the crack, bond the concrete together,

restoring the strength and integrity of the structural elements of the concrete.

• Urethane Injection – stop actively leaking cracks (waterproofing)• Injecting an expandable urethane into an actively leaking or wet crack where the

urethane expands when in contact water creating an impenetrable gasket to fill the crack and stop the leak

• Rout and Seal• Repairing small surface cracks by grinding a channel through the center of the

crack and filling with a sealant to prevent infiltration of water and other contaminants from penetrating into the concrete.

Concrete Crack Repair

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Methods of Epoxy Injection

• Epoxy Injection can be executed by using a hand-held caulking gun with cartridges or a dual component, metered electric pump.

• The electric pump is the preferred method for professional repair contractors.

Epoxy Injection

Applying surface seal Injecting epoxy into prepared crack

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Chemical Grouting

Polyurethane foams are injected into the crack in a liquid form. This allows a gentle and slow filling process that will completely fill the crack.

After a few minutes the polyurethane will begin to react with the water in the crack to begin foaming. Water is the catalyst that converts the liquid polyurethane into foam. This foaming action increases the volume of the polyurethane up to 30 times its liquid form.

Once the foam is hardened it creates a gasket to stop the infiltration of water.

Urethane Injection on a Parking Garage Wall

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Urethane Injection on a Parking Garage Wall

Routing cracks or joints using a walk behind saw. Once cut, fill with a flexible sealant to seal the crack.

Rout-and-Seal

Expansion joints are placed in concrete to accommodate expansion and contraction of concrete slabs and to prevent expansive cracks formed due to shrinkage and thermal movement.

Concrete expansion joint seals are designed to prevent moisture from seeping under the slabs. The expansion joints allow for expansion and contraction during extreme heat and cold, dryness and humidity.

When these joints wear out, the concrete becomes more vulnerable to the weather and atmospheric conditions and can quickly deteriorate. Looking for signs of wear before actual damage in the concrete is visible can save you time and money, and that is why prompt concrete expansion joint replacement is essential for the health of your deck and garages.

Expansion Joint Maintenance

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Expansion Joints

Traffic Deck Coatings

Traffic deck coatings are used in parking garages to protect the concrete from weather, abrasion and chloride infiltration. A properly installed coating will lengthen the life of the parking garage saving costly repairs and maintenance.

Traffic deck coatings also provideThe following advantages:• Aesthetic improvement• Slip resistance• Easy to maintain and clean

Traffic Deck Coating

2nd Ave Parkade – Prince George, BC

Other Coating Options

Penetrating Sealers Thin Bonded Overlays(Silanes & Siloxanes) (Epoxies, Methyl methacrylates)

Memorial Street Parking Garage Rehabilitation

Scope of Work

• Parkade repairs were phased over many years to allow for areas of the garage to remain open for use. Repairs included the following:

• 40,000 ft2 (~3700 m2) of 3” (~7 cm) deck removal and replacement (Demo by Hydro Demolition)

• Installation of new drains• New Expansion Joints• Concrete repairs – Soffits, Columns, Deck and Curbs• Installation of a traffic bearing membrane• Guardrail repair and painting• Stairwell Repairs – Masonry, Doors, Concrete Stair repair and Coating

Through-Slab Repairs

Expansion Joint Repairs

The expansion joints were all replaced using a rubber, winged compression seal joint system. The nosings are poured using a high-strength, flexible elastomeric concrete.

Column Repairs

Strengthening Concrete – Composite Materials

CPA Webinar:February 9

Andrew Broecker

Post-Tension Solutions

CPA Webinar:January 12

Michael Kernan

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Concrete Corrosion Solutions

Click to add text

CPA Webinar: December 8

David Simpson

CPA Webinar: November 10

Travis Marman

QUESTIONS?

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Contact Jeff

Jeff Jezzard

VP – Business Development

Vector Construction

West Fargo, ND

Office: 701-280-9697

Cell: 701-866-3062

JeffJ@Vector-Construction.com

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WEBINAR RECORDING & FUTURE EVENTS

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