A Look at Reactive Resin Chemistries:

Bonding Agents, Structural Anchoring Adhesives and Polymer

Repair Mortars

Growing in Use Everyday

Chemistries

Properties / Specification

Applications

CHEMISTRIES

Type of Chemistries

• Concrete & Mortars

Cementitious - Hydraulic Crystalline Hardening

• Epoxies, Polyureas, Urethanes, Polysulphides

Stoichiometric

• Polyesters, Vinyl Esters & Acrylics

Free Radical

Overview of Chemistries• Cementitious

– Cement + Water (+aggregates)• Epoxy

– Diglycidyl Ether of Bisphenol A + Amine Hardener• Polyurea

– Reactive Isocyanate + Amine Hardener• Polyurethane

– Reactive Isocyanate + Polyol (+Catalyst)• Polyesters & Acrylics (Methacrylates)

– Polyester (& Styrene) or Reactive Acrylic + Catalyst and Peroxide

They All Have In Common:THERMO-SETTING =

HEAT DRIVEN REACTIONS

Non-Reversible

REACTION PROCESS

Polymer

Resin

Cement

Hardener

Catalysts

Water

Mix A with BWorking

TimeGel

Time Hardens Solid

HEAT DRIVEN

ReactionInitiates

ReactionStabilizes

A

B

Cure Time Diagram

What Governs Heat?

• Ambient Temperature• Substrate Temperature• Material Temperature• Sunlight (Seasonal/Location Dependent)• Bulk Mass• Wind• Temperature Rising or Dropping?

Cementitious: The chemical reaction starts a crystal-type growth in the

cement

Epoxies

• Two Part Products– Part A (Epoxy) + Part B (Hardener) = Adhesive

• Defined Mix Ratio• Thermo-setting - Temperature Sensitive

– Heat Driven & Mass Driven• Inherently Strong Bond To Concrete, Wood,

Metals, Mortars & Many Rock Types

Epoxies

• Thermosetting• Temperature Dependent• Epoxy & Amine• Shrinks upon cure• Inherently Strong Bond to Concrete, Mortars,

Metals and Wood• Stoichiometric Mix Ratio

– Predetermined or Required Mix Ratio

Epoxy Technologies

• Epoxies– Bis, A– Bis, F– Novalac

Epoxy Technologies

• Amines– Polyamides (good flexibility, poor properties)– Amidoamines (very poor low temp cure, excellent

bond)– Aliphatic (very good cure at low temps, poor

bond) – Cycloaliphatic (good cure at low temps and moist

conditions, good bond)

Stoichiometric Reaction

• Requires a predetermined amount of Amine to react with a known amount of Epoxy.

• Typically…100 Parts of Epoxy to 50 Parts of Amine

• Mixing – Number one cause of Problems

Pot-life of Epoxies (working time)

• Pot Life – The time at which 60gms of combined Epoxy/Hardener Resins react to become a hardened gel.

• Typically, every 150F rise in temperature cuts pot-life in half.

• Typically, every 150F drop in temperature doubles pot-life.

Thin Film Set Time

• EPOXY–Thin film set time (20 mils) is 10- 15

times the pot life.• Polyester

–Thin film set time (20 mils) is 5-10 times the pot life.

Benefits, Epoxies

• Bond Tenaciously to Concrete– Inherent affinity to bond to polar substrates

• Forgiving– 15% off on mix ratio

• Resilient• Volumetrically Stable

– Does not shrink after initial cure

Benefits, Epoxies. Contd.

• Highest Mechanical Properties of all typical resin systems – 3-5 times greater

• Very High Dynamic Loading• High Modulus• Flexible• Chemical Resistance

Considerations

• UV Stability– Turns Yellowish

• Low Thermal Capacity– Tg of 1300F-1400F

• High Coefficient of Thermal Expansion• High affinity to water.

Polyesters – Vinyl Esters

• Thermo-Setting Resin• Free-Radical Reaction

• Unsaturated Polyester Resin & Styrene

• Heat Dependent• Forgiving Mix Ratio• Shrinks After Cure (Avg. 15%)

Polyesters – Vinyl Esters

• Most reliable cure due to low mix ratio sensitivity.• Moisture insensitive when cured.• Easy to use in a wide range of temperatures.• No heating of cartridge required.• Ideal for high/low temperatures.• Low Mechanical Properties – 3-5 times lower than

epoxies.

Chemistries

Properties / Specification

Applications

Physical PropertiesCompressive Strength

The surface area equal to a 8.5”x11” sheet of paper of a material having 10,500 psi compressive strength will support

1 MILLION LBS. of Dead Load

Cementitious: Low-High Resin: Low-High

Physical PropertiesHardness and Abrasion

Air

70D

80D

98D

Aggregate

Cured ResinCement Paste

94D

Greater the Hardness, the better abrasion resistance

Physical Properties

Tensile Strength

Cementitious: Low Resin: High

Physical Properties

Flexural Strength

Cementitious: Low Resin: High

Bond StrengthDefines the strength at which a material will shear or pull from the substrate at the interface.

Shear Bond Tensile Bond

CEMENTITIOUS: HIGHRESIN: HIGH

Bonding Characteristics

Repair Material

Concrete Substrate

Cementitious – Mechanical Bonding• Cleaned & Opened Pore Structure• Roughened to Increase Surface Area• Pre-dampen

Resins – Chemical & Mechanical Bonding• Cleaned & Opened Pore Structure• Roughened to Increase Surface Area

Bond Strength is the last and slowest to develop. Once compromised, will not regain strength.

Physical Properties

Coefficient of Thermal Expansion

T1

T2 (Concrete)T

L

T2 (Resin)

Thermal CompatibilityCoefficient of Thermal Expansion (in./in.0F)

• Concrete – 0.000008• Concrete Structures – 0.0000055• Epoxy – 0.000310 (4-6 times greater) • Polyester / Vinyl Ester – 0.000069 (8-14 times

greater)• Acrylic – 0.000130 (16- 26 times greater)

Modulus of Elasticity

Measures the stiffness of a material. The lower the modulus

the greater the deformation under a given load. The lower the modulus, the greater the

coefficient of thermal expansion.

Young’s Modulus of Elasticity

• Concrete– Modulus of Elasticity 3,700,000 to 4,500,000 PSI

• Resin Based Materials– Modulus of Elasticity 250,000 to 700,000 psi

Factor of 6 – 18 Times Greater

Thermally Induced Stress = Young’s Modulus of Elasticity

* Coefficient of Thermal Expansion

* Thermal Variance

Factor of 24 – 108 for a Neat Epoxy

Cementitious

•Slow – Fast Setting•Variable Mix Ratio•Strong Bond to self•One-dimensional Physical Properties•Moderate Shrinkage•Very High Modulus•Very Low Thermal Expansion Coefficient

Epoxy•Slow - Fast Setting•Moisture Insensitive•Critical Mix Ratio•Inherently Strong Bond•Nominal Shrinkage•High Physical Properties•Low - Moderate Modulus•High Thermal Expansion Coefficient

Polyurea•Very Rapid Setting•Moisture Sensitive•Critical Mix Ratio•May Have Poor Bond•Low- Moderate Strength•Nominal Shrinkage•Low - Moderate Modulus•High Thermal Expansion Coefficient

Polyesters Acrylics

•Very Rapid Setting•Moisture Tolerant•Non-critical Mix Ratio•Good Bond•Moderate - High Shrinkage•High Physical Properties•Moderate Modulus•High Thermal Expansion Coefficient

Resin-Based Repair Materials

• Preclude the use of Resin Based Mortars under conditions of frequent or large temperature fluctuations.

• When the cause of concrete failure was reinforcing steel corrosion. Because, the different electric properties of the resin mortar vs. the concrete will set-up an incipient anode effect.

Governing Specification ASTM C 881

• Categorized into Three Groupings– Usage “Type” – Load Bearing / Non-Load Bearing

• Seven Types

– Viscosity “Grade” – Low “1”, Medium “2” and Gel “3”

– Application Temperature “Class”• Six Classes, “A” Below 45F; “B” 45F-65F; “C” 65F+“D” Below 45F; “E” 45F-65F; “F” 65F+ (Type VI & VII)

ASTM C 881 ClassificationsASTM C 881 CLASSIFICATIONS

Type I

Type II

Type III

Type IV

Type V

Type VI

Type VII

Grade

Class A For use below 40°F (4°C) the lowest allowable temperature to be defined by the manufacturer of the product

B For use below 40°F and 60°F (4 and 16 °C),

For bonding and sealing segmental precast elements with internal tendons and for span-by-span erection when temporary post tensioning is applied.For use as a nonstress carrying sealer for segmental precast elements when temporary post tensioning is not applied as in span-by-span erection.

C For use above 60°F (16°C) the highest allowable temperature to be defined by the manufacturer of the product.

1 Low Viscosity 2 Medium Viscosity3 Non-Sagging

Consistency

For use in non-load bearing applications for bonding hardened concrete to hardened concrete and other materials, and as a binder in epoxy mortars or epoxy concrete.

For use in non-load bearing applications for bonding freshly mixed concrete to hardened concrete.

For use in bonding skid-resistant materials to hardened concrete, and as a binder in epoxy mortars or epoxy concretes used in traffic bearing surfaces (or subject to thermal or mechanical movements).For use in load bearing applications for bonding hardened concrete to hardened concrete and other materials and as a binder for epoxy mortars and concretes.

For use in load bearing applications for bonding freshly mixed concrete to hardened concrete.

ICC ER vs. ES REPORTS• ICC ER- Legacy Report (AC-58)• ICC mandated that ER reports are outdated• ICC drafts Building codes such IBC, IECC, IEBC and

many more. State dependent.• ICC is an independent Business (non-governmental)• ICC ES Legacy Report (AC-308) • Fully Comply to AC-308

– Cracked and Uncracked Concrete

ICC ES Reports

• DOT’s have not welcomed AC 308 or AC 58– Except for Caltrans and Utah

• ACI is always adopted as building code.• ACI drafted ACI 318 which requires AC 308

Conformance. Building Codes are not relate to pavements / bridges.

• ACI 318 requires that contractors that install anchors specified under ICC (ES AC 308) must be independently certified (by ACI).

Non-Structural

• Dispersions or Emulsions• Conforms to ASTM C 1059 Type I or II

Dispersions are Classified by:

• ASTM C 1059 TYPES• Type I is Non-Reemuslifiable

– Must be used as a Slurry Coat– Can not be allowed to dry– Minimum Slant Shear Bond Strength 1,000 psi

• Type II is Reemusifiable– Can be used neat– May be allowed to dry– Minimum Slant Shear Bond Strength 500 psi

Dispersions

• Thermo-Plastic• Must Coalesce

– Minimum Film Forming Temperature– Glass Transition Temperature

• Must be used in a film or mix with cementitious material

• Bond Enhancifiers

Chemistries

Properties / Specifications

Markets / Applications

Markets

• Anchoring/Fasteners• Adhesives / Glues

Anchoring Market

• Cast In Place• Post-Installed

Post Installed Market

• Mechanical Anchors• Bonded Anchors (Chemical Adhesives)• Grouted Anchors (Cementitious)• Forced Entry Anchors (Pneumatic)

Mechanical Anchors

• Static Load• Ambient Temperature Applications• Poor exterior Performance – Corrosion• Easy to Use• Very Common

Bonded Anchors

• Static and Dynamic Loads• Ambient Temperature Applications• Versatile• Good Exterior Performance• Good Chemical Resistance

Grouted Anchors

• Static Loads• High and Low Temperature Use• Good Exterior Performance• Good Chemical Resistance

– Except Acids

Forced Entry Anchors

• Static Loads• Ambient Temperature Use• May Damage Host Substrate• Edge and Corner Issues• Speed of Application Can be Very High

Applications

Chemical Adhesives - Bonded AnchorsBonding Agents

GENERAL CONSTRUCTION APPLICATIONS

• Rebar doweling into concrete• Anchoring threaded rod or rebar into brick,

block and stone.• Attaching steel angles or ledgers to brick or

block.• Attaching sill plates to concrete.• Stadium and auditorium seating.

GENERAL CONSTRUCTION (cont.) APPLICATIONS

• Quick-setting crack injection surface sealer• Injection resin to repair• Bonding concrete to concrete• Facade pinning• Concrete repairs and patching

HIGHWAY CONSTRUCTION APPLICATIONS

• Highway guard rails• Pavement highway reflectors• Railings and fences• Rebar doweling for highway widening and

repair projects• Light poles• Highway sign installations

BRIDGE CONSTRUCTION APPLICATIONS

• Rebar doweling into concrete• Highway lane ties• Concrete repairs/patching• Guard rails and fences• Pavement reflectors

PLANT MAINTENANCE

• Anchoring vibratory equipment and conveyors• Machinery anchoring• General plant maintenance• Anchoring in corrosive environments• Railings and fences• Supports and brackets for pipes• Floor repairs

RAILROAD CONSTRUCTION APPLICATIONS

• Support brackets for rail systems• Railroad concrete tie repairs• Third rail anchoring

PORT CONSTRUCTION APPLICATIONS

• Concrete dock repairs• Bridge pier reinforcement• Pier cap repairs• Mooring cleats• Underwater anchoring• Anchoring bumpers

CORRECTIONAL FACILITIES APPLICATIONS

• Pick-proof sealants for doors and windows• Pipe supports and brackets

General Grouting Applications for Non-Shrink Cementitious Materials

• Railings• Anchors• Anchor Bolts• Dowels• Reinforcing Steel• Threaded Rods• Machinery Bolts• Sign Post

• Parking Meters• Traffic Signs• Ties• Hooks• Ornamental Iron

Work

Anchors Summarized• Each Anchor Type has it place in the

Market.• Mechanical - Easy to Use…Static Load• Bonded – Dynamic Loading…Very High

Strength…Exterior Applications.• Grouted – Static Load…High Temperature…

Cheap• Forced Entry – Very Quick Installation…

Static Load or Temporary