ICRI 710-2-2014

TECHNICAL

TECHNICAL

GUIDELINES

GUIDELINES

Prepared

Prepared by by the the International International Concrete Concrete Repair Repair Institute Institute October October 20142014

Guideline No. 710.2–2014

Guideline No. 710.2–2014

Copyright ©2014 International Concrete Repair Institute

Copyright ©2014 International Concrete Repair Institute

Guide for

Guide for

Horizontal Waterproofing

Horizontal Waterproofing

of Traffic Surfaces

Copyright © 2014

Copyright © 2014 International Concrete Repair InstituteInternational Concrete Repair Institute All rights reserved.

All rights reserved.

International Concrete Repair Institute International Concrete Repair Institute

10600 West Higgins Road, Suite 607, Rosemont, IL 60018 10600 West Higgins Road, Suite 607, Rosemont, IL 60018 Phone:

847-Phone: 847-827-0830 827-0830 Fax: 847-Fax: 847-827-0832827-0832 E-mail: [email protected]

E-mail: [email protected]

Guide for Horizontal

Guide for Horizontal

 W

 Waterpr

aterproofing of

oofing of

Traffic Surfaces

Traffic Surfaces

Guideline No. 710.2-2014

Guideline No. 710.2-2014

TECHNICAL

TECHNICAL

GUIDELINES

GUIDELINES

Prepared

Synopsis

This guideline is intended to provide information for the selection and application of materials for fluid-applied waterproofing systems to concrete  pedestrian and vehicular traffic surfaces.

Concrete is subject to deterioration by a variety of mechanisms. Properly selected and applied traffic membrane systems can protect concrete from deterioration caused by abrasion, moisture intrusion, environmental forces (freezing-and-thawing cycling), and chemical attack. This guideline provides information on the common service conditions, basic review of the properties of concrete, surface preparation, system designs, and materials used for traffic membranes.

Keywords

Membranes; polymers; traffic surfaces; water- proofing.

Producers of this Guideline

Subcommittee Members

Kevin A. Buck, Chair  Mark LeMay, Co-Chair 

George Reedy Jeffrey Smith

Dan Wald

ICRI Committee 710,

Coatings and Waterproofing

Mark Nelson, Chair  Kevin A. Buck Peter Golter  Michel Jalbert Alfred Kessi Mark LeMay Jeff Ohler  George Reedy Monica Rourke Jeffrey Smith Dan Wald

About ICRI Guidelines

The International Concrete Repair Institute (ICRI) was  founded to improve the durability of concrete repair and enhance its value for structure owners. The iden-tication, development, and promotion of the most  promising methods and materials are primary vehicles  for accelerating advances in repair technology. Working through a variety of forums, ICRI members have the opportunity to address these issues and to directly contribute to improving the practice of concrete repair.  A principal component of this effort is to make carefully  selected inform ation on important repair subjects readily accessible to decision makers. During the past  several decades, much has been reported in the liter-ature on concrete repair methods and materia ls as they have been developed and rened. Nevertheless, it has been difcult to nd critically reviewed information on the state of the art condensed into easy-to-use formats. To that end, ICRI guidelines are prepared by sanctioned task groups and approved by the I CRI Technical  Act ivi tie s Co mmitt ee. E ach guideli ne is de sig ned

to address a specic area of practice recognized as essential to the achievement of durable repairs. All  ICRI guideline documents are subject to continual review by the membership and ma y be revised as approved by the Technical Activities Committee.

Technical Activities Committee

Fred Goodwin, Chair 

James E. McDonald, Secretary Frank Apicella Jorge Costa Brian Daley Pierre Hebert Gabriel A. Jimenez Ralph C. Jones Peter R. Kolf  Kevin A. Michols Mark Nelson Lee Sizemore John Weisbarth

This document is intended as a voluntary guideline for the owner, design professional, and concrete repair contractor. It is not intended to relieve the professional engineer or designer of any responsibility for the specication of concrete repair methods, materials, or practices. While we believe the information contained herein represents the proper means to achieve quality results, the International Concrete Repair Institute must disclaim any liability or responsi bility to those who may choose to rely on all or any part of this guideline.

Contents

1.0 Introduction ... 1

1.1 Scope ... 1

1.2 Features and Benefits ... 1

2.0 Definitions ... 1

3.0 System Design Considerations ... 2

3.1 Owner Requirements ... 2

3.2 Service Conditions ... 2

3.3 Type(s) of Construction ...2

3.4 Existing Condition of the Structure ... 3

3.4.1 Concrete Surface Conditions ... 3

3.4.1.1 Surface Strength ... 3

3.4.1.2 Efflorescence ... 3

3.4.1.3 Intercoat Adhesion ... 3

3.4.2 Physical and Chemical Damage...3

3.4.3 Voids, Pinholes, and other Defects ... 3

3.4.4 Joints and Cracks ...4

3.4.5 Moisture in Concrete Floor Slabs ...4

3.4.6 Poor Construction and Thermal/Structural Movement ... 4

4.0 Materials ... 5 4.1 Material Properties ... 5 4.2 Material Types ... 5 4.2.1 Polymers ... 5 4.2.1.1 Polyurethane ... 6 4.2.1.2 Polyurea ... 6 4.2.1.3 Epoxy ... 6

4.2.1.4 Methyl Methacrylate (MMA) ... 6

4.2.2 Cementitious ... 6

4.3 Appropriateness for Application ... 7

4.4 Appropriateness for Substrates ... 7

4.5 Warranties ...7 5.0 Project Implementation ... 7 5.1 Contractor Selection ... 7 5.2 Pre-Installation Meeting... 8 5.3 Mockups ... 8 6.0 System Installation ... 8

6.1 Inspection of the Concrete Substrate ...8

6.2 Repair of Structural Defects ... 8

6.3 Repair of Concrete Surface Imperfections and Irregularities ... 8

6.4 Surface Cleaning and Decontamination ... 9

6.5 Surface Preparation ... 9

6.6 Cracks and Joints ... 10

6.7 Application Process ... 10 6.7.1 Priming ... 11 6.7.2 Material Installation ... 11 6.7.3 Terminations ... 12 6.7.3.1 Floor ... 12 6.7.3.2 Wall... 12 6.7.4 Skid Resistance ... 12

6.8 Testing and Inspection ... 12

6.9 Maintenance ... 12

7.0 Health and Safety ... 12

7.1 General Overview ... 12

7.2 Employee Protection ... 13

7.3 Employee Personal Protective Equipment ... 13

7.4 Vapors ... 13

8.0 References ... 13

8.1 Referenced Standards and Reports ... 13

1.0 Introduction

1.1 Scope

This guideline has been developed to specifically assist in the selection and application of fluid-applied high-build waterproofing systems for horizontal traffic surfaces. Concrete is subject to deterioration by a variety of mechanisms. Prop-erly selected and applied traffic membrane sys-tems can protect concrete from deterioration caused by environmental and service conditions (Fig. 1.1 and 1.2).

not limited to, budget constraints, operational considerations, Code Requirements and Regula-tions, and material warranties.

1.2 Features and Benefits

Some of the features and benefits provided by the application of vehicular and pedestrian traffic membranes to concrete include:

• Concrete substrate protection against chemi-cals, oil, and other contaminants from vehicles; • Prevention of permeation or intrusion of water; • Aesthetically pleasing concrete surfaces that reduce deterioration caused by weathering and traffic (Fig. 1.3);

 Fig. 1.3: Waterproofing membrane applied to  pedestrian plaza

• Enhanced light reflectivity and slip resis-tance to improve visibility and reduce poten-tial safety hazards in areas such as parking structures and warehouses, along with iden-tifying and delineating traffic lanes and safety zones;

• Providing a temporary containment of chem-ical splash and spills while enhancing the ease of cleaning the surface; and

• Prevention of water and waterborne chloride-ion penetratchloride-ion to the embedded steel rein-forcement bar, preventing corrosion and related concrete deterioration.

2.0 Definitions

ICRI provides a comprehensive list of definitions through an online resource, “ICRI Concrete Repair Terminology” (www.icri.org/GENERAL/ repairterminology.aspx). Definitions provided herein compliment that resource.

Traffic membrane system —A high-build film-forming liquid or a liquid with fillers, rein-forcement, or both that is applied to a substrate and cures by heat, moisture, or chemical reaction  Fig. 1.1: Example of deck waterproofing

application

 Fig. 1.2: Example of balcony waterproofing application

The target audience for this guide includes the owner, designer, developer, operator, material supplier, installer, and property manager. Each of these parties plays an integral part in the suc-cessful implementation of a concrete protection strategy. For them to do their parts properly, each  party must have good information on which to  base design, selection, installation, and product

development decisions.

This document addresses the primary concerns and requirements that the owner may have with traffic membrane systems. This includes, but is

to form a thermoset or thermoplastic polymer that  bonds to and protects the substrate and provides

a barrier for fluids.

Ultraviolet (UV) stability —A combination of two different performance criteria: discolor-ation and physical property retention.

3.0 System Design

Considerations

Waterproofing systems for the protection of concrete structures may be formulated to provide a wide range of properties. Because material  properties affect performance of the traffic mem- br ane sy stem, select ing the prop er system involves consideration of several important fac-tors. The proper design of a waterproofing system for traffic-bearing surfaces should take into account the following items:

• Owner requirements; • Service conditions;

• Type(s) of construction; and • Condition of the structure.

In many instances, more than one water- proofin g system will satisfy the esta blis hed requirements of the project. Final selection of the system should be based on the balanced relation-ship between cost and performance.

3.1 Owner Requirements

Detailed discussions with the owner are critical in understanding the goals and expectations of the completed work. Project objectives need to  be clearly defined at the onset and provide a reference to measure the success of the project. Objectives and requirements may encompass, but are not limited to, the following:

• Life expectancy of the structure;

• Desired aesthetics of the finished product; • Installation constraints, including anticipated

closures for critical access areas; and • Budget constraints.

3.2 Service Conditions

With the variety of materials applicable for traffic-bearing horizontal waterproofing systems, the systems can be tailored to meet a wide range of service conditions. The waterproofing system designer can assist the owner in understanding various service conditions that may affect the  performance of the waterproofing system. These

conditions may include:

• Abrasion—An attempt should be made to understand the frequency and any potential

sources of traffic. This may include foot or vehicular traffic; types of wheels (such as rubber and steel); or any other location-spe-cific item, such as snow plows or pallets; • Chemicals—Traffic membrane systems

ex- posed to vehicular traffic may come in contact with common fluids, such as gasoline, ethylene glycol, brake fluid, or engine oil;

• Climate—Different climates may require specific performance characteristics. This may include increased resistance to snow removal equipment and deicing chemicals for colder climates or improved UV performance in warmer ones;

• Impact areas—Areas subject to repeated stress, such as repair bays, drum storage rooms, manu-facturing, or loading/unloading areas may have the potential for the traffic membrane system to be damaged through normal use;

• Thermal shock—If the traffic membrane system is in an environment where it would  be exposed to significant differences in tem- perature, it may experience stress cracks due to different thermal expansion rates between the membrane and substrate. Use of fabric reinforcement, fillers, or combinations thereof may reduce this effect.

3.3 Type(s) of Construction

With the exception of some of the cementitious systems, horizontal waterproofing systems typically form a barrier on the surface of the concrete, preventing passage of moisture vapor through the membrane. These membranes are also known as Class I vapor retarders, having a permeability < 0.1 perms, as determined by ASTM E96/E96M. Consequently, these sys-tems are not usually applied to concrete that is subject to significant amounts of moisture vapor transmission, such as slabs-on-ground, elevated concrete slabs placed on unvented metal decking, and concrete topping slabs  placed over a waterp roofin g membra ne (also called sandwich slabs). Applications to these types of substrates can result in unacceptable  bliste ring and premature failure of the water- proofing system.

ICRI has created a certification program (www.icri.org/Certification/Certification Classes.asp) to train and certify individuals in concrete slab moisture testing procedures that should be performed to determine the suitability of substrates for the application of non-breath-able waterproofing systems.

3.4 Existing Condition of

the Structure

Manufacturers of horizontal waterproofing mem- branes typically require materials to be applied to clean, sound substrates. Existing structures are generally evaluated to determine:

• Concrete surface conditions; • Physical and chemical damage; • Voids, pinholes, and other defects; • Joints and cracks;

• Moisture in concrete floor slabs; and

• Evidence of shrinkage, thermal movement,  poor construction, or structural movement.

It is important for the system designer to iden-tify potential deficiencies in the substrate and specify the necessary repairs to restore the sub-strate to a sound condition, bringing it into com- pliance with the material manufacturer’s require-ments. Refer to ICRI 210.4 for guidance on nondestructive evaluation methods for condition assessment, repair, and performance monitoring of concrete structures.

3.4.1 Concrete Surface Conditions

3.4.1.1 Surface Strength

Many traffic membrane system manufacturers and design professionals specify minimum con-crete tensile bond strength, or 100% cohesive failure in the concrete substrate depending on the type of system and service conditions. ASTM D4541 describes a procedure used to test the  pulloff strength of polymer systems, while ICRI

210.3R and ASTM C1583/C1583M describe  procedures used to field-test the surface sound-ness of concrete and adhesion of bonded systems. Concrete substrate compressive strength may also  be determined and evaluated.

3.4.1.2 Efflorescence

The presence of efflorescence, crystalline deposits, or both on the concrete surface will lessen the adhesion of waterproofing systems. If efflorescence is detected, the cause should be determined and remedied prior to application of the traffic membrane system. Wet cleaning and wet surface preparation methods may cause addi-tional efflorescence on the concrete’s surface.

3.4.1.3 Intercoat Adhesion

Concrete surfaces may have a previously applied  protective system. Exercise caution when applying a new system over an existing system to ensure a successful application. Consult the system manu-facturer and conduct adhesion testing on test areas

to determine if the new waterproofing system is compatible with the existing system. With many replacement systems, traces of the old system should be removed. If the old system is compatible with the new system, it may then be evaluated for soundness and uniformity. Loose, delaminated, chalked, or otherwise unsound areas must gener-ally be removed. Before being recoated, an existing system should have a uniform surface  profile and exhibit adequate bond strength to the substrate, especially along any edges. Test appli-cations should be made to evaluate the bond of a new system over an existing system in accordance with the material manufacturer’s recommenda-tions, or as described by ASTM D4541. Use of a  proprietary adhesive primer may be required to

achieve adequate bonding.

3.4.2 Physical and Chemical Damage

Existing concrete structures may have been sub- jected to mechanical damage (by impact or abra-sion), chemical attack, or corrosion to the reinforcing steel. Deteriorated concrete must be removed and replaced prior to the application of the traffic membrane system (Fig. 3.1). Cementi-tious, polymeric, or monomeric repair materials

 Fig. 3.1: Physical damage to concrete structure are often used for making repairs in concrete. ICRI 320.2R can assist in selecting and speci-fying repair materials, and ICRI 510.1 provides guidance on electrochemical techniques to miti-gate corrosion of steel for reinforced concrete structures. The traffic membrane system manu-facturer should be consulted to determine com- patibility with replacement and repair materials.

3.4.3 Voids, Pinholes, and other Defects

Surface voids, pinholes, and excess porosity can affect the performance of traffic membrane systems, and are typically remedied prior to application. Unfilled voids may trap air, which could expand to create a condition known as

outgassing. This results in the formation of  bubbles during or immediately after the traffic membrane installation. Bubbles that pop and  backfill are not a problem. However, porosity in the concrete surface can result in pinhole development that does not pop and backfill, resulting in avenues for moisture and moisture- borne chemical intrusion.

Rough edges and protrusions in the surface of the concrete, such as trowel chatter, mortar splatter, ridges, or sharp projections, are typically removed during surface preparation because they can cause a nonuniform thickness of the traffic membrane systems.

3.4.4 Joints and Cracks

Cracks may develop in concrete as a result of shrinkage, thermal cycling, dead-load settling, or live-load traffic. Cracks often allow more rapid ingress of moisture, chlorides, and carbon-ation, resulting in accelerated corrosion of em- bedded reinforcing steel. Existing joints (Fig. 3.2) and cracks are usually identified and the move-ment determined prior to selection of the traffic membrane system.

 Fig. 3.2: Typical joint in concrete deck 

Monitoring joints and crack widths over time can determine whether they are dormant or active. However, cracks have the potential for movement and can therefore be treated as active cracks. Joints and cracks are usually sealed and treated with an initial application of the base coat material (detail coat) over the crack (refer to Section 6.7) to prevent reflective cracking in the waterproofing system. More flexible traffic membrane systems can bridge some cracking and are not as dependent on the jointing system as are more rigid systems. Additional information about the identification of joints and cracks and their expected movement due to the other factors mentioned is given in ACI 224R, ACI 302.1R, and ACI 504R.

3.4.5 Moisture in Concrete Floor Slabs

As noted previously, moisture vapor transmission through the concrete substrate can be detrimental to the performance of a horizontal waterproofing system. The presence of excess moisture in con-crete floor slabs can cause discoloration, interrupt  polymerization of components of the water- proofing system, compromise adhesion, and contribute to premature failure or delamination of the waterproofing system. Sources of excess moisture fall into three distinct categories: • Moisture present at the surface prior to

appli-cation (Fig. 3.3);

• Moisture within the concrete that moves out during and after application; and

• Moisture in contact with the concrete.

 Fig. 3.3: Excessive moisture due to inadequate  surface drainage

Moisture within the concrete can come from an external source or be the result of residual mixing and curing water. One often-discussed reason for waiting 28 days prior to the instal-lation of waterproofing systems over new concrete is to allow excess moisture to evaporate (Aldinger 1991). However, the evaporation rate is dependent on the quantity of excess moisture, the temperature and humidity differential  between the interior of the concrete and the exterior ambient environment, air flow, concrete thickness, and concrete permeability. In existing concrete slabs, the age of the concrete may also influence its rate of drying. This does not pre-clude older concrete slabs from being tested for excessive moisture. Further information on this topic can be found in ACI 302.2R.

3.4.6 Poor Construction and

Thermal/Structural Movement

Exposed reinforcing steel on the concrete surface or inadequate concrete cover over embedded steel is an example of poor initial construction, which can affect the short- and long-term

dura- bility of the concrete. Properly installed traffic membrane systems can prevent moisture intru-sion, which exacerbates concrete deterioration caused by corrosion of embedded steel elements. The degree of thermal and structural move-ment will have an impact on the amount of flex-ibility required in a traffic membrane system. For example, because precast double-tee beam construction tends to deflect more under traffic loads than cast-in-place floor slabs in parking structures, membrane systems for precast garages need to have a higher degree of flexibility.

4.0 Materials

There are five basic chemistries used in traffic- bearing waterproofing applications. They are:  polyurethane, polyurea, epoxy, methacrylate, and

cementitious.

4.1 Material Properties

The selection of the proper material for the waterproofing system will vary, depending on the specific application requirements, location, and substrates. Table 4.1 is intended to be a guideline tool to help narrow the search for the  proper material type for the system application. More specific information for material per-formance is provided in the individual material sections that follow.

4.2 Material Types

4.2.1 Polymers

Most of the polymer material types are available in either one-component or two-component variations. The one-component options only require mixing of the material in the provided container to ensure consistency of the end coating. One-component systems cure by reacting with ambient moisture. As a result, the cure rate may be significantly affected by changes in temperature or humidity.

With two-component polymers, it is critical to properly mix the components together. It is important to comply with the manufacturer’s written instructions and only mix full units. If the product is not properly proportioned and mixed, the traffic membrane system may not cure or perform properly. An advantage of multi-component products is the cure rate can  be tailored to provide a faster cure and quicker

turnaround if desired.

In some cases, traffic membrane systems may contain solvents. Proper application and safety  procedures should be followed in all cases. Also, a complete traffic membrane system may use more than one of the polymers listed in the fol-lowing sections. For instance, a flexible mem- brane may be placed under a rigid system to improve the overall system’s ability to bridge Table 4.1: Material Type and Performance

Polyurethane, single-component Polyurethane, two-component Polyurea Epoxy, low modulus Methyl methacrylate Cementitious  Aromatic Aliphatic Aromatic Aliphatic Aromatic Aliphatic

Single-component Two-component UV resistance (Note 1) Property retention Color stability *** **** ** **** *** *** * *** **** **** ** *** ** *** ** *** * *** *** *** Scratch resistance ** *** *** *** *** *** **** *** ** *** Tensile strength ** *** **** **** *** *** **** **** * * Resistance to tear ** *** ** *** **** *** **** **** * * Crack bridging **** **** ** **** ** *** ** ** * * Hardness range ** *** *** *** *** *** **** *** ** *** Durability ** *** *** **** *** *** **** **** ** **** Breatheability ** ** ** ** * * ** * **** **** Low odor ** ** **** **** ** ** *** * **** **** Ratings (Note 2) * Poor ** Fair *** Good **** Excellent

NOTES:

(1) UV stability may depend on the inclusion of UV stabilizers, the usage of a fully broadcast aggregate or whether a UV stable topcoat is used

(2) Ratings are based upon the comparison of properties published on product data sheets from several manufacturers for similar products and on collective committee experience

cracks. Experienced design professionals and material manufacturers can assist with the task of developing a system that best suits the perfor-mance requirements needed. ICRI 710.1 pro-vides a more detailed description of various  polymer types.

4.2.1.1 Polyurethane

Polyurethanes are organic polymers formed by a reaction of an isocyanate with a hydroxyl-func-tional resin. They are available in either one-component or two-one-component versions and the isocyanate may be either aromatic or aliphatic in nature. Aromatic systems are more economical,  but not as UV-stable as the aliphatic products.

Typically, polyurethanes have good abrasion resistance, flexibility, and overall durability and are usually applied with a single base coat and multiple top coats, depending on project require-ments. Due to the tendency for discoloration,  polyurethane systems may be pigmented light gray, charcoal, or tan. Other colors may be avail-able, depending on the manufacturer.

4.2.1.2 Polyurea

A pure polyurea elastomer is derived from the reaction product of an isocyanate component and an amine-terminated resin blend. Similar to  polyurethanes, polyureas can be either aromatic

or aliphatic in nature. Polyurea will generally  provide superior physical properties over

poly-urethanes and have slightly better color stability. Generally, polyurea has a fast-set chemistry, requiring high-pressure, multi-component spray equipment. Upon application, polyurea can be dry to the touch in as little as 10 seconds.

Additional variants may be available with slightly slower cure times for joint sealants, as well as brush-grade systems for repair applica-tions. Systems approved for use with potable water (NSF/ANSI Standard 61) are available.

4.2.1.3 Epoxy

Epoxies are two-component materials, based on organic chemistry, which have been widely used in the construction industry since the early 1960s and are perhaps the most common interior sys-tems used in construction today. These syssys-tems may range from thin-set epoxy terrazzo to those with high chemical resistance. One of the limita-tions of epoxy is its inability to expand and contract the same as concrete when exposed to temperature extremes. Therefore, it may not be appropriate for exterior application. Another limitation is that epoxy will change color when exposed to UV light because of its aromatic

characteristics. Epoxies also get softer in the heat and harder in the cold and tend to become brittle over time. Low-modulus epoxies are somewhat more flexible than higher-modulus epoxies. The majority of the epoxies available today are 100% solids, so they contain almost no volatile organic compound (VOC), and have only a slight amine odor that may be objectionable to nonconstruc-tion personnel.

Exterior use of epoxy traffic membrane sys-tems is often restricted because of their rigid responses to loads and thermal movement. When used outdoors in applications such as bridge deck overlays, they may use a semi-rigid or flexible epoxy loaded with aggregate. However, reflec-tive cracking from the substrate through the epoxy traffic system is possible with the more rigid versions.

4.2.1.4 Methyl Methacrylate (MMA)

Methyl methacrylate, or MMA, as it is widely known, is an acrylic resin cured with a specified amount of benzyl peroxide. MMA compounds are 100% reactive and may range from soft coat-ings, similar to contact lenses, to hard mem- branes, such as acrylic glass. MMA is naturally colorless, volatile, and flammable, with limited solubility in warm water. It has a distinctive, acrid odor, although the detectable threshold of 0.08 parts per million (ppm) (0.3 mg/m3_{) is well}

 below the OSHA-defined limits.

MMA traffic membranes are resistant to many acids, salts, and alkalis. However, they are not recommended for exposure to many industrial solvents. In general, these products have excellent UV resistance, although this should be verified with the manufacturer for the specific system under consideration. Some  products are NSF-rated for sanitary areas (NSF/ ANSI Standard 61). MMA systems have varying degrees of flexibility, which is a consideration where the concrete will experience significant ranges in temperature.

4.2.2 Cementitious

Cementitious waterproofing products have a distinct difference from the polymer types previ-ously described in that they contain a dry aggre-gate mixed with liquid materials on site. They are readily mixed and applied using a variety of tools and methods, including trowel, roller, spray,  broom, and notched squeegee with back roll. A variety of colors, textures, and decorative faux finishes can also be incorporated into the coating installation for architectural enhancement.

Cementitious systems are typically applied thicker than the polymers and, as a result, require  polymer modification when used for thin

hor-izontal surfaces. The polymer modification enhances physical properties, including adhe-sion, freezing-and-thawing resistance, abrasion resistance, tensile and flexural strengths, dura- bility, and permeability of the coating.

The advantages of cementitious water- proo fing mater ials include grea ter moisture vapor transmission rates, usually no require-ments for primers, and inherent anti-slip charac-teristics. However, cementitious waterproof coatings have limited elongation properties, and as a result will not perform well in applications where crack bridging is a key requirement.

4.3 Appropriateness for Application

 Not all traffic membrane systems are ideal for every application. For instance, cure times may  be an important consideration when access to existing facilities may be required. Also, indi-vidual product data and test method s should be considered when comparing material perfor-mance relative to the desired application loca-tion and substrate. Users should consult with the respective manufacturers to determine if their product has been designed for the specific end use.

Potential application locations for traffic membrane systems include:

• Parking decks; • Helix; • Mechanical rooms; • Vehicular bridges; • Pedestrian bridges; • Plazas; • Loading docks; • Stadiums; and • Balconies.

4.4 Appropriateness for Substrates

Although traffic membrane systems may be designed for use on different substrates, discus-sion herein is limited to the application of mem- brane systems on concrete substrates.

Best practice is for recently placed concrete to cure for 28 days or until the moisture content is within acceptable limits for the waterproofing system. The contractor must verify that the moisture content of the concrete is within the limits as recommended by the membrane system manufacturer. Typical test methods for assessing moisture in concrete include ASTM F1869, ASTM F2170, and ASTM F2420.

It is further recommended that the concrete substrate have a minimum concrete surface  profile (CSP) of 3 (ICRI 310.2R) or as recom-mended by the manufacturer. If the substrate is highly profiled, it may be necessary to use a leveling compound, such as a high-build primer or mortar, to fill in low spots. It may also be necessary to include the use of a primer prior to applying the traffic membrane system. It is up to the contractor to verify system performance via adhesion testing prior to the application.

Previously coated surfaces present unique challenges for the application of new traffic membrane systems. Without complete removal of the existing membrane system, considerations must be given to the compatibility of the existing membrane with the new system.

4.5 Warranties

The majority of manufacturers provide warran-ties for their materials ranging in duration from 1 to 5 years. Contractors who install traffic membrane systems also provide similar warran-ties for the application portion of the work. In some cases, manufacturers and contractors will  provide a joint warranty on a single document.

It is important for the owner to understand what the warranty does and does not cover, the limitations and exclusions that are listed on the warranty document, the maintenance require-ments for the traffic membrane system to keep the warranty in force, and what requirements are  placed on the owner in the event of a claim.

5.0 Project

Implementation

5.1 Contractor Selection

Prior to actual contractor bidding or negotiation on the project, there are some critical activities that need to take place for the project to proceed smoothly. Contract documents should be com- pleted, including a qualification standard for applicators. This may be satisfied through manufacturers’ certified applicator programs or independent training conducted by a trade school, trade association, or community college, to cite a few examples. Once qualified bidders have been identified, then an invitation to a pre- bid conference may be in order, or contractor negotiations may take place, depending on the complexity of the project and the system chosen for concrete protection. This process ensures that all parties fully understand the project scope and

can ask any clarifying questions that will ulti-mately result in more accurate estimating and  provide the groundwork for a successful project.

5.2 Pre-Installation Meeting

Once the contractor/applicator has been selected, a pre-installation meeting will enable all involved parties to resolve any issues that might hinder the project. First and foremost, any safety issues must be identified and dealt with at this time, prior to mobilization. Other items discussed may involve site access, sequence of work between trades, scheduling anomalies (such as weather), maintenance of access, and noise restrictions. A clear understanding of likely obstacles and establishing the process to  be used for resolving subsequently identified difficulties is very important if a project is to move ahead without undue delays.

5.3 Mockups

To establish a standard for acceptance of the waterproofing system, a mockup installation of the waterproofing system should be required. The mockup should include the treatment of cracks, joints, deck-to-wall transitions, termi-nations, penetrations through the membrane system, and other detailing that will impact the  performance and aesthetics of the system. The mockup should be of sufficient size to provide the owner with a clear understanding of the color and texture of the final product, includ-ing expected variations in appearance. Once ap proved by all parties, the mockup becomes the standard by which the installation is judged. In most cases, the sample installed is left in place as part of the final installation and can also be used to validate the adequacy of surface prepara-tion, material applicaprepara-tion, intercoat adhesion, and finishing.

6.0 System

Installation

6.1 Inspection of the Concrete

Substrate

Inspection of the concrete substrate is conducted to determine the general condition, soundness,  presence of contaminants, moisture vapor emis-sion, and relative humidity to identify the best methods to prepare the concrete surface to meet the requirements of the system manufacturer. Hydrophobic contaminants can be identified by

lack of absorption of water drops on the concrete surface. Simple nondestructive testing (NDT) techniques such as hammer sounding and chain dragging can help to identify unsound sections of concrete. A proper evaluation leads to the selection of the proper materials, installation methods, tools, and equipment to accomplish the objective. Refer to ACI 201.1R and ICRI 210.4. The traffic membrane manufacturer’s guidelines should be used to evaluate the condi-tion of the concrete.

6.2 Repair of Structural Defects

A structural defect is a major, unintended dis-continuity in a structure (Fig. 6.1). Some defec-tive members may be repaired, while others may require removal and replacement. Spalled con-crete with exposed reinforcing steel, corroded reinforcing steel, or extensive cracking in con-crete members are conditions that should be investigated by a licensed design professional. Structural defects require an engineered repair that is beyond the scope of this guideline.

 Fig. 6.1: Structural defect to correct prior to membrane installation

6.3 Repair of Concrete Surface

Imperfections and Irregularities

Once structural repairs have been completed, it may be necessary to correct other defects, such as surface pitting or scaling, minor spalls, cracks (Fig. 6.2), slopes, and areas near transition zones, such as around drains and doorways, to achieve the desired performance level. High spots may wear prematurely, whereas excess product  pooled in surface depressions may slow or com- promise development of the desired protective  properties of a traffic membrane system. For some systems, it is not necessary to have all surfaces of the concrete in the same plane as long as transitions are gradual and smooth. The traffic

membrane system material manufacturer should  be contacted for recommendations.

 Fig. 6.2: Cracks leading to surface irregularities

6.4 Surface Cleaning and

Decontamination

Decontamination of the concrete surface involves the removal of bond-inhibiting materials such as oils, grease, wax, fatty acids, and other contam-inants. The decontamination process can be accomplished by detergent scrubbing, chemical cleaning, low-pressure (less than 5000 psi [35 MPa]) water cleaning, or steam cleaning. The suitability of these methods is dependent on the depth of penetration of the contaminant, the contaminant’s viscosity, the contaminant’s solu- bility, the concrete’s permeability, and the dura-tion of exposure. Note that in areas contaminated with hydrophobic materials (oils, greases, fats), it may be necessary to decontaminate, then obtain the required surface profile, and again taminate the prepared surface, as most decon-tamination procedures (including water, steam, and chemical cleaning) are only effective on the surface and do not significantly penetrate the concrete. Other contaminants can be identified  by pH, infrared spectroscopy, or other

chemical-analysis test methods. Acids and alkalis can be removed by neutralizing to form a water-soluble salt and then cleaning with high-pressure water. In areas where the contaminants cannot be removed, complete removal and replacement of the contaminated concrete may be necessary.

CAUTION:Decontamination methods that introduce large amounts of water can contribute to moisture-related problems (refer to Section 3.4.5). Visual inspection is not always an accu-rate indicator of proper decontamination or cleanliness. Other considerations include: • The decontamination method may create a

 bond breaker if not completely removed; • Disposal of the wash residue may require

special handling to meet environmental guidelines; and

• Because the cleaning method may introduce large quantities of water to the concrete, additional tests to determine the acceptable level of moisture vapor emissions and relative humidity are required prior to application of the traffic membrane system.

6.5 Surface Preparation

The objective of surface preparation is to produce a concrete surface that is suitable for application and adhesion of the traffic membrane system. The quality of the surface preparation step and  performance of the specified system are directly related. The system manufacturer should provide detailed instructions, in the form of a specifica-tion, for preparation of concrete surfaces to receive their system.

Creation of a satisfactory surface profile can be accomplished by a number of methods, each using a selection of tools, equipment, and materials dependent on the type of surface to be pre pared and the type of system to be installed. Most manufacturers recommend a concrete surface profile (CSP) of 2 or 3 (refer to ICRI 310.2R). The service temperature and type and thickness of the selected waterproofing system also play an important role in the surface  prep aration sele ction process. ICRI 310. 2R

 Fig. 6.3: Concrete surface profile (CSP) chips on prepared surface

 provides a comprehensive description of surface  preparation methods, the tools/equipment avail-able, and the results of using the methods. A set of molded replicas (chips) are also available with the guideline as visual guides (Fig. 6.3) for verification of acceptable surface profile for the application of industrial sealers, coatings, and  polymer overlays.

Depending on the concrete condition, one or more methods of surface preparation may be specified. Among the most frequently used methods include:

• Acid etching—Diluted hydrochloric acid is used to remove concrete laitance and weak  paste at the surface. This provides a relatively even surface profile but may not be aggressive enough to achieve a CSP 3 surface profile; • Grinding—A labor-intensive approach,

gener-ally employing a handheld or walk-behind machine with grinding wheels. Minor grinding is particularly suitable for small areas not accessible to other forms of surface prepara-tion, such as joint faces, areas along walls, and in confined spaces; while major grinding is typically used for terrazzo and big-box-store concrete floor polishing. The use of aggressive grinding discs will provide a CSP 2 profile, adequate for some traffic membrane systems; • Abrasive blasting—Generally employs wet or dry sand or other abrasive mixed with com- pressed air and propelled at high velocity through a nozzle. This method of surface  preparation is highly effective and can produce slight to deep surface profiles from CSP 2 to 7, depending on the concrete hardness, velocity of impact, and choice of abrasive medium; • Shotblasting—The most commonly used and

 preferred method for preparation of concrete surfaces to receive coating (Fig. 6.4). ICRI 310.2R provides information on the effect of steel shot size and resulting surface profiles

from CSP 2 to 9. The profile is affected by the speed at which the machine is operated and the number of passes; and

• Scarifying and scabbling—Scarifying gener-ally employs a rotary cutter (toothed washers) that impacts the surface to fracture and pul-verize the concrete. Scabbling employs  piston-driven cutting heads to create a chip- ping and pulverizing action. Both methods are effective in removing concrete and brittle coatings up to 0.25 in. (6 mm) thick.

Prior to application of the waterproofing system, it is prudent to test for adequacy of the surface preparation. Testing and inspection of the prepared surface takes into account bond strength, profile, cleanliness, pH, moisture vapor emission, and relative humidity.

6.6 Cracks and Joints

Existing cracks must be addressed prior to appli-cation of the traffic membrane system. The system manufacturer should be consulted for recommendations specific to their system.

Typically, dormant cracks with widths less than 1/16 in. (1.5 mm) may be pretreated with either a primer or the base coat of the traffic membrane system to fill and seal, prior to the general priming of the deck. Moving joints and active nonstructural cracks may be routed and sealed with elastomeric sealants, if approved by the material supplier, after proper surface  preparation. The traffic membrane may or may

not be terminated at the joint edge depending on the specification or manufacturer’s recom-mendation. Damaged joint nosings must be repaired per the materials suppliers’ recommen-dation prior to placement of the traffic mem- brane system.

6.7 Application Process

The specific application method will vary depending on the particular traffic membrane system chosen. These methods may include squeegee, roller, low-pressure spray, or trowel application. Most systems are applied in layers consisting of one or more of the following:  primer, base coat, intermediate coat(s), and top coat (Fig. 6.5). The respective manufacturer’s installation instructions should be consulted for  proper techniques and requirements.

The application process must be completely understood by everyone involved in the project. In cases where other trades will be working on the project, it is also useful for them to under- Fig. 6.4: Shotblast surface preparation

stand the basics of the application process so they do not inadvertently contribute to unneces-sary delays, or, worse yet, safety issues. For example, if a worker in a nearby area is welding while an MMA or other system containing solvents is being installed, the fumes, which concentrate and migrate along the ground, could  be ignited.

 Fig. 6.5: Waterproofing membrane application in a stadium

Experienced applicators know how to plan ahead for an efficient application process. Units of material are often staged at intervals accor-ding to the coverage rates required by the sys-tem manufacturer. For example, on a 60 ft (18.3 m) wide section of deck with a coverage rate of 100 ft2_{/gal. (2.4 m}2_{/L, one 5 gal. (19 L)}

unit will be placed every 8 ft (2.4 m) along the length of the deck. Spiked shoes are worn by workers who must walk in the wet coating to  perform back rolling or aggregate spreading. Material being applied continuously is always applied to a wet edge.

6.7.1 Priming

Priming is required with some systems, but not with others (Fig. 6.6). In each case, it is neces-sary to understand whether and under what conditions priming will be required, and any

consequences in the overall performance of the system. One must also understand the conse-quences relative to material cost and the con-struction schedule prior to selecting a traffic membrane system. In some cases, the extra time and money consumed by priming are more than offset by a quicker turnaround and faster return to service for the client.

6.7.2 Material Installation

In general, single- or two-component poly-urethane, epoxy, and MMA systems are typi-cally applied by pouring the mixed material onto the deck, then pushing the material using a notched squeegee. The V-shaped notches in the rubber portion of the squeegee vary in size and control the amount of material placed on the surface. Rollers are used to spread the material evenly over the surface. Aggregate is then  broadcast into the wet material at various rates to improve adhesion of subsequent coats, and to provide slip resistance for topcoat applica-tions (Fig. 6.7). For some systems, it may be  permissible to spray-apply the material. Vertical surfaces may require the use of higher-viscosity or special vertical-grade versions to help pre-vent sagging. Specific installation recommenda-tions from the material manufacturer should always be followed.

 Fig. 6.6: Primer application

Polyurea systems are spray-applied using heated plural component pumps. Application thickness is achieved by performing multiple  passes over the surface. Depending on the cure time for the system, it may be possible to broad-cast aggregate into the wet material prior to setting. Stipple textures can also be achieved with some systems. The material manufacturer’s installation requirements and procedures should  be consulted.

Some material suppliers provide thinner cementitious systems that can be spray-applied  Fig. 6.7: Application of broadcast aggregate

in one or more lifts (layers) using hopper gun spray equipment, textured sprayers, or rotor/stator pump equipment. Once the mate-rial begins to set, the desired texture can be achieved using sponge or plastic trowels. Thicker cementitious systems are most often trowel-applied. Manufacturer’s product data sheets typically list minimum and maximum appli-cation thicknesses.

6.7.3 Terminations

6.7.3.1 Floor

The most common termination in a floor is where a floor intersects a wall or other vertical surface. There are two basic ways to terminate the mem- brane system under such conditions:

• A cant bead of sealant applied where the floor meets the wall or vertical surface. This condi-tion occurs when a wall or other vertical surface is sitting directly on the slab. A bond  breaker tape is installed at the intersection and an elastomeric sealant is placed over the tape, adhering to the floor and the wall or other vertical surface to either side of the tape. Reinforcement cloth (fiberglass or scrim) for dimensional stability is often recommended at wall-to-floor transitions. Manufacturer’s instructions should be followed as the primary guide for the use and installation of materials at these locations.

• A saw cut is installed in the deck surface and the coating system is turned down into the saw cut.

6.7.3.2 Wall

A common termination for a traffic membrane system on a wall is to install a piece of bond  breaker tape at the termination height, typically

4 to 6 in. (100 to 150 mm), then apply the mate-rial up to the tape. Once the application is com- plete and prior to final cure, the tape is removed. In some cases, a flat metal strip, called a termina-tion bar, is mechanically anchored to the wall covering the top of the membrane, and then a  bead of sealant is installed on the top seam of

the bar.

6.7.4 Skid Resistance

Most exterior traffic membrane systems applied to pedestrian or vehicular areas will incorporate a nonskid aggregate for safety considerations. Interior traffic membranes may or may not con-tain a skid-resistant aggregate depending on anticipated end use. The system manufacturer’s instructions should be followed regarding the

type of aggregate to be used, application rates, and timing of the aggregate application.

6.8 Testing and Inspection

Coating thicknesses are commonly specified in a unit of measurement called mils (0.001 in. [0.0254 mm]). Mil gauges are simple, hand-held, often credit-card-sized instruments used during the application process to measure the thickness of the material being applied. ASTM D4541 is sometimes used to test random areas to ensure  proper adhesion of the traffic membrane system.

6.9 Maintenance

After installation, traffic membrane systems should be regularly cleaned to maintain their appearance and so that any defects that develop can easily be identified for repair. Areas subject to high traffic and extreme conditions may require periodic maintenance to maintain their effectiveness as a traffic membrane or their nonslip properties, especially if sand and salt used for ice and snow conditions result in exces-sive wear. In many cases, it may be possible to apply an additional topcoat to restore the nonslip  properties of the system.

6.10 Inspection and

Performance Analysis

Frequent inspections of installed traffic mem- brane systems will identify damage and defects early in their development and minimize the cost and complexity of repairs. In some cases, a cleaning and maintenance program is a condition of the manufacturer’s warranty.

7.0 Health and Safety 

7.1 General Overview

ICRI 120.1 provides guidelines and recom-mendations for safety in the concrete repair industry. In all cases, the manufacturer ’s mate-rial safety data sheets (MSDS) should be con-sulted for all materials. MSDS are a source of information on the hazards and handling of hazardous materials. They are essential reading  prior to hand ling any materials. Poten tially hazardous materials encountered during the handling and installation of horizontal water- proofing systems may include cleaning solu-tions, abrasive media, by-products of surface cleaning and preparation, resins, catalysts, and solvent materials (CFR 29-1910.106).

 Numerous health, safety, and environmental regulations address worker safety—a topic beyond the scope of this guideline. Primary among these is Title 29, Part 1926 of the Code of Federal Regulations (CFR 29-1926), an Occupational Safety and Health Administration (OSHA) regulation important to the construction industry, including the installation of traffic membranes. Requirements may include permissible exposure limits, respiratory protection, and exposure to crystalline silica.

7.2 Employee Protection

Prior to the start of work, a thorough preplan-ning review of the specific job site should be conducted by the contractor to determine how various conditions will affect their employee’s safety and the safety of others during the appli-cation of the traffic membrane system. The degree of protection required for employees and the public is dependent on the application method; weather conditions such as tempera-ture and humidity; type of chemicals contained in the traffic membrane system; and whether the area to be coated is exterior, interior, in an enclosed space, or is a permit entry confined space. Elevated locations may require fall  protection, swing stages, frame scaffolds, lad-ders, or man lifts. Engineering and task proce-dures should be identified and assessed during the preplanning process and implemented as appropriate on a particular job to reduce risks. Examples may include:

• Air quality monitoring; • Cleaning and purging; • Fall protection;

• Hazard communication; • Lifting safety;

• Lock-out and tag-out; • Material selection; • Pedestrian control;

• Permit entry confined space; • Personal protection equipment; • Scaffolds;

• Scheduling (other contractors in work area); • Traffic control; and

• Ventilation.

7.3 Employee Personal

Protective Equipment

The contractor must ensure that risk assessments are carried out to identify those aspects of the work hazards for which personal protective equipment (PPE) is appropriate. The contractor

must take all necessary steps to ensure that employees are properly trained at using the PPE correctly. Provisions should be made for the storage, cleaning, maintenance, and replacement of PPE.

7.4 Vapors

Solvents and solvent-containing traffic mem- brane systems may have hazards associated with fire, solvent toxicity, and chemical toxicity. The contractor and his/her employees should be familiar with product labels; MSDS; product data sheets; and guide specifications that describe specific hazards, proper use, and storage recom-mendations. Flammable and combustible liquids must be kept away from heat, sparks, flames, or other sources of ignition, such as static electricity,  pilot lights, and mechanical/electrical equipment. All equipment must be grounded when transfer-ring from one container to another. The National Fire Protection Association (NFPA 30) and the International Code Council (2012 International Fire Code [IFC]) have developed guidelines for the safe storage and use of flammable and com- bustible liquids. OSHA has developed mandatory regulations for the safe storage and use of flam-mable and combustible liquids for general industry (CFR 29-1910.106) and the Construc-tion Industry (CFR 29-1926.152).

8.0 References

8.1 Referenced Standards

and Reports

The standards and reports listed as follows were the latest editions at the time this document was  prepared. Because these documents are revised frequently, the reader is advised to contact the  proper sponsoring group if it is desired to refer

to the latest version.

American Concrete Institute

ACI 201.1R, “Guide for Conducting a Visual Inspection of Concrete in Service”

ACI 224R, “Control of Cracking in Concrete Structures”

ACI 302.1R, “Guide for Concrete Floor and Slab Construction”

ACI 302.2R, “Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials” ACI 504R, “Guide to Joint Sealants for Con-crete Structures” (Note: This document has been withdrawn by ACI and is available for informa-tional purposes only)

ASTM International

ASTM C1583/C1583M, “Standard Test Method for Tensile Strength of Concrete Sur-faces and the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials by Direct Tension (Pull-off Method)”

ASTM D4541, “Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers”

ASTM E96/E96M, “Standard Test Methods for Water Vapor Transmission of Materials”

ASTM F1869, “Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride”

ASTM F2170, “Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes”

ASTM F2420, “Standard Test Method for Determining Relative Humidity on the Surface of Concrete Floor Slabs Using Relative Humidity Probe Measurement and Insulated Hood”

International Code Council

2012 International Fire Code (IFC)

International Concrete

Repair Institute

ICRI Technical Guideline No. 120.1, “Guide-lines and Recommendations for Safety in the Concrete Repair Industry”

ICRI Technical Guideline No. 210.3R, “Guide for Using In-Situ Tensile Pulloff Tests to Evaluate Bond of Concrete Surface Materials”

ICRI Technical Guideline No. 210.4, “Guide for Nondestructive Evaluation Methods for Condition Assessment, Repair, and Performance Monitoring of Concrete Structures”

ICRI Technical Guideline No. 310.2R, “Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair”

ICRI Technical Guideline No. 320.2R, “Guide for Selecting and Specifying Materials for Repair of Concrete Surfaces”

ICRI Technical Guideline No. 510.1, “Guide for Electrochemical Techniques to Mitigate the Corrosion of Steel for Reinforced Concrete Structures”

ICRI Technical Guideline No. 710.1, “Guide for Design, Installation, and Mainte-nance of Protective Polymer Flooring Systems for Concrete”

National Fire Protection Association

 NFPA 30, “Fla mmab le and Combustibl e Liquids Code”

NSF International

 NSF/ANSI Standard 61, “Drinking Water System Components – Health Effects”

U.S. Department of Labor

CFR 29-1910.106, “Hazardous Materials—  Flammable Liquids”

CFR 29-1926, “OSHA Safety and Health Regulations for Construction”

CFR 29-1926.152, “Fire Protection and Pre-vention—Flammable Liquids”

Referenced standards and reports can

be obtained from these organizations:

American Concrete Institute 38800 Country Club Drive Farmington Hills, MI 48331 www.concrete.org

ASTM International 100 Barr Harbor Drive

West Conshohocken, PA 19428 www.astm.org

International Code Council 500 New Jersey Avenue, NW Washington, DC 20001 www.iccsafe.org

International Concrete Repair Institute 10600 West Higgins Road, Suite 607 Rosemont, IL 60018

www.icri.org

 National Fire Protection Association 1 Batterymarch Park  Quincy, MA 02169-7471 www.nfpa.org  NSF International 789 N. Dixboro Road Ann Arbor, MI 48105 www.nsf.org

United States Department of Labor  200 Constitution Avenue, NW Washington, DC 20210 www.dol.gov

8.2 Cited References

Aldinger, T. I., “Coating New Concrete: Why Wait 28 Days?” Proceedings SSPC 1991, Pitts- burgh, PA, 1991, pp. 1-4.

10600 West Higgins Road, Suite 607 Rosemont, IL 60018

Phone: 847-827-0830 Fax: 847-827-0832 Website: www.icri.org