36C24918B0361-021.pdf

06-11

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SECTION 04 72 00

CAST STONE MASONRY

PART 1 - GENERAL

1.1 DESCRIPTION

This sections specifies repairs damaged or Spalling concrete units to simulate a natural stone.

1.2 RELATED WORK

A. Repair and resurface damaged Cast Stone sills and other simulated natural cast stone. Epoxy mortar will be used to repair all spalled or damaged simulated natural cast stone.

B. Color and texture will be the same as existing simulated natural stone.

1.3 APPLICABLE PUBLICATIONS

A. Publications listed below form a part of this specification to extent referenced. Publications are referenced in the text by basic designation only.

B. American Society for Testing and Materials (ASTM):

C882/C882M.............. Standard Test Method for Bond Strength of

Epoxy-Resin Systems Used With Concrete.

C395 - 01(2006) ........ Standard Specification for Chemical-Resistant

Resin Mortars.

C. International Masonry Institute: Recommended Practices and Guide

Specifications for Cold Weather Masonry Construction.

1.4 SUBMITTALS

A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT

DATA, AND SAMPLES.

B. Manufacturer's Literature and Data:

1. Description of each product to be provided.

2. Application and installation instructions.

3. Maintenance Instructions: Submit manufacturer’s written instructions for recommended maintenance practices.

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c. Shop Drawings: Include plans, sections, component details, and attachment to other trades. Indicate layout of the following:

1. Patterns match existing.

2. Edge configuration will match existing surface.

D. Certifications and Approvals:

1. Manufacturer's certification of material and substrate compliance with specification.

2. Contractor's certificate of compliance with Quality Assurance requirements.

1.5 QUALITY ASSURANCE

A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT

DATA, AND SAMPLES.

B. Manufacturer's Literature and Data:

1. Description of each product to be provided.

2. Application and installation instructions.

3. Maintenance Instructions: Submit manufacturer’s written instructions for recommended maintenance practices.

1.6 WARRANTY:

A. Warranty exterior of epoxy resurface material, adhesion, and cohesive failure, and subject to terms of "Warranty of Construction", FAR clause

52.246-21, except that warranty period shall be extended to two years.

B. General Warranty: Special warranty specified in this Article shall not deprive Government of other rights Government may have under other provisions of Contract Documents and shall be in addition to, and run concurrent with, other warranties made by Contractor under requirements of Contract Documents.

PART 2 MATERIALS

2.1 RAW MATERIALS

Resurface product designed for the repair of cast stone with epoxy mortar.

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2.2 COLOR AND FINISH

A. Color will match existing surface.

B. All surfaces intended to be exposed to view shall have a fine-grained texture similar to natural stone, with no air voids in excess of 1/32

in. (0.8 mm) and the density of such voids shall be less than 3 occurrences per any 1 in2 (25mm2) and not obvious under direct daylight illumination at a 5 ft. (1.5m)distance.

PART 3 - EXECUTION

3.1 EXAMINATION

Installing contractor shall check cast stone repair materials and finish prior to installation.

3.2 JOB CONDITIONS

A. Epoxy materials may be skin irritants or sensitizers to many people.

1. Accordingly, advise applicators to avoid contact with eyes and skin, inhalation of vapors, and ingestion. Make protective and safety equipment available on site. Heed all label warnings by manufacturer.

Make application in accordance with applicable safety laws.

B. Installer will construct barriers and entryway covering(s) to protect pedestrians, vegetation and equipment from falling material.

C. Installer will follow all safety standards in accordance with local, state and federal safety standards

3.3 REPAIR

A. Preparation of concrete surfaces: Concrete surfaces to which epoxies are to be applied shall be newly exposed parent concrete free of loose and unsound materials.

B. Mechanical abrasion-Use sandblasting, scarifying, waterblasting, or other approved means.

C. Inspection of concrete surfaces prior to mortar application

1. Inspect all concrete surfaces prior to application of mortar.

2. Surfaces shall be sound concrete which exhibits a minimum 100 psi pullout strength when tested in accordance with Appendix A of “Use of Epoxy

Compounds with Concrete,” reported by ACI Committee 503.

3. Surfaces shall be free of any deleterious materials such as laitance, curing compounds, dust, dirt, and oil. All concrete surfaces shall be dry

04 72 00 -4 and surface temperature shall be at least 40 F to permit wetting of concrete surface by epoxy coating.

A. Evaluate moisture content for concrete by determining if moisture will collect at bond lines between old concrete and epoxy coating before epoxy has cured. This may be accomplished by taping a 4 x 4 ft polyethylene sheet to concrete surface. If moisture collects on underside of polyethylene sheet before epoxy would cure, then allow concrete to dry sufficiently to prevent the possibility of moisture between old concrete and new epoxy.

4. Mix epoxy components in a clean container free of harmful residue or foreign particles.

5. Condition epoxy compound components to be at a temperature between 60-100 F (16-38 C), unless otherwise recommended by manufacturer.

6. Thoroughly blend epoxy components with a mechanical mixer to a uniform and homogeneous mixture. Mix small batches (up to 1 qt) by use of spatulas, palette knives, or similar devices.

C. Mortar application

1. Apply epoxy mortar to concrete surface by trowel or screed.

Thickness shall be within the limits recommended by the manufacturer.

2. Work mortar into place and consolidate thoroughly so that all contact surfaces are wet by the mortar and entrained air is reduced to the level recommended by manufacturer.

3. Finish surface of mortar to texture, color, and smoothness required for the specific application.

4. Upon completion of finishing operations, allow mortar to cure in accordance with manufacturer’s recommendations.

3.4 CLEANING

A. Protect concrete surfaces, beyond limits of surface receiving mortar, against spillage.

B. Immediately remove any epoxy compound applied or spilled beyond desired areas. Perform cleanup with material designated by epoxy mortar manufacturer. Avoid contamination of work area.

C. Fresh compound accidentally smeared on adjoining surfaces: Scrape off immediately and rub clean with a solvent as recommended by the manufacturer.

D. After repairing of cast stone, remove all masking material and forming to expose finished surface.

E. Leave adjacent surfaces in a clean and unstained condition.

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