Section 03366 TOOLED CONCRETE FINISHES

Section 03366

_{TOOLED CONCRETE FINISHES}

PART 1 - GENERAL

1.1 THE REQUIREMENT

A. The CONTRACTOR shall furnish labor and equipment for all specified tooled concrete finishes and construct test panels as required by this specification.

1.2 QUALITY ASSURANCE A. Mock-ups:

1. Test Panels for Concrete Finishes:

a. Prepare test panels for F-4 and F-5 finishes and tie-hole repairs for review by

ENGINEER.

b. Accepted panels shall serve as standard of quality and workmanship for project.

2. Test Panels Showing Horizontal and Vertical Joints: Prepare test panel showing horizontal and vertical joints proposed for project for review by the ENGINEER. Refer to finishes as specified in this Section.

3. Test Panels Indicating Methods for Making Concrete Repairs: Prepare test panels for proposed repairs at beginning of project for review by ENGINEER.

a. Panels shall serve as standard for repairs during the project.

1.3 DELIVERY, STORAGE, AND HANDLING A. Packing and Shipping:

1. Deliver and store packaged materials in original containers until ready for use.

PART 2 - PRODUCTS (NOT USED) 

PART 3 - EXECUTION

3.1 CONCRETE FINISHING A. Cement for Finishes:

1. Addition of white cement may be required to produce finish which matches color of concrete to be finished.

B. Vertical Concrete Surfaces: Use Following Finishes for Vertical Concrete Surfaces as Indicated in Article 3.2: Concrete Finishing:

1. Finish F-1: No special treatment other than repair of defective work and filling tie holes and depressions 1/2 inch or deeper with mortar. Tapered tie holed shall be roughened prior to filling with mortar. The procedure for roughening and filling

tapered tie holes with mortar shall be submitted to the ENGINEER for acceptance.

2. Finish F-2: In addition to the requirements of F-1 Finish, all offsets and projections shall be ground smooth and all voids larger than 1/4 inch in depth or width filled with mortar. Provide consistent color.

3. Finish F-3: In addition to requirements of F-1 and F-2 finishes, the concrete surface shall be sacked using burlap or other approved means with a mortar consisting of one part cement, 1-1/2 parts fine sand passing the No. 100 screen, an emulsified bonding agent and water. Prior to applying the mortar, the surfaces shall be thoroughly wetted. The surfaces shall be wiped clean and moist cured. Provide consistent color.

C. Horizontal Concrete: After proper and adequate vibration and tamping, use following finishes for horizontal concrete surfaces as indicated in Article 3.2:

1. Finish S-1: Sufficient leveling and screeding to produce an even, uniform surface with surface irregularities not to exceed 3/8 inch. No further special finish is required.

2. Finish S-2: After sufficient stiffening of the screeded concrete, surfaces shall be float finished with wood or metal floats or with a finishing machine using float blades. Excessive floating of surfaces while the concrete is plastic and dusting of dry cement and sand on the concrete surface to absorb excess moisture will not be permitted. Floating shall be the minimum necessary to produce a surface that is free from screed marks and is uniform in texture. Surface irregularities shall not exceed 1/4 inch. Joints and edges shall be tooled where shown or as determined by the ENGINEER.

3. Finish S-3: After the floated surface (as specified for Finish S-2) has hardened sufficiently to prevent excess of fine material from being drawn to the surface, steel troweling shall be performed with firm pressure such as will flatten the sandy texture of the floated surface and produce a dense, uniform surface free from blemishes, ripples, and trowel marks. The finish shall be smooth and free of all irregularities. Steel-trowel finish, free from trowel marks and all irregularities.

4. Finish S-4: Steel trowel finish (as specified for Finish S-3) without local depressions or high points. In addition, the surface shall be given a light hairbroom finish with brooming perpendicular to drainage unless otherwise shown. The resulting surface shall be rough enough to provide a nonskid. Stiff bristle brooms or brushes shall not be used. Finish shall be subject to ENGINEER’s acceptance.

D. Unformed surfaces shall be finished according to the following schedule:

UNFORMED SURFACE FINISH SCHEDULE

Area Finish

Grade slabs and foundations to be covered with concrete or fill material S-1

Floors to be covered with grouted tile or topping grout S-2

Slabs which are water bearing with slopes 10 percent and less S-3

Sloping slabs which are water bearing greater than 10 percent S-4

Slabs not water bearing S-4

Slabs to be covered with built-up roofing S-2

Interior slabs and floors to receive architectural finish S-2

E. Concrete to be Painted: Concrete surfaces to be painted shall be brush sandblasted after curing and prior to finishing. Surfaces to be painted shall receive an F-3 finish for vertical work and an S-3 finish for flatwork. Paint shall not be applied until a minimum of

_{14 days have elapsed from the time of finishing.}

F. Concrete Floor Surfaces to Which Surfacing Material Is Applied: Finish smooth with tolerance within 1/8 inch in 10 feet in any direction from lines indicated on the Drawings.

3.2 CONCRETE FINISHING

A. Finish concrete surfaces as indicated on the Drawings. Where not specified or indicated on the Drawings, finish surfaces as follows:

1. F-1 Finish for Following Vertical Surfaces:

a. Tunnel walls.

2. F-3 Finish for Following Vertical Surfaces:

a. Concrete surfaces specified or indicated to be painted. b. Concrete surfaces, interior or exterior, exposed to view.

3. Architectural Finish:

a. Smooth Concrete Finish: Immediately after the forms have been stripped, the concrete surface shall be inspected and all poor joints, voids, rock pockets, or other defective areas shall be repaired and all form-tie fastener holes filled as specified herein.

b. After the concrete has cured at least 10 days, the surface shall be wetted, and a grout shall be applied with a brush. The grout shall be made by mixing one part portland cement and one part of fine sand that will pass a No. 16 sieve with sufficient water to give it the consistency of thick paint. The cement used in said grout shall be 1/2 gray and 1/2 white portland cement as determined by the ENGINEER. White portland cement shall be Atlas white, or Royal white, Or Equal, furnished by the CONTRACTOR. Calcium chloride in the amount of 5 percent by volume of the cement shall be used in the brush coat. The freshly applied grout shall be vigorously rubbed into the concrete surface with a wood float filling all small air holes. After all the surface grout has been removed with a steel trowel, the surface shall be allowed to dry and, when dry, shall be vigorously rubbed with burlap to remove completely all surface grout so that there is no visible paint-like film of grout on the concrete. The entire cleaning operation for any area shall be completed the day it is started, and no grout shall be left on the surface overnight.

c. Surface Overnight: Cleaning operations for any given day shall be terminated at panel joints. It is essential that the various operations be carefully timed to secure the desired effect which is a light-colored concrete surface of uniform color and texture without any appearance of a paint or grout film.

d. Before beginning any of the final treatment on exposed surfaces, the CONTRACTOR shall treat in a satisfactory manner a trial area of at least 200 square feet in some inconspicuous place selected by the ENGINEER and shall preserve said trial area undisturbed until the completion of the job.

e. All architecturally-treated concrete surfaces shall conform to the accepted sample in texture, color, and quality. It shall be the CONTRACTOR’s responsibility to maintain and protect the concrete finish.

f. Sandblasted Concrete Finish: Sandblasting shall be done in a safe manner acceptable to local authorities, SCAQMD and per OSHA requirements. The sandblasting shall be a light sandblast to remove laitance and to produce a uniform fine aggregate surface texture with approximately 1/32- to 1/16-inch of surface sandblasted off. Corners, patches, form panel joints, and soft spots shall be sandblasted with care. The sandblasting work shall not proceed until after treatment of surface defects as specified herein, are completed.

g. A 3-sq ft sample panel of the sandblasting finish shall be provided by the CONTRACTOR for acceptance by the ENGINEER prior to starting the sandblasting work. The sample panel shall include a corner, plugs, and joints and shall be marked after acceptance. All other sandblasting shall be equal in finish to the sample panel.

h. Protection against sandblasting shall be provided on all surfaces and materials not requiring sandblasting but within or adjacent to areas being sandblasted. After sandblasting, the concrete surfaces shall be washed with clean water and excess sand removed.