USACE / NAVFAC / AFCESA / NASA UFGS-09 97 23 (April 2006)
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Preparing Activity: NAVFAC Replacing without change
UFGS-09965 (August 2004)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 09 97 23
METALLIC TYPE CONDUCTIVE/SPARK RESISTANT CONCRETE FLOOR FINISH
04/06
NOTE: This guide specification covers the requirements for metallic type conductive/spark
resistant concrete floor finish for ordnance and other similar structures.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
NOTE: Do not use the type of floor finish specified in this section in hospitals,
laboratories, or other similar occupancies where sanitation is a primary consideration.
This guide specification does not cover tile or fluid-applied conductive flooring.
Such systems may be found in Section 09650 RESILIENT FLOORING or Section 09670
FLUID-APPLIED FLOORING.
NOTE: This is a very specialized product and should be well researched before
this specification is used. Check with using activity to ensure that this type
of floor finish is chemically compatible with explosives and solvents contemplated
for use in proposed facility.
NOTE: On the drawings, show:
1. Extent of metallic type conductive and spark resistant concrete floor finish.
2. Required slopes, floor drains, and appropriate details.
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[ASTM INTERNATIONAL (ASTM)ASTM C 150(2007) Standard Specification for Portland CementASTM C 33(2007) Standard Specification for Concrete AggregatesASTM C 494/C 494M(2008a) Standard Specification for Chemical Admixtures for ConcreteASTM C 94/C 94M(2007) Standard Specification for Ready-Mixed ConcreteASTM F 150(2006) Electrical Resistance of Conductive and Static Dissipative Resilient Flooring]1.2 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are [for Contractor Quality Control approval.][for information only. When used, a designation following the
"G" designation identifies the office that will review the submittal for the Government.] The following shall
be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-03 Product Data
Dust-on metallic surfacing material (conductive)
Curing compound
Water reducing, set controlling admixture
High range water reducing admixture
SD-04 Samples
NOTE: If the design thickness of the topping is less than 50 mm 2 inches, insert
design thickness in the blank and remove the 50 mm 2 inch requirement.
Conductive and spark-resistant floor finish
Before work is started, prepare, test, and submit sample of conductive and spark-resistant
floor finish, 1.22 meters 4 feet square and [50] [_____] mm [2] [_____] inches thick. Cast
sample on 12 mm 1/2 inch thick plywood base covered with polyethylene film. Mix and apply topping
in accordance with this specification, including troweling, curing, and protection.
SD-05 Design Data
Modifications to topping mix
SD-06 Test Reports
Cement
Aggregate
Admixtures
Conductivity and Spark Resistance
Test floor finish sample for compliance with the conductivity and spark resistance requirements
specified herein. Perform testing using an approved independent testing laboratory.
SD-08 Manufacturer's Instructions
Preparation of base slab
Mixing
Placing concrete topping
Metallic surfacing
Curing of floor finish
SD-10 Operation and Maintenance Data
Conductive spark-resistant floor finish, Data Package 1; [; G][; G, [_____]]
Submit in accordance with Section 01 78 23 OPERATION AND MAINTENANCE DATA.
1.3 PERFORMANCE REQUIREMENTS
1.3.1 Conductivity
NOTE: Include requirement for minimum resistance when electrical convenience
outlets are provided around or above floor area. This usually occurs only in
work and equipment assembly areas. Use 5000 ohms for 120 volt service, 10,000
ohms for 240 volt service, and 20,000 ohms for 440 volt service. If electrical
service is greater than 440 volts, consult NAVSEA for guidance.
Floor finish shall have a [minimum electrical resistance of [5,000] [10,000] [20,000] ohms and a] maximum average
electrical resistance of 1,000,000 ohms. Measure electrical resistances on conditioned sample slab and on conditioned
project slab using method of test specified herein.
1.3.2 Spark Resistance
Floor finish shall produce no spark when tested using method of test specified herein.
1.4 ENVIRONMENTAL CONDITIONS
Do not start work unless environmental conditions conform to manufacturer's printed instructions. Maintain recommended
environmental conditions without interruption during application and curing processes.
1.5 MANUFACTURER'S REPRESENTATIVE
NOTE: The requirements for the presence of a qualified technical representative
of the metallic surfacing material manufacturer should be retained only for
applications where strict compliance with installation procedures is considered
to be critical.
Have manufacturer's technical representative present during start-up of each phase of work including inspection
of grounding materials, preparation of base slab, mixing and placing concrete topping, application of dusted-on
metallic surfacing, curing and testing.
1.6 DELIVERY, STORAGE, AND HANDLING
Deliver manufactured materials in manufacturer's original unbroken packages or containers plainly labeled with
manufacturer's names, brands, lot numbers, and product expiration date. Use moisture-resistant containers. Store
materials in dry, weathertight enclosures and handle in a manner that will prevent inclusion of foreign materials
or damage by dampness.
PART 2 PRODUCTS
2.1 FLOOR FINISH MATERIALS
2.1.1 Portland Cement
ASTM C 150, Type I [or II].
2.1.2 Aggregate
ASTM C 33, except as specified below. Provide pea gravel, silica, traprock, or other approved materials of equivalent
hardness. Gradation shall conform to the following:
Mesh Percent Passing
9.5 mm 100
4.75 mm 95-100
2.36 mm 65-80
1.18 mm 45-65
0.60 mm 25-45
0.30 mm 5-15
0.15 mm 0-5
Mesh Percent Passing
3/8 inch 100
No. 4 95-100
No. 8 65-80
No. 16 45-65
No. 30 25-45
No. 50 5-15
No. 100 0-5
2.1.3 Admixtures
NOTE: Specify these admixtures where increased slump is beneficial with respect
to ease of placement, consolidation, metallic hardener application, or where
a delay of initial set is desirable due to high temperature and low humidity
conditions.
ASTM C 494/C 494M. Water reducing, normal setting (Type A); water reducing, set controlling admixture (Type
D); or high range water reducing admixture (Type F). Admixtures shall not contain more than 0.05 percent chloride
ions.
2.1.4 Water
Potable and free from such amounts of mineral and organic substances which could affect hardening or durability
of cement-mortar topping finish.
2.2 GROUNDING MATERIALS
NOTE: Ground rods should be specified for slabs on grade. Grounding studs should
be specified for suspended slabs. Division 3, "Concrete" sections of project
specification should specify that ground rods or grounding studs be maintained
in position to prevent misalignment before and during placement of structural
concrete.
2.2.1 Ground Rods
NOTE: Specify hard copper or copper clad steel rods for normal conditions.
Specify brass or stainless steel rods where electrolytic corrosion will be encountered.
[Hard copper] [Copper-clad steel] [Brass] [Stainless steel] not less than 20 mm 0.75 inch in diameter, 3 meters
10 feet long. Die stamp each ground rod near top with name or trademark of manufacturer and length of rod in
meters feet.
2.2.2 Grounding Studs
Hard copper, or brass, 12 mm 1/2 inch diameter and of such length as to project into structural concrete base
slab not less than 75 mm 3 inches when installed.
2.2.3 Grounding Connector Disks
Approximately 50 to 100 mm 2 to 4 inch diameter or 50 to 100 mm 2 to 4 inch square pieces of copper or brass
hardware cloth, 4 mesh, 1.2 mm 0.047 inch wire diameter.
2.3 METALLIC SURFACING MATERIAL
2.3.1 Graded Iron Mixture
A factory-prepared dry mixture of graded iron particles, cement, and chemicals; suitable for application by the
dusted-on method; and free from nonferrous metal particles, oils, grease, soluble alkaline compounds, rust and
materials intended to disguise rust, and any other contaminants.
2.3.2 Water Content
Provide water absorbent metallic aggregate containing not more than 0.075 percent water soluble materials.
2.3.3 Cement Dispersing Agent
A cement-dispersing agent, a pozzolanic material capable of combining with free lime to form a water insoluble
compound, and an approved binder shall be combined with metallic aggregate.
2.3.4 Purity
Do not add material to factory-prepared product at job site.
2.4 CURING COMPOUND
A product of the manufacturer of the metallic surfacing material or a type recommended by the manufacturer of
the metallic surfacing material.
PART 3 EXECUTION
3.1 INSTALLATION OF GROUNDING MATERIALS
Provide at least one ground [rod] [or] [stud] for each 37 square meters 400 square feet or less of floor area.
Place grounding materials at least 50 mm 2 inches clear and free of pipes, conduits, sleeves, anchor bolts, floor
drains, or other metal building material that projects through floor finish. Place tops of [rods] or [studs]
at an elevation not more than 10 mm 3/8 inch below top surface of finish floor. Do not allow [rods] or [studs]
to project above finish floor elevation. Center grounding connector disks on top of [rods] [or] [studs]. Braze
disks to tops of [rods] [or] [studs]. Connect each ground [rod] [or] [stud] electrically to concrete slab reinforcement
steel. Connect using a copper or brass braided strap. Braze to both reinforcing steel and ground [rod] [or]
[stud].
3.1.1 Ground Rods
Drive ground rods vertically into earth. The maximum resistance to ground of driven ground rod shall not exceed
25 ohms when tested in accordance with paragraph "Grounding Tests." When work in addition to that indicated
and specified is directed in order to obtain specified resistance to ground, provisions of the contract clause
entitled "Changes" will apply.
3.1.2 Ground Studs
NOTE: The last sentence presumes ground studs used with an existing concrete
base slab. Other site conditions require a different design and wording.
Connect studs together electrically using a continuous No. 6 AWG copper wire brazed to each stud and to a common
ground wire connected electrically to an approved ground. Place stud interconnecting wire on, shape, and fasten
to existing concrete base slab to prevent wire from lifting when concrete topping is placed.
3.2 PREPARATION OF BASE SLAB
NOTE: This guide specification is based on use of a bonded floor topping with
thickness of 50 mm 2 inches or greater. For other installation procedures,
edit specification accordingly.
3.2.1 Cleaning
NOTE: Choose from one of the following three paragraphs. Use first paragraph
for wet cured slabs less than 3 days old. Use second paragraph for cured slabs
between 3 days and a week old. Use third paragraph for cured slabs more than
a week old.
Wash dirt and debris from surface of base slab.
Remove dirt, oil, grease, laitance or other foreign matter from surface of base slab. Scrub surface and rinse
thoroughly with clean water. Keep base slab wet for a period of not less than 12 hours preceding application
of topping.
Remove dirt, oil, grease, laitance or other foreign matter from surface of base slab. Scrub surface with a 10
percent muriatic acid solution and rinse thoroughly with clean water. After rinsing, a litmus test of the wet
surface shall indicate no trace of acid solution.
3.2.2 Bond Coat
Remove excess water or dry slab until there is no free water. Apply a cement paste, latex, latex cement, or epoxy
bond coat.
3.3 PROPORTIONING AND MIXING OF CONCRETE TOPPING
NOTE: Where bonded topping or base slab is of very low slump (less than 75
mm 3 inches) consider deletion of reference to excess water. Metallic surfacing
material, which is a dry shake material, will require sufficient water to adequately
mix with concrete topping or base slab.
3.3.1 Proportioning
NOTE: Use either compressive strength option or specified mix design.
[Proportion concrete topping mix to provide a 28-day compressive strength of 34.5 kPa 5,000 psi, with a maximum
slump of 75 mm 3 inches or less. If high range water reducing admixture is used, slump may be increased to 200
mm 8 inches.] [Proportion concrete topping mixture by volume with one part portland cement and 2 3/4 parts 10
mm 3/8 inch maximum size aggregate. Use a maximum water-cement ratio of 0.45 including moisture contained in
aggregates.] Topping mix may be modified, as approved, to conform to requirements of manufacturer of metallic
surfacing material.
3.3.2 Mixing
Perform mixing in mechanical mixers of a type in which quantities of water can be controlled accurately and uniformly.
Introduce and mix aggregates so that materials are distributed uniformly throughout the mass. Add water gradually.
After cement, aggregates, and water are in mixer drum, mix for two minutes. Ready-mixed concrete shall conform
to ASTM C 94/C 94M. Do not retemper topping mixture with water. Additional dosage with high range water reducing
admixture may be permitted with prior approval of the Contracting Officer as to methods and procedures. Use
only admixture specified and approved in proposed mix design.
3.4 PLACING, FINISHING, AND CURING
3.4.1 Placing Concrete Topping
NOTE: For bonded toppings, use as thick a bonded topping as design constraints
will allow. A 25 mm one inch bonded topping is extremely difficult to install.
Bonded toppings of 50 mm 2 inches to a maximum of 75 mm 3 inchesare much easier
to construct. Generally, the thinner the bonded topping, the more problems
that will be encountered during construction and in future use.&
Place, compact and strike-off topping mixture to the full depth of the [50] [_____] mm [2] [_____] inch screed
strips. Tamp thoroughly with a grill-faced tamper (do not use a flat-faced tamper) or vibrate with a small vibrator
to compact concrete topping, force out entrapped air, and ensure maximum density. Take extreme care in placing
and tamping so that grounding system will not be damaged or misaligned. Form a slight cup-shaped pocket or depression,
about 75 mm 3 inches in diameter and 20 mm 3/4 inch in depth in topping finish surrounding grounding connector
disks on tops of [rods] [and] [studs]. Keep disk free of topping mix by protecting disk with a plastic sheet.
After compacting, screeding and leveling floor surface, remove excess water by an approved method. Mechanically
float surface.
3.4.2 Placing and Finishing Base Slab
NOTE: Use this paragraph for monolithic slab placement.
Where metallic surfacing is to be placed directly upon base slab, place slab in accordance with Section
03 30 00 CAST-IN-PLACE CONCRETE. Take extreme care in placing and consolidating concrete so that grounding system
is not damaged or misaligned. Form a slight cup-shaped pocket or depression, about 75 mm 3 inches in diameter
and 20 mm 3/4 inch in depth in the finish surrounding grounding connector disks on the tops of the [rods] [and]
[studs]. Keep disk free of concrete and mortar by protecting disk with plastic sheet. After placing, consolidating,
striking off and leveling, remove excess water by an approved method. Mechanically float the surface.
3.4.3 Metallic Surfacing
Before opening, shake surfacing material containers to ensure uniformity of ingredients. After floating floor
surface, dust dry metallic surfacing material uniformly on surface at a rate of not less than 4.4 kilograms per
square meter 0.9 pound per square foot of surface. When metallic aggregate has absorbed surface moisture, mechanically
float surface. After floating, uniformly dust on surface remaining dry metallic surfacing material to achieve
a total rate of not less than 8.8 kilograms per square meter 1.8 pound per square foot of surfacing material
for the two dusting operations. Apply second shake at right angles to first for even application. Repeat floating
operation.
3.4.4 Finishing
NOTE: Use 6 mm in 3 meters 1/4 inch in 10 feet unless operational requirements
dictate the flatter floor. Floors with a tolerance of 3 mm in 3 meters 1/8
inch in 10 feet cost considerably more to place. Floor finish checking is required
from initial placement of concrete for floors with a tolerance of 3 mm in 3
meters 1/8 inch in 10 feet.
Finish floor to a smooth surface, free from blemishes. Test floor surface with a straight edge to ensure a tolerance
of plus or minus [6 mm1/4 inch] [3 mm1/8 inch] in 3 meters 10 feet. Take extreme care so that conductive metallic
aggregate contained in surfacing material is in full and firm contact with disks attached to top of grounding
[rods] [and] [studs]. Do not float or trowel surfaces excessively in a manner that buries metallic aggregate
or contaminates surfacing material during floating and trowelling operations. Protect flooring from contamination
by subgrade material, tracked or spilled concrete, sand, stone, or other material during finishing operations.
Remove flooring contaminated and replace with new flooring. Match approved finish floor sample in all respects.
3.4.5 Curing and Protection
Cure and protect floor finish for not less than 30 days unless a longer period is recommended by the manufacturer's
printed instructions. Strip floor finish of conductive curing compounds only in those areas where acceptance
tests will be performed. Strip non-conductive curing compounds completely.
3.5 FIELD TESTS
Conduct testing in the presence of the Contracting Officer.
3.5.1 Grounding Tests
Test ground [studs] [and] [rods] and interconnecting ground wire before the concrete slab is placed and again
before the topping finish is placed. Before final wiring is connected to the ground rods, test each rod or group
of rods for ground resistance using a portable ground testing megohmmeter developing an A.C. voltage. Equip
the instrument with a meter reading directly in ohms. Use two reference ground rods of 20 mm 3/4 inch copper
clad steel, not less than 1.2 meters 4 feet in length, driven 1 meter 3 1/2 feet deep. Install rods in a straight
line from the ground being tested. Connect No. l4 AWG stranded wire leads with at least 600-volt insulation
to the ground being tested and the two reference grounds and to proper binding posts on the instrument. Where
there is more than one ground within a circle of 3 meters 10 feet at a particular location, use reference rods
as driven for the "first" test for tests on the other rods without changing their location.
3.5.2 Acceptance Tests
Make tests for conductivity and spark resistance of metallic finish after floor finish has been cured and dried
for 30 days. Perform at least one test for each 37 square meters 400 square feet or less of floor area for conductivity
and for spark resistance.
3.5.2.1 Conductivity Tests
Conduct conductivity tests of finished floor surface in accordance with ASTM F 150. For compliance, the average
of maximum resistances shall be within the limits specified with no value greater than 5 megohms.
3.5.2.2 Spark Tests
Determine spark resistance of finished floor surfaces in a darkened space by stroking the floor vigorously with
a 300 mm 12 inch metal file in a 1.8 meter 6 foot arc. Perform spark test five times in each 37 square meters
400 square feet or less of flooring area. Areas with no visible spark production will be accepted as having
necessary spark resistance.