NATIONAL BUREAU OF STANDARDS REPORT

PERFORMANCE OF FLOORING MATERIALS IN MILITARY KITCHENS

by

Thomas H. Boone

and

William A. Bender

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1004-1 2- 10448 30 April 1964 8339

PERFORMANCE OF FLOORING MATERIALS IN MILITARY KITCHENS

by

Thomas H„ Boone

Organic Building Materials Section

Building Research Division

and

William. A0 Bender

Buildings and Grounds Branch, Military Construction Directorate

Office of the Chief of Engineers

Sponsored by

Office of the Chief of Engineers

Department of the Air Force

Bureau of Yards and Docks

IMPORTANT NOTICE NATIONAL BUREAU OF S

for use within the Government

and review. For this reason, t whole or in part, is not auth Bureau of Standards, Washinj

the Report has been specificall

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015.

ress accounting documents intended

Is subjected to additional evaluation

re listing of this Report, either In

the Office of the Director, National

jy the Government agency for which

copies for its own use.

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

PERFORMANCE OF FLOORING MATERIALS IN MILITARY KITCHENS

1 . INTRODUCTION

Floors in kitchens,, the adjoining dishwashing rooms,, and preparation

rooms for raw foods are subjected to extremely severe conditions,, The

floors are exposed to grease; cooking oils; fatty, vegetable, and fruit

acids; frequent scrubbing and cleaning, sometimes with strong alkaline

detergents; and around stoves to temperatures as high as 275°F (135°C) 0 In many areas the floors are almost continuously wet from spillages

around dishwashing machines, sinks, live steam pipes, and from the

dumping of hot food liquids directly on the floor adjacent to, but

usually many feet from, the floor drain (see Figure 1). Mechanical

damage is also encountered such as the shuffling of feet at work tables

and serving lines, the dragging or impact of the edge of fully loaded

garbage cans and the agitation of stif f -bristled scrubbing brushes. It

requires an exceptional floor to withstand such a combination of exposure

From the service life of floorings used in military kitchens, the following conclusions and opinions have been reported;*

(1) Portland cement concrete with well selected aggregate,

properly mixed and placed, provided 3 to 4 years of service

before areas adjacent to ranges, sinks, and drains were

eroded severely and the aggregate exposed.

(2) A Portland cement concrete with high water-cement ratio,

and/or poor curing had somewhat less service than that of

a "good"' concrete as just mentioned.

(3) Proprietary Portland cement concrete toppings over a thoroughly scarified and cleaned old concrete floor with all the

recommended installation procedures carried out carefully,

provided 4 to 7 years of service before areas adjacent to

ranges, sinks, and drains were eroded severely.

(4) Magnesium oxychloride floors were not satisfactory in

kitchen areas since the excessive amounts of water caused

deterioration in less than one year.

*Boone, T. H., P„ A. Sigler, and H. R. Snoke, "Evaluation of Flooring

Materials in Army Installations”, National Bureau of Standards Report

No. 2485, May 11, 1953.

FIGURE

1.

KITCHEN

FLOOR

AROUND

THE

AREA

EXPOSED

TO

STEAM

AND

HOT

LIQUIDS

.

THE

QUARRY

TILE

FLOOR

WITH

FURAN

JOINTS

AND

BED

SHOWN

ABOVE

IS

FIVE

YEARS

OLD

2

(5) Thin floor coverings such as asphalt tile, vinyl asbestos

tile, and rubber tile were not satisf actory„ The tiles were

damaged readily by impact and contact with hot cooking utensils.

Bond failures were severe near areas of water spillage.

(6) Quarry tiles with Portland cement mortar jointing and bedding

provided 3 to 4 years of service before joints eroded and the

tiles became loose. The tiles remained in good condition.

Some specially treated inorganic cement mortars extended the

service from 4 to 7 years.

In order to find flooring systems which would provide a more extensive

service in military kitchens than those mentioned above, test installations

were made of recommended and laboratory tested flooring materials at

military posts near Washington, D. C. During the past ten years a record

has been kept of the methods of installation, the type of materials used,

and the overall performance of these test floors. As new systems and new

materials were developed, additional installations were made in kitchens

as nearly similar in use and condition as the first.

Two approaches were made, first to investigate materials which could be

troweled over the old concrete and second to investigate materials which

could be used as bed and joints for quarry tile floors. It was hoped

that either or both of these systems would provide 7 to 10 years of

service under the harsh conditions encountered in the kitchens.

2. GENERAL DESCRIPTION OF THE TEST AREAS

The kitchens used in these experiments contained approximately 800 square

feet of floor area and were in frame mobilization mess hall buildings con- structed during World War II. Each kitchen contained the usual commercial

kitchen equipment including three ranges, a deep fat fryer, two sinks,

a dishwashing machine, a hot water heater and large storage tank, a heated serving table, refrigerated cabinets, and a dry storage room.

Each of the buildings selected were of the same size and type, and used

for the same purpose, i.e. to prepare and serve food; three meals a day

for approximately 200 men a meal.

Originally the kitchens were floored with strip-pine over 1-inch thick

subfloor placed on 2- by 8-inch joints 12 inches on center. Within a short time these wood floors deteriorated badly and were repaired by

covering with 2-1/2- to 4-inch thick reinforced concrete. Extra

supporting columns and beams were placed under the floors.

- 3

-

3. EXPERIMENTAL TEST FLOORS

The flooring materials selected for this investigation were latex-modified

cements, latex cement compounds, resin-based thermosetting surfacing com- pounds, and quarry tile floors with resin-based thermosetting bed and

joints.

From the beginning of these experimental installations, it was recognized

that even the best materials could be jeopardized by careless or un- trained mechanics. The test floors that are described in this paper were therefore placed under the best possible conditions. Highly skilled

mechanics, thoroughly familiar with the products and in most cases employees of the manufacturer were used to install the floors. All

recommendations of the manufacturers as to the method, thickness, and

conditions of application were followed.

None of the flooring systems were designed for or intended to add or provide strength to the floor.

Only those floors that were exposed to comparable service are reported.

3.1 Latex-modified Cement and Latex Cement

The latex-modified cements were composed of cement, aggregate, and

latex (see Table I). The addition of latex of approximately 57. solids,

based on the total solids of the composition, was claimed to give good

bonding strength to clean substrate, allow for thinner coatings, and

offer higher chemical resistance.

The sample designated as floor number 1 was a concrete modified with

styrene-butadiene latex and placed 3/4- inch thick over concrete. The

floor had a very high dirt retention. Within three months signs of

erosion were noted around the floor drain. In a little over one year

the erosion of the matrix throughout the kitchen area had caused a physical breakdown to an extent that the experiment was discontinued

and the floor removed.

Floor number 2, which was identical to floor number 1, except a polyvinylidene chloride latex was used, failed in a little over one year

because of severe erosion.

The latex cement floors, numbers 3, 4, and 5, were prepared from a mixture of inert aggregate, latex, and high alumina cement (see

Table I). The resistance to erosion depends on the type of cement

and latex used. In general, a high latex-alumina cement mixture

will withstand more acidic conditions than alumina cement alone.

Three installations were made over concrete with a latex containing

Table I. Formulation of Latex Floors

Parts by Weight

Floor number 1 2 3 4 & 5 Base

Coat

Top

Coat

Inert fillers 3.0 3.0 3.0 3.0 3.0

Portland cement 1.0 1.0

Alumina cement 1.0 1.0 1.0

Latex 0 .4^ 0.4“^ 0.4—/ 0.9^/ 0.9^/

Water 0.1 0.1

Styrene/butadiene latex containing 48% solids. —

2 / Polyvinyl idene chloride latex containing 48% solids.

3/ — Polyvinyl chloride latex containing 40% solids.

- 4

-

a high percentage of a vinyl latex with alumina cement. Floor number

3 was placed in two coats to a total thickness of 3/8-inch over a latexed primed concrete. The other two floors, 4 and 5, were placed

with the same thickness in one coat over latexed primed concrete.

All three floors had very low resistance to abrasion when wet and were softened by heat. The materials were worn down to the substrate

in heavy traffic areas in a little over one year,

A summary of the results of the latex floors is given in Table III,

3,2 Resin-hased Thermosetting Floor Toppings

The epoxy toppings have been widely used as a corrosion-resistant

shield over industrial concrete floors because of their ability to

withstand heavy traffic and to prevent the deterioration of concrete

floor slabs due to acids, alkalies, and solvents. The characteristics

of cast concretes prepared with epoxy resins have been examined and

compared with inorganic concrete by many laboratories. In general

it can be stated from laboratory results that the epoxy resin concrete

has higher compressive and tensile strength; the shrinkage of certain

floor mixes corresponds with that of Portland cement concrete; swelling

is less and creep is no higher and may be lower than Portland cement

concrete. Because of its resistance to chemicals it is unquestionably

more suitable for certain applications.

The principal ingredients of epoxy floors are epoxy resin, hardener,

and filler. The epoxy resin is the binder which holds the mass together and bonds it to the base floor. The hardener converts the

liquid epoxy resin into a solid. The filler, which can be of most

any material fairly inert to chemicals, adds to the impact strength

and brings the coefficient of thermal expansion of the epoxy closer to

that of the base slab.

Two monolithic epoxy floors, numbers 6 and 7, were placed by corrosionengineering concerns specializing in chemical resistant linings and

floorings, A brief formulation of floors 6 and 7 are given in Table II,

Floor number 6 was placed on a roughened, cleaned and dry concrete in

August 1959, The temperature at the floor level remained at approximately 75°F (24®G) during the installation and for 4 days after installation. An epoxy primer was brushed onto the concrete and the

topping was placed 1/4- inch thick in one application. The building

was not occupied for 30 days.

Table II. Formulation of Epoxy Toppings and Mortars

Parts by Weight

Floor number 6 7 8

Base

Coat

Top

Coat Bed Joint

Inert filler 5.0 3.0 8.0 4.0 1.5

Epoxy resin 1.0 0.7 0.7 0.7 0.7

Hardener 0.1 0.3 0.3 0.3 0.3

Table III, Summary of Results of Experimental Floors

Floor number

Latex -mod if led

cement

12

Age of

floor

years

1

1

Latex cement

3

4

5

11

1

Monolithic epoxy

6 3

7 1

Quarry tile-epoxy

8

9

Quarry tile-furan

10

Duration before

major failure

years

Cause of failure

poor

bond heat erosion wear impact

1

1

1 XX 1

1 XX

3 XX 1

4 X X

X

X

X X

X X

X X

X X

1 / The kitchen containing this test floor has only been occupied about 507o of the

3-year period.

2 / This floor has had no major failures and is still in use.

- 5

-

Within one year small, sections of the floor had to be replaced near the

ranges and at the floor drains. By 1962 large sections of the epoxy

had delaminated from the concrete and were no longer serving their

function. Chemical degradation of the epoxy flooring seems to be

taking place in areas of high temperature.

The concrete base of floor number 7 was cleaned with a hydrochloric

acid solution, scrubbed,, thoroughly rinsed with water, and dried.

This installation was placed in August 1959, under the same conditions

and temperatures as floor number 6. An epoxy sandfilled base coat was placed 1/16-inch thick with a glass matt overlay. A non-filled

epoxy was worked into the top surface of the matt. Over this was placed two coats,, a 3/16-inch filled coating and a high resin content

skim coat (see Figure 2)« The building was not occupied for 20 days.

Within one month the following observations were made:

(1) bond failure between base epoxy and concrete at areas near

ranges,

(2) separation of skim coat from the hr v of the epoxy around

the floor drain area^

(3) numerous indentation spots caused by impact of food serving

trays and garbage cans.

By the fall of I960, this floor had completely failed. Large sections

had delaminated, other sections had broken away from the concrete.

A summary of the results of the monolithic epoxies are given in Table

III.

3.3 Quarry Tile Floors with Resin-based Thermosetting Bed and Joints

The weaknesses or faults which have been noticed in quarry tile floors

used in kitchens were the slipperiness of the smooth tile surfaces, the

early breakdown of the joint materials and the need of a rigid subfloor.

Non-slip conditions were obtained by using tile with aluminum oxide

particles embedded in the surface. Two thermosetting resins, epoxy

and furan, were investigated for better joints and bed mortars. A

floor design was used on floors numbers 9 and 10 that would permit the

installation of quarry tile over wood (see Figure 3) 0

The old concrete surface in the kitchen for floor number 8 was cleaned

with hydrochloric acid solution, scrubbed, thoroughly rinsed with

water, and dried. An epoxy primer was brushed on the concrete, and

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SCHEMATIC

DIAGRAM

OF

TEST

FLOOR

NUMBER

7,

MULTI-LAYER

EPOXY

COATINGS

THERMOSETTING

RESIN

GROUT

FIGURE

3.

QUARRY

TILE

FLOOR

CONSTRUCTION

OVER

WOOD

SUBFLOORING.

6

the epoxy resin bed composition as given in Table II was placed 3/4-inch

thick and the tiles set into the bed with 1/4- inch wide joints. The

tiles were 6- by 6- by l/2-inch. The backs of the tiles were "V1 * scored or grooved about 1/16-inch deep. The face surfaces were embedded

with aluminum oxide abrasive particles and coated with wax. When the

epoxy resin cement mortar setting bed had set hard;, freshly mixed

epoxy mortar was spread and worked into the joints of the tile. The

floor area was allowed to remain undisturbed for three days before

cleaning the top surfaces of the tiles.

The first signs of deterioration were noted after 2 years of service.

The epoxy joints under and adjacent to the ranges and the hot water

heater had completely failed and could be removed by hand. By the

fourth year the floor had to be replaced. On lifting the tiles it was noted that the binder in the base epoxy had completely disintegrated leaving only the sandy fill which was easily and completely

swepth away exposing the old concrete surface.

The concrete was removed in the kitchen used for floor number 9 and

5/8-inch thick exterior grade waterproofed plywood in 8- by 8-foot

sheets was placed over the sheathing. The end joints of the plywood

were staggered and securely nailed on 6- inch centers in two directions

with hot-dipped galvanized flat head nails 1-3/4 inch long.

The epoxy bed* was spread over the cleaned plywood with a notched

trowel having 3/8-inch deep notches 1/4-inch apart.

From this point on, the same type of tiles and the same method of

application were used as in floor number 8, except that no wax was placed on the face of the tiles, and the tiles were cleaned just

after setting of the Joints.

This kitchen has been occupied only 507o of the three years since its

installation. Softening of the epoxy Joints near the heated ranges

has been noted.

Test floor number 10 was installed over plywood similar to floor

number 9 and illustrated in Figure 3, except that furan resin was used as the bed and Joint and the top surfaces of the tiles were

waxed

.

*The manufacturer of this product would not reveal its formulation.

- 7

-

Furan resin is a furfuryl alcohol resin, which;, when treated with a suitable acid catalyst system, polymerizes into a thermosetting solid

resin„

This floor was installed in the winter of 1954-55 by tile setters

inexperienced at working with thermosetting resin mortars. Difficulty

was encountered in mixing the compound, in obtaining a completely

cured floor,, and in cleaning the tile surface.

With the exception of a few hairline cracks in the joints and a small

amount of tile impact damage this floor has performed very satisfactorily for 9 years (see Figure 4), Many other military kitchen floors

of furan and quarry tile have also performed satisfactorily since 1958.

A summary of the results of the quarry tile floors with epoxy and

furan are given in Table III.

4. ACKNOWLEDGMENT

The authors acknowledge with thanks the tecnical advice and services

given by the following concerns: The Atlas Mineral Products Company;

Bisonite Company,, Inc.; The Camp Company, Inc„ ; The Ceilcote Company;

Dasco Chemicals Company; The Dow Chemical Company, Plastics Department; Flintkote Company, Industrial Products Division; International

Pipe & Ceramics Corporation, Electro-Chemical Products; Tile Council

of America, Inc.

USCOMM-NBS-DC

TEST FLOOR NUMBER 10, QUARRY TILE WITH FURAN JOINTS AND BED. WITH THE

EXCEPTION OF A FEW HAIRLINE CRACKS IN THE JOINTS AND A SMALL AMOUNT OF

TILE IMPACT DAMAGE THIS FLOOR HAS PERFORMED VERY SATISFACTORILY FOR

NINE YEARS.

FIGURE 4