f

^2Z0h^lCiC: Ii:i<02MA2I0N OU BJILDIKCi llaTERlJiLS

?OE USE IE TEE JESIGII OF LO.-COST HOUSING

TISII 54

THE HETIOxIAL EJRSxiU 0? S‘(ExlH)iEtH)S

'Jxj ITE.0 STAi'xjS DiiPARuT'/lijiri.' OF COi-.iiVujrLCE

ilASHIEGTOH, 0. 0.

O(yto^oer 9,__19S7

RELATIYE RESISTAITCS OF FLOOR COVSRIITG ^LAPEHIaLS TO ABiL.SIOE

Invastigaticns ivare condacted to measure t'ne relative resistance to

o-trasion of various floor covering materials, ranging from tlie so-called

hard or stone t-'-pes to the soft or organic and fiorous types.

All of the tests v;er 3 made with the mod.ified Kessler machine. The

essential feature of this machine is a hollow shaft mo’xited in a vertical

position, 'Which may he rotated at co;istant' speed and is free to move up-

’"ard or dowiiv/ard. Tho lo\.er eiid of the shaft is fitted v/itli a cylindrical

foot, two inches in diameter, 'w»ith a one-inch hole drilled through the

center.

Four radial slots, one-cuarter inch v^ide, v.'Orj cut in the lower face

of the shoe to allov/ the ahrasivo, fed down through the shaft, to flow

continuously across th.e surface un6.er test. The abrasive used was 60 mesh

alimdum, fed at the ra.te of 3 to 4 grams per minute. The foot has a hearing S'orface of 1.83 sg. in. Means ware provided for vaiy/iiig the pressure

upon the foot. Loads of 4 s/4, S l/2, and 14 l/4 Ih. per sq. in., respectively, were used in tests.

The shaft was rotated at 100 rpirn. The test v;as rxi for t’'’enty minutes.

The loss in thickness was measured hy means of a di^al gauge reading to one thousaixdth of an inch.

Tests were made using a stoel and a wooden foot at each pressure.

The resuTLts showed that the relative resistance to ahrasio.a of the samples,

e-s indicated hy th-e loss in thiclcness, was dependent upon the nature of

the foot and the prassiure. (Soe Tahle 1) Consequently , a foot was provided -;.o carx’y strips of sole leather, and a vveighted average of the results obtained, at uhe three pressures was taken as a measure of the relative

resistance to abrasion.
0;.ie-tentl'i of an inch v/as taken as the availaklo thiclnioss of flooring

materials having a weo,raole thicloioss eqnal to or greater than that amount.

Host of the flooring materials tested fall vithin this class, their thickness ranging from l/8 in. to 2 1/2 in. Soma materials, however, such as the printed linoleums, do not have an available thickness equal to one- tenth of an inch. In the case of these materials the availe.hle tiiiclaiess

is determined hj actual laeasurement . The available thickness is limited

in the case ox the thicker flooring materials by reason of the fact that,

irrespective of the total thickness, the condition of the surface is the

govoi’ning factor. Under service conditions, the surfaces of floors are not

worn evenly, but in grooves, caused by concentration of traffic. It is believed that when grooves reach a depth of one-tenth of an inch, the flooring would require re-sxu'facing for proijer iriaintenance.

The weighted average was c-lculated in the follovi'ing mamier; ^he abrasion tests were raade at three pressures in the ratio of 1:2:3. For each

test the percent residual available thickness was calculated as the resistance of the material at that pressure. Credits of 16, 34, and 50 rospectivoly, totalling one hundred, and approximately in the ratio of 1:2:5 were allowed for tests at each of the pressures. As a result of the test,

at 4 3/4 lb. per sq. in. the percent residual thickness wa,s multiplied by

16; at 9 1/2 lb. by 34; and at 14 l/4 lb. by 50. The sum of those products

was taken as the weighted average. The weighted average became a measure

of the relative resistance to abrasion of the different samples based upon

tests at three different pressures using a leather foot. (See Chart I)

To study the effect of tempora.ture upon the resistance of flooring

materials to abrasion, samples wer ;; tested at room temperature and at 100°F.

The results are shown in Chart II

.

The resistance of flooring materials to abrasion, tested under wet and

dry conditions, is shown in Chart III.

Conclusions

The niodiiisd Kessler machine is suitab].e for measuring the resistance

to abrasion of a variety of floor covering materials.

The relative resista-nce to abrasion of floor covering materials is

dependent upon the nature of the foot and the pressure exerted upon it.

Using a leather foot and combining the results of tests at three different pressures, a weighted average is obtained v.Hich serves as a measure

of the relative resistance of flooring materials to abrasion.

Abrasive resistance is not directly related go iiardness. Some of the

so-called "soft" types of flooring resist a,brasion better than some of the

"hard” types.
Sa.ri"l3s of the saino t^^pes of flooring differ greatly in resistance to

aorasion. flie saiuple of VeriTiont marhle v/as nuch less resist-.nt tlia.n that

froai f eoi,i.33see. Linoleurn o,vA ruDher tilvO sauiples shovj a v/ido range i'l re~

sistai.ce, prohahly caused op conaitions of rflanufacture.

T’nere v;as no appraciahlo difference iu the resistance of flooring materials to abrasion at room temperature, as compared wirh tests conducted at

10C°F.

r^su.lts indicate that abrasion under vjet conditions is more severe than under dry conditions.

In selocting floor covering raaierials, the resistance to hbrasion is

an important f-.ctor, but othei charo.cteristics of the norbori'l should be

coiis iaered. Quietness, thenn-.l insulation, o.nd comfort mo.y govern tno

selection of flooring for certs.in uses. For example, gr-anite having a high resistance to abrasion vjouid not generally be chosen for use in a private d’oelling.

It should be borne in mind that the comparison of flooring samples

shov/n in Chart I is based upon resistance to abrasion cnl;r, mea-surod under

empirical conditions. Hesistance to ween- includes several fo.ctors besides

resistaiice to abrasion.

o
TalDle

Flooring ; Loss in Thiclaiessin Ihonsandths of an Inch.

le.tarial

s

"sy'1 HyTn.'"

Rress'-'n’e

: 3' ,l/2 Ib/in.^-

; 'Pros sure

»

1 14 i/d

pros sure

•

• STEAL FOOT

Liiioleoxa 10.0*'^^ 17.o(2) 23.5^^'

C 0 rk

* 15.5'"^' 17. 5^^) 17.5^^)

Asphalt • 13.5^^^ 23.o(-) 32.5^^^

Rahher

• 7.5(1) 11 . 5 ( 1 )

I'.Iaple ; 11. 21.0'^"^ (4) 25.5^

Man'ble

( 6

)

31.0 55.5^'^^ 70.0

; hOOLSh FOOT

Linoleum 18.5'^^ 161. 0^

Cork 1

( 5 ) 24.5 57. o‘®’ 95.0^"^

Asphalt ... .(4) lo.o IS.O^^'^

In \ 23.0

Rubber 6.0^^' 8. oil) 30.5^^)

Ma-gle n.o'®> 16.5(1>

Fiarble 17.0^^^ 25.5^^^ 38.0^"^^

Rote; The niuTibers in parentheses indicate the order of resistance to

ahrasion.

- 4 -
CHAHT 1 Relative ilcsisfance \o Abrasiori of Floor Covering AAaicrials.

(3a sed upon weighted average of tesb at three different pressures

4^, 9/4, end 14!^^ lbs per sq. inch respectively

Linoleum

Cork Tile

Linokum Tile

l^ubber Tile

Cork Carpet

0 10 20 30 40 50 60 70 80 90 100

Leather foot

60 mesh Aiundum

ZOOO lievolutions

Asphalt Tile

Oak- ordinary

Oak-qijgrkred

j Mopk - strip

j Maple- edge

j Fir - edge

IPine * edge

i Pressedivood

,1 Asphaltic-fdtl

ii base- painted / surface '

i; (jrar.ite

iix

ii lerrazzo

j i-ime- 7ho(

j! stone /k/>7/7. !’5andstone

! Quarry Tile

; i Slate

1

1

I Concrete

! Magnesite

Marble. Vf. Tenn

i

I

Loss

in

ThickTness

-

.Ool

r HA 2; i

i

2claii v'e \'^<z.'ar of V)\fTcrzru I'VxciU:''

g\-z, ar Ordmory

(2oom Tetrioerature and ot iOO^F ; 5 fee! Foot —

prof^sure on foot = Abrasive -A'i'^^durn

I 0 0 a o 1 50 n s 4% pound*; p<ii sq, inch

(3 - 4 <3 i O ms pxr rn inu : <2 )

Loss

in

Thicj^ncss

-

.001

C li/A 'USX li I 2.cia^ VG Wear of Difforzni A\aforic;Is uheri Abrjsi/e

\f> fo-d v\ith and wiThotjl Water

ibC

5t«Gj foot ^

'— ICGO Q_e.vo\uho ns Pressure on^foyf - 4*/4 pounds per sq in:h

V'/ntor Peed - PO cc per minute

Abrasive - Alundum (3“4c;rGms per iTiinuto

!vy n

*30

120

1 1C i

100

Qo

'7^

_1

W:

*1

D

Wet Abrasion

D ~ Dry Abrasion

fc o X w _

t.L- «

c — tro

aa

y>

o

CMoc

,J!i: V .4- ^ 0 ^ d

‘r _J

Cj -f