105
' 760

 

A PRELIMINARY STUDY OF
POINT! AS AN ADMIXTURE FOR
CONCRETE

M ‘0' '50 Dow 00 I. 5.
MW STATIW
S. W.Cufliu
1948

   

A Preliminary Study of Portite

as an Admixture for Concrete

A Thesis Submitted to

The Faculty of
MICHIGAN STATE COLLEGE
of
AGRICULTURE AND APPLIED SCIENCE

by
S. W. igrtiss

Candidate for the Degree of

Bachelor of Science

June 1948

THESIS

0 C1.»

(”WW

"The question ugpermost in the minds of engineers
and contractors is whether the use of admixtures is

the cheapest way to secure the desired results.”

Edward E. Bauer

206024

’1’
Introduction

The'use of cementing material dates back to the time of
the ancient Egyptians, but portland cement, as known now, is
a comparatively recent discovery. The first modern develop-
ment of cement began in the early 18th century. In 1&24,
Joseph Aspdin, a bricklayer of Leeds, England was granted a
patent for a product he called "portland" cement for its
resemblance in color to a building stone found on the isle
of Portland.

31th the discoveries of Aspdin and others, by the middle
of the 19th century portland cement was advanced to basic—
ally the same product it is today. It was first imported to
this country in 1e65, and manufactured here shortly after that
time. Since then the manufacturers have concentrated their
research on new methods of production. The result has been
lowered costs of production and lowered selling prices, thus
greatly increasing the use and importance of concrete.

Originally, strength was the major consideration in
good concrete, and the concrete mixtures were designed with
that aim predominate. However, as concrete was adapted to
more and more uses, other requirements grew in importance.
Today, the durability, he worhability, and the economy of
the concrete are considered fully as important as the
strength. Strength, of course, must always remain a very
important design factor. A means has been sought, therefore,
to provide the most economical concrete mix that includes

the maximum durability and worhability without sacrificing

the desired strength.

Research on this subject in the last decade led to the
investigation of the use of admixtures in Concrete. it the
cresent time there are many admixtures on the unrest.
nether than attenpting to describe all admixtures produced,
the author has chosen to ianstigate the possibilities of
Just one. It is the purpose of this thesis to conduct a
preliminary study of the general practicability of Fortite,
manufactured by Hooper ?roducts, inc. of Kew York City. in
View of the limited time and facilities, no attemyt will be
made to verify all the claims made by the manufacturer con-

cerning the performance of Portite.

'1. w-

':i'.§"";‘ 75"”; I“ ; Gfl‘a:‘-'.?."'J‘
3"-k‘1aé—‘i vU-‘o 6-D J-J. Daub L uJ.

A brief backgrOlnd of the subject at hens is in order
to give th; reader a broeuur understanding of the purpose of
this thesis. The feliswing deflnitien is used to clarify the
meaning sgplied to acmixtures. An aimlxture is defined as a
substance other than pertlsnd cesent, aggregate or water that
is used as an ingredieit for concrete.

Usually the purgese of using an admixture is to medify
the properties of the concrete in such a way as to case it
more suitable for a given job. Unuer certain conuiticns, the
use of a suitable admixture may is;srt cesireeble character-
istics which cannot be secured as economically by other
methods. It is cmyhusizcd, however, that no smciut or kind
of admixture should be considered as a substitute for the use
of structurally sound well—graced concreting materials or
good concreting practice.

From the time asmixtures were first yrcmcted for use in
concrete, two schccls of thought have arisen regarding their
value.

many engineers argue that admixtures of any form are not
worthwhile. They point out tie fact that the mixer Operator,
or even a special hand, must tsse the tise to add tie sub-
stance at the mixer. In additiun some means must be made to
store, deliver the material to the ccustructicn site, and in
some cases, even prepare it in the prcyer form before t csa
be used. Further, there is the basic fact that it tsses

sddlticnsl money to buy the admixture.

The hosting engineer points out EJd fact thct many
admixtures tend to coercoso tho ultlmsto strength of the
slab. Since strength hill sizays ho tJo sojor assign factor,
this argument receivos justifiobly strong suggort. in orucr
to be truly practicable any admixture that reduces tho strongth
of tho hordonod concrete must offor sufficient aGVantugcs to
warrant reassign of ths mixture to roach the desired strength.

The idea of increasing the general utility or life of a
concrete structure, or of dccrcasing the amount of labor
necessary in the molding or finishing process sounds like a
vague promise to many field engineers. Anyone who has over
sorted with an experienced concrete construction engineor is
well aware of his inherent suspicion of new building technique
dovelOped in the laboratory. This suspicion is readily
understandable, whom one Cousiuors the fact that a good field
man works with so many different mixes, he feels ho complstoly
understands concrete. This prejudice has long been a strong
obstacle to admixtures.

Probably the greatest single objection to admixtures,
however, comes from the group that considers admixtures a
substitute for cement or a proper mix. It is true that
additional cement can provide many of the advantages offered
by admixtures. The general effects of increasing the cement
ratio are: increased strength, workability, imparmesbility,
frost resistance, hast development, volume change, and in-
creased surface erasing if the placed concrete receives much

manipulation.

It can readily be seen, therefore, that an increase in
cement content would not always be entirely satisfactory. in
admixture, on the other hand, may be beneficial in one or more
of the following ways; it may improve the texture of the mix;
it may have cementitious progerties of its own; or it may be
poszolanic. It is with the first of tnese refinements, this

hesis is most con erned. The most common textural improve-

6'

ments are achieved by increasing the fines or by increasing
the entrained air.

The apparent result of the improved texture is increased
durability, workability, homogeneity, and waterproofness. The
ncei for increased durability is most urgent in concrete that
is exposed to severe climatic conditions.’ In northern states
many concrete pavements, for example, have undergone surface
scaling caused by severe frost action, by direct applications
of flake calcium chloride or rock salt to remove ice, or by
repeated applications of granular materials impregnateu with
these salts. Increasing public demand on his way departments
to keep roads open to traffic and to provide safe traveling
conditions during winter months has in recent years led to
widespread use of such salts, a practice which has been pri—
marily responsible for the derelopient of this scaling prob—
low.

In the last few years a comprehensive prograsci'PeSBaPCh
has been carried on to solutions to this situation. A means
was sought to develop concrete which could hev: nigh resist—

ance to severe frost action, and immunity to the action of

W
“b“

sodium chloride and calcium chloride as Commonly engloyou on
rural roads and urban streets. It has been conclusively
demonstrated that concrete having excellent durability to
withstand such hazards can be produced with air-entraining
agents.

An alr-entrnining agent, when combined with assent, meter,
and aggregates n the process of mixing, introduces into the
resulting concrete minute and well—distributed air bubbles
and interts other characteristics not found in norms concrete.

The need for curable concrete is not, by any means,
limited to pavements or to fros and salt resistance. Dur-
ability of concrete is effected also by alternate netting and
drying, heating and cooling, capillary water, deposition of
salts by percolating water, dissolving of certuin procucts by
the percolating water, and by tne dissolving of the cement by
certain acids. Ehe water-cement ratio of the six influences
the persecbility of tae pesto, and, in turn, the durability
of the concrete. An a‘rixture, therefore, that can effect-
ively reiuce the water~ccmont ratio of the mix, all other fnc~
tors being equal, will definitely increase the durability.

At times it may be desirenble to increase the workability
of a concrete mixture (e) if the concrete is hersh because of
aggregate grading or aggregate characteristics; (b) if the
concrete must be placed around closely spaced reinforcement
or in difficultly accesible sections; (0) where Special nouns
of placement are required, such as with tremie or ranging

methods. The desired results may be obtained by redesigning

-7...

the mix or by tic use of admixtures.

Aitlough air~entraining agents are considered primarily
for use because of their effect on the durability of concrete,
their effect on the woruobility of leaner leoS is so pro-
nounced as to merit sention as woruebility agents. The
incorporation of numerous soall veil-distributed air bubbles

n the concrete acts as a lubricating medium, generally
increasing the "fatness“ of the mix and wareedly imyroving
the placoability of otherwise harsh concrete.

Corta“n organic coiyounus or mixtures increase the
slump of concrete of a given water content and, therefore,
gecoit concrete of a given slump to be Lroduced at a reduced
water content. These agents, in many ccses, do much to
increase the morguoility of tie mix.

ldmixtlres can variously be used to increase homogeneity
and watcrgroofness; and to cecrease porosity and cosorgtion,
bleeding, one segregation. These factors were grouped
together because of the general correlation to one and an—
other. In turn, these factors are often related to general
durability and workability. In Some cases even a well-des-
igned mix fails to provide satisfactory control over the
above factors.

Basically, these admixtures isprove the mix by increas-
ing the density of the concrete. They may accomplish this
by increasing the fines, by decreasing the water content, by
increasing the fluidity witnout increasing the water, or by

-a cachination of these techniques.

From the proceeding remarks, it can resuily be seen
that admixtures can be an asset to concrete construction if
used intelligently. The use of an acmixture may increase
the cost of the concrete. Therefore, even though a given
admixture may produce a desireeble effect, the value of that
effect should be weighed against its cost. fioreover, the
effect of a given admixture can usually be obtained, at least
in some degree, by other means or by other admixtures.
Hence, whenever possible, the cost of an admixture should be
compared with that of alternate materials or methods for get—

ting the desired result.

Description of Portite

Portite is‘a reddish brown liquid of about the consis-
tency of light machine oil. It is readily soluble in water,
dissolving with very little agitation. than rubbed between
the fingers, it feels very much line liguid soap. Drying
somewhat sticky, it is readily removed with water. it is
somewhat alkaline and has a slight odor not unliae that of
fish oil. This odor is not noticeable in the finished con—
crete, and it does not discolor tJe mix.

The following is a description of the auvantages of this
product as claimed by the manufacturer. is mentioned before,
the author has mane no attempt to substantiate all these
claims. The author has merely attempteu to formulate an
unbiased prelimiiary study of this abent.

Portite is described by hepger Products, Inocryorated,
its manufacturer, as a stable, neutral, organic compound,
made and supplied as a concentrated liquid. In the recom-
mended amount of 4 ounces per bag of cement, it acts as a
physical and disyersing agent to produce highly homogeneous
cement mixtures and to bring out the best qualities inherent
in any aggregate.

This product does have a definite tendency to reduce the
required water content by increasing the Slqu of a normal
mixture. Reuuction of the water-cowent ratio is reCognized
as being conducive to concrete introvenent.

One of the advantages of a reduced water content is a

reduction in the yercentabe of shrinaage. Shrinaage may be

-19-

 

Portite—iwproved concrete being placed for floor of

new garage to house U. S. Post Office trucks at

Yonkers, H. Y.

an important consideration in the design of large sections or
precise work. In many cases, consistently smaller shrinhafie
ans greater climatic stability would persit fewer expansion
Joints in the design of the structure.

Concrete, with the subject added, does have increased
workability from the workman's Viewyoint. The six has a
Jelly—liae agpearance or buttery consistency. All tests made
in this study were wit: a constant waterucesont ratio for the
sake of comparison. It was noted, however, that the water
content very well could have been rouuceu in the mixes con-

taining the admixture without less of wornabiiity. The

-11-

‘4‘
(.-
N

were from 1; to inchus greater tlxan tic e of the

(I)
*4
t
I...

.- 1
b4!

3 " ' I.
\"- ?:-""-'_ ‘ "VJ-11",
1.341 4-:LA~£- a..J...n.'uL4. ~30

The ficwarh Testing L5bcr5tpries, 35555:, 355 Jersey,
vogtrtcd definite air entr5inwent ch5racteristics in their
tests 551 exauinatiun of Port4t5 '5? Huyger Pruuucts.u The
entruLh eat of air nauld b5 55 i5y0rt55t coutrib5ting factor
to the incrtu5eu wotzability and other refinement5 to concrete
wrought by this 55t55151.

Anothc: 51¢55t5bI is gre5tcv homogcmetty with no dusting

ta .5 .5 , .‘ -L ‘ 1 1",. . , 1 - t. a. ‘ ~-. _.~.‘-,. .p- ‘A r a! ' .' a ‘ It a. 1.
UL tzU conccutc 55?;555, puttuf tuttcnal phystcul buluube,

P-
PJ
r4

and Vi"tu&l y no 5 gregzt5*n. The test cylinders 5555

f?!

connection with this report 555555 to verify this. After
rupture, the internal structwre of the cylinuers was closely
examined un5er a magnifying glass. It was found that the
“105 containing the test liguid 550555 more uniform fie-
pusits of fines on the 151J3r sec ctions 01 005 5-6 aggregate
than in the normal mix samples.

when required, absolute int egr5l “5ttc’ruofhu s is
015155d by the use of 8 ounces of} artite per b5g of cemcut.
It is 5155 r51utea to have the progerty of unusual auhesion
to brick and old concrete, but these cha acterlstics were
b w; 11d the 550; e of tilis the~5 5. They were mentioned merely
to include he full range of its 5553.

But more impor ant to tile builder are the statements
hat the agent is uun-cuntam mating, mun—irritating, nun—
toxic, unreactive, does not affect the tl5e of set, and has

no bad after effects. Also, the Newark Testing Laboratories

reported that bond to steel was apyrooiably increased, while
absorption and porosity was definitely decreased.

Regardless of the advantages of an aauixturo, a con-
tractor should first determine its economy of age. The man»
ufacturer points out the economy of this groouct by emyha~
sizing simplicity of use and high effecioncy. It entails no
special handling, is concentrated in form, and stable in
Further

storage. savings are made by its ease of_ose

         

vvvv
....

Driveway at Refined Sugars aha Syrups plant at
Yonhora, E. Y. Local ground and chemical con¢
ditiona had always caused serious surface diffi—
culties. Portiteuimproved concrete laid in 1846,
showed no signs of deterioration over one year

later.

~13~

increased ease euo steed of glocement of the concrete, and
easier and quieter finishiog. Further discussion of the
economy of the agent may be found farther along in this
report.

Because of unfortunate results in the gust, it would be
wise to investigate the effect of any actixture considered
for use uyon the ultimate strength of the structure. Irre—
gardlose of other beneficial changes an agent may give to
concrete, if it requires counter-active incrooSos of cement,
the resulting cost may make its use prohibitive. It is for
this reason the author determined to check the effect of
Portite on the cowyreeeive strength of the batch. Tue fol—
lowing portion of this r>yort is devoted prioerily to single

strength tests.

-14...
Laboratory Tests

The laboratory tests made in connection with tsis stuuy
were eomlaritively simple and brief, 5 nce this use a lrelis—
inary stuiy aimed at investigating the fracticability of this
product.

Previous to the strength test a single ca;erisent was

I'

conducted showing the presence of and general effect of air
ntraining rroperties. Similar sat les cf the sanu, used as
fine aggregate in the stronoth tests, were placeu in three
identical boaters. though water was auaeu to all three
boaters to wane a harsh, seal-mobile mixture. Portite was
cases to the second and third beahers, tits suction agplieo
to the second beater to withdraw the air. is a result; the
first mixture was harsh; the second mixture, containing sanu
and cater plus the aunixture minus air, was also harsh; but
the third mixture, Containing sand and water plus the assis-
ture with any air it produced remaining, was noticeably more
plastic.

Thus, it seems that entrained air in sand improves its
placticity. It would seem that this action is due to a re-
duction of particle interference. This improvement would,
similarly, react Fri arily upon the sand constituent of ccn~
crete. It is readily seen that lean sixes will entrain cor-
respondingly more air than rich sixes since the fine aggregate
is in relatively high yro;ortion to the total. Therefore,
as the cement content increases, the advantage gained by the

use of an air entraining agent decreases. The need for

improvement in ooasistency is decreased by the action of tne
sur;lus cement, while the per entabo of air entrained decreases
“itll the decrease in total :rogortion of sand.

Conse oeatly, that: so iew tes cylinue rs are made, it is
desireable to maae them of a near~avorage richness. in a
problem of the s«rt the: e caa be only txu variables. One of
the variables is the constituents, naturally the other is the

esult which would be the dependent variable. '

Since this admixture was adv-*rtised as a mater-reoucing
agent, was known to entrain air, and the comparative strength
was the unanown; it was de cic oi to vary only the quantities
of admixture used. A reduction of the tater—cement ratio
will enerally lacrosse the stroegth, bat wany air-entrain—
ing agents tend to decrease that important item.

Two sieve analyses were conflicted on both the fine and
coarse aggro gates,a ad an avc‘a‘e value «as taaen. An aver-
age of two dryuroedod unit weight weasareaents gave a unit
weight for sand of 107.5 pounds 1er cubic foot and a unit
weight for gravel of 131.5 ponies per cubic foot.

Severe 1 trials 5110VJGd that the mix that would most
nearly aprroach a theoretical yield of 5.5 bags of cement
per cubic yard as well as good g'ading was a mix of lzfiégoi
by volume with a water-co.ent ratio of eibut tenths, or a
mix by weight of 1:2.86:3.51 with a water-cogent ratio of
fifty three one ha.nc rodths.

One slump test was made for each differcht percentage

of admixture. flack cylinder tested was made in a seperate

-16...

batch to serve as a check on errors.

Since the degree or woraability varies to Some extent
with the mixing tise, it was isportant to seey the mixing
time as near constant as yossible. Each batch was mixed by
hand for 2 to 2% minutes, at which time the workability
seemed to remain constant.

All of the aggregate needed for the test was spread out
and allowed to air dry over night. Corrections were made for
the moisture contest of both fine and coarse aggregate.

The results of these tests appear in tabular form on

the following pages.

-17-

 

Qate

___Materia1

Fine_Asanesate

 

 

April 22. 1948

 

$128 of shaker
Time of shaking

Maghine

 

115 minutes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

weight of sample 1000¥grams
Total Total ‘Total Fractional
Sieve weight percent percent percent
retained retained passing passing
First Sieve Analysis
f 4 7.8 gns. 0.78 % 99.22 % 10.01 %_~
__§ 8 107.9 gms. 10.79% 89.21 % 19.54 2
_J# 16 501.5 gms. 50.15 % 69.87 % 20.95 %
#'50 510.8ggms. 51.08 % 48.92 % 50.18 E
i 50 812.6 gms. 81.26% 18.74_z_n___16.55;£__
# 100 975.9 gms. 97.59 % 2.41 2 2.41 %
Passing 1000.0 gmsii 100.00% 0.0 % 0.0 %
Second Sieve.Analysis
# 4 4.6gms. 0.46 % 99.54 % 10.57 %
f 8 108.5 gps. 10.85 % 89.17 % ¥l§.92 %
# 16 297.5 gms. 29.75 % 70.25 % 20.99 %
gfi 50 507.4 gms. 50.74 % 49.26 % 29.54;£__
# 50 800.8 gms. 80.08 % 19.92 % 16.95%..1
# 100 970.5 gms. 97.05 % 2.97 % 2.97 z ,
Passin 1000.0 gms. 100.00 % 0.0 % 0.0 Z
Average Sieve Analysis
__# 4 6.2ggms. 0.62 % 99.58 % 10,gl.z _
# 8 108.1 gms. 10.81 % 89.19 % 19.13 %
_J§ 16 299.4 figs, 29.94 g 70.063_____20191;5__.
# 50 509.l¥gms. 50.91% 49.09 % 29.76 %
# 50 806.7 gms. 80.67 2 19.55 % 16.64L%
# 100 975.1 ggfi. 97.51 % 2.69 % 2.69 z
Passing 1000.0 gns. 100.00 % 0.0 % 0.0 %

 

 

 

 

~18-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

m W
Date April 22, 1948
__gzpe of shaker flannel
Time at shaking 25 times
‘ Weight of sample 3000_grams
Total Total Total Fractiondl
Sieve weight percent percent percent
retained retained passing passing
First Sieve Analysis
1 a 590.0 gm. 15.05} 86.97 5 20.42 5
—3Q n 1005.8 gas. 55.45 1 88.55 x 95.54 1
1’9 0 1785.8 ms. 5849 1: 41,21 1 99,20 2 l
# 4 2971.4 gm. 89.05 s 0.85 x 0.95 1
Second Sieve Analysis
1} 595.5 am. 15.12 5 86.88 5 16.18 x
374 a 879.1 gms. 29.50 g 70.70 x 25.85 5
1/ 2 I 1654.0 gins. 55,35 5 4_4_,:B7 5 4.5.12 1
{A 4 2987.l§ms. 98.90} 1.10} 1,10 5
Passing 5000.0 w. 100.00 5 0.0 x 0.0 75
Average Sieve Analysis
1-" 392.2 gms. 13.07% 88g93 5 18,81 2 p
7/5 a 941.4 3193. 51.58 5 88.62 5 25.5613
”9 ' 1708.9 Es. 56.98 1 45404 5 42.92 g _
.5 4 2969.2;525. 88.98 s 1.02 5 1.02 i ,
Passing 5000.0fl. 100.00 9 0.0 5 0.0 i

 

 

 

-13-

Characteristics of mix

Cylinder number

Cement, grams
Fine Assresate, grams
Coarse Aggregate, grams
Tater, grams

Portite, grams.

Portite, ozs./bag

Average Slump, inches

iorkability

Segregation

Distribution of Aggr.

(after breaking)

Surface of cylinder

(after set)

"Pulling" of gravel

(in rupture)

5,750

1,086

Good

Slight

Varied

Smooth

Kormal

2,000
5,730
7,020
1,006

6.?

Very good

hegligiblo

Uniform

Smooth

Normal

5 & 8

Very good

negligible

Uniform

Smooth

Hormel

-24-

Compressive Strength

Cylinder Portite/Bag Force
7 day strength

1 -0- 52,590
2 -O- 51,930
3 4 025. 58,990
4 d " 56,039
5 8 7 04,000
6 8 7 85,500
Estimated 28 day strength

1 ~O- 78,750
2 -0- 70,530
3 4 025. 87,000
4 4 " L4,SJJ
5 8 " 56,000
6 8 " 97,750
Average 7 day strength

1 a 2 -0~ 51,750
5 & 4 4 055. 57,000
5 a 8 8 n 64,750

Average estimated 28 day strength

5 a 4 4 02.. 85,500
5 a 6 8 n 90,875

lbs.
8

13

lbs.

1!

lbs.

f!

1'

lbs.

"

Strength
1,857 p.s.i.
1,811 "
2,052 n
1,580 n
2,266 “
2,517 "
2,880 p.s.i.
2,717 "
0,078 "
2,882 "
6,395 "
6,478 "
1,834 p.s.i.
2,020 "
2,285 "
2,802 p.s.i.
5,050 "
3,458 "

Conclusions

Kituin the scoie of these tests Cohuucted as a {art or
this regcrt, the agent shewed sefficieut merit to warrant
further stuuy of its cagabil-ties. It net only did but re-
duce the ultimate strength in cemyrcssion, but actually
siewed an increase for this ,articular six. The mixture,
even without any aueitieh of admixture, was designed by tro—
ger, accepted methods. The author does not believe that any
admixture shtuls be used as a substitute for good design
techniques.

Zith the additienal strength tanen into Ceasiueratiou,
the results of a test made with reuucel water-content and
reeuced cesent ratio would be the next natural step in the
investigation of the Iracticeeility of this product. it
would be interesting, indeed, to See if the normal strength
and the added we Lability and reduced water content Could
be maintainei in a leaner mirture. That is, replace a snail
amount of cement with the admixture.

A theoretical example of the cost of using_Portite ap-
years on the following ,age. It woulu be iugossible to ob-
tain accurate cost figures without detereluiug the size and
location of the were as well as the cost and availability of
all ingredients. Transgertation costs figure so highly in
the cost of both the cesent and tee aggregate only a cougar-
ative figure can be obtained for the general ctst of the
agent. It is readily apyarent, therefore, that under one

set of conditions, only, are these figures correct.

A

-gfi-

Illustrative Example

Yield

Cement, 1 secs of 54 lbs. 94

0.4:“) cu. ft.

5.1 x 62.4w

Sand 84 x 2.88

:l.6£34 " n

2.65 x 62.4

Gravel 54 x 5,51 3.1.058

fl 1!

Eater, 6.7 gal. 6.7 x 5.55
62.5
Absolute volume of one—sacs batch

Quantites Required for One Cubic

Cement ; 27 .7. 5.42 sacks 3; 1.55 b‘ol.‘l
4.566
Sand 3 5.42 X 9'4 X 2.36 3 1,457 lbs.

 

Gravel :. 5.42 x 94 x 3.51 3 1,788 lbs.
‘53th z 5.42 x 607 X 8.33 z 502 1135i

Portite';|5.42 x 4

Example Costs

;o.eee " n

4.556 n "

Yard of Concrete

:3 0.729 ton

:_0.854 ton

:. 56.5 0.3. gal.

;_21.68 023.

Cement :_ $5.00 I 1.55 2. 55.55 per cu. yd.

Sand :2 $2.00x0.725; 231.46 It
Gravel ; $32.25 x 0.504 3 532,93, "

Total without Portite :_ $7.46 "
Portite ;, 50.025 x 21.60; 50.50 "

Total with Portite ' ‘3 57.96 n

I?

'1

fl

'1

1!

In the above illustrative example, the cost of

Portite, used in 4 ounces per sack doses, would

be $0.50 per yard or 6.7% of the total cost of

all other ingredients.

r23

Illustrative Example

 

 

Yield
Cement, l seca of 54 lbs. - A. 94 2 0.486 cu. ft.
3.1 x 62.4
Sand 2: x aestzlbe‘l " n
2.65 x 62.4
Gravel 94 x o 51 ;.1.be8 " "
Water, 6.7 gel. 6,? x babe :_U.888 " "
62.5
Absolute volume of one-seek batch :_4.806 9 ”

Quantites Required for One Cubic

Cement :. 2'? .1: 5.42 sacks :2. 1.33 bbl.
4.866
Sand 3 5.42 x 94 X 2.66 :1 1,457 lbs.

 

Gravel _._._ 5.42 2: e4 2: 3.51 ; 1,788 lbs.
eater .-.-. 5.42 x 6.7 x 8.33 3 2202 lbs.

Portite ::'. 5.42 x 4

Example Costs

Yard of Concrete

"' ‘EJO lb 0
u

3 0. 728 ton

3.0.394 ton

36.3 U.S. gal.

: 21.68 023.

Cement .: 45.00 x 1.55 .: t5.89 per cu. yd.

Sand 3 22.00 x 0.7229 ; 31.4.5 :1

Total without Portite :_ $7.46 fl

Total with Portite ' ‘3 $7.96 N

1!

H

fl

1'

In the above illustrative example, the cost of

Portite used in 4 ounces per sack doses 'would
I o

be $3.50 per yard or 6.7% of the total cost of

all other ingredients.

This study is by“ no .22.“... 22 cos; le te int": stl aetion of
the subject. On the basis of the C’"TaCtv£lgClC of fortite
as demonstrzltei b, test or by obs-2vetion, however, a 1e2
general uses of the product present these elves.

The advantage gained runs in an inverse grogortlon to
the richness of the mixture. As a converse theory, it is to
be espected that the agents ith tell be a desires ble adeltion
to a lean nixtll e that e"ulblte harsh clarecteristics.

The water—r cuuc -ng i‘actor coulu be put to good use to
reduce bleeding and to decrease the enclnt of time required
for fin shing were. One contractor stated that this water
reduction sale it possible to trowel-finish floors 2 to 23
hours earlier than before. On an eve'age xour for that
particular structure that meant a saving of apyroximstely
t 1.10 per yard in concrete finishing time.

The reduction of segregation is most iwtortsnt on these
Jobs where chutes are used. This can mean an styrecleble
lowering of: .andllng costs. Further, conside‘eble effort
can be eliminated on intricate form pours by the'increaseu
workability.

The reader will 1 nd no evaluation of these qualities
in the theoretical exasyle. Ho two Jobs would present the
same difficulties, so no cosysrison is possible in the time
allowed. The author suggests consideration of the use of
Portite in he danger of segregation or excessive labor

sts aha tine oelays on fifllQUllb were. If subsequent

tests show that this admixture is a consistent elr—entrelning

-;.";t-'

agent, its field of use could be broadly ergauuca. It is
wholeheartedly recommended, therefore, that tho subject of
the air-entraining characteristics of this a5out be Considered

as a worthwhile future thesis.

Bibliography

American Concrete lnstitete Journal
Volume 43 June 1344
Volume 41 Seyt. 1344
Voluge 41 Nov. Aoee

Volume 42 June loco

American Concrete Institute aanuel of Concrete Inapection

J. 1:)". iLb‘lly’ 00mm. 611

Cements, mortars and Concretes zyron S. Felt
Plain Concrete Edward 2. Bauer

Principles of Plain and Reinforced Concrete

3. Probst

An Introduction to the making and Testing of ?lain Concrete

H. E. %V13 8". G. E. Troxell

Construction Cstimetee and Costs H. E. Pulver

Portland Cement Association Bulletins

No. H3 1e

30. ST 53

Bibliogreghy (Continued)

The Bleeding of Fortlenu Cement Paste, Aortar and Concrete

To C. PUWGI‘S

notoriels

The Fortlte used in this exyeriment was furnished by
Fortite Division of Hopyer Products, Inc., 12 best elst
Street, Row York 17, New York, through the courtesy of or.
Edward T. Campbell. All cement and aggregate wag yrovided

by the cement laboratory of Lichigen State College.

 

 

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h a. I . u . y n . "a W 4 L! II. N IIIII. . . F III!

ROOM USE ONLY.

 

 

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