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THE USE OF ASPHALT AS A FILLER

FOR BRICK PAVEMENTS

A Thesis Submitted to the
Faculty of
MICHIGAN STATE COLLEGE
OF
AGRICULTURE AND APPLIED SCIENCE
.by

Martin H. Strasen

 

Candidate for the Degree of
BACHELOR OF SCIENCE
June 1929.

 

CONTENTS

£_a._g_e_
Acknowledgment ------- - .......... --- .......... - ......... -- 1
A brief history of the use of asphalt-— .......... - ....... 2
Purpose of this thesis- ------- - .......... - ....... - ...... - 4
A comparison of the three main types of filler used ...... 5
Observations of Ohio State Highway Test Section ---------- 9
Devices used for application of filler ------------------- 11
Preparation of the test section ------------------------- - 13
Description of apparatus used ----------------- - -------- -- 15
Data of tests performed----- ----- ---- ----------- --------- 21
Results of tests -------------------- ---- -------- --------- 25
Conclusions drawn from tests--- ------------ ---- ----- ----- 29

Conclusion --------------------------------- - ............. 31

. {'J.'$.-"r' A)
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ACKNOWLEDGMENT

 

I, hereby wish to express my appreciation and thanks
to Mr. E.A. Finney for his advice and Whole-hearted aid
which he has so willingly put forth.

I also wish to thank the officials of the National PaV1ng
BIICK Association for their support. Mr. Schlessinger for
giving this thesis so much of his personal attention. mr. Watts
and Mr. Gunnell for the interesting and helpful trip to Columbus
Ohio. And also for all of the pamphlets which they furnished
pertaining to the subject.

Much of the success of this thesis has been due to their
efforts and I hereby thank them again for the interest which they

have taken.

2.
A BRIEF HISTORY OF THE USE OF ASPHALT.

The use of asphalt can be traced as far back as 3000 B.C.
to the pre-Babylonian inhabitants of the Euphrates valley.
These people, known as the Sumerians, were skilled in carving
and decorating stone, and in the making of their statues asph-
alt was used to cement the eye-sockets in place.

The early Egyptians used the asphalts for preserving their
dead rulers, by wrapping the bodies in cloth and coating them
with liquid or melted asphalt. These preserved bodies are known
as mummies, and at one time the words "asphalt" and "mummies"
were synonymous.

The Babylbnians also used the asphalt as a means of holding
brick to-gether in the building of walls around castles and
cities. They also used the asphalt-filled brick pavements and
it seems peculiar but the idea was not tried again until late
in the nineteenth century when stone-block pavements were con-
structed using asphalt as a filler. There are still examples of t
the Babylonian brick pavements still clinging firmly tn-geth-
er.

And so on to the present time asphalt has been used to a
great extent and for a variety of purposes. In 1917, 1,586,

105 tons of asphalt were used in the United States.

Thecchief use of ashalt at preseht is for road building
purposes, that is for, Sheet asphalt pavements, asphalt-block
pavements, bituminous macadam, bituminous dust-laying oils,

filler for joints, and filler for brick, stone-block, and wood-

 

'

block pavements.

Asphalt is also used quite extensively in construction
work for, asphalt mastic flooring, roofing fabrics, water
proofing, sheathing, and insulating purposes. More and more

is being used every year indicating its importance in modern

industry.

4.

PURPOSE OF THIS THESIS.

The purpose of this thesis is to determine the effect
of heating the brick prior to filling the openings with the
asphalt filler. A comparison of the pre-heated brick and the
cold-poured brick will be made, as to, effect of penetration
of the filler into the openings, adhesion of filler to the
sides of the brick, ease of application of the filler, sur-
plus of filler left on the surface, and the amount required

to pour the section.

JI-zl-

 

 

A COEPARISON OF THE THREE MAIN TYPES OF FILLER USED.

There are three main types of filler which have been used
for brick pavements namely, sand, cement grout, and asphalt.
The only purpose for which the sand was used,it seems, was to
fill up the small openings between the bricks in order that
the brick would not shift, The sand did not even serve this
purpose adequately as the traffic passing over the brick jarred
the brick to such an extent as to force the sand out of the
cracks, the wind then blowing it away. It was also discovered
that a substance was needed which would prevent the water from
running down between the bricks for water underneath the bricks
would freeze and cause the brick to heave and ruin the pave-
ment. Cement grout was tried and seems to have served its pur-
pose in a few cases as can be seen from an inspection of some
of the grout filled pavements ten to twenty-five years old.
These cases are rare however, for most of the grout filled
pavements show many bad spots along their route. The cause
ofvthis failure can be traced directly to the expansion and
contaction due to changes in temperature. From an inspection
of a group of grout filled pavements I have noticed that there
is a tendancy for the pavement to buckle or pile up at some
point or points. At Howell Michigan, for instance, the grout
filled brick pavement buckles at the three streeet intersections
from a distance this appears as though it is simply the crown
of the intersecting streets but upon close inspection it will
be found that considerable buckling has taken place. There are
numerous cases identical to the one at Howell, Plymouth, Detroit,

Ypsilanti, and Ann Arbor all have existing examples of buck-

5.
ling. This buckling naturally leaves a bump and also causes
the grout to crack away from the brick, allowing water to
seep down to the subgrade and again heaving is obtained by
frost action.

An interesting method of using grout filler came to my
attention while at Columbus, Ohio. The method consisted of
laying about four hundred feet of grout filled pavement and
then laying a strip of fifty feet of asphalt filled brick.
The strip of asphalt filled brick being layed to take care
of the expansion and contraction due to temperature changes.
All of the modern layed brick.pavements, that is, the section
between car tracks, are built this way in the state of Ohio.
It seems to be a method which could be used successfully for
brick pavements in cases where the engineer insists on using
the grout filled type.

At the present time the use of asphalt as a filler has
become very prominent. The pliability of asphalt allows for
expansion and contraction and it also serves its purpose of
making the joints water tight. Up to the present time there
is one objection to the use of asphalt filler, however, and
this is the trouble undergone with the application of the
filler to the brick. Due to contraction upon cooling the
filler recedes into the spaces between the brick leaving
the space only partially filled. A second application is
therefore necessary and with the second application a sur-
plus of filler is always left on top of the brick. Of course

this surplus varies and if extra care is taken it can be

7.
cut down to some extent but not entirely eliminated. There
are two big objections to the surplus, first it leaves the
road in a very slippery condition. One section of asphalt
brick pavement near Columbus, Ohio, for instance, has large
signs erected along its route stating "Danger, this road
very slippery when wet." There a surplus of asphalt filler
is noticeable and numerous accidents have resulted with a
loss of several lives within the last year. The second ob-
jection is that the traffic passing over a section of pave-
ment having a surplus of filler will pick up the surplus
and deposit it in blotches or bumps on the road. There are
two main objections to the picking up of the filler. When
the filler is_picked up either a part gr all of the filler
is drawn out of the cracks and its chtef purpose taken away,
for water will seep in and cause frost action to heave the
pavement. This conditeon was readily noticeable along the
over filled section at Columbus. The second objection is
the forming of the blotches, for in time a bump will build
up and the trucks passing over this bump will break the
pavement. A rough spot soon developes and the water can also
seep through and cause heaving.

The relative cost of grout and asphalt filled pavement
show asphalt to be the cheaper. Some seen to think that the
added cost of heating the filler makes the cost of asphalt
greater but they forget that the grout must also be prepared
before it can be applied to the brick.

Not only its effectiveness as a filler but also its sal-

8.
vage value must be considered in choosing a filler. In most
cases grout filled brick have a very low salvage value while
the asphalt filled brick can be readily cleaned and relaid
for another pavement if desired.

Often times a crack will appear in the pavement after a
year of traffic,due to stresses in the base, this can remi-
died readily by taking up two or three layers of brick, fill-
ing the crack in the base, and relaying the brick. Practically
no disagreeable hindrance to traffic is encountered. With
grout filled brick the job would be a much greater one.

Another decided advantage with the use of asphalt filler
is that the traffic can drive over the road two or three hours
after it has been poured. With grout ten days is most generally
allowed for the grout to set. Flint, Michigan layed a section
of asphalt filled brick pavement through the center of the city
during the summer of 1928 and in this case it was necessary
to have the road open as soon as possible. Asphalt filler

added greatly in the solution of this problem.

9.
OBSERVATIONS OF OHIO STATE HIGHWAY TEST SECTION.

During the course of the summer of 1928 the Ohio State
Highway Department built five and one-half miles of brick
pavement using only one application of asphalt filler in order
to find out if one application would suffice. The laying of this
section was completed August 2, 1928. I inspected the section
March 28, 1929 which means the pavement had been subjected
to traffic for eight months, hardly a long enough period to
show true results and yet it had been subjected to all of the
seasons. Following are the conclusions which I have come to
in regard to the section. On March 28th, the filler was one-
quarter inch from the top of the brick which means that during
the hotter weather it will probably be one-eighth inch at
the closest to the surface of the brick. The question is
" Will the brick spall at the edges when subjected to the
heavy summer traffic? " I believe they will and think it
necessary for the cracks to be entirely filled at all times.
During the time the road had been subjected to the traffic
spalling had not taken place to any extent but the period was
mainly during the winter months during which time the traffic
is decidedly less then during the summer months. If, however,
the cracks would be filled to the top during the summer months
the ideal condition would be reached. Of course in winter the
filler would contact and recede perhaps one-eighth to three-
sixteenths inches but the traffic decreases in the winter and
also the snow and ice will fill up the remaing openongs and
thereby protect the bricks from spalling. It seems therefore

the ideal to strive for is to fill the bricks so that they will

10.
be completely protected both in winter and in summer with no
surplus accuring at any time.

It seems, therefore, unless after more time has elapsed the
conditions change, that one application will not suffice for
asphalt filler. Extra care was perhaps even taken in the lay-
ing of this section and therefore,under ordinary conditions
of working, results as good as these would not be obtained.

Nine types of bituminous filler were used in thevlaying
of the test section. Five of these were asphalt fillers, Stan-
dard F-l, Pioneer F-l, Asphalt penetration 61 to 70, Standard
A-1, and Standard A-2. No noticeable difference in the applic-
ation of the five was noticed according to Russell Levering,
special engineer assigned to the job. Also at the time of my
observation no difference was noticeable between the different
fillers. This seems to indicate that the important point is
not in the type of filler used, that is, within certain limits

of consistency, but the chief difficulty is in the application

of the filler.

11.
DEVICES USED FOR APPEICATION OF FILLER.

There have been several devices used for the application
of the filler. The first device was a cone-shaped vessel having
at the point a cast-iron tip with an opening about 1/4 inches
in diameter. The pouring can is drawn along the crack between
the rows of brick, the point resting in the crack. The opening
in the point is controlled by means of a valve with a handle
conveniently arranged so that the flow of the material can be
adjusted. As the vessel is drawn along, the material is allowed
to flow into the joints in sufficient quantity to fill them.

A helper replenishes the supply in the pouring can from time
to time so that the opening pours forth a continual stream.
Recently there have been developed multiple pouring cans with
multiple spouts which pour several joints at a time. These are
mounted on wheels and are drawn across the pavement wit; each
of the points in a joint between two rows of brick. A steering
device attached to the point serveS'to retain it in the joint.

The high labor cost of filling the joints by means of
the pouring can has led to the general adoption of a less ex-
pensive method, namely, the squeegee method, altough the
pouring can method is still used to some extent.

In the squeegee method the hot filler is poured onto the
surface from pails and then worked into the joints by means
of long handled squeegees. It is impossible to scrape allof
the filler from the surface by this method as has already been
cited. The squeegee is similar to a rake having a piece of
belting about four inches wide, or some similar material,

a ,, -‘L w
attached at the end to push the asphalt forward and Into the

12.
openings between the bricks.

Recently a sqeegee bucket has been invented, this is
a square bucket holding about fifty pounds of asphalt. The
bucket is mounted on two wheels and at the front there is
a semi-circular piece of rubber attached to the bottom of the
bucket. A three-quarter inch hole in the bottom of thecbucket
is controlled by a rod extending up to the handle of the app-
aratus. The bucket is filled and then pulled along the pavement
the valve being opened sufficiently to allow the right amount
of asphalt to escape. The semi-circular piece of rubber moun-
ted at the front sqeegees the filler into the openings.

There have been many different squeegees used but they
all resemble the ones described except for minor details.

The squeegee bucket seems to be alright if extra care is
taken in application but in many cases it has not proven sat-
isfactory. The engineer of the Ohio State test road stated
that considerable difficulty was experienced in using the

squeegee bucket.

13.
PREPARATION OF THE TEST SECTION.

The base was prepared by leveling off a section of ground
ten feet long and four feet wide. Two ordinary steel side-
walk forms were then erected, one on each side of this section,
and firmly pinned in place. The earth within the forms was
then leveled off so it was four and three quarters inches be-
low the top of the forms and was then thoroughlv compacted.

The ground was then left exposed to the sun for three days to
allow it to dry out and also to cake it to a firm base.

Three quarters of an inch of sand was placed on top of
the base and leveled off with a template. The bricks were then
placed on the sand with the proper spacing between them and
firmly pressed into the sand in order that a smooth surface
would be obtained. The section was then ready for the applica-

tion of the filler.

14.

 

 

 

 

 

VIEW OF SECTION WITH SAND VIEW OF SECTION WITH BRICK
CUSHION IN PLACE. IN PLACE READY FOR POURING.

15.

DESCRIPTION OF APEARATUS USED.

A thermo-couple was used to determine the temperature
of the brick section while the heating was taking place.
The thermo-couple is made up of an iron wire and a constant-
ine wire composed of a mixture of two alloys, connected or
soldered together at one end, the other being connected to
a scale reading in degrees Fahrenheit. The wires were bent
at an angle of 90° and placed down in one of the openings
between the bricks and thereby recorded the temperature of
the brick below the surface.

THE BURNER

The burner was made by connecting four pieces of one and
one-half inch pipe in the form of a rectangle and in one side
of the rectangele,midway between the ends, a T was placed. Into
This T another piece of one and one-half inch pipe was con-
nected. The gas was brought into this pipe by means of a
one-half inch rubber hose connected to the gas main. The end
of the hose was inserted into the pepe and the excess opening
covered with a piece of rubber tubing around the hose and over
the end of the pipe. Holes were drilled every two inches along
the bottom of the burner with a 1/8 inch drill to allow the
gas to escape and form the flames.

THE HOOD

The hood was made of sheet metal, one strip being bent
to form the top and ends and a strip riveted to each side. A
slot, two inches wide, was out from the bottom up in the cen-

ter of one side of the hood. This slot allowed the hose to be

16.
connected to the burner.
THE STANDARD
The standard upon which the burner was placed consisted
of a strip of l/B inch steel one inch wide bent U-shaped and
placed eight inches from a similar strip. These two strips
were held in place by two cross braces of the same material.
When the burner was placed on top of thecstandard it was four
inches from the surface of the brick.
THE SQUEEGEE HOP
The squeegee mop was entirely used in the construction
of the test sections, as the sections were too small forvthe
squeegee bucket. A description of the squeegee mop is given
in another part of this thesis.
THE ASPHAET
An asphalt manufactured by the Dowd Chemical Company
was used as a filler. Three tests were madc to determine the
specific gravity, the penetration, and the flash point of thig

asphalt with the following results:-

Specific Gravity -------- .938
Penetration ------------- 70
Flash Point ------------- 520° F.

The asphalt was heated by means of a cylindrucal burner
connected to the gas main leading to the heating apparatus. A
twenty-quart pail made of heavy steel was used to heat the
asphalt in.

THE BRICK

8" x 5-l/2" x 4" straight wire-cut brick were used for all

17.
of the sections. It can be seen that if good penetration is
obtained with this larger type brick it will be insured when

using the smaller type of brick.

  

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VIEW OF BURNER AS PLACED ;. ASPHALT HEATING APPARATUS
ON BRICK

 

 

VIEW OF SECTION COVERED WITH HOOD.
PROCESS OF FEE-HEATING THE BRICKS.

 

 

 

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21.
DATA OF TESTS PERFORKED.

TEST NUMBER 1

Temperature of the Air ----------------------------- 75° F.
Temperature of the Bricks -------------------------- 3000 F.
Temperature of the Asphalt ------------------------- 3000 F,
Amount of Asphalt Used ----------------------------- 12 lb.

This section was S'x 4' and therefore an insufficient amount
of asphalt was ready for application. The filler only filled
the openings to within one inch of the top or about three-
quarters full.
TEST NUMBER 2

First Application

Temperature of the Air ---------------------------- 820 F.
Temperature of the Bricks ------------------------- 550° F.
Temperature of the Asphalt ------------------------ 3000 F.
Amount of Asphalt Used. --------------------------- 7-1/2 1b.

Second Application

Temperature of the Air ---------------------------- 54° F.
Temperature of the Bricks ------------------------- 200° F.
Temperature of the Asphalt ------------------------ 300° F.
Amount of Asphalt Used for Entire Section --------- 11 lb.

The section was heated far too high in the first place as
upon application of the filler it bubbled and boiled for nearly
an hour after application, and due to this bubbling it was im-
possible to put enough asphalt on the section to fill the cracks

as it would boil on to thecsurface as fast as it was applied.

22.
‘EST NUKBJR 3

Temperature of the Air ------------------------- 770 F.
Temperature of the Bricks --------------------- 2000 F.
Temperature of the Asphalt -------------------- 3000 F.
Amount of Asphalt Used ------------------------ 11 lb.

This section was used mostly in the comparisons set forth
later in this thesis.

TEST NUMBER 4

Temperature of the Air------------------------= 54° F.
Temperature of the Bricks --------------------- 54° F.
Temperature of the Asphalt .................... 300° F.
Amount of Asphalt Used ________________________ 13 1b.

In this section the brick were not heated and the asphalt
squeegeed much harder.

TEST NUMBER 5

Temperature of the Air ------------------------- 77° F.
Temperature of the Bricks ---------------------- 770 F.
Temperature of the Asphalt --------------------- 5500 F.
Amount of Asphalt Used ------------------------- 14 lb.

The bricks were not heated in this section but the air
temperature was higher then that in the previous test and
the asphalt was heated to a higher temperature. This section
was a little easier to squeegee then the previous one. A com-
parison was made using this section as the cold brick section

as it showed the best results of the two cold brick sections.

 

 

 

[Jr I.!|J I

23.
RESULTS OF TESTS.

EASE OF APPLICATION

 

The difference in the ease of application was readily
noticeable between the pre-heated section and the cold brick
section. It is easy to see that when hot asphalt comes in
contact with the cold surface of the brick it will cool read-
ily, forming a gummy mass which interferes greatly with the
squeegee mop. After two or three minutes it was nearly im-
possible to squeegee this gummy mass, and remove the surplus
asphalt from the surface. While with the brick at nearly the
temperature of the asphalt it was an easy matter to squeegee
the filler back and forth from four to six minutes. This serves
a dual purpose, first it allows the surface to be cleaned of
excess filler, and second, it allows all of the joints to be
thoroughly filled. We must also consider the saving of energy
of the squeegee men, for, if a man does not have to work so
hard to squeegee one yard he can cover a:larger area in one day,
This means more brick layed per man per day.

EXCESS OF FILLER ON TOP

The excess of asphalt was much more noticeable on top
of the sections which had been cold poured then on those with
which the brick had been pre-heated. On the cold poured sections
there was an eighth inch surplus on many of the brick while the
only surplus left on the pre-heated brick consisted of a thin
film which the squeegee mop would not remove. The film was so thin
that it was difficult, or rather nearly impossible to remove,

while with the cold brick one could start at one end of the

24.
brick and peel off blotches of the filler with little diff-
iculty.

STRBITGT FT. OF SB 41‘ I ON .

 

After the sections had been in place for twenty-four hours
they were removed from the forms. In removing them a piece of
of pipe was forced under the section and the section pried out of
the forms. With the pre-heated brick section, the entire piece
came out intact showing the great strength of the section as
a whole. The cold poured brick came out in small sections of
from two to five brick only. I

PENETRATION.

After the sections had been removed from the forms the bot-
tom was inspected to compare the penetration of the filler into
the openings. With the pre-heated section absolute uniformity
of penetration entirely to the bottom of the brick was obtained.
' AS a whole most of the cold poured brick were filled to the
bottom but the uniformity of the preOheated section was lacking.

sea

The bricks were next pried apart and the bond compared.

In pulling two cold poured brick apart one face of the brick
was left entirely clean while the other brick held all of the
filler. The filler could readily be peeled from the brick to
which it had adheared leaving its surface as clean as it was
prior to pouring. When the pre-heated brick were pried apart
the asphalt parted about midway between the brick leaving both
surfaces covered with the filler and it was extremely diffic-
ult to remove. Even after the asphalt had been removed small

particles were found in the pores of the brick.

25.

 

o»---

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.
.
. r

TYPICAL VIEW OF COLD-BRICK SECTION
SHOWING TWO BRICKS WHICH HAVE BEEN PULLED APART
(Note clean surface of brick at the left and the
entire filler clinging to the brick at the right)

 

 

 

TYPICAL VIEW OF PRE-HEATED SECTION
SHOWING TWO BRICKS WHICH HAVE BEEN PULLED APART
(Note asphalt clinging to both brick and stringy

effect indicating the force necessary to pull
the brick apart)

26.

 

 

COMPARISON OF THE COLD BRICKS AT THE
LEFT AND PRE-HEATED BRICKS AT THE RIGHT

 

TYPICAL VIEW OF THE BOTTOM OF THE
FEE-HEATED SECTION,SHOWING THE UNIFORM
PENETRATION OBTAINED

27.
AMOUNT OF ASPHALT USED

The amount of asphalt used to pour each section was care-
fully recorddd. It can be seen from the chart of data that
13-1/2 pounds of asphalt were used for the cold brick sections,
while only 11 pounds were needed for the pre-heated sections.
The only place this can be accounted for is in the surplus left
on top of the brick. A saving of 2.8 pounds of asphalt per square
yard of pavement is accomplished by pre-heating the brick, quite
a saving if figured for ten or twentv miles of road. A saving

of approximately $175 per mile of twenty foot road.

28.

 

 

TYPICAL VIEW OF TOP OF PRE-HEATED
SECTION. SURPLUS NOT VERY NOTICEABLE.

 

 

VIEW SHOWING PART OF PRE-HEATED .
SECTION PRIED APART. NOTE THE PER-
FECT BOND OBTAINED.

 

29.
CONCLUSION DRAWN FROM TESTS.

It can be readilv seen that a decided advantage is gained
by pre-heating the brick. In the first place it is easier to
applv, therebv a gain is made in output of the workmen. Also
a cleaner surface is left after the application is completed.
Second, the excess of filler left on top of the brick is nearly
entirely eliminated thereby getting rid of the disadvantage
of the filler picking up and drawing the filler out from be-
tween the brick. Third, perfect bond is obtained between the
brick and the filler. This has two advantages. If there is an
excess left due to poor workmanship, and if the traffic does
tend to pick up the excess, it will yet be nextvto impossible
to draw the filler out from between the bricks due to the per-
fect bond present. There is absolutely no chance for the water
to seep in between the brick and the filler for. the filler
and the brick are as one body thoroughly bonded together.
Fouth, penetration is uniform leaving not a single opening for
the water to seep in and cause heaving by frosy action. With
the cold-poured section there were a few bricks which had not
been entirely filled. Fifth, as has been stated before. a sav-
ing of 2.8 pounds of asphalt per square yard of pavement was
found to result from pre-heating the brick and this saving
alone would evidence enough of the practical side of the method.

It is only necessary to heat the brick to 200° Fahrenheit,
12° below the boiling point of water. A surface burner could
no doubt be used to secure this temperature with little diff-

iculty. A burner of this type is now being used in some cases

50.
to dry the brick if they have become damp prior to filling.

The cost involved in the heating of the brick would be
more then made up by the saving in asphalt and in the increase
which each squeegee man could lay per day.

There is only one precaution necessary, and this would
probably never occur, DO NOT HEAT THE BRICK TOO HOT for the
asphalt will be heated high enough to bubble and boil and
hinder the filling of the openings, for, it is impossible to

ascertain how full the cracks are while the bubbling is tak-

ing place.

51.
CONCLUSION

In concluding I wish to state that the pre-heated section
has proven itself to be far superior in all of the points for
which it was investigated. It has also proven practicle on a

’;_"-~

small scale and I believe it would prove to be a practicle

improvement in the laying of brick pavements.

 

 

MIC HIGANI ISTATE UNIVERSITY LIBRARIE

II IIIIIIIIII

II III III

I