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TH

 

 

 

 

 

 
 

 

 

 

EES EES ee . ~
 

 

 
An Analysis of the Pavements

of Lansing, Michigan.

A Thesis Submitted to

The Faculty of
MICHIGAN AGRICULTURAL COLLEGE

By

_
\ s
an oR ; . 0
i a , i

D. Ls Wernette R. 8. Clark

Candidates for the Degree of

Bachelor of Science

June, 1920.
Section

Section

Seetion

section

Section

Section

Section

INDEX

A

-

base

A Brief History of tavements in Jeneral.

3

tage

A llistory of the srosress of Javing in

wansinz.

(%
ww @

“he Object of this Thesis.

Te

Assumptions

Ee

Survey and Censuses.

i.

tase

Frage

Page

Page

Discussion in Detail of Each of the Types

of Pavements Found in’ Lansing.

Ge

Comparisons and Conalusions. :

>

102668

/

Page

12.

16.

28.

45.
BIBLICGRALHY

Following is a list of the publications read in

preparation for this thesis:

American Highway Engineer's Handbook,
By Arthur H. Blanchard.

Construction of Roads and Pavements,
By T. it. Age.

Handbook of Cost Data,
By He FP. Gillette.

A Report on the Pavements of the City of

Lansing.
Thesis submitted 1907, L.D. Angell,
WeB. Allen.

International Library of Technology.

Past and Present of the City of Lansing,
By Albert &. Cowles.

ingineering News-record, Jan. 1919 to May 1920
‘Municipal and County kngineering. Jan. to May 1920.
Denvartrent of Labor Bulletins.

ungineering and Contracting. April 7, 1920.

Thanks are due to Mr. Ecxert, City Hingineer of Lan-

sing, for his co-operation and help in the matter of records
and estimates, and also to his brother, lir. Alfred Eckert,

Assistant City Imgineer of Saginaw, for his kindness in

furnishing sample svecifications.
SECTION A.

A BRIEF HISTORY OF PAVING
IN GENERAL
Section A.

A BRIEF HISTORY OF PAVING IN GENERAL

Paralleling as it does the history of civiliz-
ation itself, the history of paving is indeed an inter-
esting one, but like civilization the dawn of its hist-
ory is shrouded in the mystery of remotest antiquity.
Conjectures only can be made as to the date of the
first attempts at road surfacing, and it is a profit-
less thing to guess about, but the Romas historian
Atrabo avers that the streets of Babylon were paved as
early as the year 2000 B.C. The word pavement is
directly from the Latin pavimentum, a floor of rammed
or beaten earth, which word is derived in turn from
pavire, to beat, and the term was applied originally to
the footway or sidewalk of rammed earth at the side of
the street rather than to the roadway proner for vehic-
les and beasts of burden. For traffic of barefooted
porters and bearers and unshod donkeys and camels a
path of hard earth sufficed, and the early Babylonian
pavements were undoubtedly such. liost historians of
the periods of Chaldean, Assyrian, Babylonian, Persian,
and Egyptian power speak of the toyal dignways, but few
fail to mention the enormous clouds of dust which attended
and half stifled all troop columms, so that the assump-
tion may reasonably be made that earth was the road

material of ancient times.
The extension of inland domains and of commerce
Overland, however, made necessary long before the
Christian Era the adoption of more permanant mater-
ials for the construction of trunk roads. Very
briefly, paved roads have been built for two gener-
al reasons, viz: political reasons and economic
reasons.

It was for political reasons that the Romans,
about the year 320 B.C. adopted from their rival city
Carthage the idea of armoring earth roads with stones.
The natural lava of that volcanic region fumished
abundant material for the first constructions, the
soldier-rulers of that time realized that communica-
tion and transportation must knit each conquored prov-
ince to the Golden City if the Empire was to stand,
and each general, returning victorious with a host of
captives, saw in road building an etermal monument to
his own greatness. Thus it was that the arrowy
white lava tracks spread from the gates of Rome to the
extreme frontiers of the Empire in Saxony and the
Pyrenees, that the dedication of a new Way followed
each successful campaign, and that the terms, Roman,
conquorer, and road-builder became in a sense synon-
ymous. These Roman paved ways were built at a tre-
mendous cost of labor and human life, but captive
labor and the lives of captives were of course not

considered for an instant. The rapid movement of
the General's Legions and Squadrons demanded the
shortest routes ---- and straight as a string the
General made his roads. The Empire was to stand
forever ---- and as an eternal foundation a three
to five foot course of rocks was laid, cemented to-
gether with natural cement. The way mst be made
smooth for the feet of runners and strong for the
wheels of chariots ---- and the wearing course was
accordingly made of large smooth lava stones, irreg-
ular in shape but fitted cunningly together at the
edges. Expense wes nothing ---- permanence everything.

Political or military paved roads had the whole
field to themselves until the end of the eighteenth
century, although the extremely heavy construction of
the Roman roads was modified somewhat in the Calaph's
Cordova highway of the tenth century and others of the
few paved roads that the Middle Ages witnessed. Cob-
ble stones were indeed used in a few cases in Europe
and America during the seventeeth century, but they °
were more generally viewed as being in the nature of
extravagant luxuries than anything else. The great
plagues of the Dark Ages may well be laid, in part at
least, at the door of the unsanitary street conditions
and lack of paving.

About the year 1830 it would seem that the civ-

ilized world awoke to the belief that economic reasons
might justify the paving of city streets, without involun-
tary labor and at a cost which the added sanitation and
convenience Of traffic would show a profit over. [In
1835 a pavement of wood blocks was put into service in
New York City, and the scheme was later (1839) adopted
for the streets of London. Bituminous surfacing was
tried in Paris in 1839, and the progress of the art

of paving from that time to this has been steady.

Brick paving was in use in Japan in 1800, and in Holland
to a slight extent in the seventeenth century, but the
first successful brick pavement in the United States

was laid in Charleston, W. Va. in 1870. The growth

of the portland cement industry has made possible the
construction of conorete roads upon a large scale only
since 1900.

These three materials: asphalt, brick, and cement
concrete, and to a lesser extent stone blocks and wood
blocks, are the principal materials in use for paving
today, and the streets of American cities and villages
bear witness to the excellence of each when properly
laid md subjected to the sort of traffic for which it
is suited.
SECTION B.

A HISTORY OF THE PROGRESS OF PAVING
IN LANSING.
Section B.

A HISTORY OF THE PROGRESS OF PAVING IN LANSING.

For many years after its foundation in the early part
of the 19th century Lansing consisted mostly of a dam and
grist-mill, a blacksmith shop, and a store or two, but
even during that period the place was celebrated for its
inaccessability. When before the first railroad in-
vaded Ingham county, Lansing was named as capital of
the state, there was of course considerable induced traffic
in its direction with the inevitable effect upon the
dirt trails leading thither. In fact we read in an
early history of the city that as late as 1850 there
were heard from the mud-wearied Legislators numerous
opinions to the effect that a less objectionable site
for a State Capital might well have been chosen: It
may be that the completion, in 1852, of the Detroit
Plank Road on what is now Michigan Avenue did something
to relieve the situation, and it is certain that the
arrival of the M.C. Railroad in 1862 must have done so,
but at any rate the capital stayed and Lansing grew and
throve.

The need of pavenents was painfully evident, but
the hard times of the reconstruction period prevented
their materialization until 1878 when the first attempt
at municipal paving was made. In that year a section of

Washington Avenue was paved with round cedar blocks set
7.

endwise on a sand cushion and packed closely to gether.
Capitol Avenue from Ottawa to Allegan, and Michigan
Avenue from Capitol to the Grand River were later paved
with the same material. The paving was two rods wide, in
the middle of the street, the shoulders end gutters being
of cobbles. This cedar pavement was satisfactory for a
few years, but it proved to be short lived as water
easily penetrated the end grain of the blocks. When

we say that the cedar block pavement was cheap and quick-
ly laid we have about completed the list of its good
points.

Manifestly there was need for a paving material
more lasting than wood, and it was found in brick. In
fact it was generally supposed at that time that a brick
pavement would last indefinately. The first brick
pavement was laid in 1894 on Capitol Avenue from Ottawa
to Shiawassee, two blocks, and the next year a block
or two each were laid on Michigan Avenue, Washington
Avenue, and Shiawassee Street. These brick were laid
without filler, upon a sand foundation, and the fact
that some of them are bearing traffic today, after 26
years of service bears witness to the excellence of the
materials. Motor truck traffic in the modern sense of
the word was then undreamed of, and it is not surprising
that its severity has at present brought many of these
old pavements to a pitiable condition. They were never
Planned for it. With a few exceptions all the pavements

that were laid in Lansing between 1894 and 1910 were of
brick. In 1908 the use of cement concrete as a
foundation for paving brick was tried. A sand cushion
was used between the concrete and the brick, as it was
thought that in no other way could the proper resistance
to impact be obtained. Later grew up faith in the so-
called monolithic brick construction. This consists in
brick bedded in the still green surface of the concrete
foundation, and having their joints well filled with
thin cement grout. These pavements are satisfactory under
the most severe traffic conditions, but they possess the
fault of being very difficult to repair after they once
begin to fail.

The first Asphaltic concrete was laid in 1910,
and is still in excellent condition, the gutters being of
monolithic cement concrete construction. For a couple of
years (1911 and 1912) several blocks of cement concrete
pavements were laid, but the extreme danger of damage by
frost to this type of pavement as well as the difficulty
of repairing it led to its rejection in favor of asphaltic
concrete.

Since 1914 asphaltic concrete has been in turn
superceded by sheet asphalt which is just as satisfactory
and cheaper. Recent improvements in methods of refining
and treating the asphaltic ingrediments have made
possible the construction of asphalt wearing surfaces
that will not iron out into waves under any but the very

heaviest of trucking traffic, and for that matter most of

the streets that have been paved in Lansing during the
past six years are in residence districts or at most upon
moderate traffic streets. A standard parabolic section
with 6" crown has been adopted, as will be discussed in
a later section, and there is but little variation from

it in the pavements that are at present being laid.
SECTION C.

THE OBJf£CT OF THIS THSSIS.

LU.
ll.

section C.
THE OBJECT OF THIS THESIS.

The object in the preparation of this thesis
is to investigate and report on the relative efficiency
(or economy) pf the several types of pavements that
are at present in use in Lansing. Taking into account
the first cost of a typical sample of each of the
principle kinds, as well as the present traffic over
it and the cost of its upkeep and replacement, we
shall point out which kind has been the cheapest in
money outlay per unit of traffic service rendered, and
which type bids fairest to most economically meet the
pavement needs of Lansing during the next few years.
The first, or analytical object is chiefly of
statistical interest, while the second is the perpetual
problem that confronts municipalities everywhere.
SECTION OD.

ASSUMPTIONS.

12.
13.

Section D.
ASSUMPTIONS.

In the computation of the matter for the table
showing the street traffic census and for the total
volume of traffic over the various sections described

later, two assumptions seemed necessary. They are:

1. The motor traffic on the streets of Lansing,
has increased approximately in the same proportion as the
output of several of the leading manufacturing concerns of
the town and also the number of automobile licenses issued

in Ingham County.

2. The hour-to-hour changes in the intensity of
traffic upon the several selected typical sections of
pavement may be assumed as being about the same for all of

them.

The intensity of traffic upon any street is variable.
It varies from hour to hour during the day, from day to day
during the week, as well as seasonally. These changes are
not very great, but are fairly regular and will not differ
greatly from year to year. There are other and greater
changes, however, which cannot well be left out of account.
For example, the motor traffic upon Lansing's streets
fifteen years ago was practically zero while today 96% of

all the traffic upon the same streets is motor driven.
MICHIGAN AGRICULTURAL COLLEGE we

 

DEPARTMENT OF MATHEMATICE .AM3
14.

Conversely, during the same period horse-drawn traffic
had dwindled from 100% to a bare 4% of the total. Also
the total volume of traffic is now almost seven times what
it was in 1907, as is shown by a comparison of our figures
with those of the census taken in that year. As traffic
data for the intervening years is not available, it had to
be supplied through some sort of an assumption, and #1,
above, was adopted. The assumption seemed to us to be a
fair one that the total traffic has increased in about the
same provortion as a combined curve of the output of sev-
eral of the automobile plants and the total number of
licenses issued for automobiles in the county of Inghan.
As we have plotted it the curve combines the growth of

the Olds and Reo factories with the license data. From
these the direction of the curve is determined during the
years when no census data was taken. The average ratio
between our census figures and those of Mr. Angell in 1907
is 7:1, and accordingly the curve passes through a point
in 1907 having one seventh of the maximum ordinate. The
best that can be said for this curve is that it is an ap-
proximation, but we feel that it is as good an approximation
as we can arrive at with the data at hand.

Again, being limited as to time, we took only two
all day censuses (at Michigan Ave. bridge and on Washing-
ton Ave. in front of the Capitol National Sank) snd several
two or three hour censuses on the other typical streets.

This necessitated assumption #2, namely that the hour-to-
MICHIGAN AGRICULTURAL COLLEGE

     

DEPARTMENT OF MATHEMATICS
15.

hour changes in traffic are about the same for all the
streets in question. This also is evidently not an ab-
solutely true assumption, but the figures for the two
all day censuses taken show very parallel changes, #2 was
adopted as the only available means of reducing a short
census to terms of an all day one. The changes that —
took place from hour to hour in the census taken at the
Michigan Avenue bridge are showm in the second curve.
These are the changes that we assumed as being the same
for all the streets that we took census on. For the
convenience of anyone who wishes to use this data later,
however, we include in the tabulated results the actual
count taken on each of the short censuses, together with
the hours, date, day of the week and weather conditions
for which they were taken.
SECTION &.

SURVEY AND CHNSUSES

16.
17.

Section E.

SURVEY AtD CENSUSES.

There are in Lansing at the present time, May,
1920, about 22.9 miles of pavements. They are of six

different kinds, as follows:

1. Brick on sand foundation ----- about 5.3 miles.

Ze " "concrete “* #£----- uw 4.1 "

3- Cement concrete -------------- " Lek "

4. Bituminous macadam ----------- " 0.8 "

5. Asphaltic concrete ----------- " 7.7 "

6. Sheet asphalt --------------- . " 2.8 "
Total about ------ 22.9 miles.

We have made a survey of all these pavements, as
regards their present condition, and the results are
tabulated in this "Section E" together with the results
of the nine traffic censuses taken.

There are also in Lansing at this time about 3.2

miles of sheet asphalt pavement under construction.

Attention is called to the map of Lansing in the
pocket at the back of this volume. Upon this map will
be found indicated the location of Lansing's paved streets,

with a color key to the several kinds of pavements.
TABLE

1.

18.

LOCATION AUD CONDITION CF BRICK-ON-SAND PAV=l SLUTS.

 

Ottawa

LOcation Year Cost per
Laid Sq. Yd. Present condition

Michigan from ; This stretch is worn and
Regent to 1906 3 1.63 wavey. One of the worst
M6RR in the city.

Michigan from Worn out pavement. Ought
Grand River 1898 0.83 to be replaced at once.

to Capitol

Grand from Old and worn. The street
Washtenaw to 1905 1.75 intersections are sagged
Michigan in several places.
Franklin from 1899 1204 Fair condition, MCRR |
Pine to MCRR 1906 1.38 crossing in very bad shape.
Turner from In very bad condition. Two
Franklin to 1899 0.94 complete failures on this
Clint on stretch of pavement.
Ottawa from worn, Patched with new
Logan to 1906 1.63 brick in several places.
Washington Curbs cracked and heaved.
Saginaw from

Butler to 1908 1.39 Rough and patched.
washington 1.89

Allegan from

Walnut to 1903 1.59 Rough and worn out.

Grand

Washtenaw from 1.41

Townsend to 1907 1.63 Ditto.

Grand

Main from Very wavey and rough. Several
Logan to 1907 1.70 complete failures on this
Washington stretch also.

south from Pavement greatly worn but
Washington 1906 1.48 grade still good. Not

to Platt wavey.

Capitol from Not many waves on this
Kalamazoo to 1905 1.09 stretch, but bricks are
Ottawa 1.67 badly worn.

Walnut from

Allegan to 1905 1.82 Ditto
19.

TABLE 2

LOCATION AND CONDITION OF BRICK-ON-CONCR&TE PAVEMENTS.

 

Cost per
Location Year Sq. Yd. Present Condition.
Michigan
- from MCRR Pavement about worn out.
to bridge

Cedar from
Michigan
to Saginaw

Shiawassee
from Cedar
to bridge

Saginaw from
Washington
to Summit

Larch from
Saginaw to
Sheridan

Larch from
Franklin
to Ferris

‘Capitol from
Ottawa to
Shiawassee

Kalamazoo
from Capitol
to Hosmer

River from
Washtenaw
to the bridge

Chestnut
from Main
to Robert

Washington
from Main
to Mt. Hope

Turner from
Clinton to
North

1909

1909

1894

1909

1910

1910

1905
1908

1910

4 2.06

204

1.71

1.84

1.95

1.97

1.94

This stretch is in
excellent condition.

Also in excellent condition.

In very good shape

In excellent condition
including car tracks.

In excellent condition ex-
cept for three spots as
shown in photo #3.

The oldest pavement in the
city. Patched in spots with
new brick. Wavey.

This stretch of pavement
is in very.good condition
still.

Very good condition.

Intersection of Chestnut and
Isaac is badly sagged. Other-
wise in fair condition.

In good condition except that
the car tracks are heaved a

good deal.

Excellent condition.
 
TABLE 3.

20.

LOCATION AND CONDITION OF CEMENT CONCRETE PAVEMENTS.

 

Location Year Cost per
Sq. Yd. Present Condition.
Michigan :
from Regent 1916 2 Poor condition for so new a
to City Lin. pavement. Badly checked and
crown cracked.
Larch from
Kalamazoo 1912 1.63 In good condition.
to Michigan |
Cedar from
Hazel to New and in excellent condition.
Nt. Hope
Ste Joseph Badly peeled and chipped.
from Middle 1912 1.63 Several bad holes in this
to Pine pavement.
Ottawa from
Washington L9LL 1.55 Good condition.
to the river
Ionia from
Capitol to 1912 1.60 Still in excellent condition.
Grand
TABLE 4.

LOCATION AND CONDITION OF ASPHALT MACADAM PAVEMENT.

 

Cost per
LOcation Year Sq. Yd. Present Condition.
Shiawassee
from Wash. 1895 & 1.19 Still in good condition.
to bridge :
Shiawassee
from Cedar 1895 1.19 Still in good condition.
to MCRR
Division Well worn, but still in
from Main 1907 - 90 passable condition. Two
to Isaas or three holes only.
TABLH 5

LOCATION AND CONDITION OF ASHPALTIC CONCRETE PAVEMENTS.

 

Cost per
Location Year Sq. Yd. Present condition.
Penn. from
Kalamazoo 1914 $ 1.77 In excellent condition.
to Sheridan
Bingham from
Michigan to Condition excellent. Curbs
Prospect cracked here and there.
Franklin These stretches of asphaltic
from Otto concrete are all in about the
to MCRR same condition. The asphalt
part of the street is smoth
Pine from 1.63 and good, but the part between
Franklin 1913 the car tracks is paved with
to Saginaw brick and the jar or heaving
of the cars has humped the.
Pine from brick next to the rails up
Washtenaw 1913 1.76 out of line with the rest of
to St. Joe the pavement. In some places
the hump can be seen over
Butler from every tie for half a block.
Saginaw 1913 This heaving seems to be
to Isaac unavoidable.
Saginaw (
from Logan (
to west city ( |
Limits ( ALL these stretches are
( new and in good condition.
Seymour from (
Ottawa to 1914 1.68 (
Saginaw
Capitol from (
Shiawassee {
to Saginaw
Grand from (
Michigan to 1911 (
Shiawassee (
Wash ington Asphaltic concrete laid over
from Main old brick pavement as
to Kalamazoo foundation. Heaved along car
tracks.
Capitol from
Main to
Kalamazoo 1910 2e16 Still in fine shape.
TABLE 5 (Continued)

LOCATION AND CONDITION OF ASPHALTIC CONCRETE PAVEMINTS.

 

Cost per
Location Year Sq. Yd. Present Condition.
Townsend
from Main 3 Good smooth pavement.
to Washtenaw
Washtenaw
from Pine 1914 1-71 Excellent at the sides.

to Townsend

Walnut from
Washtenaw to
Allegan

Logan from
St. Joseph
to bridge

Isaac from
Logan to
Division

Baker from
. Washington
to Cedar

Cedar from
Hazel to
Mi chig an

Heaved along car tracks.

Excellent condition.

Excellent condition.

Excellent condition.

Excellent condition.

In course of construction.

Le
TABLE 6

£23.

LOCATION AND CONDITION OF SHEET ASPHALT PAVEMENT.

Location

Main from
Washington
to Grand

Grand from
Main to
Washtenaw

Isaac from
Division
to Walnut

Hope from
Washington
to Cedar

Allegan from
Logan to
Walnut

Sycamore
from Ottawa
to Ionia

Genessee
from Logan
to Butler

Saginaw
from Logan
to Butler

Shiawassee
from Seymour

to Washington

Larch from
Shigwassee
to Michigan

Shiawassee
from MCRR
to Penn.

Genessee
from Becker
to Logan

Year

1919

1919

L919

1919

1919

1919

1919

1919

L919

1919

1919

1919

Present Condition.

New and in excellent shape.
New and excellent.

Part of this is still

in course of

cons truction.

In perfect condition.

New and smooth

Excellent condition
Excellent condition
Excellent condition.
Asphalt in good condition.

Excellent condition.

Good condition. A few waves.

Only the concrete foundation
in in place here.
EX2x£LANaATICN OF THA Cunsus

TaBLEs.

a4
25.

Section E.

EXPLANATICN OF Tile CENSUS TABLES.

Two all day censuses and seven shorter ones were
taken. The points selected as typical examples of the
several kinds of pavement are, in general, those sections

On which it is our judgement that maximum traffic occurs.

They are:
Kind of Pavement. Typical Section.
1. Brick-on-sand --------- West end of Michigan Ave. bridge.
2. Brick-on-concrete ~---- Kast " " " " "

3- Cement concrete-------- Ste Joseph St., Pine to Division.
4. Bituminous macadam ~--- No census taken. |

5. Asphaltic concrete ---- Grand Ave., Michigan to Ottawa.
6. Sheet asphalt --------- West Allegan St.

The two following tables give the results of these
censuses. The figures in the colum headed "Calc. for
24 hours" are computed as is explained in the note, but
those in the column headed "Total Count" are the original
data taken in the field.

The figures in the last colum, headed "Census in '07"
are taken from a thesis on The Pavements of Lansing which

was submitted in 1907 by L. D. Angell and W. B. Allen.
TABLE 7

RESULTS OF ALI DAY CENSUS AT TH
MICHIGAN AVENUE BRIDGE
Taken on Saturday, May 1, 1920. Traffic both ways.

Weather: Fair emd sunny all day.

 

Hours A-eli. 6 7 8 9 10 Li 12 Pl 2 3 4
Pleasure
cars and £203 268 441 470 480 622 615 683 713 761
Ford del.
Heavy
trucks 9 27 27 el 16 24 20 9 24 30
loaded
Heavy
trucks 12 38 36 4121 29 41 42 47 23 42
eee

&

trucks 9 22 18 41 #=18 43 15 29 17 419

 

 

 

 

Horse
drawn | 3 85 832 35 37 34 el 42 $2 40
vehicles

Totals 236 408 5654 608 580 764 713 610 809 8928

Hours P.M. 4 5 6 7 8 9 10 11 12 AM 6 Totals

 

Pieasure

cars and 733 739 519 791 685 6523 360 180 100 9905
Ford del.

Heavy

trucks 6 5 7 4 1 2 1 1 0 234
loaded

Heavy

trucks 41 27 20 4 O 1 O 1 QO 445
empty

Light

trucks 15 7 2 13 3 5 1 O 0 276

 

 

 

Horse
drawn 24 12 5 8 6 2 3 2 0 373
vehicles

Totals 619 790 553 620 695 533 365 184:. 100 11233

26
TABLE 8

RESULTS OF ALL CENSUSES TAKEN, SPRING, 1920.

 

Place Total Calc.for Census
taken Hours Date Weather Count 24 hours in ‘07.
Michigan 6 A.M. Sat. Fair
Avenue to May and 11233 -------- 1473
bridge 12 PM lst sunny
SeWash. 6 AM Mon. Fair
at Capt. to May and 5428 -------- 1473
Nat.Bank 12 PI 3rd sunny
Grand 2 PM Fri. Cool
Avenue to Apr. and 1031 4600 550
at Kerns 5 PM 30th Showery
Michigan 1 PM Thu. Cool
east of to Apr. and 1062 4.780 635
P.M.R.R. 4 PM 29th sunny
St. Joe 7 AM Fri. Cool

at to Apre and 213 3830 None
Sycamore 10 AM 30th showery
Allegan Noon Fri. Cool
west of § to Apr. and 512 2500 496
Capitol 3PM 30th showery
Franklin 8 AM Thu. Cool
Avenue to Apr. and 396 3830 ¥1149
bridge 10 AM 29th sunny
Saginaw 1 PM Thue Cool
at the to Apr. and 307 1370 None
church 4M 29th sunny
N. Wash. lOAM Thu. Cool
north of to Apr.e and 533 3030 501
Lenawee 1 PM e9th sunny
Note:=- The 24-hour figures were computed by means of

the hour ratios obtained at the Mich. Ave. bridge.

*This census was taken on W. Franklin, not at the bridge.
SECTION F.

DISCUSSION IN DETAIL OF EHACH OF THE TYPES
OF PAVEMENT FOUND IN LANSING.

£8.
 

 

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SINSEW32A BY
a
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29.

Section F.

DISCUSSION IN DETAIL OF EACH OF THE TYPES
OF PAVEMENT FOUND IN LANSING.

1. Brick on sand.

These were among the first permanent pavements
put domm in the city. The section of pavement chosen
as being typical of brick-on-sand construction is at
the west end of the Michigan Avenue bridge. This pave-
ment was laid in 1898, upon no other foundation than
the natural sandy soil. This photograph shows a cross

section of natural sand foundation. It was taken

/
aad

 

 

dexter out on Michigan Avenue, but the construction there
is the same. It was due to lack of funds that no better
foundation was provided and that no provision was meade for
underdrainage of the pavement. It may be said here that
nowhere in Lansing has it proved te—be necessary that any

tile pavement drains +e be laid. Incidental leakage into
the storm sewers, together with the natural porosity
of the soil take care of underdrainage very well. At
the time this pavement was laid, however, the truth of
the above had not been shown by so many years of exter tence,
and the absence of drains and foundation is due, as has
been said, simply to lack of funds. It was thought
better to pave several blocks with brick-on-sand than
fewer blocks with brick-on-concrete. The traffic over
this section of pavement is the heaviest in the city not
only because of the bridge, but also because it is part of
the Detroit Paved Way ami so gets lots of cross-state
traffic.

This pavement is now 22 years old, and the bricks
are worn off rounding on top end in many places are badly
sagged into ruts and waves. (The photograph shows a wave

in the Main St. brick-on-sand pavement).

 

 

—_—_——

The fact of the extreme long service of this sort of pavement

under heavy traffic is without doubt due to the splendid
dl.

natural drainage through sand banks to the river.

When it was laid, this pavement cost only 83 cents
per sqe yd. It was a contract job. An estimate of the
cost of doing a similar job today, based upon qmrrent

prices and Gillette's Cost Data, shows:

Smoothing up grade ------ per sq. yd. $0.09
52 Pavers at $43/M ------ 1 nw nn 2.28
Hauling brick (1 Mi.) --- " "™ " -16
Laying brick -#---------- " " " e012

Total, per sq. yd.------ $2265

This does not include any grading, as there was
none included in the cost of 83 cents in the city engineer's
report.

The census taken on this pavement shows the
traffic for a bright sunny Saturday, May lst, as 11233
vehioles for 24 hours. According to our traffic curve
(Plate 1.) there have passed over this pavement since it was
laid in 1898 about 29,650,000 vehicles.

Being worn and wavey, this pavement is hard to
clean, noisy under traffic, uncomfortable to ride over,
hard on tires, and presents high resistance to traffic.
On the other hand, it was cheap to lay, and has had
practically no maintenance. Also it is not slippery.

This pavement was put down against the best engineer-
ing judgement and advice, yet it has stood the test of time
and traffic marvelously, and though it ought to be replaced

with new, it stands today as a example of furtunate bull-

headed construction as versus engineering practice.
— ee eee ee
2. Brick on concrete.

The first pavements that were lsid of brick in Lan-
sing had a foundation of concrete. A typicel section of
this construction was chosen at the east end of the Mich-
igan Avenue bridge. By choosing this section, which gets
heavier traffic than any other brick-on-concrete pavement
in the city, we were enabled to use the Michigan Avenue
bridge census for both it and the brick-on-sand just
discussed. The bricks for this pavement were placed upon

a four-inch layer of concrete. This photograph shows a

 

 

cross section of the construction. We were unable to ob-
tain the exact proportions of the mix, but a sample of the
concrete showed many voids and what looked like dirty
gravel. It was easily broken with a sledge for excav-
ation. There is no especial provision for underdrainage.
This section was laid in 1895, and is now 25 years

old. It is in practically as bad condition as the brick-

_Onesand. ‘The bricks along the car track are heaved up out of
v
line with the test; in fact this condition obtains to a

greater or less extent on 70% of all the car tracks in

the city.

 

 

 

and at the car barns on Shiawassee St.
The cost of laying this pavement was $1.82 per sq.
yd., and it was laid by contract. The grading was done by

a different contractor under another contract.

33
34

The cost of laying a similar pavement today is estimated
thus, using current prices for mterial and labor md
time data from Gillette:
Excavation for curb ------ per sq. yd. $0.60
Curb, of concrete -------- " " " 0.50

Base, 6" thick of concrete " " " 0.96

 

Labor on base «------------ " " " 0.20
53 Pavers at $43f/M ------- " ow 1 2.28
Hauling brick --~---------- " " " 0.16
Laying brick ------------- row 60610

Total per sqe yd.----- £4.80

This estimate does not include grading, nor does it include
anything for cushion or filler. The pevement as laid had
no filler at all so far as we could find out, and was cush-
ioned upon an inch: of the sand that was right beside the
job. Also the base has been increased to 6" in thickness
in the estimate since this is the thickness that is more
generally laid. For 4" base reduce the third item by a
third.

The traffic over this pavement is the same as that
over the bridge, namely 11235 vehicles for a maximum day‘s
count, but since this pavement has been in service 25 years
its total traffic up to this time has been about 30,300,000
vehicles.

Like the brick~on-sand example this pavement is
dirty, noisy, rough, and of high traffic resistance. It

lacks the advantage of cheapness, and so far as we can tell
-_-_ ——

° * °
— . - -
- - ~
35

has proved in no way better than the brick-on-sand west
of the bridge. The survival of both must be attributed,
as has been said, to natural drainage.

There are other examples of brick-on-concrete
(South Washington Avenue, for instance) where the grade
is still good after 12 years of heavy service, but they

have the 6" base that has become standard.
?

 

 

This photograph shows brick starting to fail by crushing
in the 10 year old monolithic brick-on-concrete pavement

on Turner St.
3. Cement Concrete.

There is not very much of this kind of pavement
in the city. In 1911-12 the authorities thought they saw
in cement concrete the solution of the paving problem ----

a cheap, permanent, satisfactory pavement. Events, however,
36

failed to bear out these expectations, and this type of
construction was abandoned in favor of the asphaltic con-
crete. The typical section selected was St. Joseph
Street, and a census was taken there between Pine and
Division Streets. This pavement, like the rest in
Lansing, has no particular provision made for underdrain-
age, except the crown of the subgrade, which amounts to
6" on a 40 ft. Street.

The St. Joseph Street pavement was placed in
1912, and hence is 8 years old at present. Part of it
was laid late in the fall, so that much damage resulted
from frost. When frozen, green concrete does not set
up properly but peels off in flakes 1/4" thick and soon
develops holds 4" or so in depth. This photograph was

 

 

taken on St. Joseph Street, and shows one of these holes.
There are many such on this piece of pavement.

fhe city engineer's report shows $1.60 per sq. yd.
37

as the original cost of this pavement in 1912. An es-
timate of the cost of the same construction today, fig-
ured on a cubic yard basis is:
0.95 bbl cement at $2.80/bbl----- per cu. yd. $2.66
0.45 ou.yd. sand at $1.20/cu.yd-- "™" " " 0.54
O.91 " " gtone at 33.00/ou.yd- " " " 2.73

Labor and management ------------ " " " £263
Mixer, repairs, depr. etc. ------ " " " O.50

Total per cu. yd. 39.06

This pavement is 6" thick with no ourbs at all, and the
cost per sq. yd. would therefore be one sixth of the above
figure, or $1.51. Like the rest of the estimates, this
does not include grading. The original cost of $1.60
must have included this item, or else the lateness of
the season mst have hindered the work, for it ought to
have been done cheaper than it was. Perhaps the fact
that this pavement was in the nature of an experiment
tended to make the job more expensive.

The traffic over St. Joseph Street, as computed
from a 3-hour census taken on a rainy Friday morning,
is 38350 vehicles per 24 hours. We believe that 4500
would better represent a normal day's traffic. Using
this figure, our traffic curve gives a total of about
7,580,000 vehicles using the street since 1912.

This pavement, it should be said, is in much
worse condition than the one on South Cedar, owing no doubt

to the late fall work as mentioned above. In general this
358

pavement is of fairly low first cost, is smooth to
travel over, has low traffic resistance, and if laid
under ideal conditions will stand the heaviest kind of
traffic. It is also fairly easy to clean, and is a
sanitary kind of surface, being practically impervious
to water. On the other hand, concrete pavements are
noisy, slippery, very difficult to repsir satisfactorily,
and require about a month to set before traffic can be
admitted over them. Another trouble with concrete pave-
ments is that expansion and contraction, due to heat and
cold, are very liable to cause cracks. The edges of
these cracks soon ship off and crumble and a rough un-
sightly spot, if not an actual failure, is the result.
Various arrangements of expansion joints have been tried
on pavements all over the country, but our inquiry or
reading has not shown a really satisfactory and uniformly

successful solution for this trouble.

4. Bituminous Macadam.

As there are only five blocks of bituminous
macadam pavement in Lansing, and none of these is on a
street which gets even medium traffic, we did not take
a census On any of them. They were laid more as an
experiment than anything else, and as such they have not
been repeated. The older section on Shiawassee street
was originally laid in 1896. We found no record of its

having been resurfaced, but attribute the fact that it
bg

is still fairly smooth to the lightness of the traffic
over it. Part of it has indeed been torn up and
replaced with brick-on-concrete. The other section,
laid on Division street in 1907 has been worn out for
some time past. These sections of pavement cost the
city $1.19 and $0.90 per sq. yd. respectively to build.
There are no curbs or gutters on these pavements, with
the exception of a few yards of low curb on the part

between Grand Avenue and the bridge on Shiawassee.

5. Asphaltic Concrete.

The asphaltic concrete pavement chosen as a typical
example is on Grand Avenue north from Michigan Avenue.
It was laid in 1911, 9 years ago, and the exact specifi-
cations are not known at the city engineer's office. The
pavement, however, is about 6" thick, and no especial
provision was made for underdrainage. The pavement is
in good shape today, except for a few wrinkles or small
ruts just where it joins the brick of Michigan Avenue. The
cost of laying this pavement is given as $1.29 per sq. yd.,
which agrees very well with costs given by Blanchard for
that year. Without specifications it is impossible to
estimate costs today, but it would doubtless be at least
twice as much as it was in 1911, since labor has increased
in cost from $1.50 to 35.40 per day, and teams with drivers
from $5.00 to $9.00 per day since then.
40

The cost of the asphaltic concrete pavements
laid by the city of Battle Creek in 1918 averaged $2.20
per sqe yd. The advance in price of asphaltic materials
since then is about 66%. Allowing that $1.20 of the above
cost was for materials for the asphaltic concrete, and
applying the 66%, an estimate results of $2.60 per sq.yd.
today. This Battle Creek pavement did not include curbs,
which were already in place, but the result checks in a
general way our estimate above of twice $1.29 or $2.58.

The census of this section indicates 4600 vehicles
per 24 hours, and from our traffic curve the total number
of vehicles since 1911 would be 9,420,000.

The asphaltic concrete pavement has stood up

very well under traffic and most of those in Lansing are in

 

 

 

good condition today. This photograph, taken on Hosmer
street is typical of an asphaltic concrete pavement with car
tracks, expect that the bricks along the track are not

heaved up out of line as they are along most of the tracks.
41

Asphaltic concrete pavement is rather expensive to lay,
and when moist is slippery, but it is pleasing in ap-
pearance, smooth to ride over, presents little resistance
to traffic, is easy to clean, silent under traffic, and

may be cheaply patched when holes do appear. |

6. Sheet Asphalt.

For the past two years only sheet ashpalt pavements
have been laid in Lansing. Most of the paving has been
done in residence districts, and a uniform cross section
30 feet wide with a 6" crown and parabolic shape has been
chosen. The curb is of monolithic concrete construction
with 18" gutter 6" deep. A 6" slab of concrete is laid as
a foundation for the asphalt. Next is laid a binder course
and on top of that a wearing course which just comes to
the top of the gutter floor. Following this section will
be found a set of svecifications for the sheet asphalt pave-
ments of Saginaw, Michigan. As corrected they are as des-
criptive of the pavements of Lansing as of Saginaw, as the
construction is practically identical. Specifications for
paving in Lansing are not printed at all, because the work
is done by men working for the city under the direction
of the city engineer, and is not let out to contractors at
all. There being no contractor in the case, there is no
necessity for a set of iron-bound specifications to make a
contract crook-proof.

As a typical example of sheet asphalt pavement,
42

West Allegan street was chosen, and a census was taken
there. This pavement was laid last year, (1919) and like
all the other pavements in Lansing it depends upon natural
drainage entirely. Being new, it is in perfect condition.
This photograph and the one on the following page
: were taken on Sparrow

U Ne Avenue where a similar
pavement is now under
construction. The first
shows the grade being
smoothed up. The curbs
are already finished and
cured. The other pic-
ture shows the foundation
course in place. It is seen

that the manholes project

 

just enough above the

concrete to come flush

 

with the top of the asphalt.
Plate 2, at the beginning of this Section shows the completed
cross section of a sheet asphalt pavement taken on Hast Main
street. The curb is divided into sections about 5 feet
long. Thin gteel partitions are inserted in the form before
the concrete is pouted. They serve as spreaders for the
form boards, and are withdrawn before the concrete is set

firmly enough to grip then.
43

The cost of sheet asphalt pavement (not including

grading, which is let by contract) to the city during the

 

 

season Of 1919, together with an estimate of the same items
for the present season of 1920, was obtained from the city
engineer and are tabulated below:

1919 1920

per Sqeyd. per sq.yd.
Drainage, changes in catch basins,

new catch basins, etc. -- $0.20 $0.32
Curb, incl. material, labor, etc.-- 0.40 0.60
Base, Gravel and cement ----------- 0.80 0.96
Asphalt, delivered hot at plant --- 0.75 1.10

Street work on asphalt, incl.
hauling from plant to
street ------------------ 0.25 0.33

Repairs and depreciation on plant,
trucks, and equipment --- 0.15 0.20

 

Totals per sq. yd. ------ $3.13 $4.25
A three-hour census of traffic was taken on the
selected typical section on Allegan street. The day
was a rainy Friday, in fact the first hour of the census
was taken in a drizzle. The computed traffic for 24
hours was 2500 vehicles, but it is probable that 2800
would better represent an average day's traffic.

The slipperiness of sheet asphalt pavement is about
the worst objection to it. In this connection, Blanchard
points out the fact that asphalt is not so slippery during a
downpour as it is during a drizzle. Sheet asphalt is as.
rather expensive pavement, but it is cleanest and smoothest
of all, very easy to clean, and presents little resistance
to the passage of vehicles. Also it can be very readily,
cheaply, and satisfactorily patched.

There is very little trucking on this street. The
census showed scarcely 2% of horsedrawn traffic; most
of the vehicles coming under the heading of "Pleasure cars

and Ford deliveries".
SECTION G.

CONCLUSIONS AND COMPARISONS

45
46

Section G.
COMPARISONS AND CONCLUSIONS.

As a good means of cOmparison of the various types of
pavement that we have investigated in Lansing, we have pre-
pared in graphical form the meterial given in Blanchard's
Highway Engineers Handbook (p.p. 1362-3) under the heading
"Tabulation of Valuated Properties of Roads and Pavements".
The "eleven characteristics" as we have them tabulated are
given the weights that Blanchard assigns to them, but we
have in some cases modified the ratings of the various
pavements as regards some one or the other of the
characteristics. For instance, as regards cost Blanchard
rates sheet asphalt and brick-on-concrete at 3 and 5
respectively as against an ideally cheap pavement rated at 10.
Now our own estimates, and those of hire Eckert, the Lansing
City Engineer, convince us that at present sheet asphalt
is the cheaper of the two, and we have rated sheet
asphalt and brick-on-concrete at 8 and 5 respectively, as
against an ideal rate of 15.

Having thus checked up the table to show, as well
as may be, conditions in Lansing today, rather than general
average conditions, we plotted the accompanying graph. ‘The
"Tdeal Pavement" curve is an arbitrarily drawn straight
line. Under each of the characteristics respectively we
plotted ordinates proportional to the ratings of the various

pavements as regards that characteristic. The several
 

 

TAL LE

°
VATED PROPERT/ES OF PAVEMENTS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Li Stee haa: ar a
| ON ee ie
23 fee aa 3 | ao Ge
: A | 1 Ps . S ni ] |
. : i eee cee «ae Fs
| | Faden se aaa
OT Oe Oe ad ie . Paya ee
eee ee
ieee eon Poss
rei eas foe ee
es ET ko be cc fa! Ud a
}———|-____-_+—___}.-— -|
st Cost as PV POLO) ad
+ ——--++——-- ¢ - —-
Teneancse Cost EY ae 20 | 20 i ie :
a 7 5 eee ae
. of Meintengnce a? 7 8 ro | 7 vA
Seer et ese ee eel ees | ED
| x
Trractive Presistance S: T Ss x “t + | a 4...
el TEES ES | OPER Cea s 3 a : =
lariness 5 so | <4 ip a ee a
Sa = —-—-} = +. =
«lessness ot Rt ph Ss fe 5S 4
res ee a Fs a | a | 3 4
———__-—--
ableness to Trave/ 8 6 5: a 6 8
nnn a -_-__o Bia! fe _~Ss- C- as | einai 74
Slippriness nd be | 7 Ss - ee =}

 

 

 

 

CURVE
Shewing ek = Characteristias
The Pavements of Lansing

and
Compar;son To an /ldea/

Pavement

 

 

 
47

points representing each kind of pavement were then
connected by straight lines, and the result is a graphical
representation of the comparative excellence of the several
types of pavements in each of eleven respects. The data is
not Original with us (except several modifications like

the one noted above) nor is the idea of the graph a new one.
We merely present it here because we think it to be a rather
lucid comparison of pavement qaracteristics.

In concluding our study of the pavements of Lan-
sing, several facts are obvious --- others less so. It is
clear from the inspection tables that a great many of the
Older pavements of the city should be replaced at once.

It is less obvious to the casual observer, however, that,
poor as the old brick-on-sand pavements are, they have given
exceptionally splendid service in proportion to their cost.

The census figures show that traffic has assumed such
proportions as to forbid the use in the future of any but
slab foundations or concrete construction, end a cOmpar-
ison of the cost estimates would seem to point to either
cement concrete or sheet asphalt as the logical type to use.
It is less easy to understand why sheet asphalt, the more
expensive of the two, has been chosen. The Gharacteristics
Graph does not give a satisfactory answer to the question.
We believe that it is because the concrete pavement has been,
in a sense, the viotim of circumstances. It has been laid
late in the fell in several cases, and the damage resulting

from frost has prejudiced many people arsainst it. It is
48

our opinion that cement concrete could very profitably be
used in replacing the old brick-on-sand pavements. After
some years of use as a concrete pavement it could still be
used as a base for sheet asphalt. The cost of the wearing
surface of asphalt is not excessive. Nearly a mile of
resurfacing with sheet asphalt over old brick pavement was
done in Battle Creek, Michigan, in 1919, at a average cost
of $1.53 per sq. yd., and the resulting pavement is a satis-
faction both to the engineer and to the townspeople. It is
needless to say, of course, that green concrete mst not be
allowed to freeze, as a failure under traffic is sure to be
the result.

Another thing peculiar to Lansing's paving conditions
is this: There seems to be no necessity of any underdrain-
age wrks at all. The leakage into the storm sewers and
the seepage into the soil seem amply adequate to keep the
water table well below the pavement. ‘So long as this
condition obtains it would be a waste of money to place tile
drains under the curbs, since they are very lisble to stop-
page and breakage due to excavation for house connections for
sewers and the like. Tile drains seldom function properly
for more than a few years at the best, and whem broken or
plugged they are worse than useless because the water table
near the break is often actually raised by the head of water

in the drain.
S1

As was stated in Section I*, the present accepted
type of pavement construction in Lansing is sheet asphalt.
It is thought by the City ingineer to be cheaper than
brick-on-concrete, and the advantases of smoothmess, ease
of maintenance, noiselessness, etc, as before enumerated,
have helped to win it ascendency, (It should be said
here that lire Yelley, the Battle Creek City &ngineer, is
of the opinion that brick-on-concrete and sheet asphalt
would cost very nearly the satie amounts per sq. yd. to lay
at present. His estimtes are; Brick 34.20, Asphalt $4.26).

we believe that sheet asnhalt is the logical
pavenent for Lansing's requirements, but as a modification
we would suggest the use of the foundation course of con-
crete alone as a pavement for several years before laying
the asphalt wearing course. A pavement life of 7 to 10
years could thus be saved, the base would become well
settled, and any heaving from frost or other causes could
be compensated for in the thickness of asphalt wear-
ing course. This plan would furnish a solution to one of
the worst objections to concrete pavement, namely,
difficulty of repair. The asphalt course would be sup-
ported exactly @s well by concrete which wes beginning to
need repair as by new concrete, and the necessity of
concrete repairs would be obviated. An objection to
the plan might be claimed in the adjustment of manholes,
catch-basins, and gutter lines to the concrete and asphalt

grades. There are on the market at present adjustable
manhole covers of various types,.and some cities (as
Cleveland, for example) follow the practise of setting
Manhole covers in asphalt instead of in concrete, so that
future adjustments may be more readily made. The use of
horizontal discharge catch-basins mipht be advisable in
connection with the plan.

It is not our purpose to work out a desig for
future pavements in this thesis, mt in offering the
above suggestion we are convinced that the details would

not present any but readily solvable difficulties.
49

SALLE SricIFPICATIONS
FOR
SHEST ASPHALT PAVELUINTS
in the city of

SAGINAW, MICHIGAN.

Owing to the fact that the city of Lansing does its
own paving work under the direction of the city engineer no
contracts are let and hence no printed specifications are to
be had. The following specifications, for which we are in-
debted to Mir. Alfred Eckert, Assistant City Engineer of
Saginaw, are for a pavement practically identical with that
which is at present being laid in Lansing. We have expunged
such passages as refer to the contractor specifically, and
as they stand the specifications would be simply in the
nature of instructions to the executive or foreman directly

in charge of the work.
GENERAL SPECIFICATIONS

EXCAVATION AND GRADING.

The street shall be excavated and graded to lines given by the Engineer, which lines must be
strictly followed, and according to the plan and cross-section on file in the Engineer’s office, together with
any drawings herein referred to, or hereafter made to show any details of the work, which are hereby
made a part of these specifications. The roadway shall be excavated to the necessary depth below the sur-
face of the completed pavement, as determined by the thickness of the pavement, and to the form shown
on the plans and cross-section therefor. The sub-grade surface shall be smoothly graded and shaped to
the form shown on the cross-section, trimming to be done with mattock and shovel, after which, if possible
to operate it, the sub-grade will be rolled with a steam roller, weighing at least seven (7) tons, until the
surface is made compact and smooth. Any depressions caused by rolling or teaming shall be filled with
fing eprth or gravel, and rolled or tamped in place; or the depressions may be filled with concrete at the
Gontebetorle expense at the time of laying the foundation.

LAWN GRADING. .

The lawn spaces between the curb line and sidewalk line, shall be excavated or filled with earth
from the excavation as required, to conform to the lines and grades as given by the Engineer. The surface
shall be graded to the satisfaction of the Engineer. This grading, excavating and filling will be under-
stood as included in the price paid for excavation. Trees standing within the line of the improvement
shall not be disturbed, marred or injured.

CROSSWALKS, ETC.

All stone, cement and brick crosswalks, flag-stones, curbstones, cobble stones and castings not re-
quired to be replaced, shall be carefully removed, and shall become the property of the City, te—be-remeved

y—t+he-Contracter-te

tit—e€ 3 pt—pFiee—paid—feor—eneavatic All driveways, walks, bridges, carriage blocks,
platforms, hitching posts obstructing the work shall be carefully removed, cared for and replaced in as good

condition as found, -without—cost—to—_the—City,

 

ENCUMBRANCES.

All such materials and encumbrances and all surplus excavation found on the work unless retained
. /
by the City or claimed by the adjoining property owners, shall be removed -and disposed of by >

a ne Cit other than the osice paid
ADJOINING PAVEMENTS.

In connecting with any brick, asphalt or other pavement, the catheter will be required to relay
so much of the said pavement as is necessary, in the judgment of the Engineer, to join same with the new
work, where the grades are the same, and the old pavements are in good condition. Where the new work
joins concrete headers now in place, the same shall be trimmed down to the top of the concrete base and
the space paved with new material. This work will be done without extra charge.
ADJUSTING MANHOLES, SEWER INLETS, ETC.

The Conscbotos must take special care of all manholes and water valve covers, stop-boxes, gas pipe,
water pipes, monuments or other public fixtures in the street, and will be held responsible for all damage or
injury thereto. The will be required to raise, remove, fill up or lower, as the case may require,
to the proper grade and line, all manholes, sewer inlets and other fixtures on the line of the improvement.
He will be required to furnish all the necessary materials, of an approved quality, and perform such work
with skilled workmen, to the satisfaction of the Engineer. No extra allowance will be made for this work,
but it will be understood as included in the price paid for excavation.

EMBANKMENT.

If the earth excavation is not sufficient, or of suitable quality to fill all low places, the deficiencies
shall be supplied by the C&ki@otos, fer—which—he—will +ecenc_theprice—bid_torembankment—orAliags, All
embankments shall be of good earth, satisfactory to the City Engineer. No perishable material will be used
therein, and it will be measured in place by the Engineer, without allowance for shrinkage.

MEASUREMENTS.

The excavation of the roadway on unimproved streets shall be computed on the actual depth from
the present contour of the street to the sub-grade surface of the pavement, as determined by the plan and
cross-section therefor; the width shall be computed at two (2') feet more than the width of the completed
pavement. The excavation between the curb and sidewalk lines, and the excavation on old pavements and
repaved streets, will be computed according to exact dimensions of the work actually done, or as may be
specifically hereinafter provided. In measuring the width of the pavement laid, the width of street railway
rails will be included therein; all other measurements will be of exact dimension of the work actually done.

PRICE PAID FOR EXCAVATION.

Includes the cost of removing the earth, including old pavements, crosswalks and other encum-
brances in roadway, the filling of all low places in the street, the finishing of the sub-grade surface of the
pavement, the grading of lawns and such other work as above required.
CATCH BASINS, MANHOLES, ETC.

The work under this head shall be started as soon as the grading is in shape to allow it, and must
proceed expeditiously and be completed as soon as possible.
CATCH BASINS SHALL BE CONSTRUCTED. |
Catch basins shall be constructed at the places shown on the plans or as located by the Engineer,
in accordance with the details drawings on file in the office of the City Engineer. They are to be con-
structed of Portland cement concrete, of the quality specified herein.

CONCRETE.

The concrete shall be composed of one part cement to three (3) parts sand and five (5) parts stone.
The sand shall consist of clean coarse particles, that will pass a sieve with holes one-quarter (%") inch
mesh. The stone shall consist of the best quality of hard limestone, gravel stone, or equally good stone
retained by a sieve with mesh one-quarter (%4”) inch square, and passing a screen with holes two (2”)
inches square. The sizes of the particles shall be so proportioned that those passing a sieve with three-
quarter (34”) inch mesh will fill the voids of the portion retained by the same without more than ten (10%)
percent excess. Six (6) parts of bank gravel may be used with one (1) part Portland cement when the gravel
shows by test that it comes within ten (10%) percent of meeting the requirements specified for sand and
gravel combined. All stones having their greatest diameter over two (2”) inches shall be removed.

The cement shall meet the City’s Standard Specifications for Portland cement.

Mixing shall preferably be done by the use of a batch mixer. Materials must be proportioned dry,
and then deposited in the mixer all at the same time. The mixer must produce a concrete of uniform con-
sistency and color with the stone thoroughly mixed with the water, sand and cement.

If hand mixing is used the sand and cement shall be thoroughly mixed dry, and then sufficient clean
water shall be added to make a paste of proper consistency; the stone and gravel after being thoroughly
drenched with water, shall then be added, and the whole mass quickly turned over with shovels, at least
three (3) times, so that the stones shall be thoroughly mixed with the water, sand and cement. The mix-
ing shall be done in a tight box or board floor.

The proportions of cement, sand and stone, may be varied by the Engineer, and when the same are
fixed, such proportions shall be rigidly adhered to. ,

In placing the concrete the same shall be spread to fill the forms even full, and be at once thor-
oughly compacted by ramming, until free mortar appears on the surface. Special pains shall be taken in
mixing, placing and tamping the concrete, that a uniform concrete may be secured, and that all surfaces of
the structure shall be smooth and well filled. In conveying the concrete from the place of mixing to the
place of deposit, the operation must be.conducted in such a manner, that no mortar will be lost, and the
concrete must be so handled that the same shall be of uniform consistency throughout, showing no excess
or lack of mortar in any place.

Retempering, that is re-mixing with additional water, mortar or concrete that has partially hard-
ened will not be permitted, and no concrete shall be used after it has begun to set.

No concrete shall be mixed while the air temperature is below 32 degrees F., and in no case shall
any material containing frost be used; and if this temperature is reached, such methods as the Engineer
may direct shall be used, to insure good construction and shall be done by the Genteweter -witheut—eost

+o—the—Gity
CENTERING AND FORMS.

, , Cit .
All centering and forms are to be furnished by the ontmeter and are to be made strictly ac-
cording to the drawings furnished, and must be so constructed as not to yield under any pressure to which
they may be subjected. Such forms shall preferably be of steel, collapsible type. No centering shall be re-
moved nor any backfilling done until the concrete has sufficiently set to prevent any injuries to the work.
After the forms have been removed, all mortar and rubbish must be removed from the interior of all work,
and all work left perfectly clean.

CHUTES.

Each basin shall be connected with the sewer by a chute of nine (9”) inch pipe, with joints thor-
oughly cemented with mortar, consisting of one (1) part Portland cement to two (2) parts sand, and all
pipes thoroughly cleaned as the work progresses. Basin chutes shall have the ends built firmly into the
walls of the basin, manhole or sewer. The chute at the basin end shall be at the bottom of basin as shown
on plan therefor, and shall be laid from sewer to basin betore the connection is concreted into the basin.
The pipe shall be laid true to line and grade in straight lines from end to end as far as possible, and when
changes in the line or grade must be made they shall be made with the proper bends or Y branches. No
underground work must be covered until the inspector has examined it and found it to be in proper con-
dition. All old chutes, if used, shall be in good condition, and shall be relaid, as far as necessary, to secure
proper drainage before connecting new basins to them. All pipes shall be cleaned of mortar and dirt as
the work progresses. The trench must be kept free from water while the pipe is being laid, and until the
mortar has set. Soft or insecure bottom must be made secure in such manner as the Engineer may direct
before laying the pipe thereon.

BACKFILLING TRENCHES.

When backfilling trenches or excavations the earth shall be mixed with said one to one, and shall
be tamped solid in uniform layers not exceeding six (6”) inches in depth. Special care must be taken in
ramming immediately around and over the sewer to make the filling as compact as possible, and at the
same time, not to injure or disturb the masonry or pipe.

CASTINGS.
All castings will be furnished by the City along the line of work, and such castings shall be fully
bedded in cement mortar and set to true line and grade.
Where a steam roller is used on the street any and all castings likely to be damaged during the

process of rolling shall be removed and the masonry work covered wit! plank and fine gravel until the
rolling is finished.

 

 

air # CASTINGS TO GRADE. |
The Lontehotor, shall at @ée own expense, bring to the surface of the pavement all manholes, sewer,
and other fixtures, and adjust any basin inlets along or adjoining his work, and shall connect old work with
the new in a workmanlike manner to the satisfaction of the Engineer. Any castings found broken be-
fore commencement of work will be furnished and replaced by the City. Where sewers, water pipe or
conduits are laid after the contract is awarded, the castings will be brought practically to grade, -after—whieh

a. C e tJ eet et wa ae 2 4A) Cy OF) Ci A eVe@
re Frew 5 Pee 5 - 2 PR a 4

taking the contract
CHANGES IN MANHOLES.

The upper three (3) feet of such manholes shall be rebuilt when so directed by the Engineer jand—
‘the-Contractor-will_be-paid-therefor-at-the-priee—bid-_pertfoote Said work shall be done as provided herein-

before under ““Concrete,” and as per detailed drawing.

ROLLING TRENCHES.
The backfilling and all excavation shall be brought above the sub-grade foundation, as directed, to
permit compression by the steam roller, and more sand or earth shall be added as the filling settles. It
shall afterwards be taken out, as is necessary, Preparatory to laying the concrete foundation, -whieh—extea-

 

 

 
TILE DRAINS.

Tile ‘shall be laid on each side of the street under the curb stone, when ordered. The tile shall be
sewer pipe of such internal diameter as shown on the plan. Each pipe is to be laid on a firm bed and in
conformity to lines and levels given by the Engineer. All irregularities in the trench shall be filled with
suitable material to procure a solid foundation. When the ground does not present a sufficiently firm
foundation for the pipe, the ontdetos shall excavate to such increased depth as may be necessary, filling
to the required form and line, or such other course may be taken to secure a good foundation as the City
Tengineer may direct. The pipe shall be carefully laid so that the bottom of the inside of the pipe will con-
form to the true grade and line, and they shall be turned and placed so that there will be no shoulder or
unevenness on the bottom of the inside of the pipe, and, after inspection, covered with clean, coarse gravel,
or stone, and gravel with excelsior covering over joints only. Connections of the tile drain with manholes
and basins shall be made in places where, and in the manner as directed by the Engineer.

 

DITCH DRAINS.

Six (6”) inch sewer pipe drains shall be laid on each side of the intersecting streets, back of the
curb, when ordered. The sewer pipe is to be laid on a firm bed three (3’) feet below the grade of the curb;
all pipe shall be carefully laid to conform to the true grade and line given by the Engineer. Connections
of the tile drain with the catch basins shall be made in places where, and in a manner as directed by the
Engineer. The ditch end of the tile drain shall be raised at the street line to the grade of the bottom of

the ditch. All joints shall be thoroughly cemented with mortar, and the backfilling shall be done with fine
earth, compactly rammed into place.

 

atF se) ;

STREET CAR TRACKS.

Where electric street railway tracks are in the street, the tracks, including switches, turn-outs, etc..
will be rebuilt by the street railway company, and any excavation below the foundation of the pavement
shall be done by the street railway company. The ties shall rest upon a continuous strip of concrete, and
the rails, securely spiked thereto, placed to the proper grade and line, and the spaces under and between
the ties filled with concrete, rammed and tamped solid to the proper height for the sub-foundation. All
of said work to be done by street railway company. No cars will be permitted to run over the tracks until
the concrete is thoroughly set, at least ten (10) days after it is put in place.

The street railway may complete the pavement included in the width of space to be paved by it,
including all excavation, otherwise the -Gomlepiter-will be required to place concrete thereon and complete
the pavement in the said space. Care must be taken to fit the pavement close against the head of the rails
and to leave the surface to the exact height of the rails, the space below the head of the rails to be filled
with Portland cement mortar and the surface material placed against it. If the street railway company
lays only the concrete paving base in connection with the foundation for its track, the CSnktdetor- will be
required to furnish the necessary materials, and lay the wearing surface of the pavement, as required by
the plans and specifications, between the rails, and one (1) foot each side, for the price bid for .

. : . . . . CIF;
pavement in street car space, exclusive of concrete foundation; and if a T rail section is used, the-Contedetos
will provide and furnish a proper grooved block, providing for a flange way on the inner side of each rail,
which will be understood as included in the cost paid square yard of the pavement in street car space.
OLD BASINS ABANDONED.

All basins to be abandoned shall be cleaned and filled with good material, thoroughly rammed in
place. The iron castings, all sewer traps and upper two feet of basin shall be removed and the outlet shall

be thoroughly sealed with brick and mortar or concrete. +hie—-werk—chall_be—-dene—by—the—Gontractorwith-

 

OLD BASINS REBUILT.

Where old basins can be used and adjusted to the lines and grades for the new improvement, the
same shall be used. The upper part shall be rebuilt and adjusted and fitted with new castings in the same
inanner as provided under new basins. The old basins shall be thoroughly cleaned, and all brick work,
where brick are crumbling or disintegrating shall be rebuilt with new brick of same quality. All joints of
the brick work on the inner side shall be scraped, refilled, and repointed with mortar; the mortar to be
used in brickwork. unless otherwise specified, shall consist of one (1) part of Portland cement and three (3)
parts clean, sharp sand, screened through a one-eighth ('%”) inch mesh. The cement and sand shall be
thoroughly mixed to a uniform color before wetting, and then brought to a uniform consistency. All traps
and basin end of connections shall be relaid and readjusted as directed and such other incidental work
shall be done as is required to be performed to make such basins a neat and workmanlike job satisfactory
to the Engineer, and will be paid for at the price bid for rebuilding old basins.

CLEANING.

Alf basins shall be thoroughly cleaned and left in good condition on completion of the improve-
ment.

PRICE PAID FOR NEW BASIN.

The price paid for new catch basins includes the digging of the pit for basin and the pipe trench,
the laying of the pipe, the backfilling of the trench with sand, the placing of the castings, and the work of
stripping and filling abandoned basins.
Specifications for Concrete Corb and Combined Curb and Gutter

ask EXCAVATION AND GRAVEL BASE.

The shall excavate on each side of the proposed pavement a trench of sufficient depth
that the curbstone can be set on six (6”) inches of gravel and of such width as shown on detail plans there-
for. The gravel shall be placed in the work, and thoroughly saturated with water before the curb is set,
and the concrete curbstone placed thereon and the gravel thoroughly and compactly rammed around to
firmly set and hold the curb to true line and grade. The curb, or combined curb and gutter shall be built
to conform to the detail plans therefor.

FORMS.

The forms shall be smooth, free from warp and of sufficient strength to resist springing out of
shape. Mortar and dirt shall be removed from forms that have been previously used. The forms shall
be well staked and thoroughly braced and set to the established lines, their upper edge conforming to the
grade of the finished curb. The work shall be blocked out in sections which shall not measure more than
six (6) feet in length and not less than four (4) feet. The cross forms shall be of One-eighth (}") to one-
quarter (4”) inch metal, as the Engineer may direct. The cross forms shall be of a depth to correspond
to the depth of the proposed work, and shall extend the full width of the work. They shall be left in place
until after the wearing surface has been floated. Wood forms shall be moistened before concrete is placed.

BASE CONCRETE.

The concrete shall be composed of one part cement to three (3) parts sand and five (5) parts stone.
The sand shall consist of clean coarse particles, that will pass a sieve with holes one-quarter (%4”) inch
- mesh. The stone shall consist of the best quality of hard limestone, gravel stone, or equally good stone
retained by a sieve with mesh one-quarter (14”) inch square, and passing a screen with holes two (2”)
inches square. The sizes of the particles shall be so proportioned that those passing a sieve with three-
quarter (34”) inch mesh will fill the voids of the portion retained by the same without more than ten (10%)
percent excess. Six (6) parts of bank gravel may be used with one (1) part Portland cement when the gravel
shows by test that it comes within ten (10%) percent of meeting the requirements specified for sand and
gravel combined. All stones having their greatest diameter over two (2”) inches shall be removed.

The cement shall meet the City’s Standard Specifications for Portland cement.

Mixing shall preferably be done by the use of a batch mixer. Materials must be proportioned dry,
and then deposited in the mixer all at the same time. The mixer must produce a concrete of uniform con-
sistency and color with the stone thoroughly mixed with the water, sand and cement.

If hand mixing is used the sand and cement shall be thoroughly mixed dry, and then sufficient clean
water shall be added to make a paste of proper consistency; the stone and gravel after being thoroughly
drenched with water, shall then be added, and the whole mass quickly turned over with shovels, at least
three (3) times, so that the stones shall be thoroughly mixed with the water, sand and cement. The mix-
ing shall be done in a tight box or board floor.

The proportions of cement, sand and stone, may be varied by the Engineer, and when the same are
fixed, such proportions shall be rigidly adhered to.

In placing the concrete the same shall be spread to fill the forms even full, and be at once thor-
oughly compacted by ramming, until free mortar appears on the surface. Special pains shall be taken in
mixing, placing and tamping the concrete, that a uniform concrete may be secured, and that all surfaces of
the structure shall be smooth and well filled. In conveying the concrete from the place of mixing to the
place of deposit, the operation must be conducted in such a manner, that no mortar will be lost, and the
concrete must be so handled that the same shall be of uniform consistency throughout, showing no excess
or lack of mortar in any place.

Retempering, that is re-mixing with additional water, mortar or concrete that has partially hard-
ened will not be permitted, and no concrete shall be used after it has begun to set.

No concrete shall be mixed while the air temperature is below 32 degrees F., and in no case shall
any material containing frost be used; and if this temperature is reached, such methods as the Engineer
may direct shall be used, to insure good construction and shall be done by the Genkcaetor ~withott—cost
tothe City.

FACING OR WEARING SURFACE.

The top, or wearing surface, shall be composed of one (1) part Portland cement and two (2) parts
sand, mixed with sufficient water to produce a mortar of a consistency which will not require tamping and
which can be easily spread into position with a straight edge.

The mortar for the facing shall be mixed in a mortar box, and spread in place immediately after
mixing in such a manner as to thoroughly unite with the backing and must be put on before the latter has
set. In no case shall more than thirty (30) minutes elapse between the mixing of the concrete for the base
and the covering of the same with the wearing surface.

The facing or wearing surface of the curb shall be placed on the inside of the form as the body of
the curb is being built up.

The face is understood to be all surface exposed to view in the completed work, as shown on the

plan. °
The thickness of the facing or wearing surface shall be three-quarter (34”) inches.
After the facing has been worked to an approximately truc plane, the surface shall be troweled
smooth and then lightly brushed. The application of neat cement to the surface in order to hasten harden-
ing is prohibited. The section marking shall be made directly over the joint of the base, and shall be made
with a tool which will cut entirely through and entirely separate the surfaces of adjacent sections.

PROTECTION.

When completed the work shall be kept moist for four (4) days and protected from traffic and the
elements for at least ten (10) days.

BROKEN CORNERS.

Curb with broken corners or loose seams or damaged in any way will not be allowed in the work.

STREET CORNERS.

At street corners of paved streets the curb will be cast to a true circle of such radius as is shown
on plan, except where there are corner basins, where it shall be fitted as directed by the City Engineer,
and paid for at the same price per lineal foot as straight curb.

THE PRICE PAID.

The price paid per lineal foot for the concrete curb or combined curb and gutter, includes the fur-
nishing of all materials (except the cement), the making of the necessary excavation below the sub-grade
of the pavement to receive the curb, and the concrete used and all labor and material incident to the full
completion of the curb.

RETAINING CURB OR HEADERS.

At street intersections where the paving joins an unimproved street or at such other places as the
engineer may direct, a concrete retaining curb or header shall be constructed in place six (6) by twelve (12)
inches in size; the upper surface shall be troweled and shaped to conform to the crown of the pavement.
When completed the Gontretter- shall protect the same until it has thoroughly hardened.
CONCRETE BASE OR FOUNDATION.

Upon the sub-grade prepared as above specified, there shall be placed a six (6) inch concrete base
or foundation proper, to be prepared as follows:

CEMENT.

The cement required in this work will be furnished by the City along the line of work, ~thewt

BEPOREO to the Lonitactos-- shoe Contractor wall he held responsible for all Seen poncl 2447-20474 oowaleo wheal

wesw & a VSN TECwW ures Ww ES WT
Sor

Loli | to inet the Ci

SAND.

The sand must be clean, coarse, sharp, bank sand, or fine gravel, entirely free from all foreign mat-
ter and uniformly graded, ranging in size from one-quarter (14) inch down.

STONE.

The stone shall be the best quality hard lime stone, field boulders, gravel stone, or equal thereto
in the judgment of the Commissioner of Public Works. Stone shall be free from all foreign matter, and

properly graded, ranging in size from a quarter (14) inch up to a size not to exceed two (2) inches.

NATURAL MIXED AGGREGATES.

Natural mixed aggregates shall not be used as they come from deposits, but shall be screened and
semixed to agree with the proportions specified. (The remixing to be done on the job.)

- CONCRETE.

The concrete base shall be composed of Portland cement, sand and stone, mixed in proportion of

1, 3 and 6; this proportion may be varied, the exact proportion to depend upon the size and character of
the stone and sand furnished and will be determined by actual trial, and when the exact proportions are

fixed, that proportion shall be rigidly followed.

MIXING.

A power driven batch concrete mixer shall be used. The matcrials must be proportioned dry, and
then deposited in the mixer all at the same time. The mixer must produce a concrete of uniform consis-

tency and color, with the stone thoroughly mixed and covered with the mortar.

CONSISTENCY.

The materials shall be mixed wet enough to produce a concrete of a consistency that will flush
readily under light tamping but which can be handled without causing a separation of the coarse aggregate
from the mortar.

Retempering, that is, remixing with additional water, mortar or conerete that has partially hard-
ened, will not be permitted.
PLACING CONCRETE.

The concrete shall be deposited in a layer on the sub-grade in such quantities that, after being
thoroughly tamped in place, it will be of the required inches in thickness, and the upper sur-
face shall be true, uniform, parallel to and below the grade of the surface of the finished pavement.

In conveying the concrete from the place of mixing to the place of deposit, the operation must be
conducted rapidly and in such a manner that no mortar will be lost and the concrete must be so handled
that the foundation will be of uniform composition throughout, showing no excess nor lack of mortar in
any place. "

PROTECTION.

The concrete base or foundation shall be kept moist for not less than two (2) days, and when
ordered by the Engineer, the ‘ shall sprinkle the base between the hours of sunset and sunrise
as often as may be deemed necessary. The concrete base shall be protected from traffic until the concrete
has thoroughly set and attained sufficient strength for the purpose of laying the wearing surface upon it.
In cold weather, or weather unsuitable for concrete work, the Gonteadtes. shall suspend work when so noti-
fed by the Commissioner of Public Works. If work is permitted while the air temperature is below 35
degrees I*°., the c&eaes shall take such additional precautions as the City [Engineer directs aithous—any

\ditional ex hei
In no case shall any matcrials, containing frost or affected by the weather, be used. Any precau-

tion which the City Engineer may consider necessary to avoid injury to the concrete shall be used by the

All boards, templets, stakes, or other a pljances, required in laying the concrete or in preparing
. . i
the sub-foundation, shall be furnished by the Gontrabtas at hie expense.
Frevised /9/9

SPECIFICATIONS FOR SHEET ASPHALT PAVEMENT.

FOUNDATION.
Upon the concrete base as hereinbefore specified under specifications for the particular pavement,

g

the wearing surface shall be laid.

SHEET ASPHALT SURFACE— REFINED ASPHALT.

Refined asphalt to be used for paving mixture herein required shall be derived in the following
manner:

1. By heating, if requiring refinement, crude, natural, soltd asphalt to a temperature of not over
450 degrees I*., until all the water has been driven out. Crude, natural, solid asphalt shall be construed to
inean any natural mineral bitumen, either pure or mixed with foreign matter, from which, through natural
causes in the process of time, the light oils have been driven off until it has a consistency of harder than
100 penetration at 77 degrees I’. At least 98% per cent of the contained bitumen in the refined asphalt
which is soluble in cold carbon disulphide, shall be soluble in cold carbon tetra chloride. In no case shall
such asphalt be prepared at the refinery with any product not hereinafter provided for.

2. By the careful distillation of asphaltic petroleum -with—eentinueue—agitetion- until the resulting
hitumen has a consistency not harder than 30 penetration at 77 degrees F.

(a) All shipment of material shall be marked with a lot number and penetration, and ten
samples taken at random from each lot shall not vary more than 15 per cent from the average
penetration, providing no part of any shipment shall be below 30 penetration at 77 degrees F.

(b) The solid bitumen so obtained shall be soluble in cold carbon tetra chloride to the
extent of 98% per cent. If the solubility in cold carbon tetra chloride is less than ninety-
nine (99) per cent the bitumen shall yield upon ignition not more than fifteen (15) per cent of fixed
carbon; if the solubility is 99 per cent or more, the bitumen shall yield upon ignition not more
than 18 per cent of fixed carbon.

(c) When 20 grams of material are heated for five hours at a temperature of 325 degrees
F., in a tin box two and one-half (214) inches in diameter after the manner officially prescribed, it
shall not lose over five (5) per cent by weight, nor shall the penetration at 77 degrees F., after such
heating, be less than one-half the original penetration..
bo (d) The solid bitumen, at a penetration of fifty (50) shall have a ductility of not less than
4@ centimeters, at 77 degrees F. If the penetration varies from 50, an increase of at least two (2)
centimeters in ductility will be required for each five (5) points in penetration above 50, and a cor-
responding allowance will be made below 50 penetration. This test shall be made with a briquette
or cross-section of one square centimeter, the materia] being elongated at the rate of & centimeters
per minute (Dow moulds).

3. Refined asphalt produced by combining crude, natural asphalt with either of the following:

(a) Residuums obtained by the distillation of petroleum oils, as specified under fluxes.

(b) Asphalts obtained by the distillation of petroleum oils, as specified.

In the use of these mixtures of refined asphalts for asphaltic cement, only asphaltic or semi-
asphaltic fluxes shall be used, except in those cases where the solid, natural asphalt is of such character that,
when mixed with paraffine flux, without the addition of any other material, it will produce an asphaltic
cement complying with the requirements set forth under that head. In such cases, any of the fluxes else-
where specified may be used.

The preparation and refining of all asphalt admitted under these specifications shall be subject to
such inspection at the paving plant and refineries as the City Engineer may direct.
FLUX.
The fluxing material may be of paraffine, a semi-asphaltic or an asphaltic residue, which may be
tested with, and found suitable to the asphalt to be used.

The residuums must have a penetration of greater than 350 with a No. 2 needle at 77 de-

erees E., under 50 grams weight for one second. AI! residuums shall be soluble in cold carbon tetra
chloride to the extent of 99 per cent, and must remain soft after heating for five hours at 400 degrees I’.

(a) The paratfine residuum shall have a specilic gravity of .02 to .04 at 77 degrees F.

It shall not flash below 350 degrees F., when tested in the New York State closed oil tester, and
shall not volatilize more than 5 per cent of material wien heated five hours at 325 degrees I., in a tin box
“13 inches in diameter, as officially prescribed. The residue, after heating, shall flow at 77 degrees I, and
shall be homogeneous and shall show no coarse crystals.

(b) Semi-asphaltic residuum shall have the same general characteristics as paraffine residuum, ex-
cept that it shall have a specific gravity of .94 to .98 at 77 degrees F.

(c) Asphaltic residuum shall have the same general characteristics as paraffine residuum, except
that the specific gravity shall be not less than .98 nor more than 1.04 at 77 degrees F. The asphaltic
residuum, after evaporation, at 500 degrees F., to a solid of 50 penetration, shall have a ductility of not
less than 30 centimeters (Dow method).

ASPHALTIC CEMENT.

The asphaltic cement prepared from materials above designated, shall be made up from the refined
asphalt. or asphalts, and the flux, where flux must be used, in such proportions as to produce an asphaltic
ecinent of a suitable degree of penetration. The proportion of the refined asphalt comprising the cement,
shall, in no case, be less than 40 per cent, by weight.

When the weight of flux in the asphaltic cement prepared from solid, natural asphalt exceeds 25
. ux . . UL
per cent thereof, asphaltic , or semi-asphaltic eentefte shall be used.

Kefined asphalt and flux comprising the asphaltic cement shall, when required, be weighed sep-
atately in the presence of the authorized inspectors or agents of the City Ingineer.

Relined asphalt and flux used in preparing the cement shall be melted together in a kettle at a tem-
peratuie ranging from 250 degrees to not over 375 degrees J]*., and be thoroughly agitated, when hot, by
vir, steam) or mechanical appliances, until the resulting cement has become thoroughly mixed into a homo-
eeneous mass. The agitation must be continued during the entire period of preparing the mixture. Cce-
iment shall always be of uniform consistency, and if any portion should settle in the kettle between inter-
vals of using the same, it must be thoroughly agitated before being drawn for use.

(a) The asphaltic cements shall have a penctration of from 40 to 85, which shall be varied be-
tween these limits to adapt it to the particular asphalt used in the paving mixture, and to the traffic and
other conditions.

(b) When 20 grams of the asphaltic cement of the penetration to be used in the paving mixture
shinll ‘he heated for five hours to a temperature of 325 degrees I’, in an oven as officially specified, there
must not volatilize more than five per cent of the bitumen present, nor shall the penctration at 77 degrees
I’, after such heating, be less than one-half of the original penetration.

(c) <A briquette of the asphaltic cement, when at a penctration of 50, having a cross-section of
one square centimeter, shall clongate to the extent of not less than 20 centimeters at 77 degrees EF. If
the asphaltic cement, as used in the paving mixture varies from 50 penetration, an increase of at least 2

centimeters in ductility will be required for cach 5 points in penctration above 50, and a corresponding al-
lowance will be made below 50 penetration (Dow moulds).

SAND.
The sand shall be hard grained and moderately sharp. It shall be so graded as to produce in the

maished mixture, the mesh requirements elsewhere specified. It shall contain not to exceed —& per cent of
sand that will pass a No. 200 mesh sieve.
BINDER STONE. ou!
Stone to be used for asphaltic concrete binder shall be hard and durable, free from all foreign sub-
stances and of uniformly varying sizes. The largest passing a }4-inch sereen to the finest.

ASPHALTIC CONCRETE BINDER.

Asphaltic concrete binder shall be made as follows: The binder, stone and sand, as above: specified,
shall be heated to from 300 to 3bé- degrees F., in suitable appliances. Stone and sand shall be. measured
off separately, and then be mixed with sufficient asphaltic cement, prepared as heretofore spe tied, in such
proportions that the resulting aggregate will contain, by weight, material~ passed sheoutiy.d No. 10 mesh
screen, between 25 and 35 per cent, and bitumen in quantity from 5 to 8 per cent ‘of the entire mixture.
Linder thus prepared shall be a compact mass containing a minimum of voids. :

NOTE.—Inasmuch as the percentage of bitumen in the binder will depend upon the grading of
the aggregate, proportion of the materials used in the above may be varied by the City Engineer, but only

within the limits designated.

LAYING ASPHALTIC CONCRETE BINDER.

The asphaltic concrete binder shall be brought to the work in wagons covered with canvas or other
suitable material, and upon reaching the street, shall have a tempcrature of 806 to 325 degrees F. It shall be
placed upon the street and raked to a uniform surface, to such depth that, after being rolled and thor-
oughly compacted, it shall have an average thickness of one inch.

The surface after compression shall show at no place an excess of asphaltic cement, and any spot
covering an area of one square foot or more, showing an excess of asphaltic cement, shall be cut out and
replaced with other material. Smaller spots may be dricd by the use of stone dust and smoothers. Any
asphaltic concrete binder broken up’ during the process of laying, must be removed and replaced with new
materials. No more binder shall be laid at any one time than can be covered by two days’ run of the
paving plant on surface mixture.

No binder shall be laid when in the opinion of the City Engineer the weather conditions are unsuit-
able or unless the base on which it is to be laid is thoroughly dry, clean and free from leaves and other
foreign matter. °

ASPHALTIC SURFACE MIXTURE OR WEARING COURSE.

The surface mixture shall consist of asphaltic cement, stone dust, and sand, proportioned by
weight, so that the resulting mixture will contain average proportions of the whole mixture, as follows:

situmen, soluble in cold carbon disulphide.................. eens eee 10 to 13.5 per cent
Stone dust passing a No. 200 Sieve... .. 0... . eee eee eee teen teen eeee 10 to 15 .
Sand passing a No. 80 Sieve... .... cc cee cc eee tee teen eeeeeees 18 to 36 “
Sand passing a No. 40 Sieve......... ccc ccc eee tee tneeeees 20 to 50 .
Sand passing a No. 10 Sieve... .. cc cece ec ccc ee ce ete teen eee eesencs 8 to 25 .
Sand passing a No. 4 SIEVE... .. ccc cee ee ce tee nee eee et nets up to 10 “¢

The item designated (as stone dust passing a No. 200 sieve) within the limits herein named, in-
cludes in addition to the stone dust, fine sand passing a No. 200 sieve, not exceeding four and one-half
(414) per cent of the total mixture, and such 200 mesh mineral dust naturally self-contained in the refined
asphalt.

Sand and asphaltic cement shall be heated separately to about 300 degrees F. The maximum tem-
perature of the sand at the mixers shall in no case be in excess of 375 degrees F., and the maximum tem-
perature of the asphaltic cement shall not exceed Sie degrees |}. at the discharge pipe. The stone dust
shall be mixed with the hot sand, in the required proportions, and then these shall be mixed for at
least one (1) minute with the asphaltic cemenje“at the required temperature and in the proper proportions,
and in a suitable apparatus so as to effect a thoroughly homogeneous mixture.

The proportion of asphaltic cement shall, at all times be determined by actual weighing with
scales attached to the asphaltic cement bucket.
The stone dust and sand must also be weighed unless a method of gauging approved by the City
Engineer shall be, used. al/ equipment
/7@262.648ar a
The Gontfector shall furnish “every-facilitg: f or the verification of-all-seales-or-meacuses The work.

The sand gradings and bitumen may be varied within the limits designated, in the discretion of
the City Engineer.
LAYING THE WEARING SURFACE.

a nveyaence

The asphaltic wearing surface shall be hauled to the work in  ramone. provided with a ganvas or
other suitable dofering. As placed in the street, it shall have a minimum temperature of 250 to $80. degrees
F., as suitable for the asphalt used.

It shall be dumped at such distance from the work that all the mixture must be turned and dis-
tributed to the place where it is to be raked, and shall be spread while hot, to such depth upon the asphaltic
concrete binder, which must be thoroughly dry, free from leaves or other foreign matter, that after receiving
its ultimate compression by rolling, it shall have an average thickness of one and one-half (114) inches.

Before the surface mixture is placed, all contact surfaces of curbs, manholes, etc., must be well
painted with hot asphaltic cement. After raking, the surface nuxture shall at once be compressed by roll-
ing and tamping after which a small amount of cement shall, be swept over it and it shall then be thor-
oughly compressed by a steam roller, weighing not less than dee pounds to the inch width of tread, the
rolling being continued until a compression is obtained which is satisfactory to the City Engineer. Such
portions of completed pavement as are defective in finish, compression or composition, or that do not com-
ply in all respects with the requirements of these specifications, shall be taken up, removed and replaced
with suitable material, properly laid, in accordance with these specifications, at the expense of the Gen

a Whenever so ordered by the City Engineer, a space of twelve inches next to the curb shall be
coated with hot asphaltic cement which shall be ironed into the pavement with hot smoothing irons.

No wearing surface shall be laid when in the opinion of the City Engineer the weather conditions
are unsuitable, or unless the binder on which it is to be placed is dry. The finished pavement must be
well protected from all traffic by suitable barricades until it is in proper condition for use.

NOTE.—AIl! tests herein provided must be conducted according to official methods on file in the
office of the City Engineer.

All penetration indicated herein, unless otherwise specified, refers to the depth of penetration in
hundredths centimeters, of a No. a\caimbric Heedle, weighted with one hundred grams at 77 degrees F., act-
ing for five seconds.

STANDARD METHODS FOR CARBON TETRA CHLORIDE TESTS.

Weigh off one (1) gram of material. Cover with 200 c.c. of carbon tetra chloride in Erlenmeyer
flask, about four o’clock in the afternoon. Allow to stand overnight in dark cupboard. Next morning at
ten o’clock, Gooch crucible with felt is weighed and solution poured therein. Wash with carbon tetra chlor-
ide; dry at 100 degrees Centigrade, and weigh.
 

 

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