Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1921-10-01
7 - hours, down to about $12o0 a day
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| Rhode Island Detours

4
construction. let me say that this sub
ject is most thoroughly treated in the
last annual report of the Rhode Island
State Board of Public Roads. The
matter is so we'll discussed there that
I cannot do better than to quote quite
fully from their discussion, hoping in
this way to secure additional publicity
for the same:
1T is argued sometimes that roads
should not be closed to traffic during
their Improvement but that they
should be built half at a time, IL the
Improvement consist only of resurfac-
than the pavement existing and if
therefore no heavy grading is re-
quired. II is practicable under some
conditions to lay pavements half at
time and not close the road. Whether
or not it is practicable to do this. de-
ponds upon the type of pavement and
upon the width to which the pavement
is built. In general pavement which
is cast. as is a concrete pavement can
more readily be built half at a time
than can pavement which must b.
rolled by steam roller. 1t is almost
impossible to secure perfection in the
contour of the wearing surface of a
hituminous macadam p1Sement when
it is built half at a timeunless there
is car track in the center of the
street to restrain the half first con-
structed from lateral displacement.
Upon an 1S-foot road. unless there is
a,o car track to confne the crushed
there is a depression formed in the
center of the road when it is built
half at a time. This is always
source of-trouble involving constant
expense for maintenance. since water
is retained in the depression and rapid
deterioration of the pavement at the
point results There is also consd-
cradle difficulty in rolling properly Il
bitumnouS macadam road 20 feet or
less in width when it is built half at
a time. Where a pavement of this
type is constructed half at time. it
is considered very essential TO spread
first laid at least two feet wider than
the width to which the bitumen is to
be applied in order that the edge will
not feather out under rolling before
the remaining half is built. Where
| traffic is heavy the loose crushed
stone upon this narrow strip not
bound with bitumen very rapidly is
ddi iSt ny w wh Sc Is covered with
vents proper adhesion of ~ bitumen
and the individual stones are so
ahraded by the traffic that the sharp
edges become rounded so that proper
mechanical bond is not secured Upon
roads of very generous width this is
not so apt to occur, but our state law
limits US to IS feet Of width
"A bituminous concrete road also
n
> considerable difficulty as far as secur-
ing perfection in the surface is con-
y cerned. The difficulties experienced
in preparing crushed stone'' base
where the pavement is laid half at q
/ time are exactly the same as the diff
culties experienced in the case OF
@ bituminous macadam. The bitumi-
|, nous concrete top also of course must
!, be rolled and there are difficulties in
r securing effective rolling where the
i pavement is laid half at time. There
e. also is difficulty in properly bonding
l. at or near the center of the road the
). 1.-TWO strips of pavement.
: The concrete pavement lends itself
S most readily to building half at time
q because this pavement is not rolled
Il with a steam roller. but is simply
$ cast in place between side forms. 4
- considerable added expense. however
=, is inevitable where a concrete pave
J. fment is laid half at a time because OF
g the necessity for a center form and
because of the necessity for protecting
~ the concrete for considerable period
J., from injury by traffic passing upon
. the portion of the road not under con
= struction. 1t is also argued by SOM
i, that a longitudinal joint in a narrow
concrete pavement ,nullfcs t0 some
# extent the benefit or tho monOlithc
feature of concrete and is there fore q
s. Source of weakness.
n THE previous discussion concerns
If only the difficulties as far the
" pavement proper is concerned where
:, the plan Of building half at a time is
!" adopted. That feature, however, is
C not the most serious one. 1t is the
/; work of grading and laying founda-
: tons which is most handicapped by
: building half at time. Through
a heavy rock cuts Of course it is impos-
r sble to maintain traffic because the
blasting operations cannot be confined
: to definite lines. since the effects OF
: blasts cannot be gagged accurately;
Il '1n heavy earth excavation also
!, machine work is impossible where the
: pavement is built half at a time
Here in New England whore earth ex-
= difficult by the presence OF bouders
" in large numbers, steam shovel is
= considered to be the most effective
IS machine, for performing this work A
). steam shovel. however is a very bulky
- piece of machinery and therefore
z upon an 1S-foot road steam shove
q is very effective barricade to traffic
; In the case Of the building of roads
:, previously; heavy grading as rule
e is inevitable. Heavy grading, how
: ever is not confined to roads of this
u class because many of our older roads
! are not graded according to the mod
o ern standards so that the grades
i must be revised and pockets of I'M
!. stable subsoil under the road must bo
e excavated and replaced with coarse
> gravel or large stones in order &c
= prevent demolition of the pavement by
q frost action. If the excavation there
! fore Is to be accomplished so that
traffic may always employ one-half o;
8 the road, hand work only can be EN-.
E ployed. The difference in cost of do.
: ing the excavation by hand and by
> machinery is very considerable in IA
: vor of doing the work h. machinery
8 In the case of heavy grading also it Is
:. almost impossible to do the work hall
at a time even by hand.
I'm addition to the construction
l. difficulties referred to above we must
l. consider the increase in cost resulting
from building roads half at time
There is invariably a greater cost in
volved by constructing pavements
e half at time. 1t is impossible, how
+ ever. to state in general the percentage
l. of increased cost. The difference IL
l. cost depends upon great many condi
g tions and it is necessary therefore Il
IS study each separate project before al
e estimate Of the difference in cost may
It be made intelligently. Frequently
n upon our projects at least % per cent
d more would be paid for building o
n roads half at time and with som,
= types of pavements inferior result.
r. would be inevitable With roads cost
& ing at present as high as $4,000 pc
II mile an increase of % per cent in cos
It amounts to a great deal. 1t is ap
n parent therefore that this problem /!
lie serious because it is a case of tn,