The evening times., 1900-01-17
little methane. and practically nothing

little methane. and practically nothing
| else.
Il have ascertained by experiment that
| one part by volume of asphalt cement will
! absorb forty-two parts of illuminating
| gas in somewhat over a month. / have
| also practically shown that asphalt is
| much softened by absorbing gas, the ordi-
| nary asphalt cement becoming as soft as
| thick maltha after being in an atmo-
sphere of Illuminating gas for several
months. AS to the quantity of gas con-
tanned in the affected payements, this of
course varies, but in one instance 1,00C
C. C. of pavement gave off 800 C. C. of gas
Must Stop the Leak.
There is but one way to stop the dis
integration of a pavement from this
cause, and that is to stop the leak of gas;
for it is useless to patch the pavement,
as it will not be long before the patch
disintegrates. / have known of cases
where a pavement so affected was re-
paired and in fourteen months the patches
were showing signs of disintegration.
''Disintegration by water entering a
pavement by oozing up through the base:
l believe if more thorough investigation
were made into the cause for the disinte-
grating of pavement this would be found
to be one of the most common, especially
in small towns and cities where there are
terraces or considerable lawns in front of
houses There have been a number of
cases in this city where the water has en-
tered terrace or parking where they were
above the grade of the street and worked
its way up through the concrete base To
the asphalt surface.
This disintegration manifests itself diff
ferently, depending on the character of the
pavement II the asphalt surface is soft
or the concrete smooth the first defect
noticed will be the tendency of the pave
ment to crowd in warm weather. This is
due to the under portion OF the surface
mixture rotting, so TO speak. thus destroy
ing the cementing properties of the as
phalt. The upper portion although good,
being deprived of the support of the af
fected mixture under it, will be crowded
out by traffic. This crowding is assisted
by the concrete base being smooth and also
the bond between the base and binder are
destroyed by the moisture.
Result of Investigation.
I'm cases where the concrete base is
rough and the surface mixture hard, the
principal disintegration will take place in
cold weather. nothing abnormal being no.
ticed until the pavement begins a rapid
crumbiing away in the affected spot under
traffic.
'0n examining a section of asphalt sur
face disintegratng from this cause, espe-
clally where II has not been going on for
too long time, there Will be found a layer
of perfectly sound and good material at
the surface of the pavement. while under
meath the mixture win show evidence of
being disintegrated by water-that is, the
sand viii appear clean and white in spots
as though there had been an insufficiency
az aGrhalf 10 > ha 70
base under the affected pavement will gen.
orally be found damp or even wet We
have prevented the destruction of several
pavements from this cause by the use OF
blind drains put in under the gutter next
to the lawn or terrace. and even run her
under the pavement.
This last cause for disintegratiOn would
of course not occur in a pavement con-
structed with an asphalt that was unacted
on by water but water soaking up through
a concrete base might injure any pave
ment by freezing.
1T is always advisable where a pavement
shows signs cf disintegrating TO examine
into the cause in a most careful manner
and not pass snap judgement 1t seems only
tco easy fer the majority OF people, wheth-
er experienced or not, TO place the blame
for the failure OF q pavement on the manu-
factu-ers. | have heard men with cSnsid-
cradle experience, commenting on bad
place in pavement that they did not care
fully examine. remark, they used bad oil
or asphalt in that piece OF work They
have not taken into consideration that al!
but possibly a square yard of the pave
ment is in good condition. and that il would
be no economy to r contractor to use
bad material in one small place of the
pavement \ careful examination into the
of a pavement may. in many
cases. show cause that is entirely for
eign to the composition Of the materials |
and q cause that could be easily remediel |
with little common sense"