Gloucester County Democrat., 1912-07-25
IAN|ESITE FOR TURNPIKE J
(By Colonel Stevens)


four years. AS laid at this time it is
quite different from the earlier mate
rial and the changes made are gener-
ally believed to have produced a better
pavement. Ieabelongs to the so-called
mixed method or bituminous concrete
class of roads, and is the only one of
these roads in the market that is
laid cold, though other cold mixtures
could be used, | am told, without in
fringement.
All these roads are composed of
stone, sand and asphalt, generally as
sociated with so-called filler, fine
powdered material, such as Portland
cement or limestone dust These ma
teFials are mixed much as ordinary
concrete, in mixing machines of
various kinds before being placed on
the roads. They are. supposed to be
the best process of work for highway
construction
They are all controlled by the War
rem patents. These patents are very
wide, and if ultimately upheld no such
road in which the mineral aggregate,
the stone, sand and filter, possesses in
herent stability, could be built with
out infringing. This inherent stability
is practically the stability of an or
binary macadam road and is the OBJ
ject aimed at in the design of these
mixed method roads. The patent is,
therefore, a basic one.
Amiesite has the advantage that it
can be mixed at permanent plants by
unskilled labor Its application does
not require any special processes or
plant in the field. 1t is, therefore,
tractor
The hot mixed material requires a
special plant, skilled labor and greater
care in the field The additional cost
of these seems to be greater than the
increased cost of freight on Amiesite.
Generally when in competition the
lowest bids are on Amiesite.
From the nature of the material
and the methods of its preparation
Amesite does not yield as dense a
pavement as the hot mixed methods.
Its life would probably not be as great.
On the other hand it is much easier
to repair. 1t has been usual to re-
quire a greater thickness of Amiesite
fairest method of securing competition
is by requiring the same weight of
material for both classes of pavement.
All of these pavements are specially
sensitive to defects in formation or
drainage.
The results obtained to date must
be considered in view Of the fact that
to make these pavements economical
they must, in most cases, have use
full life of about ten years.
Our oldest piece of Amiesite is
about four years old. The Amiesite
heretofore laid is generally in good
shape Analyses show that in the
earlier samples there has been some
washing of the bitumen, but not
enough to indicate early failure.
Omitting cases of bad workmanship,
the causes of failure have been mois-
ture penetrating the material from the
surface or from the foundation and
insufficient foundation. Bad material
can be and is usually detected while
being laid or before the work is COM
pleted. Water if it gains access to the
interior of the structure will in the
end disintegrate it. The material will
mot sustain traffic unless supported on
a solid base of stone.
The principal cases in which failure
has taken place more or less fully are.
las follows:
Neptune Township, Monmouth Co..
due to the presence Of wind forming a
wet blanket on the road and to the
back of an impervious surface, laid in
1909.
Mt Kimbell avenue, Morris County,
probably due to faulty foundation.
Springfield avenue, Essex County,
cause not definitely known, not laid
under State supervision.
Lawrence, Trenton. imperfect drain
age and deficient foundation.
Newark Turnpike. insecure founda-
ton.
1t must be borne in mind in judging
any pavement that the structure must
be strong enough to carry its load. It
is doubtful If Amiesite even on a per-
/ feet base could carry the Newark
Turnpike traffic, but the same is also
probably true of any other bitumiIlous
pavement.
/ hold no brief for Amiesite. | feel
that considering the fact that it has
3ADG0Il III USE 1tgI lOttI Cc3o dtiu tA1et1
to compete with a properly maintained
penetration road it should last ten
years. more OF it has been laid in this
State than is advisable. Its selection,
however, at least during the past year,
has been due to the wishes Of the local
authorities. These base their prefer
/ ence on the facts hereinbefore stated,
and upon the lack of success of many
1 roads built by the penetration method.
i Such roads require great care in con-
struction and considerable knowledge
fof the art in the inspector. This at
4 the statutory wages it is not always
possible to obtain
/ trust that the fullest possible ill-
vestigation may be given to this whole
subject
Alcyon Park.
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