East Oregonian : E.O. (Pendleton, OR) 1888-current, 1912-04-24
SCIENCE FOUND IN
Street PAVING
PLANT FURNISHES
AN INTERESTING FIELD
Trip OF Inspection Leads One Through
Rock Crushers and Chemical Lab
oratories-Where Hourly Tests Are
Conducted.

If anyone happens to have the idea
that the laying of a durable pavement
only means the mixing up of a little
cruSed rock with tar and the slap
ping of the compound on the street
to be rolled, he or she would have
that idea quickly dispelled by a visit
to the different scenes in this city
where the various departments of the
Warren Construction company are in
operation. An inspection of the work
under the guidance of one of the
company officials will prove that the
making of pavement has been devel-
oped to a science by at least one
firm and that rather than employing
haphaZard methods it conducts its
plants along lines of mathematical
precision.
For instance, laboratory is main
tanned at central points (for this dis
| trict in Portland) and before opera
tions are commenced, a sample of the
rock found in the zone of operations
is sent there to be examined, weighed
| and tested This having been done
| a proportion of mixture is worked out
and sent to the plant Inspector In
order that this proportion be main
tanned throughout the work. the in,
! spector is required to make a test
each hour of every work day and al
the end of each day send in to the
Portland laboratory a sample of the
pavement being laid. If this sam.
pie varies the slightest degree from
the formula given, upon q chemica
analysis, the correction is made anC
if it varies very perceptible, the pave
ment is torn up and replaced for tht
company figures that under it's guaran
tee it is easier to make the change a
once than be under the necessity o
making constant repairs
Through the courtesy of Superin
tendent Lonergan, Sales Manage
Garrow. Foreman Duin and Inspec
tor Calef, representatives of the Eas
Oregonian were shown the variou
stages of the complicated process o
the making of bitulithic pavement ant
in the belief that many will be inter
ested in knowing something of tn
methods used, brief outline of tn
work is here given.
Work Is Interesting.
The quarry work does not differ
great deal from ordinary quarry worl
except that the company operates tw
rotary rock crushers in connection
with its work there and the rock whel
crushed is passed though severa
screens SO that the particles of differ
ent size are segregated.
The paving plant proper, locate
on Thompson street adjoining the o.
w. r. & n. yards, is by far the mos
interesting part of the process. Her
is where the "hot stuff is made. Thi
hot stuff consists of about te
parts of rock to one of bitumen an
into the compound there are twely
different sizes of rock ranging fror
an inch and half down to dust. B
proportioning these different grade
properly, the resultant product mimi
the bitumen is almost solid rock, tn
| voids being so filled that a ninet
per cent solidity is secured. The re
naming ten per cent is filled wit
bitumen which besides acts as binC
er and gives residence to the paw,
rnent.
The twelve parts rock is shovele
into an elevator in proper proportion
i and is carried into a revolving dru
heated to $50 degees Fahrenhei
where it is heated and cleaned, Il