Early in 1918, Yamhill County requested that the concrete pavement laid
in 1917 be continued to a total length of four miles, and offered to pay
for all grading necessary in connection therewith. This request was
granted by the Highway Commission and in the early spring, construction
was started on the additional 2.2 miles.
The type of pavement laid on this section was the same as that laid in
1917, except that crushed rock aggregate was used instead of gravel, and
the mix was reduced to 1:2:31/2.
[Illustration: STATE OWNED PAVING PLANT IN OPERATION NEAR SHERIDAN IN
YAMHILL COUNTY. ON THE YAMHILL NESTUCCA HIGHWAY]
The coarse aggregate consisted of crushed stone ranging from 1/4 inch to
21/2 inches. For the fine aggregate, both Columbia River and Willamette
River sand was used. The stone was crushed from a quarry operated by the
State on Deer Creek which was near the center of the job and consisted
of an altered basalt of rather coarse texture. The quality of this
stone is not equal to the true basalt; but tests made by the Oregon
Agricultural College showed that it was of good quality. The average
haul on this material was .6 of a mile.
Crushing was begun early in March and 1200 cubic yards of material
stored in a stock pile which was rehandled later by means of an
automatic loader purchased by the State Highway Department for this
class of work. The output of the crusher was insufficient to keep the
mixer running and by means of this stock pile it was possible to keep
the material coming on to the road steadily and finish the job in a
minimum length of time and with the least inconvenience to traffic.
In this connection the experience on this job shows the advisability of
using a stock pile of material to draw from in case of emergencies. When
this is done the work is allowed to go ahead steadily, although a
breakdown at the crusher may occur. The saving made by a steady run more
than offsets the cost of rehandling the material, which is done very
reasonably by the use of machinery.
The sand was shipped to Ballston and Sheridan by railroad, approximately
equal amounts being shipped to both places and was so divided as to get
a minimum length of haul on this material. The average haul was 3.5
miles. At Ballston the sand was unloaded from the cars into bunkers,
which dumped directly into trucks, while at Sheridan no bunkers were
available and the material was unloaded on the ground and rehandled by
means of an automatic loader. No delay was caused by car shortage as we
used our stock pile at Sheridan in emergencies. All the material was
hauled and handled by means of trucks, two of which belonged to the
State Highway Department, others working on a yardage basis.
The pavement, after being struck off, was finished by the roller and
belt method; being rolled from two to four times, according to the
condition of the concrete and later belted with eight and ten inch
belts. The eight inch belt being used first. By using this method of
finishing, we were able to eliminate the use of skilled labor, which
showed a material saving in the finishing item, and at the same time
secured a very satisfactory surface.
As soon as sufficiently hardened, the pavement was covered with earth
from the roadside and kept moist for at least one week while curing. The
earth covering was later removed by means of an ordinary road grader,
when ready to be opened for traffic, the elastite joints being trimmed
at the same operation.
A short stretch of pavement was left out at Deer Creek to allow a fill
to settle during the winter rains. In conformity with our general
practice, sufficient crushed rock was left on the job to complete this
stretch and make repairs.
Elastite joints were placed every thirty feet and extended the entire
width and depth of the pavement. Continuous forms were used on a portion
of this pavement and were found to be much superior to the ordinary
type, and the Department has adopted the continuous form for future
work. These forms are made by using two pieces of form lumber 11/2 inches
by 51/2 inches nailed together. The joints are lapped one-half the length
of the stick. The finished form is 3x51/2 inches and is easily placed on
either tangents or sharp curves.
The concrete was mixed with a sixteen cubic foot Koehring Mixer equipped
with bucket and boom. The plant is owned by the Department.
The grading was paid for by Yamhill County and the crusher, roller,
grader, and scarifier were also furnished by them free of charge. Earth
shoulders were built along the pavement by means of road grader.
Mr. J. M. Baker was Superintendent of Construction on this work.
COST STATEMENT--2.2 MILES, 16-FOOT CONCRETE PAVEMENT, EAST OF
SHERIDAN--BUILT IN 1918