64

FORM B
Specifications for BITULITHIC PAVEMENT on Bituminous Base
[sketch of pavement and base]

1. Excavation. Shall be paid for at the price bid or agreed on per cubic yard. The roadway shall be excavated to
the necessary depth below the established grade of the finished roadway, to provide for the thickness of
pavement, and thoroughly rolled with a heavy steam roller, until the surface of the sub-grade is solid, and
approximately parallel to the proposed surface of the contemplated pavement. Soft and springy places
not affording a firm foundation shall be dug out and refilled with good sound earth, cinders, gravel slag
or stone, as the city may direct, such extra excavation and filling to be paid for at actual reasonable
cost of labor and materials, plus 15%. All excavated material shall be deposited as directed by the engineer
at any point within a half-mile of the excavation.

2. Foundation. On top of this sub-foundation stone or slag, which will pass a three and one-half inch (3½")
ring, shall be spread to a depth of six (6) inches, which shall then be thoroughly compressed with a
heavy steam roller. On this foundation, after rolling, shall be spread a heavy coating of WARREN'S
NO. 2 PURITAN BRAND BITUMINOUS CEMENT or BITULITHIC CEMENT, for the purpose of
making the foundation readily unite with the Bitulithic wearing surface. One gallon of the Bituminous
Cement shall be used to each square yard of bituminous foundation.

3. Wearing Surface
On the foundation prepared as above shall be laid the wearing surface, which shall be composed of
carefully selected, sound, hard, crushed stone, mixed with bitumen and laid as hereinafter specified.

After hearing the stone in a rotary mechanical heater to a temperature of about 250°F., it shall be
elevated and passed through a rotary screen, having sections with various sized openings. The difference
in the width of openings in successive sections shall not exceed one-fourth inch (1/4") in sections having
openings smaller than one-half inch (1/2"), and shall not exceed one-half inch (1/2") in sections having open-
ings greater than one-half inch (1/2"). The several sizes of stone thus separated by the screen sections
shall pass into a bin containing sections or compartments corresponding to screen sections. From these
compartments the stone shall be drawn into a weigh box, resting on a scale having seven beams. The
stone from these compartments shall be accurately weighted, using the proportions which have been
previously determined by laboratory tests to give the best results; that is, the most dense mixture of
mineral aggregate, and one having inherent stability. If the crushed stone in the wearing surface does not
provide the best proportions of fine-grained particles, such deficiency must be supplied by the use of not
to exceed 25% hydraulic cement, pulverized stone, or very fine sand. From the weigh box each batch
of mineral aggregate, composed of differing sizes accurately weighed as above, shall pass into a "twin
pug," or other approved form of mixer. In this mixer shall be added a sufficient quantity of WAR-
REN's PURITAN BRAND NO.....21..... BITUMINOUS WATER-PROOF CEMENT, or BITU-
LITHIC CEMENT, to thoroughly coat all the particles of stone and to fill all voids in the mixture.
The Bituminous Cement shall, before mixing with the stone, be heated to between 200°F and 250°F., and
the amount used in each batch shall be accurately weighted and used in such proportions as have been
previously determined by laboratory tests to give the best results,- that is, to coat all particles of stone
and fill the voids in the mineral aggregate. The mixing shall be continued until the combination is a uni-
form bituminous concrete. In this condition it shall be hauled to the street, and there spread on the pre-
pared foundation to such a depth that, after thorough compression with a steam road roller, it shall have
a thickness of two inches (2"). The proportioning of the varying sizes of stone and bituminous cement
shall be such, that the compressed mixture shall, as closely as practicable, have the density of solid stone.

4. Surface Finish
After rolling the wearing surface, there shall be spread over it, while it is still warm, a thin coating of
WARREN's QUICK DRYING BITUMINOUS FLUSH COAT COMPOSITION, by means of a suitable
flush coat spreading machine, so designed as to spread quickly over the surface a uniform thickness of
Flush Coat Composition. This spreading machine shall be provided with a flexible spreading band and
an adjustable device for regulating, to any desired amount, the quantity and uniformity of Flush Coat
Composition to be spread. On grades of over 4% a mineral flush coat may be used in place of the liquid
flush coat.

While the Flush Coat Composition is still warm, there shall be spread over it, in at least two coats
fine particles of hot crushed stone, in sufficient quantity to completely cover the surface of the pavement.
These stone chips shall be spread by means of a suitable stone spreading machine, so designed as to pro-
vide a storage receptacle of at least five (5) cubic feet capacity and to rapidly and uniformly cover the sur-
face of the pavement with the desired quantity of stone. This spreading machine shall be provided
with an adjustable attachment for regulating uniformly the quantity of stone spread at each operation.
The hot stone chips shall be immediately and thoroughly rolled into the surface until it has become cool.
The purposes of the Flush Coat Composition and the fine particles of hot crushed stone are to not only
fill any unevenness in the surface, but also to make the surface water-proof and gritty, thus providing a
good foothold for horses.

5. General
Each layer of the work shall be kept as free as possible from dirt, so that it will unite with the suc-
ceeding layer.

The bituminous composition or cement shall in each case be free from water, water gas tar, or inferior
process tars, and shall be especially refined to remove the light volatile oils and other matter susceptible
to atospheric influences.

The price bid per cubic yard of bituminous foundation must include the furnishing of all materials,
labor and implements necessary to complete the foundation as specified in paragraph 2 above. Measure-
ments to be on basis of cubic yard of crushed stone, shall be made at the option of the engineer, either
in wagos delivered on the work, or in cars as received.

The price bid per square yard of BITULITHIC must include the laying, mixing and furnishing of all
materials, labor and implements necessary to complete the wearing surface, including the surface finishing
course, as specified in paragraphs 3 and 4 above.

Bids will be received on the following items covering the pavement proper:
(a) EXCAVATION per cubic yard.
(b) BITUMINOUS FOUNDATION per cubic yard of some of slag used.
(c) CONCRETE FOUNDATION per cubic yard
(d) BITULITHIC surface including surface finishing course per square yard.

To CONTRACTORS.

Attention of all contractors is called to the agreement of Warren Brothers Company,
filed with this city, in accordance with which agreement Warren Brothers Company agrees
to license all contractors desiring to bid for the work to lay the BITULITHIC PAVE-
MENT in accordance with its patents and the terms of said agreement.