US2229872A

US2229872A - Road surfacing process

Info

Publication number: US2229872A
Application number: US537489A
Authority: US
Inventors: Harold B Pullar
Original assignee: Colprovia Roads Inc
Current assignee: Colprovia Roads Inc
Priority date: 1931-05-14
Filing date: 1931-05-14
Publication date: 1941-01-28
Anticipated expiration: 1958-01-28

Description

lit

UNITED STATES PATENT. OFFICE ROAD SURFACING PROCESS Harold B. Pullar, Chicago, Ill., assignor to Colprovia'Roads, Inc.,

poration of New York Rochester, N. Y., a cor- Serial No. 537,489

9 Claims.

This invention relates to a process of road construction and refers specifically to a process whereby the component parts constituting the finished road may be mixed and worked upon the road itself.

it has heretofore been proposed, particularly as embodied in the patent to Radcliffe No. l,655,240, to coat a. stone aggregate with bituminous materials, characterized 'in that the aggregate is first coated with a liquid binder having a melting point lower than is necessary to resist summer heat, subsequently before or during the drying applying to the coated aggregate while cold a powdered bituminous binder having a melting point higher than is necessary to resist summer heat and subsequently lay the same as a macadamized road. However, Radcliife found it necessary to perform all of the mixing operations previous to the laying of the road, namely, the stone aggregate was first mixed with the liquid binder in a conventional mixer and prior to the drying thereof, powdered bituminous material was added and mixed with the coated aggregate. This operation was contemplated to be performed remote from or adjacent the site of the road.

My invention is in one specific aspect directed to a method comprising applying to a gravel, broken stone or similar type of road or pavement, a liquid binder and immediately thereafter spreading over the surface a layer of stone or liquid binder and remove the objectionable characteristics thereof, and set the road so that it may be opened to traflic at once. All of said operations may be performed upon. the road itself and consequently nothing but raw material need be transported to the road side. I I

In carrying out my invention 1 may apply to a gravel, broken stone or other similar type of road or pavement, a quantity of road oil or residuum oil, which is a heavy viscous oil produced from the refining or cracking of petroleum oil;

This oil may be sprayed on the road in any suitable manner and in. quantities of approximately of a gallon per square yard.

A layer of stone or gravel may be immediately spread over the oiled surface in quantities of approximately '75 pounds per square yard. The

stone or gravel may then be mixed on the road by means of a road maintainer, drag or similar apparatus until the stone has been completely covered with the oil and presents a uniformly coated mam.

After the road has been treated as above described, I may apply to the surface, by means of a suitable spreader or the like, a relatively thick layer of powdered asphalt having a melting point or softening point of from approximately 250 F., to 350 F., and a penetration of approximately to 7. Previous to the application of the asphalt the same may be ground or pulverized to a relatively finely divided state.

The ground, powdered or pulverized asphalt may be applied in quantities of approximately one-half pound, more or less per square yard. After the application of the asphalt the surface of the road may again be subjected toa mixing action by a road maintainer or any other suitable device which may mix and uniformly distribute the powdered asphalt through the mass of stoneand oil.

Due to the ailinity of the powdered asphalt to the oil, the asphalt rapidly disperses through the oil, absorbing the light oils and forming a gummy adhesive mixture which, under weather and traffic conditions, amalgamates into a uniform consistency, setting the stone or road metal into a solid relatively homogeneous wearing surface.

The action of the powdered asphalt on the oil immediately absorbs the light oils and removes the objectionable characteristics of the liquid oil, and sets the road for traflic at once.

It is to be understood, of course, that I do not wish to be limited to specific quantities of materials described, inasmuch as the quantity of oil used depends upon the thickness and grading of the stone, gravel or other road metal and the amount of asphalt used depends upon the consistency of the. finished product desired; the more asphalt that is used the harder the road surface may become, and under some circumstances as much as fifty percent of asphalt may be used in the mixture.

It is also possible in some types of road surfacing to spreadthe asphalt over the surface and permit the same to disperse freely through the oil without the necessity of further mixing.

It may be found desirable to use a lighter or '50 heavier oil than that hereinbefore specified. Consequently, I do not wish to limit my invention to the precise type of oil mentioned. As a lighter or heavier oil is used, the amount of asphalt may be adjusted accordingly; the lighter the oil the more asphalt it may require to produce the required consistency; while conversely the heavier the oil a lesser-quantity of asphalt may be found suilicient.

6 The-use of my invention makes it possible to treat a large mileage or road surface in a most economical and simple manner by building a'uniform asphalt bituminous mat on the surface without the objectionable oily mass obtained by 10 the use of road oil or other similar products. In addition, the handling of the materials and the transportation thereof to the site of the road is facilitated and the cost thereof is reduced to .a minimum since nothing but raw materials are transported to the road site.

I claim as my invention: a

i. A process cfmaking a bituminous road sur face which comprises the following successive steps distributing a predetermined quantity of relatively heavy hydrocarbon liquid upon the surface of the road in the cold state, spreading 1 a predetermined quantity of mineral aggregate upon said coated surface and mixing said aggregate with the oil upon the surface, distributing a. predetermined quantity of comminuted bituminous material upon said mixed mass and mix-' ing said mass with said bituminous material in the cold state.

2. The process of surfacing roads which conso sists in coating the road with a liquid asphaltic oil, applying thereon. a layer of aggregate, and then spreading a layer ofcomminuted solid bituminous material at normal temperatures and causing the latter to dissolve where it contacts with the oil to form a homogeneous plastic binder between the road and the aggregate.

3. The process of surfacing roads which consists in coating the sub-base of the road with .a liquid asphaltic oil, applying a layer of aggre- 40 gate thereon and then spreading a layer of comminuted solid bituminous material at normal temperatures and causing the latter to absorb the oil to form a homogeneous plastic binder between the aggregate and the sub-base without rendering tacky the surface area of said material.

4. The. process of surfacing roads which consists in coating the sub-base of the road with a liquid bituminous binder, applying a layer of in aggregate thereon, covering the road with a layer of comminuted solid bituminous material at normal temperatures and causing said liquid binder to be absorbed outwardly toward the surface of the layer of material.

3 5. The process of surfacing roads which consists in coating the sub-base of the road with a liquid asphaitic oil, applying a layer of aggregate over the sub-base and oil, spreading over the road a layer of comminuted solid bituminous material at normal temperatures and capable of 5 absorbing said oil, forcing said bituminous material into the voids of the aggregate and absorbing the oil in the bituminous material to form a binder in contact with the aggregate and the sub-base. l0

6. The process of surfacing roads which consists in coating the sub-base of the road with a liquid asphaltic oil, applying a layer of aggregate over the sub-base and oil, spreading over the road a layer of comminuted solid bituminous 15 material at normal temperatures and capable of solution in said oil, forcing said bituminous material into the voids of the aggregate and absorbing the excess of oil in the material without rendering the surface'of the latter viscous. 20

7. The process of surfacing roads which comprises coating the road with a liquid bituminous oil, applying thereon a layer of aggregate, and then spreading a layer of comminuted solid bituminous material at normal temperatures and 25 causing the latter to dissolve where it contacts with the oil to form a homogeneous plastic binder between the road and aggregate.

8. The process of surfacing roads which comprises, coating the road with a liquid bituminous 30 oil, applying thereon a layer of aggregate, mixing the aggregate and oil, and then spreading a layer of comminuted solid bituminous material at normal temperatures and causing the latter to dissolve where it contacts with the oil to form 35 a homogeneous plastic binder between the road and the aggregate.

9. A method of making a bituminous road paving layer which comprises mixing in situ aggregate and a bituminous binder of relatively low stability and causing to be incorporated with the aggregate and bituminous binder of low stability while they are on the road a powdered bi-. tuminous material so that the powdered bituminous material is commingled with the binder 5 of low stability and is distributed substantially throughout said aggregate, the resulting composition being disposed as a paving layer on the road and said powdered bituminous material gradually amalgamating with the binder of low 60 stability to form a relatively stable .binder for the said paving layer substantially throughout its thickness.

HAROLD B. PUILAR.