US1705068A - Construction of roads having alpha foundation course of sand - Google Patents

Description

March 12, 1929. 5, sQs R 1,705,068

CONSTRUCTION OF ROAD HAVING A FOUNDATION COURSE OF SAND Filed Aug. 28, 1926 Samuelfi 5a alt/er,

TNES 434W Y, M

Patented Mar. 12,1929.

UNITED STATES PATENT" or FICE.

. saimnr. s. SADTLEB, or srmnormnn 'rownsnrr, mou'reounmr COUNTY, ramminvanm, ASSIGNORTO mmsrrr. FOUNDATION country, A CORPORATION or DELL CONSTRUCTION OF ROADS HAVING A FOUNDATION COURSE OF BAND.

Application ma August as, 1926. Serial no. 131137.

My invention relates to the construction of roads, particularly. in sandy soils and it is theaim and purpose of my invention to utilize such sand as the foundation course of f the roadway. 1

A further object of my invention is to simplify and reduce the cost of building satisfactory roads through a sandy soil by rendering the road foundation composed of such sand sufficiently rigid to prevent lateral movement of the sand after the road is constructed.

A further. object is to provide a road construction wherein sand is used as the main and essential constituent of the foundation course and wherein such sand is protected from theaction of Water thereon and from liability of being shifted laterally under the load of trafiic thereon.

A further object of my invention is to provide a road construction wherein the load of moving 'trafiic on the surface thereof will be transmitted to a foundation course of normally shifting consistency, but over a relativelylarge area of said foundation course, by two courses of different flexible fabrics between the foundation course-and the top or surface course and operative to prevent any lateral or transverse movement of the material comprising the foundation course.

Other objects of my invention will appear in the. specification and claims below.

In the'drawings forming a part of this 5 specification and in which the same reference characters are used throughout the various views to designate the same parts.

1 is a somewhat diagrammatic view in transverse cross-section, of. a road em- 0 bodying my invention with the various courses or layers employed in the construc tion spaced one above the other and Fig. 2

is a similar cross-sectional view of the completed roadway.

half of a complete cross-section of the road is indicated in the drawin s it being understood that both sides of t e road are alike.

Nor do the drawings strictly indicate the relative sizes of the various. courses of the road. The thickngs: of certain coupses lis eatl exa gerate o the purpose 0 ma i nfg th e con structionffiar in the drawings.

In these drawings a little more than one- This will be referred to again below with more particularity.

In making a road through a sandy soil 1,

Ifirst bring the surface of the soil to the top 2 of the foundation level by dragging or excavating to provide a foundation 2 of sand having the necessary grade and crown.

The foundation 2 of sand having been' crowned and graded I then preferably form on opposite sides of the foundation 2 suitable trenches 3 for the reception of the curbing 4 which. is preferably of concrete cast in ing 4 provides a retaining wall which prevents lateral movement of the said founda tion 2. I I

Inbringing the top 2' of the. foundationlevel to proper grade and crown, I may have inserted into the sand suitable stakes 6 (preferably creosoted),' the tops of which are positioned so as to indicate the level or plane to which the top of the foundation should be brought. If,'however, such stakes were not used in the making of the foundation, then I may insert suchstakes 6 (preferably creosoted) into the crowned foundation driving them down until the tops thereof are flush with the top surface 2, of the foundation course 2. In ei'thercase'I'preferably position a row or series of stakes 6 relatively close to the curbing 4 so that a subsequent course of the road may be secured thereto along the sides of the -road adjacent the curbing as will be referred to again below.

In order to compact the sand of the foundation course 2, I preferably wet it with water to make the course damp to a depth of from 6 to 10 inches. Over the surface vor top 2 of this damp compacted foundation course 2, I then lay a protective course 7 composed of :strips or pieces or sheets 7. of a coarse textile fabric, which may be the jute bagging in which lime and similar materials are usually contained. The adjacent edges of these sheets 7' of textile fabric are overlapped to shed water as clearly indicated in the drawings. This protective fabric course 7 when treated as described below, is to prevent water from above from entering the traffic over a large area of-the foundation 7 ging a small amount or layer or course of,

sand foundation after the road is completed and to assist in distributing the load of course. After the textile fabric has been thus placed over the surface 2 of the founelation, I apply to the upper surface thereof a course or layer or sprinkling or painting 8 of asphaltic material, such as asphaltic road oil, which may be heated to render it quite liquid and capable of being absorbed by the fabric. I preferably provide more of this thin liquid than'can be absorbed by the fabric so that this asphaltic oil will pene-.

trate and pass through the coarse fabric and become mixed with the sand below the fabric. After the oil has been thus applied, I may sprinkle over the upper surface of the bagsand 9 to absorb the excess oil above the fabric course v7. When this has been done and the roadway is completed there will be above and below the fibrous fabric 8 a comparatively thin or light course 89, composed of sand intermixed with asphaltic oil." U

On top of this course 89, on the fabric 8, I then lay a course 10 of fabricated metal material, such as galvanized chicken wire, of preferably: about oneinch mesh and I secure it to the posts or stakes 6 .by any suitable fastening means 11, such as nails, tacks or staples. In so securing the wire mesh fabric 10 to the stakes I stretch it so that it will lie smoothly down on the upper surface of the coarse fabric 8 or the thin course 89 of asphalt and sand thereon. This chicken wire is obtainable in strips of suit able width and in laying it upon the foundation, as above described, I preferably bind the edges of adjacent strips firmly together with wire.

The len th of each strip of wire fabric is prefera ly somewhat longer; than the distance between opposite curbs so that the ends thereof may be bent and lapped up against the curbin 4. In this way the'wire fabric 10 and the fibrous fabric course 7 are securely attached or anchored to the. posts 6' in the foundation 2 and bed of the roadway.

Although the wire mesh fabric 10 is preferably a galvanized wire fabric, I prefer to make it certain that it is thoroughly protect.- ed from corrosion. I, therefore, over the wire fabric, next preferably lay or sprea' or sprinkle a coating or course .12 of asphalt-i c material, such as asphaltic oil or liquid'ase phalt so as to thoroughly coat the strands of the wire mesh fabric with asphalt.' In Fig.

2 of the drawing, this course 12 of asphalt-i0 material appears as resting on or above the top of the wire mesh fabricIO but, of course, in practice, the asphaltic material will settle down into the wire mesh fabric 10, and la ers 89 on each side thereof. In the wire fa ric the mesh'i's preferably of about lone-inch. Moreover, the size-of the nails and the size After the surface course 18 has been placed, it is preferably given a thin dusting or coating 14, of cement, sand or other material'and rolled with a heavy roller, thus compacting the whole roadway and bringing it to the level of the inner edge-of the gutters 5 when the curbing 4 is' provided with-gutters.

A road constructed in the manner above set forth and having a surface course of amiesite or similar black surfacing material operates under traffic to transmit the load of traffic from the surface course 13 by the two fabric courses 10 and7 t0 the sand foundation 2 but in this transmitting the load, they distribute it over a relatively wide area of the sand foundation course so that the sand or foundation course is not pressed or moved transversely or laterally but offers a firm rigid support for the traffic or load on the road.

When desirable may treatthe sand foundation 2 chemically} before placing thereon the bag ing cdurse 7 Thus instead of compacting t e sand by sprinkhng water thereon, I may sprinkle it'with a liquidmixture' of silicate of soda, sulphuric acid'and water to compact it and to' make the sand more rigid and water-resisting. I'may form The amount of sul huric acid to the sodium silicate solution being substantially as 1 to 4.

When this solution dries it becomes insoluble and the sand foundation will be provided with a crust downwardly into the foundation course'from the surface thereof.

In the roadabove constructedl have thus provided two courses of different materials for distributing the load of the traflic on the the liquid by mixing substantially 10 volumes of a commercial grade of silicate of soda, diluted with 90 volumes of water, with 'a 10% aqueous solution of sulphuric acid.

road over a large area with the sand foundation. The course 7 of bagging preserves the surface 2' on the sand oundation stationary. That is to say, the traffic does not cut into it. The textile fabric-holds the surface'stationa although of itself the bagging-is very exible and the wire mesh fab ric 10 distributes the load over -it.' The course 10 of fabrieatedwire is more rigid and has great tensile strength. 1 It is secure- 1y anchored to the posts 6 as above described but is prevented from sinking into the sand under the load on the surface by the fabric course 7. v

The wire mesh fabric therefore substantially rests on a sand foundation course which virtually has a tough inextensible upper surface, formed by the textile fabric course, on which the wire mesh fabric lies,

and the wire mesh fabric spreads and distributes the load of traffic over a relatively large area of sand foundation made firm by the textile fabric course.

flush with thcitop of said foundation course,

sheets of coarse woven textile fabric having their adjacent edges overlapped to shed water laid on the top of said foundation course, strips of reticular metal fabric laid on said textile fabric, fastening means securing said textile fabric and said metal fabric to the tops of said osts, the top surface of said textile and t e metal fabric being coated with a surface of liquid asphaltic material,

and a surface course of stone aggregate bound together with asphaltic material supported on said reticular metal fabric.

2. A roadway comprising a foundation course composed of sandy soil, a course of jute bagging coated with liquid asphaltic material lying on the top of said sand foundation, strips of open mesh metal fabriclying on said fibrous material and coated with said liquid asphaltic material, and a surface course of stone aggregate bound together with asphaltic material supported on said metal fabric, the stone aggregate in said surface course and adjacent said metal fabric being of a size lar er than the size of the mesh in said metalfa ric.

3. A roadway comprising a foundation course composed of sandy soil, lime and water and having a series of stakes therein extending alon edges thereo a fibrous course comprising sheets of, coarse woven jute fabric on the surface of said foundation course with their adjacent edges overlapping to shed. water and impregnated with liquid asphaltic material, strips of open mesh wire fabric lying on said jute fabric course and coated with liquid asphaltic material, the adjacent edges of said wire mesh fabric being secured together and means to secure said wire fabric and said jute fabric course to the top ends the roadway near the sideof said -stakes, and a surface course on said metal fabric comprisin stone aggregate bound together with asp altic material.

4. A roadway comprising a foundation course of sand wctted and compacted with a mixture of silicate of soda, sulphuric acid and water, a course of coarse woven' textile fabric impregnated with a liquid asphalt lying on said sand foundation, an.o en mesh metal fabric lying on said aspha t coated textile fabric course, and a surface course of stone aggregate, the stones of which are coatedand bound together with an asphaltic material, the stone aggregate in said course adjacent saidmetal fabric being of a size larger than the size of the mesh in said metal fabric. I

In witness whereof, I have hereunto set my hand this 26th day of August, 1926.

SAMUEL s. SADTLER.

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