US2672295A - Structure and method of preparing same for railroad crossings - Google Patents

Description

March 16, 1954 J. H. coNE I 2,672,295 STRUCTURE AND METHOD OF' PREPRING SAME RoR RAILROAD cRossINGs Filed Nov. 18, 1948 FIG. I

ROADWAY RAILROAD I2 la I5 Patented Mar. 16, 1954 STRUCTURE yAND'METHOD QI!"PREPARINGL` SAME' FR t'lIrROAD CROSSINGS J ohn-H. Cona-Baytown, Tex., assigner; lyniesne assignments, to

Delaware K Standard,` Oil'i Development" Company, Elizabeth, N.' Je,

af corporation of` Application Novemben 18, 19448,` lSerial-Nc. 60,737 solaires. (c1. :assass- The@ present invention. is. directed tofan iin-v provedstructure and method for preparing same whichis useful-in roadvvays. More particularly, theinvention is directed to a reinforcedasphaltic cement which is capable of standing severe shock.

Itfhas been known for aconsiderable number of. yearsthat` asphalts eitherk natural or those producedfrom oil and coaltar may be used in preparing. roadways; Infactsince the time of macadam, asphalthas become increasinglyuse'- ful as a road construction material.

It; has also been known to mix the several kinds; of.. asphalt including those derived from oil, coaltar,and natural sources with aggregate,Y sand, and mineral llers to. impart to the asphalt mechanical strength which it has lacked to some degree,-v Thus. properly designed: mixes of aggregate, sand, mineral ller and asphaltic cement have been` mixed and' applied hott for use in.` road construction forV the past several decades. Roads constructed inA this vmanner have performed very.v satisfactorily provided proper foundations` were laid` and` provided they.

ability. to ,withstand sudden severe .shocks underi: heavy traific .such as has been l observed at.A rai1+ road. crossings' and at.- street. bus,` stops. Under. these'vparticular: conditions, localized areas are. exposed 'to'.shocks... by` heavy, fast moving traflic quickly losing momentum by sudden application of the Vehicle-s brakes.l Thusftremendous forces areexertedl against the asphaltic concrete sur face: RapidJloadi-ng and unloading' of the'as;

ph'alticsurface in this manner usually-produces,` after-'repeated application off the forces, heavingl ofthe=surface and Vvinternalsurfacebreaks.`

A-similar condition prevails at railroad cross` ings,l Where the asphaltic mat extends over the-v crossing. In v: primary highways this'condition maybe corrected by placing steel cr-ccncretemats adjacent to the rails. In secondary and feeder roads the mats are usually applied over the total track" crossing.A Under these conditions after short periods of exposure to the heavyV traiic the asphalt may heave'and become displaced: withina comparatively rshort period of time.

In concrete roadways 'it hasl also been the practice' to'stopthe concrete short of the actual railroad crossing andv to Vemploy asphaltic fillers of the type -mentioned to make available' a con; tinuous roadway., It" has been' observed that" underth'ese latterc'onditions the asphalt'becomes cracked and squeezed from areas. adjacent the rails' and failsafter -a short exposure' timerequire ing its replacement.

Itis; therefore; an object'ofthe'present'nvnL tion` to`provide' aniinproved `nretlriod for p'repar;

ing' an" esprima@ met which capable ofwvith-y standing'heavyand 'repeated severeshock y Another object' of the presentiinventiom is .to' provide-an improvedstructure cornpri'sin'ga` reinforced'* asphalti'c concrete:

The objects of the" present* invention' may' 'be achieved by providing an improved" asphalt s-ucture'M in roadways and in areas" receiving: heavy loading andunloadingfwhichincludesa binder course and a'surfacecourse interniediateY of which and l embedded"thereirrarep1aced"criss= crossed reinforcing steelrods;

The linventiorrmay bebrieiiy described a's'involving the laying*V of a` binder course` on* the" area' to be; protected inv accordancewitlithe'presl ent invention following-which a layer of" criss= crossed reinforcing steel rods' or'y otherrw metallic rods having sulcient mechanica-l'j strength are" finished to makethe finished roadway:

The binder course eiriployediin thepresentinvention :will-usually *have-1 a" composition approxiin mating that Agiverrirr the`followin`g 'tablet TABLEIv Stone :Gradaticn': Percent; Passing 1%. screen 1002 Passing. 1f screen 91741003 Passing 1" screen, retained .on' 1/21,l

screen (lr-655 Passing 1/. "screen, retained ond/44' screen 10i-.15a- Passing 1215 screen, retained'on' 10.

mesh 1025; Passing losmesh screen; 20i-35 lfisphalt,v Weight? 2r545-.-5r

Thus, it Will be seen include stones of Ivarious gradations' and" asphalt.

inTabl-II.

TABLE II u Percent?. Aggregatepassing` screen. l A100.. Aggregate. passing.-%,. screen. Svi-1.00

Aggregatepassingf-Vs screen, retainedon 10i/mesh r e Aggregate passing l mesh, retained on 40 mesh 3-l0 Aggregate passing 40 mesh, retained on 80 mesh 6-12 Aggregate passing 80 mesh, retained on 200 mesh 4-10 Aggregate passing 200 mesh 4 8 Asphalt, wt. 4 6

It will be seen that similar to the binding course the surface course also contains aggregate of different gradations.

The stones and aggregate employed in the practice of my invention may include gravel, crushed rock such as crushed limestone, pea gravel, oyster shell, and many other minerals which have characteristics which will impart mechanical strength to roadways. Low grade iron ore has been used in building roadways including asphalt may also be used in my invention. 1t will be understood, of course, that the stones, ore, aggregate, and the like must be properly sized before using.

The amount of asphalt employed in my invention will vary widely over a range from about 2% by weight to about l by weight of the roadway. Usually an amount in the range between 2% and by weight will give satisfactory results.

The asphalt employed in both the binder and surface courses may be either an oil, coal tar, or a natural asphalt. Oil asphalte may be obtained by light hydrocarbon precipitation such as propane precipitation of heavy crude petroleum fractions or by distillation of crude petroleum to the heavy residual fractions. The coal tar asphalts are usually the heavy fractions remaining after the destructive distillation of coal tar. The natural asphalts may be obtained from the natural sources such as from the Island of Trinidad and many other natural sources which are known throughout the world.

The penetration of the asphalt employed in usual road building will vary depending on the type of roadway, but usually will include a penetration for the binder course of an average of about 55 penetration to about 135 penetration while the surface course will usually include an asphalt penetration of about 55 to about 90.

The steel rods employed in the method of the present invention and in producing the improved structure is a lattice work of steel rods. A convenient size of the steel rods may be about l/l inch in diameter. Although rods of this size are preferred, larger rods up to about 5X; inch in diameter may be used. These steel rods may be crisscrossed and welded to form a lattice or mesh whose openings are either rectangular or diamond shaped.

The invention will now be further illustrated by reference to the drawing in which Fig. 1 is a View looking downward on an asphaltic concrete roadway which is crossed by a railroad, and

Fig. 2 is a detail showing one method of anchoring the steel mesh or mat to the individual rails of the railroad of Fig. l.

Referring now to the drawing, numeral i i designates a roadway including an asphaltic concrete surface which crosses a railroad l2 consisting of parallel rails I3 and i4. In the improved method of preparing the structure, a base course such as a binder course of the type illustrated in Table I is laid adjacent the parallel rails i3 and I4 and in between the parallel rails. Over this base course in the area between the two parallel rails I3 and I4 and for a distance of about three feet extending on each side of the rails is laid a. specially constructed lattice work I5. This lattice work is constructed of steel rods having diameters of about 1/4 inch and which are crisscrossed and welded to form a coarse mesh as indicated in the drawing. The end of each particular rod of the mesh is positioned perpendicular to the rails and may be bent downwardly at an angle of to form footings IB. These i'ootings i6 are turned down from the horizontal about 3 inches and are driven into the binder course as an anchor for the lattice work. The other end of the lattice work is also turned under at an angle of 90 to form second footings Il to allow the lattice work to be anchored to the rails i3 and i4. These footings il turn from the horizontal about l inch and are designed to engage rings i8 and to anchor the steel lattice work or mat to the rails. After the lattice work has been properly constructed and anchored both to the rails and to the binder course, a surface course is then applied over the entire road area including the lattice work and the area extending past the lattice work. The roadway is then compacted and thus the lattice work of steel mesh is firmly anchored and embedded in the roadway on which the shock occurs.

By attaching the steel lattice work to the rails by rings, slots, hooks, shoulders, and other engaging means, vertical movement of the rails will be permitted as a train passes over the crossing. While not shown in the drawing, it will be understood that it is the usual practice for rails i3 and lll to be supported by wooden cross ties. With the arrangement of the present invention, the rails and supporting wooden cross ties may move downwardly under the load as the train passes over the rails while the structure consisting of lattice work l5 and the binder and surface courses need not move downwardly but instead may remain supported by the earth between said cross ties and by the earth beyond the ends of the cross ties. It will be understood that as the train passes over the rails the cross ties, not shown in the drawing, may not be subjected to a single downward movement followed by a single upward movement but in addition the ends may vibrate in a vertical plane and if in such vibration the motion in the upward direction carries said cross ties above their normal unloaded position an upward thrust will be transmitted to the structure consisting of the binder course, lattice work l5 and surface course. However, the major force transmitted by the movement of the train over the rails is in the downward direction. It will be understood that as the train passes over the steel rails there is no automotive tramo on the crossing so that the steel rails move up and down under the effect of the train wheels, while the structure consisting of lattice work i5 and the binder and surface courses are substantially free from stresses. Then after the train has passed and automotive traino uses the crossing, the lattice work l5 with binder course and surface course is supported both by the earth between the cross ties and by the earth beyond the ends of the cross ties so that this structure is adequately supported for automotive traino.

It will be understood, of course, that I do not intend to limit myself to steel lattice work since other metals having suicient mechanical strength may be substituted therefor. For example, alloys of nickel, chromium, steel, and some of the non-ferrous metals and alloys thereof may be substituted for the steel, although the latter is preferred. As examples of the non-ferrous metals may be mentioned magnesium and aliunid num and the like. Alloys of zinc, copper, tin, beryllium, iron, chromium, nickel, and the like, may also be used in my invention.

Figure 2 shows a detail of a means of attaching steel mat I5 to one of the steel rails i3 and also illustrates a method of attachment of the steel mat I5 and the footings i8 and il'. It will be seen by reference to Fig. 2 that the footings I 'I engage with rings I8 while the footings I8 engage with the binder course.

The nature and objects of the present invention having been fully described and illustrated, what I wish to claim as new and useful and to secure by Letters Patent is:

1. A method for preparing an improved railroad crossing wherein iirst and second parallel steel rails cross a roadway, including the steps of attaching spaced rings on each side ci said rst and second rails, forming a mixture consisting of asphalt and stone passing a 1% inch screen in an amount between 85% and 98% by weight, forming a binder course of said mixture on the road foundation between said parallel rails, forming a binder course of said mixture on the roadway adjacent each of said rails for a distance greater than 3 feet from each of said rails, forming a rst steel lattice including a web of 1A inch diameter steel rods having a width equal to the bent downwardly at an angle of 90, placing said rst web on the binder course between said parallel rails with the bent ends of the rods slidably engaging rings attached to said rst and second rails, forming second and third steel lattices each including a web of 1A inch diameter steel rods with the width of approximately 3 feet with ends of the rod bent downwardly at an angle of 90, placing the second web on the binder course at the side of the rst rail, slidingly engaging ends of one side with rings attached to the side of the the binder course at the side of the second` rail, slidingly engaging ends of one side with rings atside or said second rail, and drawing the ends of the other side into the binding course, forming a second mixture consisting of asphalt and aggregate passing a 1/2 inch screen in an amount between 85 and 98% by Weight, covering said binder course and said rst, second and third webs with the second mixture to form a surface layer and compacting said layer with said binder course.

2. An improved railroad crossing having first and second parallel rails crossing a roadway, rings attached to each side of each of said rails, a binder course of stone passing a 1% in-ch screen and asphalt on the roadway between said rails a distance greater than 3 feet on each side of each of said rails, a first steel lattice including a web of 1A, inch diameter steel rods arranged between said paralle1 steel rails on said binder course with ends of the rods on parallel sides of the web bent downwardly at an angle of and fitting slidably in rings attached to the sides of the first and second rails, a second lattice including a web of 1,41 inch diameter steel rods and extending a distance of at least 3 feet arranged adjacent the side of the rst rail with ends of the rods at one side of the wel; bent downwardly at an angle of 90 and slidably engaging rings attached to the side of the iirst rail and ends of the rod at the other side of the lattice Work bent at an angle of 90 the binder course to serve as an of 1A inch steel rods and extending at least 3 feet arranged adjacent the second rail with ends of the rods at one side of the lattice bent at an angle of 90 and slidably engaging with rings attached to the side of the second rail and the References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 394,583 Lee Dec. 18, 1888 965,794 Rex July 26, 1910 1,149,167 Schmidt Aug. 3, 1915 1,220,681 Popkess Mar. 27, 1917 1,220,682 Popkess Mar. 27, 1917 1,482,960 Alsdorf Feb. 5, 1924 1,500,451 Hacker July 8, 1924 1,547,600 Manganiells July 28, 1925 1,576,066 Ransome Mar. 9, 1926 1,707,939 MacKenzie Apr. 2, 1929 1,729,885 MacKenzie Oct. 1, 1929 1,750,105 Heltzel Mar. 11, 1930

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