US1623417A - Pavement - Google Patents

Description

1,623,417 Aprll 5, 1927. F V. LANHAM PAVEMENT Filed Jan. 7, 1927 2 Sheets-Sheet 1 I more permanent structure.

UNITED STATES PATENT. OFFICE.

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v i Application filed January 7, 1927. Serial No. 159,514.

This invention relates to new and useful invention will be hereinafter described, to- I improvements in pavements. gether with other features of the invention. It is well understood that horse-drawn ve- The invention will be more readily under 'hicles do not create such severe and dete stood from a reading of the following specino riorating conditions uplon roadways as are fication and by reference to the accompan imposed by motor ve icle traffic and the ing drawings, in which an example oft e present invention has to do with a pavement Invention 1s shown and wherein: designed, laid, and composed of m terials Fig. 1 1s a transverse sectional view of capable of withstanding such motor v hicle the sub-grade upon which the concrete e5 traflic and the loads incident thereto. foundation has been laid, One object of the invention is to provide Fig.2 is a similar view with the rocks or a pavement in which the rigidity, solidity, stones spread on the foundation and ready and strength of concrete pavement will be for 1mbedd1ng, obtained. F1 3 is a similar view showing the rocks 16 I Another object of the invention is to proimbe ded to substantially half their divide a avement in which the major portion meter, of-the investment is not subject to replace- Flg. 4 1s a similar view of the completed. ment, thus requiring onlyfa minor financial pavement, investment in that portion of the pavement ,Fig. 5 1s an isometrical view of a portion which is subject to repair. 8 f a pavement constructed in accordance It has been the practice "in the laying of l h my Invention and before the filler has pavements to partially imbed small stones or n applied, and j rocks in the surface of a cement course and F g. 6 is asimilarview after the filler has to utilize the upwardly projecting portions beell'a P -l $3 of the stones to bond a to layer onto the In t e drawings the numeral 10 designates cement course. However, t e to course has th 1 81 sub-grade, which is produced in acalways been given considerab e thickness rdance with the usual practice in this art. and is known as the wear la of the Curbs or hinder wallsll are provided along pavement. The top, or wear layer, is more a h side of the sub-grade, as is shown in 85 or less ex nsive to construct and replace. g- 1- Agconcrete foundation -12, of such A particular object of the invention is'to r ngthig-and' thickness as to support the provide a wear layer composed of stones or loads which the street or highway is to. carry, rocks, partially imbedded in the surface of {sh-1d onthe sub-grade IOand m .the course on which the wear layer is supernforced with metal if desired. SI imposed, whereby said stones or rocks will ents and consistency-inf the foul may,

take the wear directly and substantially. vary in accordance with the 1 A further object of the invention.1s' to accordance with whichthe pa fill the voids or interstices between the probuilt. jections of the stones with a filler having its While the concrete foundati green 98 40 upper surface substantially flush with the. and prior to its initial set, a

highest points of the projecting stones, mg of hard broken or crushed w ereby a smooth and easing surface is 13 is uniformly-spread in closecontact over presented. It is prefera Is to use a bitu the top surface of the foundation. It is' (I, and pleasing appearance, but serves to comtially uniform diameter, stones ofg'approxi pensate expansion and contraction, and tend g, mately two inches in diameter having given to heal or "fill cracks. satlsfactory results; however, the invention I mmous filler which not only makes a smooth preferable to use crushed stonesof 's'ubstan- 100 It is especially the aim of the invention to is not to be limited to the size of thesestonesg- I em loy' irregular shaped stones or crushed It is highly desirable that stones oi'gjirocks 51 V I0 roc which when imbedded'in close relation of irreghlar shape be used so that when they in the supporting 'course,,will, owing to their. are em edded, as is'shown in Figs. 5:}3and irregularities overhang and interlock with 6, they will overhang or interlock, thus'holdeach other, thus tendin to prevent relative ing each other against relative vertical disvertical displacement, -t ereby'making for a placement These stones are placed .prefer- 11 ably in a single la er and as close together A construction desl ed to carry out the as is practical wit out piling oneupon the other. This layer of stones is then lightly tamped or rolled so that the stones will be cu'rely anchored and fastened in the foundation when the concrete sets. When the stones 13 have thus been embedded in the green concrete those portions of the stones embedded in the concrete will be closely positioned to one another and, in some instances, they might be in actual contact. In actual practice, however, it has been found that the mortar of the concrete, being more or less plastic, finds its way between thesurfaces of juxtaposed stones so that instead of the stones actually contacting with one another they are somewhat spaced apart by an in tervening film of the mortar. Y

It has been the practice in building pavements to use small stones or crushed rocks as a bonding means between two courses, but

a such rocks or stones were not spread in close relation, but scattered and were covered with a top la er or course several inches thick.

It wi 1 be seen that the projecting upper portlons ofthe stones will provide a substantially continuous layer which will be rou h and an ular and composed almost entire y of bar durable wear-resisting rocks. After, the concrete has set, the surface of this wear layer is swe t clean to remove loose particles of stone, irt, or other forei materials, and there is then applied to t e said layer a filler 14 to fill the interstices or voids flush with the highest points of the roiectmg portions of the stones While the ig est oints-of the stones may be covered by the tier, particularly where it is fluent, ller is applied to fill the voids enough.

only an roduce' .a surface substantially flush with t e hi hest points of the stones. 'By this method on y about one-tenth the quantity of material is used for the filler, per square yard, .as' is.. used it: the usual top layer-which s bonded-to the under layer by stones, such as i's'fshownain the patents- Lake 507,683, issued, Qcto'ber 31, 1893, an Warren 916,070, issued March 23, 1909. It is preferable to use a bituminous composition which has been brought to the proper temperature-to insure an even distribution and in such quantity that after being loaded with fine mineral aggregate, will completely fill all interstices and surface voids.

After this ste clean, coarse sand, stone screenings, or 0t er suitable material in sufficlent quantity is spread over the layer 14. q- The surface may be lightly rolled or otherwise treated in accordance with the practice in this art.

A pavement constructed in accordance with my invention will i have many advantages and will tend to eliminate most of the difiiculties and causes of failure heret0- fore encountered in the construction of such layer composed of hard, dura 1e and tough stones, firmly anchoredagamst creeping or lateral displacement. The weight of trailic will at all times rest directly on the tops of the stones rather than upon the plastic filler, the stones being in such close relation that several will sustain the load of the average motor vehicle tire, thus overcoming the disastrous results which occur where the load is carried by a bituminous top layer. My pavement will possess a great advantage ,over concrete pavement, as ordinarily constructed, because the mortar which necessarily comes to the surface of a concrete pavement, due to the sinkingof the coarse ag regate therein, is not capable of withstanding abrasion, but functions merely as a bond or cement, and in my avement there is no such top mortar expose to wear.

A pavement constructed in accordance with my invention, will, it is believed, possess greater solidity, continuity and cohesion than those pavements in which two dissimilar layers are merely bonded together by'stones or rocks. It will, of course, be apparent that the bituminous filler will. add

protect the projectingportions of the stonesfrom being broken off, cracked, or chipped. The stones overhangin and interlocking, as is shown in 'Figs. 5 and 6, will not be easily dislodged, yet they will sustain the maximum wear and tear upon the pavement.

This application is filedas a continiiation in art of application, Serial No. 144,794.

arious c aiiges in the size and shape of the difi'erent parts, as Well 'as modifications and alterations, may be made within the scr$l of the appended claims.

at I claim, is: .1. A avei'nent consistin of a concrete foundation, a wear la er 0 relative] lar stones or rocks embe ded partially in said foundation with their upper portions protruding from said foundation in close relation to form a wearing surface. whereby a plurality of juxtaposedstones or rocks will substantially simultaneously engage the thread of a vehiclewheel passing over'the same, and a fillerdeposited in the voids between the portions of the rocks. or stones lar of a concrete in said trudin therefrom to form a wearing surface, t e embedded portion of each stone or rock having an interlocking relation with another stone or rock positloned next adjacent thereto, and a filler deposited in the voids between the protruding upper portions of the stones or rocks.

3. A pavement consisting of a concrete foundation, a wear layer of relatively large stones or rocks embedded partially in said foundation with their upper portions protruding therefrom to form a wearing surface, the embedded portion of each rock being closely positioned to and adapted to receive lateral support from the stones or rocks surrounding the same, and a filler deposited in the voids between the protruding upper portions of the stones or rocks.

4. A pavement consisting of a concrete foundation, a wear layer consisting of a single course of relatively lar e stones or rocks artially embedded in sai foundation with t eir upper portions rotrudin from saidfoundation in close re ation to orm a wearing surface, the embedded portion of each stone or rock having an interlocking relation with another, stone or rock p081- tioned next adjacent] thereto and the embedded portions of each rock being closely

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