US664024A - Street-paving. - Google Patents

Description

UNITED STATES PATENT GEEICE.

l PATRICK J. MORAN, OF MEMPHIS, TENNESSEE.

STREET-PAVING.

SPECIFICATION forming part of Letters IPatent No. 664,024, dated December 18, 1900. Application led April 3, 1900. Serial No. 11,376. (No modal.)

To a/ZZ whom it may concern:

Be it known that I, PATRICK J. MoEAN, a citizen of the United States, residing at Memphis, Shelby county, State of Tennessee, have invented certain new and useful Improvements in Street-Paving, of which the following is a specification.

My invention relates in general to streetpaviug, and more especially to that class known as concrete paving,in which a bonding materialsuch as cement, asphalt, or the like-is used to bond together the paving material proper.

Briefly resuming, in the attempt to provide a good paving material many different materials and combinations of materials have been tried with varying success. Among the first of these are natural gravels having a clay binding material, which are now largely in use, but which because of the poor character of the binding materials will not stand excess of wet or dry weather, and therefore are not entirely satisfactory. Macadam for the same reason is not a thorough success, and the minds of men have naturally turned to other fields which follow more or less closely the lines set out by these materials. In the manufacture of composite pavements it has hitherto been customary to use broken or granulated rock and to bond them together with Portland cement or the like and to finish oif the surface with a combination of sand and cement to give a smooth surface. This mass, being of unequal composition, cracks and breaks and is otherwise very unsatisfactory infthat it gives a surface that is originally smooth and that underwear becomes more so. Later attempts to improve these have resulted in the use of linely crushed or pulverized stone as a wearing-surface and in the use of gritty substances as a top-dressing. vThese while of value for sidewalks have no value whatsoever as street-paving proper in that they all present a surface that is excessively smooth to horses and gives them no secure foothold whatsoever.

The objects of my invention are to provide a durable wearing-surface for st reet-paving which will at one and the same time be smooth for the wheel-tread and yet aord sucient foothold for horses, one which may be laid with a correct wearing-surface and if not so laid will assume and preserve same under continuous wear, and one which will give the maximum of use with the minimum of attention and when necessarily disturbed may be repaired with minimum trouble and expense. I accomplish these objectsv by making the pavement of a comparatively hard material of sensible size interspaced with a relatively soft material and a binder, or with the relatively soft binder alone, the hard material being of sufficient size to leave, when used with the binder alone, small spaces filled with the binder, which having small resistance to wear wears down slightly'and gives a surface which is of the nature of good macadam or gravel and presents a well a smooth of large diameter.

larger spaces and a slightly-rougher surface, as will be more fully set out in the general description. I further accomplish these objects by reinforcing the pavement at the points of maximum wear.

Referring now to the drawings, in which like letters of reference indicate like parts in all the views, Figure lis a sectional perspective of a portion of a city street, showing foothold for the horse and as surface for the carriage-wheel Where an additional ma- 'l terial is used with the binder, it gives slightlyf sidewalks, curbs, and the street proper embodying the principal features of my invention. Fig. 2 is a section of the paving on an enlarged scale. Fig. 3 is a like section showing a modification in composition. Fig.:4is a vertical section showing Fig. 3 under'wear. 'In the drawings, A isa section of street, showing my paving. B is a street-car rail; C, the street-curb, and D the sidewalk.'

Since the greatest wear in any street comes near the center of same, I reinforce same or make it heavier at that point. If the street is unbroken by car-tracks, I make this gradual from the center to the sides. If, however, the street be one, as shown, with street-car rails, I find that the wear is greatest within two to .three feet on the outside of the cartrack and that from that point out decreases rapidly for a short distal then decreases in a much slower ratio to the roo ite.

f ...z tovil lng, I thelfore reinforce it uniformly from the rail B to a point E about two feet distant therefrom and then make a rapid drop, as

`5 shown, to the top level proper, sloping it thence gradually to the curb.

Taking up now the construction of the pavement, or rather of the wearing-surface for the pavement, I use a hard stone-such together wit a good grade of `gement, which is preferably Portland. I find that the proportion used in ordinary concrete-viz., six of stone, two of sand, and one of cement-is about the best mixture, and of the stone onehalf to two-thirds is to be the hard granite and the remainder the softer stone. In Fig. 3 I have shown a section of pavement as first laid, in which K represents the soft-stone constituent and L the hard or gran-A In Fig. 4 I show the same pavement after hard usage, showing that the granite L has Worn comparatively little, while the limestone K has worn suciently to give slight depressions G between the adjacent high points H. The object of combining these stones of diierent hardness is to provide these slight depressions andto prevent the pavement wearing slick under continuous wear. These depressions G are prevented from becoming excessively deep by the hardness of the adjacent points H of the granite L. I find, too, that where the crushed granite is sufficiently large (about two and one-half inches) it is possible to secure the' same ef fect, though not-in so' satisfactory a degree, by binding the granite alone and suicient sand to fill the voids with a good cement binder or, in other words, to make the topdressing for the street of coarse-stoneconcrete instead ot' finishing it with a smooth fine-crushed stone and sand-facing, as is now commonly done. In this case the depressions G, as shown in Fig. 2, are in the cement and sand part of the concrete, the high points H being thetops of the granite cubes.

While I have'in this description confined myself to the surface of the pavement only, I prefer to make the pavement homogeneous, as shown-in other words, to use the same size stone bI at the top as those J at the bottom, though this is not necessarily an essential feature of my invention. In either case this pavement possesses the essential features of correct wearing-surface, great strength, im-

' perviousness to water, and is easy t0 repair.

The correct wearing-surface, which is the rst essential, is obtained, as before stated,

by the uneven wear of the materials of construction, which uneven wear gives slight dease he life of the pav? as g r anite, flint, quartz-rock, iron sla orl hard mms e c can,

.pressions between the hard points'of the hardest material and permits foothold for the horses feet. The wear is kept even by the fact that aftera certain amount of depression has been reached the wheels grind only the projecting material and with the aid of the wear from the horses feet wear this asr rapidly as the horses feet are able to do the softer material. This surface is practically as smooth to the large-diameter wheel as the best brick, asphalt, or other known pavement, with the additional advantage of absolute hardness to prevent the sinking ofthe wheel under heavy loads, as in asphalt, by its wavy displacement or on brick by the bodily displacement of same and at the same time giving foothold for the horse, thus permitting great increase in the amount of load which can be hauled over it by any given team. The great strength is given by the uniform nature of the material providing equal expansion, but more especially by the--- thorough and strong bonding of the large pieces of stone with the cement and sand, the large pieces giving a thorough an'd interlocking bond between the parts and the feature of imperviousness to water protecting it practically from all exposure to action by the atmosphere.

Imperviousness to water is an important factor in that not only is the paving itself protected from action by the water, but the foundation underneath is protected both from addition to its moisture' or loss of what it contains by evaporation, a firm foundation for the pavement being thus preserved at all times. It is absolutely sanitary in that nothing offensive can permeate it to remain and throw out its noxious odors, and by reason of its hardness it can be swept perfectly clean loo and all such material removed. Its wear is paving, which is subject to continual tear ing u p and replacing in the laying of waterpipes, sewers, &c. In my pavement it is only necessary to recrush the concrete and mix with cement and sand to bond it together, then to tamp it in place even with the surface of the street, and the work is done, the replaced portion being practically as good as when first laid and being equally as impervious to water,and by reason of its strength and perfect bond with the original pavement is in no danger of sinking under heayy loads. In the claim I have used the word stone generically. as including all classes of material-such as crushed stone, crushed granite, iron slag, gravel, &c.-as distinguished from a narrow specific class.

What I claim, and desire to secure by Letters Patent of the United States, islp As a surface-layer for street-paving, acon- IIO coarse hard stone and a coarse softer stone, both broken approximately td pass through a two-and-one-half-inch ring, of a binding naine to this specification in the presence of two subscribing witnesses.

' PATRICK J. MORAN.

5 material of sand and cement, mixed in the Witnesses:

proportions o f about three parts each of the 'f C. W. HEISKELL,

stone, tw sandfand'one of ceme t. gELLEY. QW-Sis. ..,cb'7,38791 avlng p,

Murphy@ Q,5o1,sept.9,1879, J' 1 Ambe'rg,291 ,482,Jan.e, 1894,

Paiin,559,821 ,May 28,1895, Stone Pavement sl 'Lee-,1 88, 645,Mar,20,v187"f7,lOoncret e Pavement s Mi11s,2:5e,419,Mar.1,1es1

Hicham son,161,55o,nar,:5o,1a75, Paying,encrete,

i Reissue patent to Den,657o,Aug.,13v5, n

Qi MK1n1ey,2v8,o51,nay 22,1585, v v

crete comprising; the combination with a `In testimony whereof I have signed my

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