US888887A - Pavement or roadway and method of making the same. - Google Patents

Description

PATENTED MAY 26, l1908.

W'. s. HOUEETON. PAVEMENT 0E EOAEWAY'ANDMEEEOD 0E MAKING SAME.

APPLICATION ILIED SEPT 1907 i %\NMN\ mm; W

H18.. .17 H A @E V bak/1M www? y\\`lLL1AM S. HUlhllTON, Ol" BOSTON, MASSMllUSE'lTS.

PAVEMENT OR ROADWAY ANB METHOD 0F MAKNG Stl.

No., asses?.

Specification o1 Letters Patent.

Patented May 26, IQS.

Application led September 23, 1907. Seriai No. 3941.093.

To all whom iz may concern.

Bo it known `that l, WILLIAM S. iionon- TON, a citizen of the United States, residing at Boston, in the county of Sufiolk and- Stateo'lliassacluisctts have invented a cerl Y tain new and useful Improvement in Pave ments or Roadways and Methods of Making' Same, of which the following is a full, clear, and exact s iecification, reference being had therein to t e accompanying drawings.

My invention relates to concrete pave ments. Heretofore, pavements of this general type have Abeen constructed in courses, comprising a foundation course of concrete or broken stone, a binder and a Wearinv surface; the )urpose of the binder course heing to form a )ond between the'loundation and the wearing surface. As a rule, the wearing surface contains a percentage of bituminous material and to a large extent this bitumi-V nous material is relied upon to,secure a erfeet adhesion between the wearing sur ace and the binding course, or, in cases where no binding course is employed, between the wearing surface and the foundation. In such iavements, it is absolutely essential that the wearing course should adhere ierfectly to the under course, otherwise, wien the pavement is subjected to trafiic, the wearlng course is very liable to slide, roll or buckle and finally break up. This tendency is exaggerated by the susce tibility of b1- tuminous material to heat W ich softens it and thereby loosens the bond between the wearing surface and the underneath course. The object of my invention is to provide a )avement so constructed that any sliding, huckling or other disturbance of the wearing surface will be impossible.

Further objects are to provide a pavement of durable, elicient and economical construction.

In the accompanying drawings, which illustrate my invention and in which similar numbers refer to similar `parts throughout the several viewsz-Figure 1 is a vertical cross-sectional View of a portion of my oundation or substructure, and Fig. 2 'is a vertical cross sectional `view of a portion of a completed, pavement embodying my invention.

In the drawings, 1 designates a curb; 2, 2, broken or crushed stones; 3 cement mixture and 4 a Wearing surface.

My pavement is constructed in the following manner. After the ground or earth has been made compact and smoothed 'then spread thereon a layer of crushed or breiten' stone, the stony elements preferably ranging in diameter from one to three inches, end

roll the same until it is compact` The depth of this layer oi crushed sto may vary from four to eight inches. if parte ways and simiiar roadways where the is light, a foundation of four inches in depth would 'probably suilice, but where the road. is to be subjected to heavy raiiic, the fourniea tion should be from six to eight inches after being rolled. For reasons hereinafter explained, it is important that thestony elements which make up this foundation layer should be of suiiicient size to ieave large voids throughout the foundation after it has been rolled.

` l next prepare a mixture oi senil or screenings and dry cement (`1oreierably` Fortland cement), in the proportion or one part oi cement to three or four parts of'sand or screenin'fsand spread this mixture over the surface of the foundation', The cement miratture is then washed, by water from a hose or 1other suitable appliance, into vthe voids in vthe foundation, Where the cement sets and ,binds the stone foundation into a homogeneous mass. It is desirable and necessary in this connection that the voids should 'be j of a size suiicient' to permit the cement noirey ture topercolate entirely through the roundation and fill completely the voids from the bottom up. This washing process is reeated until the voids in the foundation ave been filled upto aline ranging from one-quarter inch to an inch below the uninet' face or surface of the stone foundation, which at this stage presents a substantially smooth surface of stone broken un by innumerable voids of varying depth ano forms.

.After the foundation has been thoroughly bound tovether in a monolithic mass by the setting o? the 'cement mixture, it isv then ready to receive the Wearing surface which may be composed or made up by any' of the Well known methods, or of any preferred composition, J l

The wearing surface 'when laid 'upon the foundation, penetrates and 'nils up open voids in the u per iortion of the foon# dation and is therey, W en hard, anchored to the foundation. It Wili be noticed that many of the voids are larger at their bottom than at their top and in such cases, those portions of the Wearing suraee which ill all the lou los

those particular Weide not es enel'lore to hold the weering surface in place. In n pavement so bonstructed, it ie olor/ions shifting or buckling of the wearing surnce is absolutely impossible and the pavement is to ell intente ein purposes en integral body.

The principal advantages of my pavement constructed es above set forth are its economy ol eonstrnetion and wearing qualities. The foundation layer of crushed or broken stone is rolled with the ordinary steam roller whiizh enables the loyer to be smoothed off rapid j; and saves the expense of-pounding or tamping the layer by hand. Furthermore by rolling, e smoother and more even sul" e can be seemed, end to this fact is me Were upper snxfnee of the foundation leyer rough end made up of alternate stimy projections and depressions. the weering surface between the projections would in time weer away and the surface of the per@ ment would become uneven and thereby tend to breek up.

By having zr comperatwely smooth upper surface on the foundation-layer, the eroslve effect ol traffic on the wearing surface does not result in roughenng the surface of the pavement, and even when the wearing surface has been worn away to the mrsnletonlng/er, pevnwnt is still smooth und even. lo View L; feature, my paver :ent doeii not :fedi re henry weering,y surlarfe and it may loe mede oompa-rzttlmt any sliding,V

due the Wearing qualities of my pavetively thin il desired. This also condnees to economy of construction.

Whitt I oieim is?- 1. pavement, consisting of e foundation layer of Crushed or broken stone, the pieces of which lieI closely Vtogether in e compnet mess having e smooth upper surface, the voids in the lower portion of seid layer being occu ied by e cement mixture which binds all o the ieces of the layer into a monolithic -mess, eno e wearing layer 'aneliored to the upper ortion of the foundation leyerluy filling t e upper voids thereof and being 1ntegrnl with the body of the wearing layer.

2. The process Vof making e pavement, consisting 1n laying a. course of crushed or broken stone, rolling the same to com act the course and to ernoo th the upper sur eee, then filling the lower voids in seid Course with ai liquid Cement mixture, 'permitting said mixture to set and applying e, suiteble wearing surface to seid structure in such e manner that the lower ortion of said weeringeurfeoe fills in all me open voids in the up er Surface of said course.

n Witness whereof, l have hereunto set my hand, in the resence of two subseribing Witmesses, this t 1e fifth day of September, 1907.

. WILLAM HOUGHTN. Vifitnesses IE. F. UNMC,

Simmons F. RICHARDSON.

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