US1537063A - Roadway joint - Google Patents

Description

B. BRIODY ROADWAY JOINT Filed vJuly 21, 1919 May 12, 1925;

.- imaNAIan` BRIonY, or CHICAGO,"

for YoUNGsToWN, omo, A(coRroRArIo-N or isfrrcrrreAN.`

" Chicago,

of Illinois, have invented a new and Im# Patented May y12, 192s.V

UNITED- STATES PATENT oFFicE.-

'ROADWAY JOINT.

Application led July 21,

To all whom it' may concer/n.: Be it known that I, BERNARD BRIoDY, a citizen of the United States, and residing at in the county of Cook and State proved Roadway Joint, of which the following is a specification.v

j This invention relates` to concretelpavements and to the `-means for preventing said' pavementssfrom cracking irregularly and at varying ancgilesqto the sides and its ob- .Y crete roa ject is to provi e means for causing the conway to crack along a predetermlned line when the contractual stresses A ofconcrete extending into themA will concrete proved joint. Fig. 2 is ajsection on the lineA 2-2 of Fig. 1.'. Figs. 3 and 4 are similar sections showing modified forms of joints.

. parts throughout the'several views.l

within the body of the concrete become too great for the tensional strength of thecon-A crete, and'to revent-the end of one section of roadway om lifting up above the adjacent end of the adjoinlng section. I

' This invention consists ina stripv of metal embedded vertically in, and extending transversely of, the pavement, and being of less depth'than the`body of the concrete there will be s ome` concrete above the top` edge of the strip.l Thru the use `ofmy invention, the roadway remains perfectly' smooth and unbroken until stresses are set up in the concrete.` When sufficiently eX- cessive stresses `do occur'tocause a crack, that crack will occur along a straight transverse line predetermined thru the location of said metal, the crack occurring immediately above and in Aline with .said metal.

T is strip of -metal is corrugated'longitudinally. Itl further* consists informing the corrugations in the metal strip, when these are used, of-such sizethat the tongues be sufficiently strong to. carry `the end ofthe slab from which they extend. 'Y

In the accompanying drawing, Fig. 1 is av transverse section of a highway having a pavement .provided with my im' Similar reference characters refer to like The olderconcrete roadways are commonly dis'gured by irregular cracks2 which, 'if lnot attended' to and when approximately parallel to theline of travel, 'soon'4 develop. into ruts. In an effort to. overcome this ob-f 'ection', parallel metal bars have been emdded inV the Aconcrete roadway at the surv1919. serial N. 312,164.

the body of the slab does not vary in tem'- slab.

wears evenly, and the annoyin 4the present roadways are avolde l nessun:-

face and transversely tothe roadway, these bars, and the asphalt orgtar between them,

constituting what are known `as expansion joints, the chief aim, however, being to protect the edges of the concrete. These joints are usually placed so as'to divide the road# way into sections of from twenty to fifty feet in length.

I havefound that .when each bar of such protection joint is secured to the` adjacent concrete that Athe. movement between the bars is very smalland that the expansion and contraction of the roadway need not be taken into account in any but the most rigorous climates. The use of these protection joints results in transverseridges onthe wearing surface ofthe roadway, which become so objectionable that insome States the use of these joints is forbidden, the resulting ridges being-a serious sourceof annoyance.

The change in length of a section of road- Y way because 'of the changes in its temperature is extremely slight for th'e reason that perature to any great extent, but ratherbecause of its conductivity, remains at nearly the temperature of the earth beneath it,.'-

Undercertainconditions, however, there is a slight contraction of the vmaterial c`on1-v 85 posin the slab, usually in very cold weather, f and t e slab may crack.- I have, therefore, provided a strip of sheetmetal, whose width is less than the thickness of the slab, which I embed in the roadway, the lower ed e of 9o` the stri being at the` bottom face o the.

lit) shrinkage sull'icient toA crack the slab does occur, the break is along the upper edge of the strip where the concrete is weakest, and, being a straight line, can be filled with tar or asphalt with theleast amount. of labor. Theroadway however bumps of` The'main reason forthe breakage of con- 100- crete roadways probably is the .uneven stresses to which the roadway is subjected 4from above and below. As of uneven fills, l'even density of the sub-grade, the upward 105 a rule, because .uneven excavat1ons, and unresistance to the .pressure bythe pavement causesshearing stresses to be set upjwlign heavyloads are hauled over-the1roadliwfay',A often4 resultingvin cracks. My improved joint :does not `prevent these cracks but it Q y 1,537,063 V' does loc-ate them. Where the sub-grade is not perfectly drained, heavy frost often causes an upheaval of the pavement and cracking results. My improved joint not only locates the cracks but causes the pavement to settle back in alinement by holding the edges of the sections into which the pavement is broken in their original positions.

In Fig. 2 the strip l is shown embedded in the concrete 2. and to be corrugated to form longitudinal ribs 3, 4 and 5 on the concrete. Then the pavement is depressed by an unusual load or lifted by frozen ground, the projecting ribs of the concrete and the corrugat-ions of the metal will cause the adjacent ends of the sections of the pavement to rise and fall together, the corrugations of the strip and the ribs on the concrete serving as keys to hold the ends ot' the sece tions in alinement. The depth of the strip is less than the depth of the pavement so that there will be no indications of the joint unt-il the pavement cracks.

In Fig. 3, the strip 7 has a single corrugation 8, while in Fig. 4 the strip 9 has two eorrugations 1() and 11, which corrugations in each case act as molds for forming the interlocking tongues and `grooves on the concrete of the pavement. The strip will, of course, be curved to the same are as the bottom of 1the pavement if that is crowned and the depth of the strip and the shape and size of the corrugations may be varied as desired by those skilled in the art without departing from the spirit of my invention as set forth in the following-:claims 1. In a roadway, abody of -concrete constituting the pavement of the radway, and a strip ofmetal embedded in the concrete and vcorrugated longitudinally, whose length is the Width of the pavement and Whose upper edge is below the surface of the roadway, the tongues of concrete formed by the corrugations on the adjacent road sections serving to keep said sections in alinement.

2. A dividenfor use in concrete andsimilar roadways consisting of a strip of metal having a straight portion at its top edge and being corrugatedl intermediate its top and bottom edges and having both of its sides in contact with the concrete.

`3. A divided for plastic bodies consisting of an imperforate Strip of metal 'having straight top and bottom edges and having a longitudinally extending corrugation between said edges and having both sides in contact with the plastic. material.

BERNARD BRIODY.

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