US1660421A - Pavement - Google Patents

Description

Feb. 28, 1928.

H. M. KNIGHT PAVEMENT Filed Aug. 10. 1921 2 Sheets-Sheet 1 Feb. 28, 1928.

1,660,421 H. M. KNIGHT PAVEMENT Filed Aug. 10. 1921 2 Sheets-Sheet 2 Patented Feb. 28, 1928.

UNITED STATES PATENT vr f s HERBERT M. KNIG T; or mountain, JERSEY.

rav'nivrnn'r.

Application filed August 10,1921. Serial No. 491,227.

This invention relates to pavements, and has special reference to pavements composed in part of pre-cast concrete units.

One of the objects of the invention is to provide a pavement built up of units, any,

one or several ofwhich may subsequently be removed and replaced. Another ob ect of the invention is to provide apavement, parts of which may be removed for the purpose of permitting underground work to be performed, while the remainder of the pavement ren'iains intact, permitting of continuous use by tratlic. Another object of theinvention is-to provide apavement built up of precast 1 a pavement built up of pike-cast unitswith means for filling void spaces which may exist beneath said pavement. Another object of the invention is to provide a pavement, one portion of which consists of pre-cast slabs resting upon and removably attached to sills supporting said slabs. A further object of the invention is to produce a unit type of pavement in which the several units composing similar parts shall be interchangeable. Still another object of the invention is to provide a pavement with ducts therein for the passage of heat for the melting of ice and snow from the surface oflthe said pavement. Another object of the invention to provide a pavement, the pre-cast slabs of which are supported inpart by the curbing along said pavement. Other ob ects of the nventuim will appear from the followingdescription and from the aiamnmanying drawings.

The accompanying drawings, Figures 1 to 13 inclusive, are illustrative of the invention, and indicate the usual and preferred embodiment thereof. They are however illustrative only and are not to be considered as inclusive of all types in which the invention may be a slab or unit employed in the said pave Inent; Fig. 4 is a section at the curb-line and shoulders 3 and 5.

Fig. 5 .a'section at an intermediate-sill; Fig.

6 is an elevation ofthe hook-bolt used for removablyconnecting the slabs to the curbs and sills; Fig. 7 is a section ofsuch a hook bolt on the line 7- 7 of Fig. 6; Fig. 8 is a section of the bolt on the line8.8 of Fig. (3 Fig. 9 is a plan of a portion of a pavement at a sill with the wearing coat removed; Fig. 10 IS a plan view of a curb; Fig. 1l is an elevation of a sill and Fig. 12 a plan-view of such asill. Fig. 13 is.a'cross-sectionof a sill and pavement showingtheir application in the support and maintenance of a rail.

Referringto the drawings inwhichsimilar figures refer to similar parts.- 1 is a precast slab partially supported by a curb 2 hav-,

mg a shoulder 3 positioned to support said slab. "lhe slab may also be supported in whole or in part by a sill 4 having a shoulder a at the upper part thereof.

Hook-bolts ('3 pass through bolt holes 7 in sa d slab, said bolts removablyengagingsa d shoulders 3 and 5. The bolt holes 7 have an elongated opening 8 in the bottom face oft-he slab and are provided witha shoulderQ for the purpose of engaging a washer 1O which is forced against the shoulder 9 by a nut 11 which engages a screw thread on the shank of the hook-bolt. The hook-boltG has an extension 13. with an upper face l l flattened to make superficial contact with the-bottoin ofthe A hole 15 for the purpose of washing or grouting material be-..

neath the pavement after the placing ofthe slabs and before'the laying of the wearing coat, and also as a. means of handling the v slabs during the processof insertion or re ing bolts and removing and handling slabs. A wearing coat 17 covers the slabs and fills the joints between the several slabs and between the slabs and curbs.

body of the slabs, th e ducts of juxtaposed slabs being in linear alinement. A boss 19 is formed upon the bottom of the sill 4 and rebates 20 on the inner faces thereof. Bolt holes 21 pass through the webs of the sills and bolts 22 are insertedin said bolt holes and securely fasten the duplicate parts of the sills together. Clips 23. are shown, positioned in the rebates 20 having bolt holes 24 Ducts 18 for the I purposeof conveying heat, are formed in the therein through which the bolts 22 pass. The upper ends of said clips 23 are provided with an offset 25 adapted to engage the base of a rail 26 andvto be secured thereto by means of a wedge 27. The upper flange of the sill 4 has a depression 28 adapted to re ceive the base of the rail 26, and a chase 29 adapted to receive the offset 25 ofthe clip 23. The chase 29 has an oblique back 30 permitting latitude of movement of theclip .23. A shoulder 31 is formed uponthe back ofthe curb 2, snpportingthe sidewalk slab 32. Sewers 33, conduits 34, water pipes 36 and gas pipes 37 are indicated as located beneath the said pavement.

In the constructmn of city pavements, as

usually performed, a foundation of concrete 71s laid upon the sub-grade, either with or without consolidation, and a wearing. coat of brick, asphalt, or other resistant or re- 7 silient material is superimposed thereupon. Subsequently excavations are made through this foundation and wearing material, 111

order to reach and repair existing sub-sun I face pipes, or for the purpose of introducing new ones. In the process of such excavation all of the foundation and other pave-' ment material removed is broken up and destroyed, and an area largely in excess of that required-is injured, such destruction and injuryentailing great waste and heavy costs for restoration. In the pavement herein illustrated, pre-cast slabs, usually of concrete, are supported upon curbs and 1011-' gitudinal sills and .removably attachedto said curbs and sills by means of hookbolts, which, while holding the slabs rigidly iii position while the pavement is in service, are quickly and easily removable, allowing the slab,-with its superimposed wearing surface to be removed from the section of the roadway, beneath which it is desired to make excavation. All of the removed paving material, being by this process preserved, is easily and quickly returned to position and the pavement immediately restored. The only portions of the wearing surface destroyed arethe portions along the cdgesof the slabs, therestoration of which is a small and inexpensive matter. The hook-bolt being of the illustrated form is easily inserted in the bolt hole through the slab, the elongated bottom of the said bolt hole permitting of the introduction of the hook-bolt so that the hook is parallel to the curb or sill, when, upon such introduction, the hook is turned through an angle of 90 degrees and the flattened face of the hook brought into contact with the lower face of the shoulder on the curb or sill and fas-' tened thereto by means of the nut resting upon the washer which is in contact with the shoulder within the bolt hole. As the bolt hole is filled with some easily removable material which is easily removable and a above freezing.

with the major axis ofthe elongated aper-y ture and withdrawing it from the pavement.

The slabs are thereupon freed from the sills or curbs-and can be lifted, andsuhsequently replaced, it being possible to rc-insert and fasten the same bolts in the same as the initial manner.

ment is the possibility of cavitiesbeing left,

One of the defects of a slab type of paveor later appearing, beneath the pavementlVhile a sub-grade can be so carefully dressed as to make the presence of such "cavities both small. or remote, provision against their arising and becoming a dangerous menace to the life or safety of the pavement are desirable. For the purpose of preventing the presence of such cavities. after the pavement shall have been laid or 'replaced,

grouting holes are provided in each of the slabs or units making up the pavementy through which earth or other material may be washed or grouted beneath the slabs, in

advance of the laying of the wearing coa:t.

By such washing or groutingall voids beneath thepavement are filled, and a'pave ment resting firmly upon the soilover its entire area is secured.

The slabs rest upon curbs and also upon loo longitudinal sills, the latter, for greater ease in manufacture and in handling, being in multiple, the said multiple sill units being assembled in relatively reversed position in the pavement and breaking joint with each other. They are connected together by bolts. Such multipliclty of members and such breaking of jointsproduces a rigid struc ture and prevents irregular settlement vof the pavement under traffic. The superficial pie-cast slabs supported by the curbs and sills, likewise are staggered so as to give a maximum ofstrength and to insure a regularity of surface. The sills are rebated, on their backs, the purpose of such rebating in} ing to provide a slot or space for the in sertion of means, such as the tie .or clip shown, for fastening a rail, or other superficial bodyor construction, to the sills or V pavement. V y a i l the greatestdrawbacks to the use One of of a smooth pavement in citvstreets, where frost conditions are liable to exist, in the colder months, is the formation of a thin coating of ice thereon, making the pavement very slippery and dangerous to either hon-ire drawn or motor traffic. Such slipper-i,- ncsscan be prevented if the surface of the pavement is maintained at a degree ortwo Again, except for excessively heavy snowfalls, the removal of the snow can be greatly facilitated,if notene tirely performed, if the pavement is kept slightly .warm, sufiiciently to melt the snow as it falls. '13 or the purpose of securing this result, ducts are shownas havingbeen formed in the body of the slabs during the casting thereof, so alined as to make a coninuous passage ,orv series ofipassages, under.

and through the pavement, such ducts lead mg to some central heating plant, from which hot a r, steam or hot water is ClICUr lated for the purpose of heating the pave-I meut to a temperature slightly above freezing.

The wearing surface, being laid in situ, and after the slabs have been attached to the curbs and SlllS, fills all cracks and other divisional lines betweenthe slabs and be. tween the slabs and curbs, and makes there units and bolts engaging under said shoul ders on said sills and removably attaching said slabs and said sills.

2. In a pavement, a pre-cast slab, a sill supporting said slab, said sill being composed of a multiple of units having rebated backs, downwardly facing shoulders on the upper portion of said units oppositely disposed to said rebated backs, flanges on the lower portion of said units, fastening means joining said units and bolts passing through boltholes in said slabs and engagingunder said shoulders on said sills and removably attaching said slabs and said sills.

3. In a pavement,- a pro-cast slab,sills supporting said slab, said sills being composed of a multiple of units, shoulders on the upper portion of said units, flanges on the lower portion of said units, fastening means joining said units, bolts engaging said shoulders on said sills and removably attaching said slabs and said sills and a superficial wearing coat upon said slabs.

l. In a pavement, a pre-cast slab, sills supporting said slab, said sills being composed of a multiple of units, rebated backs to said units, shoulders on theupper portion of said units oppositely disposed to said rebated backs, flanges on the lower portion of said units, fastening means joining said units, bolts passing through bolt-holes in said slabs and engaging said shoulders on said sills and removably attaching said slabs and said sills and a superficial wearing coat upon said slabs. f

5. In a pavement, a pre-cast slab, sills supporting said slab, said sills being composed of a multiple of units, downwardly direct ed shoulders on the upper portionof said uni.ts,ifia nges on the lower portionof said un1ts,wfasten1ng means oining saidunits,

bolts engaging under said shoulders on said slabs. engaging said shoulders on said sills and removably attaching saidslabs and said sills and groutingholes in said slabs.

7. In a pavement, pre-cast slabs, a plural ity of sills common to a plurality'of slabs and supporting the same, said sills being composed of a multiple of units, shoulders on the upper portion of said units, flanges on the lower portion of said units, fastening means joining said units, bolts engagingsaid shoulders on said $1115 and removably attaching said slabs and said sills, and ducts in said slabs, said ducts being alined in successive slabs and held in alinement by the attaching of said slabs to the common sills.

8. In a pavement, a plurality of juxtaposed alined pre-cast -slabs,'a plurality of sills common to a plurality of slabs and interposed under the marginal alined edges of portion of said units, flanges on the lower portion of said units, fastening means joining said units, bolts engaging said shoulders on said sills and removably attaching said slabs and said sills and ducts in said slabs,

said ducts in juxtaposed slab being in linear alinement, and held in alinement by the attaching of said slabs at their alined edges to the common sills.

9. In a pavement, a pre-cast slab, sills supporting said slab, said sills being composed of a multiple of units, rebated backs to said units, shoulders on'the upper portion of said units 0 positely disposed to said rebated backs, units, fastening means joining said units,

bolts passing through bolt-holes in said slabs anges on the lower portion of said cast slabs, precast curbs and sills support? ing said slabs, bolts passing through boltholes in said slabs and engaging shoulders on said pro-cast curbs and sills and removabl-y attaching said slabs 'to said curbs and sills, grouting holes i-nsaid slabs, ducts in said slabs and a wearing coat superimposed upon said slabs. l i i 12. In a pavement, a multiple of precast slabs, a hook-boltand a projecting arm to said bolt, the upper surface of which arm is flattened.

13. In a pavement,

'. the combinati on of pro-cast slabs, pro-cast curbs and ,pre-east sills supporting said slabs,,ho0k-bolts passing through shouldered bolt-holes having an elongated louver aperture, in said slabs, and engaging shoulders onsaid pro-cast curbs and prc=cast-sills,and rcmorably attaching.

said slabsxto said curbs and sills, grouting liolesin said slabs, ducts in said slabs and a wearing coat superim oed upon said slabs.

Signed at- New Yor in the county of New Yo-rk and State of New York this ninthday of August, A. V HERBERT M. KNIGHT;

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