US2746365A - Road construction - Google Patents

Description

May 22, 1956 J. A. DARNEILLE ROAD CONSTRUCTION Filed Nov. 16,

(0 71 /0 Vf' t man United States Patent ROAD CNSTRUCTION Joseph AQDarneille, Silver Spring, Md;

Application November 16, 1951i, Serial No. 256,654

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This invention relates to improvements in road construction, and more particularly to new road structures.

It is recognized that collection of water beneath a concrete roadway due to improper drainage conditions is responsible in many cases for a premature breakdown of the concrete slab. Water which seeps beneath a concrete roadway will usually form into a pool which will be continually increased in size under the constant pounding produced by the rise and fall of the slab under weight loads. This pounding causes the pool of water to enlarge the recess in which it lies, and the enlarged recess, of course, s capable of receiving more water. When the recess has become quite large, and, due to a dry spell, the water has become low or disappeared entirely, the concrete slab of road above the recess is no longer supported and will crack under a heavy load.

Under present road construction methods, it is necessary to provide transverse expansion joints at closely spaced points along the road to permit expansion and contraction of the slab under temperature changes. Frequently, the ends of adjacent slab sections will become out of horizontal alignment causing wear and breakage at the joints. Very heavy vehicles passing over the road will depress the ends of the slabs over which they are passing, thus positioning them below the plane of the adjacent end of the next slab. This, of course, will produce the result just mentioned.

The object of the present invention is to provide a road structure which will eliminate the water problem by permitting the removal and drainage of water which may seep between the slab and the roadbed, and thereby prevent its collection beneath the slab.

Another object of the invention is to provide a road structure which will absorb much of the expansion and contraction of the slab within its own length, and therefore drastically reduce the number of expansion joints necessary in a given length of road.

Still another object of the invention is to provide an expansion joint which will prevent the joint edges from becoming out of horizontal alignment.

Other objects of the invention will appear from the following description when taken in view of the drawings which accompany, and form a part of this specification.

In the drawings:

Figure l is a perspective view of a section of road constructed in accordance with the present invention;

Figure 2 is a transverse section through the road, showing the forms used in constructing the road in place; and,

Figure 3 is a longitudinal section through a portion of the road taken on the line 3--3 of Figure 2.

Referring to the drawings in detail, the invention consists generally in providing a concrete slab which has a plurality of transverse, horizontal passages through it, the passages being spaced from one another longitudinally of the slab and each having a plurality of vertical openings extending from the bottom of the passage to the bottom of the slab.

The road is constructed by the use of side forms 1 2,746,365 Batented May', 22.11956 and Z, each of; which is a. channel: member having.- a pluralityV of. horizontally extending bosses` 3. spacedt along its` vertical, web. The bossesthave openings1 throughthem for a purpose to be described'. The bossesmay'beround, oval, or other desired shape, and are; adapted to. receive the ends of ther tubular formsr 4, having-,the samexinterior shapel and size as the bossestfso as to. slipr snugly. over the. bosses. Tubes 4i are slightly tapered, fromendl to end, and. for this. reason. thebosses onl side,r form., 1. will be. slightly smaller thanthe-bosses, on.` side form tubes are of a length equal' to the width of the slab to be laid, and will serve; asA spacers to holdA ther side,V forms the proper distance aparta Eachn tube i's, provided with i a series ofA aligned openings 5, extending tl'i'e length of the tube. When the tubes are positioned between the side forms, the row of holes in each tube is positioned at the bottom. When the side forms and connecting tubes are set up the concrete may be poured to form the slab. Of course, reinforcing rods or mesh mats 7 may be used, and properly positioned before the concrete is poured.

After the concrete has set sufficiently to hold its form, but before it has hardened, a special tool may be inserted into the tubes and when the tool strikes a projecting stop 6 positioned behind each opening 5, the tool may be operated to drive a hole into the concrete from the tube downward to the roadbed. Any suitable tool could be used, and one such tool might take the form of a tube having a right angle bend at its leading end. A relatively stitl, but flexible, shaft will be inserted in the tube. When the down-turned mouth of the tube strikes the abutment 6, the shaft may be pushed through the tube into the soft concrete to form a vertical opening. When the concrete has set suiiciently, the structural forms may be removed. When the side forms have been taken away, the tubes 4 may be pulled out of the slab from the side having the large end of the tube. A tool similar to that used for pulling automobile axles may be used. This tool, as is well known, has a threaded shaft having means at its end to engage the tube, and the nut through which the shaft works has feet to engage the side of the slab. When the screw is turned the tube will be broken free from the concrete and can be drawn out.

The road resulting from this manner of construction will be in the form of a continuous concrete slab 8 having a plurality of spaced horizontal passages 9 eX- tending transversely through it. Each passage 9 will be in communication with the roadbed beneath the slab through a plurality of vertical holes 10. Trenches 11 at either side of the finished road will be lled with crushed rock to provide drainage ditches to carry off water.

With this structure, any water which seeps beneath the slab can rise in the vertical holes 10, and when the road is under weight loads, the rise and fall of the slab will cause the water to spurt up into the vertical holes into the horizontal passages 9. Due to the fact that the tubes 5 which formed the passages 9 are tapered, the openings have inclined bottoms so that the water will run to the side edge and be carried oir' in the drainage ditches. It is customary to build a concrete road in two abutting half sections, and the large ends of the tubes will be at the outside edge of each half so that all water v will be carried outward. As the water is free to rise in the openings in the slab, no pockets will be formed beneath the road, and, therefore, a firm roadbed for the slab can be maintained.

Much less overall elongation or contraction of the slab will take place in this type of road as the openings will absorb a considerable portion of it. Therefore, transverse expansion joints need be used only at widely spaced points, and then, if provided in the vertical plane of one of the passages 9, it need only bethrough that portion of the slab above the passage to prevent the surface from buckling. A joint of this type is shown at 12 in Figure l.

Whilev in the above a practical embodiment of the invention hasbeen disclosed, it will be understood that various changes may be made from the precise arrangement shown without departing from the spirit of the invention as dened in the appended claims.

What s claimed is:

l. Road construction comprising, an elongated slab of concrete having a plurality of spaced horizontal passages extending completely through said slab transversely thereof, and having a plurality of vertical openings extending from the bottoms of said passages to the bottom face of said slab.

2. Road construction comprising, an elongated slab of concrete having a plurality of spaced horizontal passages completely through said slab transversely thereof, said passages having their bottom walls sloping downwardly toward one side edge of said slab, a drainage ditch along said one sideedge, and said slab having a plurality of vertical openings communicating with the said passages and the bottom face of said slab.

References Cited in the le of this patent UNITED STATES PATENTS 283,369 Bartlett Aug. 2l, 1883 2,148,773 Ozias Feb. 28, 1939 2,254,885 Carswell et al Sept. 2, 1941 2,486,683 Sass Nov. 1, 1949 2,502,672 Royther Apr. 4, 1950 FOREIGN PATENTS 913,410 France May 27, 1946

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