US1380341A - Joint for concrete pavements - Google Patents

Description

W. L. ASHMORE.

JOINT FOR CONCRETE PAVEMENTS.

APPLICATION FILED OCT. 16. [920.

1,380,341. PatentedJune-Z 1921.

STATES PATENT FFICE;

WALTER L. ASHMOBE, OF MACON, GEORGIA.

JOINT FOR CONCRETE PAVEMENTS.

Specification of Letters Patent.

Patented June 7, 1921.

Application filed October 16, 1920. Serial No. 417,282.

' useful Improvements in Joints for Concrete Pavements; and I do hereby declare the following to be a full, clear, and exact descriptlon of the invention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to joints used in-th construction of concrete roads and pavements.

The primary object of the invention is, to provide a compressible joint to be embedded at intervals in the paving material as it is laid and before hardening so as to divide the pavement or roadway into blocks or sections adapted to permit contraction and expansion and prevent buckling in the finished and hardened pavement or road.

The invention will first be hereinafter more particularly described with reference to the accompanying drawings, which form a part of this specification, and then pointed out in the claims at the end of the description.

In said drawings,

Figure 1 represents a vertical sectional elevation of a portion of a street pavement with a broken away portion of a joint or separating device embodying my invention embedded therein; the compressible blocks being shown partly in their initial position and partly depressed as they appear in the finished pavement; e

Fig. 2 is a vertical section taken at right angles to the section shown in Fig. 1, on the line 2-2 of 1, looking inthe direction of the arrow; and

Fig. 3 is a perspective view of a compressible block of'wedge-like or tapered form.

Referring to the drawings, in which the same reference letters are usedto denotecorresponding parts in different views, the letter A denotes a su porting plate, preferably of sheet metal an of such length as may be desired to divide the pavingl material 'into blocks -.or sections of suita e len th and width, usually about four or five eet, and which is provided with a series of elongated slots at therein, near the up er edge thereof,

which extend vertically w en the plate is ar'ranged'in a vertical plane. A series of compressible blocks B are shdably mounted on the plate A so as to permit them to be pressed down into the plastic concrete in which the device is embedded. The blocks are preferably arranged in pairs, one upon each side of the plate, diametrically opposite an adjoining block, each pair being arranged in close proximity to an adjoining pair throughout the length of the plate. Each pair of blocks is secured together and supported on the base plate by means of a pin or rivet b which passes through one of theslots a so as to permit vertical or .downward movement the full length of the slot.

The blocks are preferably made of wood treated with creosote or other preservative substance and are set so that the grain of the wood is perpendicular to the road bed or line of the pavement.

In use the metal strips are arranged at sultable distances apart, with their lower edges resting on the sub base or foundation on which the concrete is laid, the blocks being raised above the surface of the paving material in which the device is embedded until the sliding pins or rivets reach the upper ends of the slots. The plates extendupwardly to a point near the surface 'of the finished pavement but slightly below the tops of the compressible blocks, when the latter are pressed downwardly into the plastic mass, and while the concrete is yet plastie the blocks are driven down until the tops thereof are substantially flush with the surface of the pavement, thuscompressin the plastic concrete below the blocks and orming a solid foundationon which the blocks may rest, the surface of the finished pavement being even with the tops of the blocks. In this position there is left a small crevice or open space between the upper ends of the bloc s and above the upper edge of the supporting plate, and this crevice is filled with asphalt or hot bitumen or other plastic substance so that when finished the surface of the road or pavement will be smooth and even. a

In the construction of concrete pavements, it is a common practice to insert at intervals pieces or strips of paper which are impregnated or coated with bituminous material, in order to separate the pavement into separate blocks or sections, such separations wet, or as it is usually called, green conv crete, while changing from a wet plastic condition to a hard solid state, loses in size by shrinking, and it not designedly separated will tear apart at irregular distances. Such thin material serves to separate the pavement into suitable sections or blocks, but the shrinkage caused by drying or hardening does not provide enough space for expansion due to heat or other causes after the pavement has hardened, and to provide for expansion as well as shrinkage a thicker joint of elastic or compressible material is desirable. This is particularly true of long continuous lengths of pavement like roadways, which are liable to buckle, or possibly one -slab or section will break and mount up over an adjacent section. Thin metal sheets have also been used, to effect a separation, such sheets being usually withdrawn before the pavement hardens, and thecrevice thus formed filled with hot bitumen,

which is elastic but wears unevenly with the pavement. Iron and. steel joints wear less and therefore soon protrude above the gen eral surface, causing a; hammer blow on each abutting side, and rapidly wears the softer material, while an elastic joint hammers down and the pavement edges spall and soon a hammer blow channels the joint out, thus necessitating repairs. The disadvantage common to all oints formed in w the construction of pavements under existing methods resides in the fact that they do not offer equal resistance to wear the same as the pavement.

My improved joint provides for separa tion or" the hardening pavement, expansion .of the hardened pavement and a uniform wearing surface. It is seated in and anchored to the pavement and is adjustable to its freshly finished surface. It will not wash out, pull out, or drive or hammer below the surface of abutting edges of the pavement.

The size and shape of the supporting plates and blocksvmav be varied tosuit the desires of the manu acturer or'user, or to meet difierent requirements in practical use The blocks are preferably square and tapered, as shown in Fig. 3, so as to provide a broad base and to increase their resistance against upward movement; the tapered form serving to eilectually anchor thehlocks and prevent them from being drawn out after they have been pressed down into the plastic mass and it has become hardened, but I preferably provide each block or each pair of blocks with an anchoring device, such as a hook C depending from and integral with or secured to a pin or rivet in sorted through the block or pair of blocks near the upper end thereof, so that the hook may be firmly embedded in the plastic con crete and prevent upward movement of the block. The supporting plates may be com struetecl of any suitab e material possessing upon opposite sides or" the supporting plate.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent is:

1. A joint for roadways and street pavements comprising a thin, comparatively long and wide supporting member adapted to be set on one edge upon a sub base, and a series of comparatively small compressible blocks mounted on and extending above'the upper edge of said supporting member, said blocks being slidable vertically to adapt them to be raised and depressed when arranged in a. vertical plane.

2. A joint for roadways and street pavements comprising a thin, comparatively long and Wide lower member adapted to be set on one edge, and a compound upper member consisting of a series of compressible blocks secured together in pairs, side by side, on opposite sides of said lower memher; said blocks projecting above the up per edge of said lower member when arranged in a vertical plane, and adapted to be moved downwardly so as to compress the plastic material on which they rest.

3. A joint for roadways and street pavements comprising a comparatively long and thin plate adapted to be set on edge upon a sub 'base, and a series of compressible blocks mounted on the upper edge of said plate and movable upwardly and downwiardly thereon when arranged in a vertical p ane.

4 A joint for roadways and street pave ments comprising a sheet metal plate adap ed to be set on edge upon a sub base, said plate having a series or oblong slots therein near its upper edge which extend transversely of its length, and a series of compressible blocks slidably mounted on the upper edge of said plate and secured thereto by pins passing through said slots.

5. A ointfor roadways and street pavements comprising a fiat metal plate adapted to be set on edge upon a sub base and having a $611650]? oblong slots therein near its upper edge which extend transversely of its length, and a series of compressible blocks mounted on and projecting above the upper edge of said plate; said blocks being arranged in pairs which are joined together dependent adjustment of said pairs transversely of said plate.

6. A joint for roadways and street pavements comprising a rigid plate of comparatively thin material adapted to be set on edge, and having oblong slots therein near its upper edge and a series of compressible bloc-ks mounted on said plate and arranged in pairs, each pair having a pin passed therethrough and through one of said slots.

7. A joint of the character described comprising an oblong sheet metal plate having a series of oblong slots therein near one edge extending transversely of its length and a double series of blocks of wood arranged on opposite sides of said plate, each block on one side'of said plate being secured to a block on the other side thereof by a pin uniting the two blocks and passed through one of said slots so as to permit vertical adjustment of the blocks when arranged in a vertical plane.

8. A device of the character described comprising a comparatively thin plate of a width slightly lessthan the depth of a body of concrete in which the plate is set on edge said late having a series of blocks of compresslble material mounted thereon and adjustable vertically when arranged in a vertical plane, said blocks having means thereing a series of joints therein, said joints consisting of comparatively thin plates set on edge upon a sub base, and a series of compressible blocks mounted on and projecting above the upper edges of said plates, the upper ends of said blocks being substantially flush with the surface of the concrete.

10. A joint for a concrete roadway or pavement consisting of a comparatively thin plate adaptedto be set on edge upon a sub base and embedded in the concrete, and a series of compressible blocks mounted on the upper edge of said plate and projecting above the same, said blocks having depending hooks thereon for anchoring them the concrete. y

In testimony whereof I aflix my signature in the presence of two witnesses.

WALTER L. ASHMORE.

Witnesses:

L. D. MooRE, RoY W. Moore.

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