US2649720A - Drainage system for airports and highways - Google Patents

Description

Aug. 25, 1953 J. N. HELTZEL DRAINAGE SYSTEM FOR AIRPORTS AND RIGHWAYS Filed March 4, 1947 2 Sheets-Sheet l Aug. 25, 1953 J. N. HELTZEL 2,649,720

DRAINAGE SYSTEM RoR AIRPORTS AND HIGHWAYS Filed March 4, 194'? 2 Sheets-Sheet 2 Patented Aug. 25, 1953 DRAINAGE SYSTEM FORAIR'PORTS AND HIGHWAYS John vNicholas Heltzel, Warren, lOhio; The 'Union Savings & A,'.lrust Company, Warren, Ohio, and Carl J. Heltzel, executors fof said John N.

Heltzel, deceased vApplication March 4, 1947, Serial N o. '732,169

11 claims.

This present invention relates to improvements in drainage `.means .used in connection with expansion joints Aof `sectional concrete road construction for .highways orairports.

Theprincipal objectof theinvention .is to provide proper drainage in airport construction. ,'.Ihe'now prevailing practice of drainage .is :to seal all the joints between the sections ofthe construction with a View of Ipreventing .the infiltration .of water from lthe topisurface ofthe airport. According tomy invention the sealing of the .joints is entirely eliminated and-open ,joints are provided through which the water on `the top surface is drained orf :and which function as expansion joints and permit the free movement of the slabs in all directions. Therefore, the joints are made kwide enough to avoid their total closing when the slabs are in a state of maximum expansion. Thus, kthe surface Water or laitance ows through the open 'joint and into a drainage pit extending parallel to the joint. Access to the pit may be had to ilush the same when desired by water conducted through Vthe drainage pit and then discharged into suitable storm sewers to be thereafter disposed of.

Another object of the invention is to provide means for rapidly and completely'draining water from a surface and for eliminating the possibility of the formation of small pools on such surface. "Thus, there is no longer any necessity of providing gutters in the surface which may be constructed level.

A further object of the invention is to dispense with the'compressible material which under the prevailing vsystem is intended to seal the `joints to prevent water from escaping therethrough. 1lhis compressible material projects, in times of high temperature, above the surface of the roadway or airport and forms a protube'rance which causes a terrific impact when `a heavily loaded wheel passes thereover. This impact results in a pounding action on the joints and causes the subgr-ade to produce a capillary attraction commonly called pumping at the joints. This pumping action deteriorates kthe subgrade and undermines the slabs at their ends. My improved construction prevents the surface water from penetrating to the subgrade and corrects. the pumping action.

A still `further object of the invention is' to provide la simple and inexpensive construction having the advantages above pointed out.

With these and other objects in view which will .become apparent Ias the .invention is fully understood, the same resides inthe novelty of construction, combination and arrangement of elements hereinafter described in their speciiic details and claimed in the subjoined claims.

The Ltiescription should beread in connection with the accompanying drawings .forming part of this .specification `and .illustrating the preferred embodiment :of 'the Iinventionland wherein.'

Fig. 1 is a vertical .section `transverse of :the joint .and perspective view of a roadway `or air- -port runway .according to my invention;

Fig. 2 is a view similar to Fig. vl but showing slab-carried .connecting means for a joint-supporting :beamg Fig. :3 is a .vertical .section .taken longitudinally7 of the joint;

Fig. 41's a. horizontal section; and.

Fig. `5 is a vertical section r-transverse of the joint and perspective view ofthe roadway .oran- .port runway accordingt'o Ja modiiied form lofmy invention. f

'in the drawings in which like characters-of reference designate :like or similar parts, numeral 5 denotes one voi? theispaced airport :or roadway slabs .each of which .rests -on as-uitable asphaltic impact .or cushion strip l. The same serves jto lessen Athe resistance to 'the 4horizontal Amovement of the slab resting on the cushion strip, .insures a :completeiseparationof the bottom of the slabs and the top of the beams and 'furthermore functions asaalubricant during the expanding `or Acon-- tracting movement of the slabs, and as shock absorber vof :a loaded'wheel passing the joint lI I.

'The cushion A:strips ..7 (which .may or may not be preformed) are supportedby a beam member i! which vextends parallel to the joint Il formed 4bythe :spacing of the slabs, :and is located in la depression formed inthe subgrade I3. Thisbeam .may vbefpreca'st and is channeled Aat the bottom as indicated by .5?5 with a view of maintaining the Yportion of the subgrade in `the channel vI5 dry. lThus the capillary attraction and pumping action referred to in the objects of v'the invention is partially corrected.

To further solidify the subgrade as a bearing surface, openings .il may be provided Vin the beam -5 and :a lean mixture of concrete or other suitable ller or bearing material may be forced through these openings down `under the beam to nll any interstices within the connes of channel i 5 V`and in the .subg-rade .and to Vform an auxiliary bearing I9. `If desired, pressure plugs 2l may be used inthe openings .Il `which plugs would tend to level or buoy the beam member up to proper grade 'before vthe slabs 5f Vare poured.

Pressure .plugs will be necessary topressure fill under `the .beam to buoy up the Venti-re structure incase the beam and slab ends may recede simultaneously `due to trailicimpact.

After forming the subgrade, .asuitable collapsiblieform 4or forms will be yused forforming the Y Further resistance to movement of the slabsin any direction is eliminated by the provision. of cushion members 2i each positioned in the lower portion of a slab and the adjacent upper portion of the beam. The cushion members are of compressble material and frustro-conical shape and, if positioned in a slab, have the smaller end at the top and, if positioned in the beam, have the .smaller end at the lower end. In order to facilitate their ready application to the tension members 3 the cushion member may be split or comprise identical halves lying on either side of the diametrcal plane of symmetry.

Each of the tension members 30 is U-shaped and acts as a reinforcement of the beam 9 and a tie between the latter and the ends of the pair of slabs separated by the joint H. Thus, curling of the slab ends will be presented, also the moving up and down of these ends during the passage of wheels over the open joint.

Each of the tension members 3b may be a solid rod or a exible member comprising a plurality of twisted rods forming a cable-like structure. The latter type of tension member 30 will lessen the resistance to slab movement and also prevent fracture due to flexing or vibration. The material of the tension member 30 may be galvanized or other rust or corrosion-proof metal.

In the preferred embodiment of Fig. 2, each cable-like tension member 30 has its upper portion terminating in radially spaced hook-like ends 32, each formed by one of the strand rods of the member and serving as anchorages in the concrete bodies of slabs 5.

In the modification of Fig. 5, the slabs 5, separated from one another by a joint Il, rest each on a separating sheet or strip which may be rubber, tar paper or asphalt-coated paper. The same provides lubrication for the slab during its movement on beam 8 and keeps moisture out of the crevice between the slabs 5 and the beam 9.

The sheet or strip 'i separating the slabs 5 from the beam S also takes up the shock of an impact of a load passing over the joint. This shock absorbing function of the sheet is important in that it prevents a pumping action on the subgrade as it is called in the art. This pumping action tends to undermine the supports of the subgrade in which the beam is embedded.

lThe casting of the beam 9 may be done on the job or the beam may be precast and hauled to the job.

|The employment of a precast beam will almost inevitably lead to cavities and irregularities between the bottom of the beam and the subgrade. Neglect of these cavities and irregularities will deprive the beam of uniform support throughout its length and the ends of the slabs will lack proper support.

n order to remedy such a situation, steps are taken similar to those outlined in the description of the preferred embodiment of Figures 1 4.

rIhe slabs have their adjacent corners cut away as at 23 forming part of a drainage conduit, the other part of which is formed by a depression 24 in the beam and which is in communication with to provide the joint II.

The form for casting the slabs may be supported by the beam and could be collapsible so that the form, after setting of the slab, may be removed through the joint il.

In each slab is a compressible cushion member 29 forming Aa hollow frustum of a cone with a top 28 for the passage of a tension member 30 which takes the form of a twisted rod or cablelike member. This member is horizontally bent at the lower end 3i in the beam and its strand rods are horizontally bent in opposite directions at the upper ends 32 in the slab.

While I have hereinbefore described and the drawings show the details of a preferred and modied form of my invention, I desire it to be understood that variations of these details may be resorted to within the scope of the appended claims without departure from the spirit of the invention.

What I claim is as follows:

1. In a road or airport runway construction or the like including subgrade-supported slabs spaced from one another to provide an expansion joint therebetween; the combination of a beam embedded in the subgrade below and paralleling the joint between the slabs, said beam having a lineally extending trough in its top surface below said joint, the bottom of said beam having a lineally extending channel, there being lineally extending side shoulders defining said channel and embedded in the subgrade, the top of the beam lying substantially flush with the bottom of the slabs, and injection passageways for ller or bearing material and extending from said trough to said channel whereby filler or bearing material can be injected into the channel at the lbottom of the beam.

2. The combination set forth in claim 1, and anti-friction material interposed between the beam and the respective slabs adjacent said joint, whereby to permit relative horizontal movement of the slabs and beam.

3. The combination set forth in claim 1, and relative horizontal movement permitting tie means connecting said beam and slabs, there being an inwardly opening recess in at least one of the opposed beam and slab surfaces through which said tie means extends, said recess providing a shift-permitting space for said tie means Vat opposite sides thereof in a plane substantially normal to said expansion joint, whereby to maintain the beam in contact with the under surface of the slabs at opposite sides of the joint so as to assure of drainage through the joint getting into the beam-provided. trough.

4. The combination set forth in claim l, and relative horizontal movement permitting tie means connecting said beam and slabs, there being an inwardly opening recess in at least one of the opposed beam and slab surfaces through which said tie means extends, said recess providing a shift-permitting space for said tie means at opposite sides thereof in a plane substantially normal to said expansion joint, whereby to maintain the beam in contact with the under surface of the slabs at opposite sides of the joint so as to assure of drainage through the joint getting into the beam-provided trough, drain means in said subgrade below the plane of said beam-provided trough, and said beam providing drain passages communicating from said trough to said drain means.

5. In a road or runway construction comprising spaced slabs forming an expansion joint therebetween, a subgrade upon which the slabs are disposed, a beam embedded in the subgrade below and paralleling the joint between the slabs, said beam having a, lineally extending trough in its top surface below said joint, a drain in the subgrade, means communicating from said beam-provided trough to said drain, the -bottom of said beam having a lineally extending channel and having lineally extending side shoulders defining said channel and embedded in the subgrade, the top of the beam lying substantially flush with the bottom of the slabs and the top of the subgrade, passages extending transversely through said beam from said trough to said channel and the bottom of the beam, whereby to admit of the pumping of' filling material therethrough and into the bottom beam-provided channel to provide support for the beam in case the subgrade provides an irregular surface presented to said beam channel, anti-friction material interposed between the beam and the respective slabs adjacent said joint, whereby to permit relative horizontal movement of the slabs and beam, aligned compressible material sleeves in the respective slabs and subjacent portion of the beam, and tie means embedded in the respective slabs and beam and extending through said sleeve means, whereby to connect the beam to each slab while permitting relative horizontal movement of the same as when the slabs expand and contract, and removable plugs closing the passage means between the drain trough of the beam and the Iunder channel thereof.

6. In a road or airport runway construction or the like including subgrade-supported slabs spaced from one another to provide an expan- Ision joint therebetween; the combination of a beam embedded in the subgrade below and paralleling the joint between the slabs, the bottom of said beam having a lineally extending channel, there being lineally extending side shoulders defining said channel and embedded in the subgrade, the top of the beam lying substantially flush with the bottom of the slabs, and injection passageways for filler or bearing material and extending from the upper portion of said beam to said channel whereby filler or bearing material can be injected into the channel at the bottom of the beam.

7. The combination set forth in claim 6 and anti-friction material interposed between the beam and the respective slabs adjacent said joint, whereby to permit relative horizontal movement of the slabs and beam.

8. The combination set forth in claim 6, and removable plugs closing the injection passageways at the upper ends thereof.

9. In a road or airport runway construction or the like including subgrade-supported slabs spaced from one another to provide an expansion joint therebetween; the combination of a beam embedded in the subgrade below and paralleling the joint between the slabs, said beam having a lineally extending trough in its top surface below said joint, the top of the rbeam lying substantially F fiush with the bottom of the slabs, and relative horizontal movement-permitting tie means connecting said beam and slabs, there being an inwardly opening recess in at least one of the opposed beam and slab surfaces through which said tie means extends, said recess providing a shiftpermitting space for said tie means at opposite sides thereof in a plane substantially normal to said expansion joint, whereby to maintain the beam in contact with the undersurface of the slabs at opposite sides of the joint so as to assure of drainage through the joint getting into the beam-provided trough.

10. In a road or airport runway construction or the like including subgrade-supported slabs spaced from one another to provide an expansion joint therebetween; the combination of a beam embedded in the subgrade below and paralleling the joint between the slabs, said beam having a lineally extending trough in its top surface below said joint, the top of the beam lying substantially flush with the bottom of the slabs, and relative horizontal movement-permitting tie means -connecting said beam and slabs, there being an inwardly opening recess in at least one of the opposed 1team. and slab surfaces through which said tie means extends, said recess providing a shift-permitting space for said tie means at opposite sides thereof in a plane substantially normal to said expansion joint, whereby to maintain the beam in contact with the undersurface of the slabs at opposite sides of the joint so as to assure of drainage through the joint getting into the beam-provided trough, drain means in the subgrade below the plane of the beam-provided trough, and said beam-providing drain passages communicating from said trough to said drain means.

11. In a road or airport runway construction or the like including subgrade-supported slabs spaced from one another to provide an expansion joint therebetween; the combination of a beam embedded in the subgrade below and paralleling the joint between the slabs, said beam having a lineally extending trough in its top surface below said joint and having its sides extending a substantial distance inwardly of the plane of the proximate joint-providing slab faces at times of maximum contraction of the slabs, the top of the beam lying substantially flush with the bottoms of the slabs, and relative movement-permitting tie means connecting said beam and slabs, there being an inwardly opening recess in at least one of the opposed -beam and slab surfaces through which said tie means extends, said recess providing a shift-permitting space for said tie means at opposite sides thereof in a plane substantially normal to said expansion joint, whereby to maintain the beam in contact with the under surface of the slabs `at opposite sides of the joint and trough so as to assure of drainage through the joint getting into the latter at all stages of expansion and contraction of the slabs.

JOHN NICHOLAS HELTZEL.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 494,620 Bedgood Apr. 4, 1893 2,072,381 Post Mar. 2, 1937 2,148,773 `Ozias Feb. 28, 1939 2,254,885 Carswell et al Sept. 2, 1941 2,280,455 Seuberling Apr. 21, 1942 2,319,049 Fischer May 11, 1943 2,330,213 Heltzel Sept. 28, 1943 2,342,181 Crom Feb. 22, 1944 FOREIGN PATENTS Number Country Date 146,471 Switzerland of 1931 351,525 Great Britain of 1931

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