US2220444A - Expansion joint - Google Patents

Description

NOV 5, 1940- sfG. GissLANDER ET AL 2,220,444

EXPANSION JOINT Filed Nov. 6, 1957 ATTORNEYS Patented Nov. 5, 1940 EXPANSION J IN 1` Sven Gustav Gisslander and Robert R.. Sterrett,

Naiigatuck, Conn., assignors, by mesne assignments, to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application November 6, 1937, Serial No. 173,141

' whims. (01.94-18) This invention relates to expansion joints such as are employed between concrete paving slabs, and more particularly to expansion joints comprising fibrous material and rubber.

Concrete roads are commonly made in sections or slabs with an expansion space between the faces at'the ends of the slabs tok allow forv expansion of the concrete due to temperature changes.

It is necessary to have the expansionv space lled With some Waterproofing seal to preventl water from flowing underneath the concrete, and vin cold weather, freezingv and causing-the concrete "to crack. LVMCommonly, these joints arefilled by pouringinranfasphaltcomposition, lor by inserting a preformed-strip of fibrous or other material,

sometimes `impregnated with asphalt, and, if de-y sired, sealing the preformed stripinto placa-by pouring in -asphaltaround the edges. `'llherevare` numerous `disadvantages ofv thus using asphalt.

When the 'joint V`is made Wholly 'of asphalt, A`the asphalt is extruded out of the joint by expansie` iof the concrete slabs in warm weather and form obje,ctienable ribs whichmust be removed.k 1n

coldweather when the concrete slabs contract? the asphalt cracks away from the Aconcrete Whe .preformed strips are used as the expansion y jointmaterial and the spacesbetween thesides 1.

estrips and the faces of the paving slabs area-filled ,with asphalt, the asphalt being essenthe concrete in its expansion and contraction, and there results a separation of the asphalt fromethef concrete which allows water to seep through to beneaththe concrete, and in cold Weather freeze and cause cracking of vthe road. There havebeen various suggestions for'using preformed strips, which are sometimes rubber covered, for filling the spaces between the paving slabs without using asphalt by inserting the strips o in the expansion space between the paving slabs under compression, but the insertion of a necessarily long strip under compression appears to have its difficulties. i

According Lto the present "inventionQloose fi-v space and a latex composition is introduced in an amount sufficient to surround the fibrous mate-- rial and form a continuous top surface over the fibers. The loose fibers may be in theform of a 50 long Wad and one or more of these wadsmay be packed into the expansion 'space prior to pouring v the latex in the;1space, or the latex-poured'nto :the expansion space and `thewad'onwads sub'- sequently packed in. In either case,;the wad may 55krst be dipped-in orsprayed withvlatex, if.' de,-

sired. The Wad orv wads should be placed far enough down in the expansionV space so that sufficient room is left above for the formation of a continuous layer of rubber on drying of the 60 latex to prevent the entrance of water into the fibrous material. When latex is poured into a space containing such fibrous material, the latex tends to penetrate the fibrous material somewhat, but largely flows around it, making when dry, a tight waterproof seal. After the fibrous material has been packed into the expansion space, as discussed above, the latex composition may bel poured in s'o that it isflush-with the surface of the road. Another. method of introducing the loose brous materials is to add the fibrous material in small clusters as the latex is being poured into the space to be lled.

I nthe accompanying drawing which illustrates the two preferred` embodiments of the invention discussed above:E

Figf2 is a cross sectional View of an expansion f joint where the fibrous material has been added in'small clusters.

Iheflbrous material used is preferably curled hair, and this may be readily formed into ylong may readily be formed into smallclusters to be added .with 'the latex. Other fibrous material, such as cotton, glass wool; steel wool, or the like,

may` also be used. The latex is preferablyk compounded to produce delayed coagulation, so that tially inelastic, does not follow the movement of *z after being poured into the expansion space, it

more or ,lessrigid condition kbefore drying, preventy any undue flowing into the interstices be' tween the bers of the fibrous material after l-being poured. It is also desirable that the latex contain alow temperature accelerator so that underatmospherc conditions the rubber which is formed on drying of the latex will vulcanize in place to form a joint having the best physical properties. As is well known, the latex may readily be compounded, as in the example below, `so thatadequate adhesion to a concrete surface will be assured. In that the faces of the ,concrete slabs are vroughit may besomewhat difficult to brousv material is inserted into the expansion between the concrete surface and the poured latex vby'virtue ofthe rough concrete wall. Itmay thus be desirable to rst apply a film of the latex composition to the faces of the slabs as by spread- 15 Fig. 1 is a fragmentary view in cross section of the expansion jointv made by packing wadsof f the fibrous material in the expansion space; and

'f wads for insertion into the expansion space, or l' ing or spraying, orif desired, a film of some other adhesive, s uch` Aas a rubber cement, or a latex of diierent composition. The latex composition maythen be poured into the expansion joint and g willadherej'to the continuous lm previcusly'applied to`the`rough face of the concrete slab. 'I'he latex maybe poured so that it does not completely fill the expansion space, and after drying a surface of asphalt may be applied on top.` The latex should, for best results, however, cover the top of Cil ' of the sodium silico fluoride.

cult to maintain adhesion between the rubber and the concrete.

The following is an example of a latex compo-A sition which may be employed in carrying out the present invention:

Dry basis Wet basis Centrifuged latex 100 160 Potsium hydroxide solution.. 5 Sulphur paste 2 3. 3 Diamyl ammonium diam mate emulsion. 1 3 Casein solution.-- 2. 5 15 Sodium silicate. 6 12 Suprex clay aqueous dispersion 50 Aluminous cement (dry) Zinc oxide paste 2 5 The diamyl ammonium diamyl dithiocarbamate is an example of a low temperature accelerator which will permit vulcanization of the dry deposit to take place at ordinary temperatures so that a vulcanized rubber joint will be formed. The casein is solubilized by the addition of small amounts of sodium fluoride and borax as is Well known. Such a latex compound is stable and may readily be transported to the place of use. A rubber joint formed from such a latex composition will readily adhere to the portions of the faces of the slabs which define the expansion space. expansion joint, it is preferable toadd 12 parts (wet) of a 33%% dispersion of sodium silico fluoride NazSiFs. The sodium silico fluoride acts as a delayed coagulant and the latex which is readily poured into the expansion space gels after a short rest period due to the coagulating action Various other delayed coagulants than sodium silicofuoride '-may be used for gelling the latex after pouring. For example, a watery emulsion of pine tar is known to produce a gellation of latex` on standing. Likewise the latex, as is known, may be compounded with a polyvalent metal salt to produce delayed coagulation at ordinary temperatures, If desired, the latex compound may be made heat sensitive by the addition of polyvalent metal salts or disubstituted guanidines, or an ammonium salt of a strong acid and zinc oxide, as is well known in the art. In cases where a heat sensitive latex which is not coagulable on standing at normal temperatures is used, it is necessary to heat the latex to produce more or less immediate gelling. A heating of the latex may readily be accomplished by playing live steam on the poured joint or otherwise heating it.

Referring more particularly to the drawing,

' concrete slabs II) and II are shown on a conventional pavement bed I2. The expansion space which is left below the road surface I3 between the faces I4 and I5 of the paving slabs I0 and II when they are formed is shown filled with an in situ formed strip ofrrubber I i in which is embedded the loose fibrous material I1. The loose fibrous material I'I aslshown in Fig. 1 was inserted into the expansion space4 in the form of Before pouring 'this compound into thetwo long wads before pouring in the latex which when dried formed the rubber part I6 of the expansi'on joint surrounding the fibrous material. In Fig. 2 small clusters of the loose fibrous material I'I were added as the latex was poured into the joint to form when dried the rubber part I6. The drawing is merely illustrative of one type of concrete paving construction. In other paving constructions the concrete slabs may be relatively deep and part of the space between the slabs above the pavement bed filled in with a filler material, which may be premolded, and which may be topped with a metal cap as well known in expansion joint constructions. In such constructions, however, there is an expansion space left below the road surface between the paving slabs in whi'ch may be formed the expansion joint of the present invention. The expansion joint of the present invention is likewise applicable to the filling of expansion spaces between lthe faces of other constructional members, as inbridge or other structural work.

The term latex in the description and claims is used to designate broadly coagulable aqueous dispersions of elastic materials, including artificial dispersions of rubber or rubber-like materials as well as natural latex, which may be preserved or compounded or otherwise treated as desired, as by vulcanization, and which may be in a normal, diluted, concentrated or purified condition produced by methods well known in the art. As various modifications will occur to those skilled in the art, it is not intended to limit the invention other than as set forth in the append ed claims. i

Having thus described our invention; what we claim and desire to protect by LettersPatent is: 1. The method of forming an expansion joint in an expansion space between spaced constructional members which `comprises inserting masses.A

of loose fibrous material in said expansion space and introducing a latex composition in said space in amount suiiicient to surround said fibers and form a continuous top surface over the fibers in said space.

i2. The -method 4of forming an expansion joint in an expansion space between spaced constructional members which comprises inserting masses of loose fibrous material in said expansion space and introducing a latex composition which will set to a gel on standing, in said space in amount suiiicient to surround said fibers and form a continuous top surface over the fibers in said space.

3. The method of forming an expansion joint in an expansion space between spaced paving slabs which comprises packing wads of loose fibrous material in said expansion space and then pouring an amount of a latex composition in said space sufiicient to surround said fibers and cover them to form a continuous top surface in said space. 4-

4. The method of forming an expansion joint in an expansion space between spaced paving slabs which comprises packing wads of 'loose fi- SVEN GUSTAV GISSLANDER.' -ROI'BERT R.' STERRE'I'I.

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