US1683881A - Expansion joint - Google Patents

Description

Sept. 11, .1928. 1,683,881

A. C. FISCHER EXPANSION JOINT Filed Aug. 21, 1926 Patented Sept; 11, 1928.

UNITED STATES ALBERT C. .EISCEER, CHICAGO, ILLINOIS.

EXPANSION JOINT.

Application nia August 21, 1926. Serial No. 130,681.

This invention relates to means for compensating for expansion and contraction in concrete and the like structures, particularly roadways, pavements, buildings and other such monolithic structures which are subject to temperature changes, and as a result must be protected against cracking and the like deteriorating conditions. i

Generally speaking, the most acceptable :0 method of fabricating expansion joint material is to make the same in the form of preformed strips in which form they are transported from the source of production to the point of installation, and subject to more or less handling during transportation and the preparations incident to installation. this account the preformed strip should be constructed so as to enable it to withstand this handling without warping, breaking Q1 2.0 becoming otherwise damaged.

With this end in view one object of my invention is to produce a strip of expansion joint material which will offer this advantage, and at the same time-keeping the/00st I 215 of production down to a minimum so that the strips may be sold at a minimum cost, without, however, sacrificing the efficiency of the joint when installed. i

In order that an expansion joint may properly function after being installed it must be imbedded in the concrete in a straight line and exactly perpendicular. If not installed 1 with a straight edge it is unsightly, especially when the color contrasts with the color of the concrete, and unless installed perpendicular itis very apt to invite a condition where'one section of the concrete will ride up over an adjacent section, so to speak, upon expansion of the concrete, and thus defeat the purpose 40 of the joint.

To compensate for expansion of the concrete the strip must offer considerable com- 5 in the manner just mentioned, and capable of functioning so as to offer the greatest efficiency.

Various attempts have been made to accomplish the above mentioned results, and since it is primarily a matter of reinforcement,

joints have been made with felt sides, burlap I of sawdust, shoddy dust, and other such finely 1 divided materials.

I have discovered that in order to produce a certain type of joint which will meet the requirements in various installations, it is necessary to do something more than simply make up a mixture of materials, such as, asphalt and fibrous material. What I really do, at least 'so far as concerns my present invention, is to develop a felted mat andpermeate the mat with an abundance of bituminous material, preferably oxidized asphalt,

the mat being made up of fibrous material.

I do not, mean by this that I first felt the fibrous material and then permeate with a bituminous material by immersing or dipping. On the otherhand I have discovered how a mat may be developed by mixing the fibrous material with the bituminous material and then subjecting the mix while in a warm plastic condition to a sheet forming apparatus.

In developing this structure I select two different kinds of fibrous material, that is to say, a relatively short fibre and, a relatively long fibre. For the purposeof illustration I will take felt, which is ordinarily a short fibre, although long enough to interlock or intertwine. For the relatively long fibre I will take," as an examp e, ordinary coreen (cocoanut fibre), which is a relatively long fibre. Right here I wish to make a distinction between fibres and fibrous material, the point'being that while sawdust, and such finely divided, material may be termed fibrous material the particles are not fibres in the generally accepted meaning of the term. In order to be of any use to me the material must be capable of interlocking and intertwining, otherwiseI could not/develop how melted so long as it is melted to the desired consistency. I equip the mixers with suitable" heating means in order to melt the asphalt tothe desired consistency. It is necessary to heat the asphalt to somewhere between 300 and 400 degrees F. ()f course after being placed in the mixer this temperature Will not be maintained, although .the heating means will prevent it fromcooling too quickly. This gives a very good idea of just what consistency the asphalt is prior to the introductionof the fibres.

With the mixer running, or operating, with the melted asphalt contained therein, I proceed to incorporate the fibrous material in successive steps; using about fifteen per cent by weight of the relatively short fibres I incorporate the same successively in small quantities until the proper amount has been introduced. The incorporation of these relatively short fibres naturally acts as a flow retarder for the asphalt and cools the same considerably, and will-be more like a plastic mass after the relatively short fibres have been mixed.

I then proceed to incor orate the relatively long fibres, using about ve (5) per cent by weight, also adding this five per cent successively in small quantities.

After the relatively long fibres have been I thus introduced I continue the mixing operation until the materials have been mixed to a homogeneous plastic mass. Let me explain here that it is not altogether important to incorporate the relatively short fibres before the relatively: long fibres, as a matter of fact either may be introduced first.

This reservation is also made with respect to the percentage of fibres used. While I have mentioned fifteen per cent by weight of the short fibres and five'per cent by weight of the'long fibres, these proportions would not be controlling in every instance, as I may vary these proportions within a reasonable range.' What-I mean by reasonable range is from fifteen (15) to thirty per cent relatively short fibres and five (5) to twenty (20) per cent relatively long fibres. In no case, however, do I use over forty (40) per cent of the combined short and long fibres, nor do I use more of the long fibres than I do of the shortfibresfthe idea being that the product should contain a. preponderance of bituminous material at all times. After thoroughly mixing thematerials as stated I remove the same from the mixer. At this time the mix is in the form of a warm, plastic homogeneous mass, and without undue loss of time,unless I am going to sacrifice the-advantages of a continuous operation, I introduce the mass to 4 a sheet forming apparatus to form the materialinto sheets, and thereafter cut it into strips of the desired dimensions. Usually the strips are in lengths of 5 feet, the thickness ranging from to 1' inch and the width or I depth about 4 inches.

The method of making and forming the material into sheets is a very important adjunct to the invention.

I know, of course, that instead of a sheet forming apparatus the strips may be extruded by a machine suitable for the purpose,

or even moulded, and instead of a mechanical mixer various other methods may be adapted, but in order to develop this felted mat the mechanical mixer and the sheet forming apparatus are the most satisfactory method that I have so far discovered.

The best way to explain what I mean by felted mat is that by taking a stri of my expansion joint .and extracting t e asphalt therefrom the result will leave a self-supporting felted mat. I do not mean that it will be a tough, board-like structure, but I do mean that the fibres will cling together so that in a smaller section or' small piece of the strip with the asphalt extracted the mat will stand on edge without falling apart. This is not;- the case where sawdust, shoddydust, sand and such materials are used, which have no definite length so that they can intertwine or interlock. In other words, anything less than. 1

tough fibre will not produce this result.

I would say that the fibresare feltedin solution, the mixing operation havingcon siderable to do w'th this felting. Likewise the sheet forming pparatus, which applies pressure, so that the fibres are really pressed and compacted during this process.

The figure inthe accompanying drawing gives a very good illustration of theform of strip'eonstructed in accordance with my invention, and in'which the relatively short fibres are represented as at A and the relatively long fibres represented as at B, the short fibres being mixed throughout the. bituminous material and the long fibres being segregated in parallel strata and separated one from another by substantial thickness of the mixture of bituminous material and relatively short fibresQ This is really the crux of the invention, that is to say, the distribution of the relatively long fibres in parallel strata throughout the strip andseparated one from another by a substantial thi'ckness of the mixture of bituminous material and relatively short fibres. i

It might be explained that the stratlficalocking tion of the fibres is produced by pressure of the sheet forming operation, which sets up a flow in the mastic mass prior to the application of pressure, which straightens outthe fibres and heads them in the direction of flow of the mass thru the apparatus.

I claim: I

1. An expansion joint comprising long, individual fibres of a tough, non-brittle material and relatively short interlocking fibres, said long and short fibres being mixed with a ductile waterproofing material and com pressed into a plastic mat-like felted strip, said lon another y a substantial thickness of said mixed mass of short fibres and waterproofing material.

2. An expansion joint comprising a homogeneous mixture of ductile waterproofing material and long, individual fibres 10f a tough, non-brittle material and relatively short interlocking fibres, said long and short fibres being mixed with the waterproofing material and compressed. into a plastic matlike felted strip, said long fibresbeing separate'd'one from another. by a substantial thickness of said mixed massof short fibres and waterproofing material, and distributed throughout the said strip in substantially parallel strata.

3. An expansion joint comprising a homobituminous materlal preponderatmg.

geneous mixture of waterproofing material and long individual fibres of a tough, non: brittle material, and relatively short intere fibres, said waterproofing material being in preponderance in the mlxture.

4. A preformed expansion joint comprising ductile waterproofing material having homogeneously incorporated therein long tenuous fibres of tough, non-brittle material and also relatively short interlocking fibres, the waterproofing material preponderating.

5. A preformed expansion joint compris ing waterproofing material having incorpo- .rated therein individual long fibres of tough,

non-brittle material and also relatively short interlocking fibres, said joint being formed by mixing the fibres into the waterproofing material while Warm in order to form a plastic homogeneous mass and then forming the mixture into strips.

' 6. A preformed expansion joint comprising a homogeneous mixture of waterproofing material having long fibres of tough, nonbrittle material and also relatively short interlocking fibres, the short fibres. being mixed throughout the material and the long fibres being dis osed in substantial parallelism and separate one from another by a substantial fibres being separated one from thickness of the mixture of the material and the relatively short fibres.

7 A preformed expansion joint composed of a homogeneous mixture of bituminous material and relatively short fibres, said mixture having relatively long fibres of tough material distrib ted therethrough and ly in parallel strafii. throughout the strip 3 .3% se arated one from another by a substantial thickness of the'mixture of bituminous material and the relatively short fibres.

8. A preformed expansion joint comprising a mixture of waterproofing binder and long and shortindividual fibres, the binder being at least sixty. per cent of the mixture and the long fibres being of tough material having relatively rough surfaces.

fibres and long tenuous fibres of tough, non- Y brittle material distributed therethrough, the

12. .A preformed expansion joint comprising a loosely felted mat comprising substan- I 'tially short fibres and substantially tough,

tenuous rough surfaced fibres interlaced throughout the mat, said mat being permeated pith a preponderance of bituminous mate'- r1a I 13. A preformed expansion joint. comprising a bod of bituminous materlal, a strengthenmg we imbedded in the bituminous material, said web comprising relativelgshort felt fibres homogeneously incorporate in the bituminous material and relatively tough, tenuous fibres interlaced throughout the short fibrl'es and imbedded in the bituminous materla r 14. The'method of forming an expansion joint which comprises melting bituminous material, homogeneously incorporating therewith a quantity of relatively short felt fibres, thereafter intermixing a lesser quantity of tou h, tenuous fibres in such'a manner as to inter ace the latter with the short fibres and finall pressing the' mass to com actthe.

fibres to orni a felted web imbedded in the bituminous material. i

- ALBERT C. FISCHER.

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