US1776468A - Asphaltic material and method of fabrication thereof - Google Patents

Description

Sept. 23, 1930. M. c. FRANK ASPHALTIC MATERIAL AND METHOD OF FABRICATION THEREOF Flled Aug. 1, 1927 IN VEN TOR.

Patented Sept 23, 1930 invention relates especiallythe use economically feasible.

tion is put.

5 mination.

AsPH LrIo' MATERIAL AND METHOD or rABRIoA'rIoN THEREOF Application .file d Au gust 1, Serial No. 209,727.

of asphaltic compositions as structural material for structures composed chiefly of asphaltic compositions. v

It is primarily the objectof my invention to improve the methods of utilization of as phalt to make its use as a structural material "Itfsan ob 'ect an improved method of fabricating asphaltic structures; and afurther' object, to providean improved method of molding asphaltic material. .7 j I "The immediate' object of my invention is to provide an improved piping ofasphaltic composition and method ofmaking the same. .Other'andancillary objects of myinvention will be suggestedin the following description and in the uses to whichmy inven- Certain of the objects of my invention may be attained with the use of less than all its preferred features. [It is desired that my invention be limited only by the claims constituting its final deter- Referring to the drawings I Fig. 1 is a medianaxialsection of an apparatus for cold-molding asphaltic pipe segments; and Fig. 2 is a diametralsection for the same, Certain elements are greatly exaggerated for the purpose of'clarity.

.Fig. 3 is a (transverse or longitudinal) section of a mold for coldemolding. asphaltic bricksor slabs under solid compression instead offluid pressure. A reinforced, slab or brick is shown therein practically completed. H j

' Fig. 4 is a fragmentary section of pipe showing a modified type of asphaltic con 'crete from that illustrated in Fig.1. the same being reinforced. I

Fig. 5 is a representation of a method of making'and sealing a joint in the asphaltic piping .of my. invention.

Fig; 6 is a perspective representation of a flooring being fabricated of completely moldedlslabs, to illustrate the feature that the asphalticslabs forroadwork (or for panelling) may be. completely molded before being laid. g i

of my invention to provide provided a solid ence characters 1 Fig. is a diagrammatic plan view of a 'form of apparatus for hot-forming asphalt slabs" or bricks. Fig. 8 is a transverse section of the same; the plane of section being indicated by a line 9-9 in Fig. 7.

' Asphalt heretofore has been limited large ly to use as a surfacing or coating material. and has been practically limited to this use its peculiar amorphouscharacteristic of creeping. Asphalt is not a true solid. The K creeping action is that of a highly viscous liquid which tends to conform to the'surface'onwhich it is placed. In order to adapt this material to structural purposes, I have ing. The steel in combination with asphalt 1s added primarily for'elasticity and ability to hold the asphalt in shape, rather than for p ure tensilestrength as in hydraulic reinforced concretel Examples of this rein,- forcing material (designated'by the referand 1) are illustrated in Figs. 3 and 4:. Preferably, the steel rein forcing should be acomplete structure in itself and should be capable of resisting the full value of the constantly-applied stresses plus the average value of the intermittent stresses, to which the combined asphalt and steel Willbe subjected. Since'the intermit-,

tent stresses may occur infrequentlyandin compensating directions, their average or mean value over an appreciable period of time is usually very slight. The very high viscosity of the asphaltic material insures its resistance to all transitorystresses of short duration and makes it especially resistant to suddenly-applied stresses. It has a. deadening effect upon shock "and vibration which practically insures the reinforcing framework against failure from this source. This combination of a highly elastic material such as steel, with a highly viscous material such as asphalt, produces an especially valuable structural combination. In fabricatingthis material'it will be noted from the drawings that a skeleton metal framework is preferred, and thatit is found most adbackbone of steelreinforcasphaltic material is not fragile and is esp'e crete essentially containing an asphalt, sand and rock aggregate in suitable proportions. If desired, some hydraulic cement may be added, and also other particles such as Woodfibres, straw, grass, cork, and the like.

Comparing this material to hydraulic con crete, two. distinctions should be noted- The cially resistant to shock. The asphaltic ma terial isresistantto many of the acids which attack hydraulic concrete. The latter feature is especially important in the pipe of my invention. Thepiping, of which is sectioned in Fig. 4, is formed of a porous steel skeleton cylindrical framework 1 of expanded metal sheet or other suitable skeleton section, .shrouded in 'asphaltic concrete ofrelatively massive form the;asphaltic concrete constituting the ma or POT? tion of the pipe, sufiicient to hold and the metal beingonly the asphaltic material in shape and resist any slight constant loads which may be appliedto it. 1 v c The asphaltic concrete is molded, either hotor 'cold, by any means preferred, and prefer ably under conslderable compacting pressure,.1nto plpe segments or sections, which slabs, bricks, or'other'forms ofthe material arelaidend-to-end or otherwise fabricated in the desired form, and are joined by merely applying localized heat .to the joints as with a blowtorch. (See Figs. 6 and'Z.) Where are employed, of course the same'principles apply. The'completely molded forms are laidcold and are joined by heating only the joints. w

-Where the time factor is relatively unimportant, the jointsmay be permitted to seal themselves without the application of heat merely by the naturalfiuidity of: the asphalt aided by gravity, pressure andwear,

causing it to flow into thejoints between segments. In general, this method of letting the joints seal themselvesshouldibe'limited to the use of asphaltstructu-ral blocks where initial leakagejpast the. new joints is not harmful.

Theabove features of my invention are un- I qualifiedlyapplicable to asphaltic structural elements whether. formed hot by any-of the lmethodswell-knownin the arts, or by a preferred hot-workmethod which I shall describelater, or byanycold-work method such as the preferred cold-work method I shall described; 3 i v The regular commercial .gradeof asphalt sold for paving work would require to be heated and molded hot. I have devised a methodfor molding the asphaltcold. As-

phaltic emulsions such as Laykold are de signed forsurfacing purposes and my method permits their adaptation to molding. When these asphalt emulsions are spread or sprayed for surfacing purposes, evaporation is relied upon to remove the water content. I have asphaltic segment and19 respectively;

into a mold (see Figs. 1 and 2), and

For formlng'pipes, a concentric pair of heavy skeleton or apertured hollow cylinders 2 and 3are telescoped to leave an annular molding space between. The cylinders are equal 'inlength,a-nd'a pair ofdisk-shaped end caps 4 and 4 are removably held in'place. by anaxi'albolt'o andmuts 6 and 7 The end 'platesmay be provided with any suitable maleand female means for forming on the ends of .thepipe sections guiding and interlocking means for connecting'them together,

as'for example, the tongue and groove 18 also, the end plates may be very slightlybowed or finished to unequal thickness to give a bowed interior surface) so that the single'bolt member will clamp the outercylinder 2 as tightly as'it does the inner cylinder .3. The inner cylinder 3 has a very to preventpassage-of asphalt from the mold when the. emulsifying agent is being squeezed.

out; Similarly the outer cylinder 2: has a "similar thin finely porous strainer plate 9;

gate or inlet forthe wrapped wanna. A mold is conveniently formed bya, pipe 10 threaded through a hole in one end caps.

It isintended thatthe requisite molding pressure will'be applied hydraulicallyby the pump 11 which fills the mold with the asfinely porous thin plate 8 wrapped around it phaltic concrete emulsion. Of course the pressure will bemaintained for an appreciable interval of time to squeeze the material 1 dry, and will be increased to finally, compact or compress the'mass. i Y

The mold is stripped b'y removing one-or both end caps, sliding out thefinishedpipe together with the two strainer plates 8 and 9,

and 'then unwinding the two strainer plates to remove them. 7 i

A mold adapted to the formation of bricks, slabs, and other shapes is shown in Fig; 3-. The body 12 of the mold is of heavy. skeleton construction, andv a removable strainer lining is formed by separate sheets 13, 13, 13" etc. of thin finely porous metal similar to the strainer sheets 8 and 9. A skeletonplunger .14 completes the mold- Pressure is applied in this instance by a downward force upon the plunger 14; the mold being filledfwith asphaltic emulsion before. the. plunger is in- V serted.

; In certain instances I have found it-desir f;

able toline the strainers with-clothywhich may either be left on the moldedproduct,

or be stripped offand reused. Especially where the higher-compacting pressuresare employed, it frequently is advantageous to applicable especially to use a small quantity of fibrous material in the asphaltic mix to form flow-lines along which the water may most readily be squeezed out.

A modified unapertured form of the mold illustrated in Fig. 8, forms the basis of an improved method of hot-forming asphalt, the large flat slabs of Fig. 7. The proportions of the mold would of course be modified in accordance with the shape of slab to be formed, and the strainer plate 13, would be replaced by an unapertured stripper plate 15 extending longitudinally along the bottom of the mold and projecting up above the mold at one end thereof. The sidewalls of the mold are reduced 7' to the height of asphalt slab desired, and the under a IJlSlEOIl 14 and strainer plate 13, 13 and 13 are dispensed with; The mold, after being filled with the properly related layers of hot asphalt and steel skeletone structure, is passed battery ofheavy rolls 16 which ride on the top edge of the mold, and compact the asphaltmuch as would a steam roller of the type commonlyused in street paving work. A Satisfactory rolls for the purpose may be apand are well-known in the To form bricks by this method it is simply necessary to place properly-spaced divider plates 17 in propriated from,

. a long channel-like mold. The divider plates may be of sheet metal or other impervious material, merely to prevent adhesion between adjacent bricks.

To strip the mold it is merely necessary to pull the exposed end 15' of the stripper plate 15.

I claim:

1. The method of forming a solid article of asphaltic concrete which comprises placing cold fluid asphaltic concrete forming material having the asphalt thereof emulsified in a mold and thereafter uniformly expressing the emulsifying liquid through the mold asphalt for adhesive union 2. The method of forming an asphaltic body which comprises the steps of placing a mixture containing asphaltic emulsion in a mold, and demulsifying the emulsion entirevly by compression of the said mixture in said mold.

3. The method of forming an asphaltic body which comprises the steps of placing a mixture containing asphaltic emulsion in a ,mold, and demulsifying the emulsion in place.

4. The method of forming an asphalic concrete which comprises the steps of placing a generally non-cohesive mixture containing asphaltic emulsion in a mold, and demulsifying the emulsion in placein said mold and at a normal temperature.

5. The method of forming an asphaltic body which comprises pressure-molding a er material therein for adhesive union with the second material.

7. The method of producing an artificial concrete of a normally adhesive and emulsifiable binder material and particles of other and solid material, which of emulsifying said first material, forming a homogeneous mixture of the resulting emulsion and said second material, and demulsifying said first material in the mixture by pressure andat a normal temperature where by to produce a cohesive mass of said mate rials.

In testimony whereof, I afiix my signature.

MAXWELL C. FRANK.

comprises the steps

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