US1570028A - Paving composition - Google Patents

Description

. Patented Jan. 19, 1926.

UNITED STATES JOSEPH HAY AMI-ES, OF PHILADELPHIA, PENNSYLVANIA.

, 1,570,028 PATENT OFFICE.

PAVI N G COMPOSITION.

N 0 Drawing.

To all whom it may concern:

Be it known that I, JOSEPH HAY Aim-1s, a citizen of the United States of America. residing at Philadelphia. in the county of Philadelphia, Stateof Pennsylvania, have invented a new and useful Paving Composition, of which the following is a specifi cation. i

The object of this improvement is .to produce the herein specified-composition, to be employed particularly, as a surfacing and resurfacing, for streets and highways. It may, however, be used for flooring, roofing and. the like.

I will now describe the production and application of the composition constituting my wearing surface for highways and the like. I take a given portion of the soil of the grade, and sieve itfinely, and then submit it to a blast heater until it attains approximately, two thousand degrees F. of heat. I then take the general soil of the grade in its natural condition and'place it within a standard mixing machine. I then wet it with a sufficient amount of boiling hot water to cause it to macerate. I then add from one to two cubic feet of the highly heated soil. to every nine to fifteen cubic feet of the common soil of the grade already placed as described within said mixer. I add thereto a suflicient amount of boiling hot water to form a thin macerated soil batter or mortar. The constituency of this mass. at this point, ought to be like that of plaster when prepared to be troweled upon walls or floors. The hot water brought in contact with the highly heated added soil forms a compressive steam thus very rapidly and effectively enablingthe full maceration of the soil contents which should now form as stated, a thin mortar. Again, at this point, to every nine to fifteen cubic feet of the soil of the grade thus treated I add from twenty to. thirty pounds of pulverized oxide of calcium in a perfectly quick condition, and caused to previously begin to slake. To stimulate and cause the slaking to continue I may add an additional amount of boiling hotwater, as by sprinkling. I now add to this macerated and heated soil contents, within the mixer, a due quantity of highly heated bituminous or other pitchy material, and thoroughly mix the same with the contents of the mixer. this process'that the said-highly heated bituminous or other pitchy materials are I have found by Application filed April 1, 1924. Serial No. 703,541.

chemically desirably affected by the slaking of the oxide of calcium. Bituminous or other pitchy materials, after this treatment, will not absorb water or air, and are practi rally indifferentto the changes of temperature, and will not volatilize or crystallize, but maintain permanently a semi-fluid conditiomthus, moreover, by this treatment the soluble salts of bituminous materials become neutralized making water absorption impossible thus preventing oxidation and providing age lasting resistance to wear and tear of trafiic. The said composition will give very great solidity of mass when very heavily rolled, tamped and forged and itwill accept compression to a perfect extent. This composition, in this condition, itis safe to aflirm, will contain less than five percent of voids, and therefore be practic-ally air and water proof. It has been asserted that twenty one percent of voids might bethe maximum secured by compression, in bituminous mixtures composed of broken stone and sand fillers, but this degree of inherent stability has never been secured in bituminous compositions having broken stone, sand and gravel contents. Twenty six percentum of voids is the lowest achievement toward securing inherent stability of which we have any record. When b,ituminous or other pitchy materials are associated with heated mineral or broken stone materials and after the greatest compression has been secured, Voids enoughwill remainto entertain a considerablev amount of water which will quickly cause the oxidation and granulation of the said bituminous or pitchy material and'thereby result in the premature destruction of the said composition when applied for a street or highway wearing surface. These destructive results I avoid as above affirmed. Moreover, broken stone, sand and gravel owing to the above facts, are capable of considerable vibrations under traffic and will therefore contribute a grinding and friction attrition upon the said bituminous materials stripping them from the mineral aggregates, thereby causing rapid destruction to the highway compositions. In sand, sheetasphalt,'the voids are never reduced to less than thirty-two percent, consequently this composition may entertain largequantities of'water.

The said bituminous or other pitchy materials should preferably have a penetration of about 60 or 65, so that when they come to the temperature of the air they will be tough enoug when duly condensed by compression as by rolling and camping and forging, to resist, without indentation the heaviest trucktraflic tonnage. This surfacing and resurfacing composition should be placed upon a sub-foundation compressed, as described, to the fullest degree of solidit practicable. The said sub-foundation shou d e placed upon a fine grade, also constructed so as to secure the greatest practical degree of compression.

Preferably, I employ a very highly heated bituminous or other pitchy material, because, in the first place, it is much cheaper, and in the second place, the street or highway surfacing or resurfacing, will submi to traffic, as soon as it comes to the temperature of the air, which is, usually, in about four to six hours. But these desirable results cannot always be determining factors, because conditions and conveniences may dictate terms in favor of the employment of a cold liquid, bituminous or other pitchy material, such as naphtha cutback or any other form of emulsified bituminous or other pitchy material. The difference in cost between the heated bituminous material and the cold liquid state thereto may not be as great as it seems to be, at first sight, because, notwithstanding, the cold liquid form of bituminous -material may be one-third higher than the hot liquid usechyet the preparation and extra costs of labor and equipment employed to secure the heated article, may considerably lessen this difference in costs. Then, again, in

many cases, convenience may outweigh all, But after all is said, the hot application is preferable, because it will be considerably cheaper, and become, as said, ready for service as soon as it arrives at the temperature of the air. And furthermore, and more important than all other considerations, it will greatly outlast the wearing resistance of any form of cold application of emulsified asphaltum. Nevertheless, convenience may make, in some cases, the cold application of emulsified asphaltum, desirable, but this can only occur inisolated instances. It is to be observed that bituminous material always inter-absorbs the soil, it does not coat units thereof but interfuses them, and therefore a complete inter-amalgama tion takes lace. Owing to this, very intense solidification is attained, and the evaporation of the volatile and essential oils, is revented, therefore, the composition ma e with cold liquid asphaltum material, in most cases, becomes impractical, be cause, it might take months before the surfacing and resurfacing of the streets or highways would become tough enough to entertain traffic, notwithstanding the fact that the cold liquid asphaltum'would come in contact with the heated soil.

The highway wearin surface should be homogeneous with the (l ensity and colloidal disposition of a properly blown vehicle or rubber cast tire. And again the sub-foundation should be homogeneous with the wearing surface. And furthermore, the fine grade should be harmonious with, although less resistance than, the surfacing and sub-foundation, but altogether should homogeneously relate, as above described, with roperly provided vehicle tires. When t is is secured the vibrations of shock and attrition will be infinitely divided and subdivided and dissipated and the entire traffic will be accepted by a sympathetic cushion like enduring superstructure.

It will be seen that I have described a highway superstructure, giving the fore going desirable qualities at a very low cost possessing complete scientific adaptation resulting in the finest qualities and greatest endurance for highway trafiic.

Having fully described the production of a bituminous composition to serve as a wearing surfacing and resurfacing superimposed upon, and related to, already devised and placed perfect fine grade and sub-foundation; V

What I claimis:

1. The process of making a bituminous paving com osition consisting of subjecting one-tent portion of the natural soil of the gradeto a temperature of about 2000 degrees F., in a blast heater, placing the balance of the natural grade soil in a mixing machine and macerating with boiling hot water then addin the foregoing heated soil to the contents of the mixer, then adding to each 9 cubic feet of this highly heated mass 20 to 30 pounds of finely granulated V quick'lime, and finally adding a quantity of'bituminous material in a highly heated state. 7

2. The pavin composition produced by the process of c aim 1.

In testimony whereof I have hereunto signed my name.

JOSEPH HAY AMIES.