US1663824A - Hectob amphion - Google Patents

Description

Patented Mar. 27, 1928. i

HECTOR AMPHIONEBATTALIOU OFCAPE TOWN CAPEPROVINOE, SOUTH." AFRIGAi ROAD-MAKING MATERIAL.

No Drawing.

The modern ractice'ofmacadamizing roads makes suc WOI'kRll enormous item in the municipal and Gdvermental expendi-' ture of all countries. The highly ClGStI'IlCtlVQ 5 action of modern motor traffic requires a maximum of binding ispower in connection with all inacadahiizing operations; The binder hBIGlII set out results in tremen (lOUSCOUSOlldfitlOD and givesa swift and per 100 This is a new 'combination,the result of experiment and analysis and .varying between the percentages hereinafter "set out. The above combination when put together from thei raw materials producestthe above eifects.

The above composition vmayvary in practice within certain maxima and minima per centages subject to slight loss Ofelficiency as hreinafteriset out. i

The-quartz sand set out above at the ideal percentage of 37%,may vary in practice between 45%.and 30%,) The result of an excess of quartz sand over and above? 45% is to makethe composition too hard with failure to secure uniformity of mixture, resulting in lack of adequate consolidation, and lack of binding power. Itmusthere be especially noted that of-all dangersdue to excessive variation from the ideal asabove set out; the danger caused byanincrease in the percentage of "quartz sand is the most serious to efii ciency. And for thisv purpose it advisable, except under quite exceptional circumstances, not to exceed a totallof 40%. I If less than 30% of quartzsand-is: used, the composition losestoomuch of 'itswcapacity for mechanical frictiongrip on the sides of the stones forming the macadam, and the petrification ultimately" set'up *bythe inter- Application flled l'anuary ll, 1924. Serial No. 686,201.

action between the ca rbonatc of calcium and the quartz sand will be definitely lessened, and the composition will lose in toughness, effectiveness and durability.

The carbonate of calcium set out above at the ideal percentage; of 35% may vary in praetice between 42% and 32%. The carbonate of calcium permits of less variation *inquantity relative to its total percentage than the oxide of iron and in practice the percentages should be limited rather more carefully between 4i0% and 35% in order to be certain of efficiency. If the carbonate of calcium. is reduced proportionately with the oxide of iron, this leaves too large a proportion of the remaining constituents. If the oxideof iron is used in a higherpercentage than 20%, this tends to give excessivepenetration and slight dessication of the carbonate of calcium by the oxide of iron, with a lossnf toughness and resiliency. The converse observation as to the simultaneous increase of the carbonate of calcium obtained is that the total amount of the re maining materials would then he too small. Thefundamental objection to any increase of brittleness orloss of resiliency as above set out is that the road would then Wear much quicker than When the limits of elliciency between 20% and 10% areobserved.

Theoxide of: ironset out above at the ideal percentage of 15% may vary in practice bctwcen20% and 10%, but these variations from the ideal in either direction tend to sacrifice thatinherent toughness of the composition contributcd to it by the oxide of iron: If these margins are exceeded in either direction, definite excessive brittleness sets in. In thecase Where oxide of iron islessthan 10% of the mixture, it becomes in operation too brittle by reason oftoo large a comparative quantityof carbonate of calcium. The "same relative comments as tothdratiosof the carbonate of calcium and the oxide of iron apply here as set out above, Wl.13l1,0f course, the incidence of these comments reversed.

It is an essential portion of this invent-ion that the sum total of the quartz sand and the carbonate oi calciumshould, as a joint contribution to the composition, not exceed 00% and not less than 45%. exceedyit would have to be at the expense of either the silicate of aluminium or the quartz Should. they sand, an undue absence oi either oi which would have results indicated hereinafter. On the other hand, if the carbonate of calcium and the oxide of iron are present in less quantity the similar results indicated hereinafter caused by excess of the quartz sand or the silicate of aluminium would result. As to the general proportions of the oxide of iron and the carbonate of calcium, each to each, the latter should exceed the former by not less than twice the quantity nor more than four times, but in either case, as already stated, variation from the ideal will give a slight, although within the limits indicated, anot very material decrease in efliciency.

Silicate of aluminum set out above at the ideal percentage of 12% may vary in practice between 22% and 7%. The result of exceeding 22% in this case is that a tendency to crack, to undue plasticity and to undue retardation of consolidation develops. The result of putting in less than 7% is that the composition loses both in compressibility and compactness with the resulting loss of consolidating strength.

The carbon which is present in a relatively small quantity in this composition and which is set out above at the ideal percentage of 1% may vary from to 2%. It must be amorphous and finely divided. More than 2% would result in a distinct loss of hardening efiect. The absence of the carbon would result in delay in the consolidating action. The use of carbon in any other form interferes with the process of recrystallization that occurs when the above composition is put into practical application with water, but amorphous carbon is too soft to cause such interference.

This composition for its best practical application in the ideal form requires reduction to a fine powder, but consolidation sufficient for practical purposes can be obtained under the following circumstances. The quartz sand must not be crushed more than to a minimum of inch or it will lose its frictional and interloekingvalue. The rest can vary from 4 inch downward but inch is best for the whole composition as this will include in practice a considerable percentage of the other constituents actually reduced to powder.

To sum up, the invention a combination of well known materials conforming as a result of selection, quantitative analysis and calculation with the ideal composition above set out within the limits of variation above indicated.

This composition slightly deadens the noise usually associated with a macadamized road. The only. condition with regard to the macadam used with this composition is that it shall not be capable of latent deterioration. In other words, any ordinary sound macadam will do.

A further feature of the invention consists in the process by which this composition is used in practice. The best result is obtained as follows.

Upon and all over the surface of the proposed road which has been roughly rolled after the ordinary levelling and rough smoothing required for the road, and of course only where the surface is not bog or otherwise unsuitable in its entirety for roadmaking or construction, a layer of m of the composition is laid. This is covered by some 4: inches to 4 inches of nnmulain with a maximum in case of need, of ti inches.

In practice 4 inches should not he exceeded. This is rolled and another layer of of the composition is spread over the top. This is then watered and rolled again, watered and rolled again, and any surface faults of an obvious nature tilled up with a little more of the composition. This road can be used within twelve hours having initial binding to hold the camber against heavy street traliic. This binding will increase with time during which it will ill]- prove with trafiic. The results of this method are as follows:

The water will saturate the ll'ltlCiltltllll from the top down carrying with it an intimate mixture of the composition laid above the macadam. On reaching the lower layer of the composition, it in part will draw this up to meet the upper layer, and carrying on downward will take portions of the lower layer into all. latent fissures,eonsolidating every crack, weakness or hole in the lower or natural road prior to the arrival of traffic thereon. This system will tl1ercfore prevent creeping downhill of the finished roadway; prevent any lateral creeping away from the artificial hill or crown of the camber, consolidating such raw or natural. crown underneath; provide a firm lower base which will effectually prevent the dropping out or displacement of the lower stones in the ma -adam by presenting to them a hard and solid foundation not penctrable by them; prevent any movement of any maeadam stone whotsoever in the mass as laid, giving adequate support to all such points of individual stones in the macadam as would otherwise be calculated to crush under the vibration of heavy tratlic, and ultimately to cause subsidence and surface potholes.

Owing to the margin required for consolidation of the ground below the lower layer of the composition (consolidation of which acts as a foundation, without extrav expenditure, for the whole structure) the lower inch of the COll'lPOSltlOll cannotbe relied upon to rise under the influence of the water, except under an exceptionally heavy roller, more than 2 inches, wherefore 4 inches is the maximum for best results. This means that if 8 inches or 9 inches of macadam is required to be used, the surplus of macadam over 4 inches must be put on as a second layer above the second layer of the composition and a third layer of the composition must be superimposed thereon. In practice, one layer of 4 inches of macadam laid with two layers of the composition as above set out, will be enough save in exceptional cases.

The characteristic features of the present invention are (1) the discovery of a new synthetic combination of Well known ma terials readily obtainable, which combination conforms with the percentages above set out within the limits indicated and which, after reduction to a powder within the limits above set out and mixed and applied to roads as above set out, results in a hard, insoluble, consolidating, cementing mass, in other Words, the discovery of a new and improved binder; and (2) a simple process of applying the said composition in layers so as to form not only a tough, resilient and tenacious road but also a secure foundation therefor.

What I claim is:

1. A binding material for macadam, comprising a mixture of approximately 37 per cent sand, per cent calcium carbonate, 15 per cent iron oxide, and 12 per cent aluminum silicate, all the ingredients being in the form of particles not exceeding 4, inch in greatest dimension.

2. A composition for the construction of roads and like surfaces, comprising a mixture of at least 37 per cent quartz sand, about 35 per cent calcium carbonate, about 12 per cent aluminum silicate, and iron oxide in sufficient quantity to make with the calcium carbonate not more than 60 per cent nor less than per cent of the mixture.

3. A composition according to claim 2, wherein the quartz sand is in the form of particles not exceeding inch in greatest dimension.

4. A composition for the construction of roads and like surfaces, comprising a mixture of about 37 per cent fine aggre ate, about 35 per cent calcium carbonate, a out 12 per cent aluminium silicate, and about 15 per cent iron oxide.

5. A composition for the construction of roads and like surfaces, com rising a mixture of about 37 per cent hne aggregate, about 35 per cent calcium carbonate, about 12 per cent aluminum silicate, iron oxide in suflicient quantity to make with the calcium carbonate not more than 60 per cent nor less than 40 per cent of the mixture, and about 1 er cent amorphous carbon.

ln testimony whereof I have signed my name to this specification.

HECTOR AMPH ION BATTALIOU.