US2026989A - Method of building roads - Google Patents

Description

Patented Jan. 7, 1936 UNITED STATES I 2,026,989 lvnirnon OF BUILDING norms Hermann Plauson, Freiburg, Germany, assignor, by mesne assignments, to T. It. 0. Corporation, Wilmington, Del., a corporation of Delaware No Drawing. Original application August 12,

19 31, Serial No. 556,616. Divided and this application January 19, 1934, Serial No. 707,341. In Germany August 15, 1930 This application is a division of my original application Serial Number 556,616, filed August 12, 1931.

It is also a continuation-in-part of my pending application, Serial No. 492,875, filed November 1, 1930, the claims of which are directed to road-pavings whilethe present application is ..directed to methods of making road-pavings. I.

4 Claims.

This invention refers to a method of road 0 building and has for its object to produce a ballast road of the well known macadam type in a simpler and more efficient way than was hitherto possible.

. My invention has particular reference to the production of road coverings in which the ballast or other mineral matter is cemented together by a kind of mortar containing hydraulic binders in combination with bituminous substances including all kinds of asphalt, road and other tar, pitch; etc.

According to the present invention and to the preferred mtfiie of practising same I arrange on the roa o be covered, which may have previously been prepared in any suitable manner, one or 26 several layers of ballast stone of some suitable kindr fthereupon place on this ballast layer the mortar mentioned above in a dry and pulverulent state and then cause this mortar to enter the interstices and cavities between the bal- 30 last stones by sprinkling the same with water to produce a fluid suspension of the mortar and by compacting the whole by rolling as usual, thereby forcing the mortar deeply and firmly into the ballast stone layer and causing the individual stones to be cemented together by the mortar as it sets under the action of the water.

In thus placing a layer of the dry pulverulent mixture of a hydraulic binder and a bituminous substance onto the ballast layer and uniting the ballast and the mortar by adding water and rolling, similar to the well known manner of proceeding in the case of waterbound ballast roads, r I obtain the advantage that the old known process of producing macadam or ballast road coverings can be retained although the binding matter is not ordinarily lime, cement, concrete or the like, but a mixture of one of these or other hydraulic binders with a bituminous substance of the kind mentioned above. This advantage is of great importance as I am thus enabled to construct a practically perfect and highly enicient road without large machinery or skilled labor as a result of which the cost is comparatively low.

As compared with the methods hitherto used PATENT OFFICE in which a hydraulic binder as such formed the means for cementing the ballast stones together, I obtain a road covering, which owing to the presence of the bituminous additions to the binder is more elastic and therefore more durable and less affected by atmospheric influences.

All methods hitherto in use in the construction of rolled ballast roads can be applied in the practice of my invention. I may, for instance, place the ballast layer onto the road and roll it, the pulverulent mortar mixture being then strewn on the ballast layer, spread thereon and in the interstices by forking and washing, whereupon the covering is rolled.

I may, however, alsostart by spreading on the road the dry pulverulent mortar, arranging thereon a layer of ballast stones, which are thereupon rolled, whereupon water is added to start the binding action of the mortar, whereupon a second rolling is effected. In this method I prefer superposing several layers of mortar and bal last.

I may, however, also mix the pulverulent mortar described above in situ with sand and convert this mixture by the addition of water into a sludge, which is now added to the ballast in the usual manner.

Example 1 I first prepare the pulverulent mortar by intimately mixing 200 kilograms hydraulic lime with 40 kilograms normal road tar in a mill. The powder thus obtained is then mixed with another 200 kilograms hydraulic lime and this mixture is intimately mixed in a suitable mixing ap- 35 paratus with 500 kilograms normal Portland cement.

I then arrange on the suitably prepared road a layer of ballast stones, the individual stones being about 3-5 centimetres in diameter, and I 40 slightly plane this layer by rolling. I now mix the pulverulent mortar with a corresponding quantity of sand, for instance in the proportion of l sand to 3 mortar, and arrange a layer of this mixture on the ballast layer, about 12 kilograms of the 45 mortar being spread on each square metre. The mortar is now driven into the interstices and cavities between the stones by forking, brushing or the like and water is then added, whereupon the covering is finally rolled. 50

Example 2 I prepare the pulverulent mortar by heating 200 kilograms finely ground trass to -100 C. and grinding same in an edge mill with kilo- 55 grams molten asphalt. I allow the mixture to cool down and grind it to powder in a disintegrator or the like. I now intimately mix with 300 kilograms of this powder 500 kilograms cement and another 200 kilograms trass reduced to the finest powder in a disintegrator or the like. I mix the pulverulent motar thus obtained with sand in the proportion of about 1:3 and arrange it on the suitably prepared road in a layer about 2-3 centimetres high. On this layer I spread a layer of loose ballast stones, which are slightly forced in by rolling. I then add water and continue rolling, thereby causing the mortar sludge to rise between the stones. In the covering thus obtained I may arrange another or a plurality of compounds layers prepared in a similar manner.

As indicated in my acknowledged copending application Serial No. 492,875, of which the present application is a continuation-in-part, an advantageous method, within the scope of the present invention, comprises arrangingon the road a. layer of ballast stones and a, dry uniformly bituminated pulverulent intimate mixture of a hydraulic binder and not more than seven per cent, calculated on the weight of the binder, of a bituminous substance, compressing the layer of stones and mortar by rolling so as to fill the interstices between the stores with the mortar and adding water to cause the bituminated hydraulic binder to set in situ thereby uniting the ballast stones into a monolithic block. The percentage of bituminous material called for by the claims is based on the weight of the hydraulic binder which, of course, is mixed with the usual amounts of sand, etc. for preparation of the mortar. The mortar may be prepared from an initially pulverulent intimate mixture of cement, another hydraulic binder, selected from a class consisting of hydraulic lime and gypsum, and not more than seven per cent, calculated on the weight of hydraulic binders present, of a bituminous sub- 5 stance.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof. 1

What I claim is:

1. The method of making 2, rolled ballast road which comprises arranging on the road a layer of ballast stones and a dry uniformly bituminated mortar prepared from a pulverulent intimate 15 mixture of a hydraulic binder and not more than seven per cent, calculated on the weight of the binder, of a bituminous substance, compressing the layer of stones and i'nortar l u gW' to fill the interstices between the stones with the 20 mortar and adding water to cause the bituminated hydraulic binder to set in situ thereby uniting the ballast stones into a monolithic block.

2. The process of claim 1 wherein the dry uniformly bituminated mortar is laid on top of the 5 ballast stones, water is then added, followed by rolling to cause the hydraulic mortar to fill the interstices and cavities between the ballast stones:

3. The process of claim 1 wherein the dry uniformly bituminated mortar is first laid, the bal- 30 last stones are placed over said mortar, water is added and the road is rolled.

4. The process of claim 1 wherein the .dry uniformly bituminated mortar is mixed with water to make a sludge prior to laying it.

HERMANN PLAUSON.