US1118756A - Roadway construction. - Google Patents

Description

T. H. FLERB.

ROADWAY CONSTRUCTION. APPLICATION FILED JAB. 13, 1913.

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THOMAS HOCAR'I' FLERE, OF ,KEW, VICTORIA, AUSTRALIA.

ROADWAY CONSTRUCTION.

Specification of Letters Patent. 1

Patented Nov. 24, 1914.

Application filed January 13, 1913. Serial No. 741,777.

Australia, have invented certain new and useful Improvements in and Relating to Roadway Construction; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention is one, of that class which relates to roadway construction intended to secure comparatively dustless and particularly durable and waterproof surfaces. My roadway will be usefully resilient, resist motor and horse trafiic, withstand the cleaning operationsof sweeping and watering,

and will give horses firm foothold. It will do away with side slipping of motor vehicles.

In carrying this invention into efiect I may use expanded metal or the like as a reinforcement in combination with other features hereinafter mentioned.

The road surface is to be given any de-, sired gradient and camber, a bed being provided of suitable material below the road surface to secure a firm foundation, which may be of concrete rubble. On the foundation I provide a cushioning resilient waterproof layer, ordinarily a bituminous compound, that is stone screenings, furnace slag :or suitable material with bitumen or the like, or it may consist of a rubber-like composition; this layer may however in some cases bepartly loose, coarsesand. On the saidlayer I set heated blocks of granite having top surfaces measuring for example 3 inches square, though the invention is not thereto limited." OrI use other knownmaterial which is not easily, for the external or eXposed-to-weather roadways, perishable like wood, or not easily ground into dust like basalt. I lay the blocks, which are ordinarily deeper than, they are broad, in rows, each row forming one or several curves or arcs; straightjoints across the roadway are avolded, as well as continuous longitudinal parallel olnts. ThIS, arrangement reduces wear; the joints are yaried uat I will, by

changing the curve radius, and the length of the arcs to include a different angle.

The blocks have either trapezoidal, square, or like suitable tops, and are to be assembled in position by the aid ofa curved or appropriate implement, at every second or third course, but there will nevertheless be cracks left between the blocks, to be filled in as described later, to produce an arrangement which I compare to some extent with the arrangement of teeth in a head,-that is, the blocks are caused to have individual resilience to shock, though they might even touch at parts. I fill the bases and middles of the cracks with dry heated powdered or granular granite, slag, quartz, or such like suitable material. I tap the blocks to make the powder settle, then I pour into the joints or cracks melted elastic waterproof nonfracturing material, for example, some artificial rubber-like compound which will re sist the street concussions and temperature changes to which the blocks are to be subjected;or melted bitumen is used. This resilient joint filling will then be located at the top of each crack, and extenddown to about the middle, but not to the base thereof.

I dress the top faces of the blocks with any suitable (as atarry) surfacing substance, free from ingredients soluble in water. This dressing, after a few days, in warm dry weather canberepeated with advantage to fill any uneveniplaces which may have developed. By the traffic and the cleansing of the road, part of the filling between the blocks will in time be removed, but I replace it periodically.

The above and further details of construction will be understood from the accompanying diagrammatic drawings.

Figure 1 represents a vertical section across part of a roadway; Fig. 2 a plan View of part of the roadway; and Fig. 3 is like Fig.2 but shows modifications, including a difference near the curb. Fig. 4 shows on a larger scale a joint and itsfilling.

In the drawings 1 represents the under part of the road foundation, 2 its middle, and 3 its upper part; any suitable foundation which is firm and dry will do.

In Fig, 1 at the right hand side, a layer 3f,-which I usein some cases,'is shown of expanded metal, or coarse wire netting. l is the layer over the foundation. This layer may consist of bitumen or material as aforesaid which will give a cushioning effect; it is in some cases mixed with a small proportion of solid material as stone screenings or slag. 5 are granite or suitable blocks, which have upper surfaces adapted to be dressed as indicated to form the roadway. Between these blocks there will be spaces 6 which I fill with in part powdered material and in part a non-fracturing material of waterproof resilient character, as referred to hereinafter. v

7 in Fig. 2 is a gutter course; and in Fig. 3 8 represents a curb; in Fig. 3 the gutter course 9 consists of elongated blocks set obliquely to curb 8. The invention is not directed to any arrangement of gutter or curbing, the illustrations being examples only of forms which may be employed.

Between the courses of blocks 5 are curved and transverse joints 10. Each curve will extend across all or only some portion of the road; a series of curves is ordinarily adopted to make up the full width.

In Fig. 2 a complete curve is shown in each course, and portions of other curves. The curve radius may be varied, and need not be the same as regards those curves which have ends which meet. In Fig. 2 the curve shown has about the minimum of effective flatness and length, and in practice the length is increased, but without reaching the length of a quadrant; or the various joints would, at the ends of the curves, run in directions which are not advantageous relatively to trafiic. Joints 10 give superior results as compared with common transverse joints.

The blocks 5 are (except as indicated later) of uniform shape and size, or approximately so; this keeps the expense of laying and replacing to a minimum. Granite blocks do not break as flat as wood blocks are cut, but it is an advantage to have them somewhat rough, so this roughness is purposely utilized. The roughness of the vertical walls of the cracks between the blocks enables the joint fillings to much better resist the pulling out of any block during traffic. Each roughness underneath a block helps the latter to grip its cushion ing layer 4i; and each top roughness helps to prevent the slipping of motor cars or horses, giving a fine grip to both. The avoidance of slipping is additionally promoted by the described positioning of the blocks relatively to one another, and by the nature of the materials used as described. Where curves "of the block courses meet, special blocks are in some cases used, as in Fig. 2, though meeting devices may be varied. As illustrated. blocks '13 are peaked onone' side ,terruptions by blocks 13.

and recessed on the other side; they may be of any suitable size. Blocks as 12 are also used in some cases different in shape to blocks 5, by having the sides making the walls of joints 6 less. nearlyparallel. Between blocks 12 is a joint 11 not continuous longitudinally of the road, on account of in- Joints 6 are not continuous longitudinally of the road from one course of blocks to the next. A filling of rubber compound or bitumen is used in all cracks between the blocks extending downward from the traffic surface, as 6, 10 and 11, the powder 14: (inserted as previously explained) being covered with this filling l5, and each block can then move slightly under trafiic. During great heat it has been found that ordinary meltable fillings between j oints rise and spread upon the road, but in my case the melted material will sink a little deeper into thelower part of the joints between grains of the powder 1 1 not previously reached.

I may 'omit or modify some details described, providing matter is retained which I claim hereinafter.

Having described this invention what is claimed by Letters Patent is 1. In a road construction, the combination with a foundation, of a surface comprising arcuate units assembled into courses multi-arcuate in" a horizontal plane, abutment units connecting adjacent arcs in alternate courses, coiiperable units connecting adjacent arcs in the remaining courses, said units having reversely-inclined meeting faces adapted to abut and form breaking joints with the abutment units of contiguous courses.

2. In a roadway construction, the combination of a foundation consisting of a bed of concrete rubble, wire netting embedded insaid concrete rubble, a layer of resilient waterproof material overlying said bed, and a surface comprising units assembled on said resilient Waterproof material in courses arcuate in a horizontal plane.

3. In a roadway construction, the combination of a foundation consisting of a bed of concrete rubble, wire netting embedded in said concrete rubble, a layer of resilient waterproof material overlying said bed, a surface comprising units assembled on said resilient waterproof material in courses arcuate in a horizontal plane, a powdered filling inserted between adjacent units and a resilient waterproof material inserted over i said powdered vfilling.

4'. In a roadway construction, the combination of a foundation consisting of a bed of concrete rubble, wire netting embedded in said concrete rubble, a layer of resilient yvaterproof material overlyingsaid-bed, -a.

surface" comprising units assembled "into courses mu1ti-arcuate in a horizontal plane, waterproof naterial inserted over said 10; abutment units connecting adjacent arcs in powdered filling.

alternate courses, e06 erable units connecta In witness whereof I have hereunto set ingdadjacenlt1 arcs in t e reimainilng courses, my hand in the presence of two witnesses. sai units aving reverse y-inc inec meeting faces adapted to abut and form break- THOMAS HOOART FLERE' ing joints with the abutment units of con- Witnesses:

tiguous courses, a powdered filling inserted GEORGE G. TURRI,

between adjacent units, and a resilient BEATRICE M. LOWE.

copies of this patent may be obtainedfor five cents each, by addressing the Gommissioner of Estimate Washington, D. 0.

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