US1973821A - Sea wall - Google Patents

Description

Sept. 18, 1934. R MASON 1,973,821

SEA WALL Filed Dec. 19, 1932 INVENTOR.

a I 4 Land 27 RMaaon o 7 BY ATTORNEY Patented Sept. 18, 1934 UNITED STATES SEA WALL Landon R. Mason, Los Angeles, Calif., assignor to Union Oil Company of California, Los Angeles,

Calif., a corporation of California Application December 19, 1932, Serial No. 647,851

9 Claims.

The present invention relates to methods of constructing sea walls, breakwaters, ripraps, levees and the like, and to a bituminous concrete block for use in sea wall, etc. constructions.

It is generally known to construct sea walls, breakwaters, ripraps, levees and the like by placing stones one above the other in very irregular courses. Reliance is placed upon the weight of the stone to hold them into a fairly compact wall. The size and weight of the stone employed usually depends upon the severity of impacts received by the wall. In certain places, such as along the sea coast, where the sea wall is subject to the impacts of large waves or swells, stones weighing from ten to thirty tons are employed to construct the sea wall so as to present sufficient resistance to the action of the waves or water. In other places, such as in relatively calm bays, the water or wave action is not quite as severe and considerably smaller stones may be used to.

construct the sea wall.

In many places where very large stones are necessary to construct the sea wall and the same are diflicult to procure except at great expense, U. S. Army Engineers have employed pre-cast blocks of reinforced Portland cement concrete weighing from ten to thirty tons. Of course, in sea wall construction, a large quantity of these pre-cast blocks are necessary to form the structure. In deep water, the expense of constructing a sea wall with these blocks is extremely high and the strength of the sea wall is problematical. For example, a breakwater constructed in Humbolt Bay, California, with pre-cast blocks of Portland cement concrete must be repaired very frequently due to the extreme storms which, in some cases, completely destroy a considerable portion of the breakwater.

It is one of the principal objects of my invention to vastly improve upon prior methods of constructing sea walls, breakwaters, ripraps, levees and like types of protecting structures.

A further object is to provide an improved block of asphaltic concrete for use in sea wall construction and a further object is to provide an asphaltic block of great tensile strength and re-' sistance to impact and one which will adhere and bind with adjoining blocks to form a practically monolithic structure when the blocks are used in sea walls.

Other ancillary objects of my invention will be suggested in the following description taken from the drawing and in the uses to which my invention is put. p

Referring to the drawing Fig. 1 is a perspective view of the block forming the subject of my invention;

Fig. 2 is a fragmentary section of said block;

Fig. 3 is a sectional view of a breakwater construction showing the placing of the blocks in irregular courses;

Fig. 4 is a fragmentary sectional view of a plurality of blocks illustrating approximately the manner that the blocks become bound to each other in course of time;

Fig. 5 is a sectionalview of a preferred embodiment illustrating the filling of the voids presented by the blocks in breakwater construction.

In its broadest aspects, my invention comprises a structure comprising a block containing asphalt for use in building sea walls or the like. An important feature of my invention resides in the use of a particular type of asphalt known as filled asphalt which may be composed of asphalt and a finely comminuted filler, such as diatomaceous earth combined in such proportions as to present a mastic of high tensile strength and resistance to impact.

Another important feature of my invention resides in the use of metallic bars for reinforcing the block, said bars protruding from the faces of the block approximately six to eight inches in order to permit adjoining similar blocks to sink into each other when laid as sea walls and thus form a rigid structure.

More specifically, my invention comprises a block composed of filled asphalt and aggregate,

the former being in amounts suflicient to exactly fill the voids in the aggregate, said block being reinforced by a plurality of metal bars running through the block and protruding some six to eight inches out from the faces of the block.

My invention also includes a rigid sea wall or the like comprising a plurality of said blocks of reinforced asphaltic concrete substantially joined to each other. The invention also includes a monolithic sea wall comprising a plurality of said blocks joined to each other by the protrusions of metal rods sinking into each other, the voids presented by adjacent blocks being filled with asphaltic concrete. The invention also comprises a method of constructing the aforementioned blocks and also a method of constructing sea walls employing said blocks.

I have discovered that if large pre-cast blocks weighing ten to thirty tons are constructed using asphalt as a binder for the aggregate instead of Portland cement that a block is presented which represents a vast improvement over the previous type of pre-cast blocks of Portland cement conof logs and similar objects tossed by the sea.

Another advantage and characteristic of the precast block, forming the subject of my invention, resides in its self-healing properties, if,- for any reason the block is cracked.

The asphaltic concrete which I particularly desire to employ for pre-casting large blocks comprises a mixture of asphalt, a carefully selected and graded finely comminuted filler or combination of such fillers, graded sand and carefully graded, sharp, crushed stone. The combination of asphalt and filler shall herein be referred to as filled asphalt or asphaltic mastic and the combination of the filled asphalt with sand and crushed rock comprising aggregate shall be termed asphaltic concrete. I particularly desire to employ filled asphalt rather than pure asphalt for admixture with aggregate to form the as-' phaltic concrete because filled asphalts possess greater toughness, reasonable high ductilities, high melting points and substantially low penetrations and have very little tendency to become unstable even when mixed with mineral aggregates in extremely high concentrations as I have ,found necessary in asphaltic concretes for filling the voids in the aggregate.

The filled asphalts whi h I desire to employ as the cementing agents for the aggregate are described in my co-pending application, Serial No. 647,850 filed Dec. 19, 1932. Briefiy, these asphalts 'may be described as comprising a mixture of D grade steam refined asphalt and a filler, such as diatomaceous earth or rock dust, or a combination of fillers, such as diatomaceous earth and rock dust. A D grade asphalt is a steam refined asphalt, having a penetration of ,40 to 90 at 77 'F., a melting or softening point of 110 to 130 F. and a ductility of greater than 100 at 77 F., all measurements being made according to the methods outlined by the American Societ of Testing Materials as indicated below.

The optimum concentrations and character of fillers to be used in the blocks of asphaltic concrete are also described in said co-pending application. The filled asphalt suitable for use in making pre-cast blocks of asphaltic concrete should conform with the following specifications:

Softening point 175 F. or over Penetration at 77 F 15 to Penetration at 115 F4120 or less Ductility at 77 F 5 or over vTensile strength ..800 lbs. per sq. in. or over Impact resistance 3 ft. lbs. or over For determining the softening point, penetration and ductility of the filled asphalt, the following methods outlined by the American Society of Testing Materials shall be used:

Softening or'melting point, ball and ring method D36-26 Penetration D525 Ductility D-113-26T The tensile strength shall be determined by making one inch cubical briquets in molds commonly used for preparing tensile strength test briquets of Portland cement. The briquets shall be composed of standard 20 to 30 mesh Ottawa sand mixed with the proper quantity of asphaltic mastic to exactly fill the voids in the Ottawa sand which comprise 32Vz% by volume. After the briquets have cooled they shall be placed for one hour or more in a water bath at 77 F. and shall then be pulled apart in a suitable testing machine for determining tensile strengths.

The impact resistance shall be determined by making two-inch cubical briquets in molds and the briquets shall be composed of standard 20 to 30 mesh Ottawa sand mixed with the proper quantity of asphaltic mastic to exactly fill the voids in the Ottawa sand which comprise 32 by vol- 1 ume. After the briquets have cooled, they shall be placed for one hour or more in a water bath at 77 and shall be tested by dropping a two-inch steel ball weighing 1.175 lbs. upon the cube, allowing the ball first to drop six inches and then progressively increasing the height of fall one inch per blow until destruction of the cube results. The impact resistance may then ,be calculated by multiplying the height of fall in feet at cube destruction by the weight of the steel ball in pounds, that is, 1.175.

An asphaltic mastic having the above designated characteristics may be produced by hot mixing from 30 to 72 o by weight of D grade steam refined asphalt and 28 to by weight of filler or combination of fillers, such as diatomaceous earth androck dust, as determined in my above mentioned co-pending application. For example, a filled asphalt composed of 72% by weight of asphalt and 28% by weight of diatomaceous earth will conform with the above specifications as to'softening point, penetration, ductility, tensile strength and impact resistance. Likewise, a mixture of 57% asphalt, 21 diatomaceous earth and 21%% rock dust and also a mixture of equal parts of asphalt and filler where the filler comprises equal parts of diatomaceous earth and rock dust will. have'such specifications as indicated above but it will be observed that the ductilities of mixture containing rock dust are less than when using straight diatomaceous earth. A mixture of30% asphalt and 70% rock dust will also be within the specifications but the ductility is considerably lower than when using diatomaceousearth alone or in admixture with the rock dust.

An asphaltic mastic of any of the above combinations of asphalt and filler will have a higher tensile strength and impact resistance than Portland cement concrete composed of 'one part Portland cement, two parts sharp, clean sand and four parts sharp, clean, broken stone which will pass a screen having one-fourth inch circular openings. For example, the tensile strength of all of the above combinations of asphalt and filler is approximately 300 lbs. per square inch and the impact resistance is above three foot pounds, whereas the tensile strength of the above Portland cement concrete is merely 229 lbs. per square inch even when cured for sevendays under water, while its impact resistance is not over 2.85 ft. lbs., this data being obtained by tests performed on cubical briquets in exactly the same manner as those for determining the characteristics of asphaltic mastic.

The preferred aggregate used for admixture with filled asphalt to produce the asphaltic concrete comprises a mixture of hard, clean, sharp, crushed stone and clean graded sand having the following specifications:

Percent. Passing a 200 mesh sieve 6- 8 Passing a 80 mesh sieve 14- 20 Passinga 40 mesh sieve 26- 34 Passing a v 10 mesh sieve 36- 44 Passing a 3 mesh sieve 54- 64 Passing a screen with in. circular openings 78- 88 Passing a screen with in. circular openings 95-100 In admixing filled asphalts with commercial aggregates, care should be taken to adjust the percentage of filled asphalt to exactly fill the voids in the aggregate since the maximum tensile strength and resistance to impact is obtained when the voids are filled exactly with the filled asphalt. The amount of filled asphalt employed will, of course, vary with the percent of voids in the aggregate and the latter may vary from 15 to 25% by volume in dense mixtures. Consequently, approximately 15 to 25% by volume of the filled asphalt must be employed to exactly fill the voids of the remaining 75 to 85% by volume of the aggregate.

It is preferable to choose an aggregate having a maximum density, that is, a minimum of voids. By carefully proportioning the amount of sand to crushed rock, it is possible to obtain an aggregate having a minimum of voids. I have found that an aggregate composed of crushed rock capable of passing a screen having inch circular openings and graded sand in the proportion 50.5% to 49.5% by volume, respectively, has a smaller percentage of voids, i. e. approximately 20.5% by volume than any other combination-of these materials. Consequently, approximately 20.5% by volume of asphalt will exactly fill the voids of this aggregate to produce an asphaltic concrete of maximum density.

In constructing my asphaltic concrete block,

' it is preferable, in order to minimize the use of weight of the block to be casted. However, these stones should not be allowed to touch one another and there must be sufficient asphaltic concrete between them in order to make the block rigid.

One of the important features of my invention resides in the use of steel or other metal rods of great strength running through the entire block and protruding about six inches to eight inches out of the faces of the block. For this purpose, it is desirable to employ old steel railroad rails or other metal bars of either circular, rectangular or irregular cross-sections. The rods or rails should be dipped or coated with asphalt or other suitable metal protective coating to prevent rust and corrosion. These rods add to the reinforcement of the block and most important of all, the protrusions permit sinking into adjoining blocks whenlaid as sea walls or breakwaters and bind with adjoining blocks, thus forming a coherent structure.

The herein described blocks forming the subject of my invention may be constructed in the following manner:

By reference to Fig. 1, it will be observed that v irregular shapes.

tangular parallelopiped having a plurality of metallic bars 10 running throughout the block and protruding from each of the six faces. However, it must be noted that I do not wish to be limited to a block construction of this exact shape since those skilled in the art will readily understand that blocks may be constructed incorporating the features of my invention having either regular or In fact, a block may be constructedhaving an extremely irregular shape similar to the large stones confmonly employed in sea wall construction.

In order to construct a block of the preferred shape as shown, it is first necessary-to provide a suitable mold or form having the proper inside dimensions desired of the finished block. It is estimated that a block weighing approximately 30 tons should be approximately 7 feet by 7 feet by 8 feet. Of course, the weights of other blocks.

would depend upon their dimensions and density of the material employed.

The mold used should be provided with suitable openings on its sides and bottom to permit placing of the rods in the interior of the mold and to a low these to protrude some 6 to 8 inches from the faces of the mold. The top of the mold may be omitted in order to permit introduction of the materials forming the block into the mold.

referably, the interior of the mold should be lined or coated with a suitable material, such as clay, to prevent the asphalt from adhering to its sides and bottom and thus to facilitate removal of the block when completed. The mold should be demountable to permit removal of the block after it has been casted.

After the mold has been set up, the. steel rods or rails 10 which have been coated with asphalt or other suitable rust and corrosion preventive material are placed inthe mold. Preferably, the openings on the sides and bottom of the mold should be aligned to permit proper spacing of the rais, to permit the rails to be placed parallel to the faces as shown in Figs. 1 and 2 and also to permit the rails running parallel to the faces to be joined at their intersections as shown at 11 of Fig. 2. The intersections may be joined by tying them with wire or cables 12 or by welding. This adds to the reinforcement of the block.

The ends of the rail should protrude from themold approximately 6 to 8 inches.

The mold is then filled with hot asphaltic concrete 14 at a temperature of 250 to 450 F. and said asphaltic concrete should have a composition such as to conform with the above stated specifications. If desired, approximately 20% of the filled asphalt composed of equal parts of asphalt and filler where the filler comprises equal parts of diatomaceous earth and rock dust may be mixed with approximately of aggregate composed of crushed rock and sand. The con crete should preferably be produced by first forming the filled asphalt by mixing asphalt and filler at a temperature of 350 to 500 F. and then mixing the filled asphalt while hot with the aggregate which has also been heated to temperatures approximating that of the asphalt. After the mold has been filled, the asphaltic concrete is tamped until no more asphaltic concrete can be added. :It is then permitted to cool and harden. When it has hardened sufficiently, the mold is dismounted to remove the reinforced asphaltic concrete block. 1

' In order to conserve in the amount of asphaltic concrete used in building the block, large size broken stone or plums 16 weighing from 10 to 50 lbs. and above may be placed and consolidated in the block during its .construction. However, these stones should not be placed so as to touch one another and there must be suflicient asphaltic concrete between them to make the block rigid.

One of the principal features of my invention is to employ the above constructed blocks for building sea walls, breakwaters, ripraps, levees, and the like, in places where large stones of 10 to 30 tons cannot be procured except atgreat expense. In constructing the sea walls, etc., the asphaltic concrete blocks 1 are placed in the water as shown in Fig. 3 and in a manner similar to the construction of sea walls of large stones or blocks of Portland cement concrete. The reinforcing rails protruding will unquestionably sink into and bind Withm adjoining blocks to form a rigid structure as shown in Fig. 4, and moreover, in the course of time, the blocks will become a practically monolithic mass due to the aflinity of asphalt for asphalt and due to'the sinking of the reinforcing rails into adjacent blocks.

If desired, the voids 20 presented by adjoining blocks may be filled with asphaltic concrete as shown in Fig. 5 during the course of construction of the sea wall. In such. cases, hot plastic asphaltic concrete having substantially the same composition as the asphaltic concrete employed in the block construction can be dumped upon each course of blocks above the low tide level and subsequently laying the next course of blocks. If desired, the voids may be filled with hot asphaltic mastic, i. e. asphalt containing a filler without the use of aggregate or 'with asphaltic .mastic containing smaller aggregate than that specified above. In fact, the crushed stone may be omitted and graded sand mixed with the asphaltic mastic ,may be used to fill the voids.

This will permit the cementing agent to. more readily flow into the voids.. If desired, large size broken stone or plums may be inserted in extremely large voids in order to conserve in the amount of asphaltic concrete for filling the voids.

Each block laid upon the asphaltic concrete then sinks into the latter and thus forms a perfect bed. In a short time the blocks and asphaltic concrete will form amonolithic structure without voids. It is not desirable to fill in the large voids on the water side of the sea wall with asphaltic concrete excepting to such extent as is required to form a firm bed for each block since it has been found that sea walls and breakwaters should preferably have very rough and irregular faces in order to most effectively absorb, deflect and break-up the impact of waves or swells. However, it is desirable to fill in as completely as possible I with the asphaltic concrete all of the voids withinthe wall in order to prevent rapidly moving masses of water from passing through the wall and washing the earth to be protected and uncracked petroleum residues, cracked and uncracked coal tar residues, pitch, tar and the like.

. The above-disclosure is to be taken as merely illustrative of a preferred embodiment of my invention and is not to be considered limiting, since to present voids and said reinforcing rods protruding from. the faces of said blocks and into the body of adjacent blocks to form a coherent structure.

3. A wall comprising a plurality of blocks of asphaltic concrete placed in irregular courses to present voids and asphaltic concrete in said voids.

4. A wall comprising a plurality of blocks of filled asphalt concrete, said blocks being provided with metallic protrusions extending into the body of adjacent blocks and asphaltic concrete in the voids presented by said adjacent blocks.

5. An articleof manufacture comprising asphaltic concrete in block shape and provided with a plurality of reinforcing rods extending through said block and protruding from the faces of said block, said asphaltic concrete comprising a mixture of approximately 15 to 25% by volume of ing a mixture of approximately 28% by weight of diatomaceous earth and 72% by weight of asphalt.

6. An article of manufacture comprising asphaltic concrete in block shape and provided with a plurality of reinforcing rods extending through said block and protruding from the faces of said block, said asphaltic concrete comprising a mixture of approximately 15 to 25% by volume of filled asphalt and approximately 75 to 85% by volume of aggregate,"said filled asphalt comprising a mixture of asphalt and filler and having a softening point of not less than 175 F., a penetration between 15 and 45 at 77 F., a ductility of not less than 5 at 77 F., a tensile strength of not less than 300 lbs. per square inch and an impact resistance of not less than 3 ft. lbs.

7. A method of constructing walls comprising laying blocks of asphaltic concrete in irregular courses and joining said blocks to each other by means of reinforcing rods protruding from the faces of said blocks and extendinginto the body of adjacent blocks. I

8. A method of constructing walls comprising laying blocks of asphaltic concrete in irregular courses, joining said blocks to each other by means of reinforcing rods protruding from the faces of said blocks and extending into the body of adjacent blocks and filling the voids presented by said blocks with. concrete containing asphalt.

9. A method of constructing se a walls comprising laying blocks of asphaltic concrete in irregular courseaioining said blocks to each other by means of reinforcing rods protruding from the faces of said blocks and extending into the body of adjacent blocks and filling the voids presented by said blocks with asphaltic concrete above the low'tide level.

' LANDON R. MASON.

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