US2083593A - Method of making protected piling - Google Patents

Description

June 15, 1937. J, w, BLACKMAN 2,083,593

METHOD OF MAKING PROTECTED FILING Original Filed Nov. 10, 1934 2 Sheets-Sheet 1- fzwelz/br. dirk/21a B. Blackmail,

June 15, 1937. w BLACKMAN 2,083,593

METHOD OF MAKING PROTECTED FILING Original Filed Nov. 10, 1934 2 Sheets-Shoat 2 lwaezz/ar.

Job? M 3. B/cmfmaw,

Patented June 15, 1937 UNITED STATES PATENT OFFICE Original application November 10, 1934, Serial Divided and this application July 22, 1935, Serial No. 32,513

5 Claims.

This invention has to do generally with protected concrete piling, and has for its principal object to provide improved methods for casting protected concrete piles that possess numerous advantages over past methods both from standpoints of convenience and facility in the pile casting operation and also the strength and deterioration resisting qualities of the pile itself. The present application is a division of my copending application, Ser. No. 752,445, filed Nov. 10, 1934, on Protected piling and method for making same, which application now deals with the pile construction itself. Attention is also directed to a second copending divisional application, Ser. No. 32,512, filed on even date herewith on Method of forming and extending driven piling, which deals with methods for protecting and extending driven piling.

The necessity has long been realized of rendering concrete piling immune to attack and deterioration by the action of sea water, alkalies, acids, frost, marine insects and the like. One of the most generally used and successful methods employed in the past has been to first cast the pile of concrete having sufficient porosity to be capable of impregnation to a substantial depth by waterproofing material, such as asphalt, tothen heat the pile to exclude air and other gases from the pores of the concrete, and finally immerse it in a bath of hot asp-halt under such conditions that the asphalt is drawn into the pores to impregnate the outer depth of the concrete. While this method of protecting piles has been found fully successful, it involves a practical disadvantage by reason of the necessity for a fairly large and expensive plant to carry out the impregnating operations. For this and the further reason that a sufiicient number of piles is not required on the average job to warrant building an impregnating plant for that job, it has been customary to cast and impregnate the piles at a distant permanent plant, and then to ship them to the place where they are to b-eused. It will be apparent, of course, that because of the great size and weight of the average concrete pile, handling and shipping involve considerable expense, particularly where the piles must be transported long distances and to places not conveniently accessible.

One of the outstanding advantages of the in vention. is that it provides a method whereby prc.- tected concrete piles may be cast on the job, at the place where they are to be driven, thus eliminating the difficulties and expense incident to transporting the completed piles. In addition,

the invention offers the further advantage of providing protected concrete piling which from structural standpoints, has greater strength and greater immunity from attack by the various agencies mentioned above, than any type of concrete piling heretofore proposed.

The present pile structure may be described briefly as one in which the concrete body of the pile is protected by a layer of slabs made of material that is fully resistant to attack and disintegration, with joints between the slabs of an equally resistant character, so that the slabs together form a continuous protective layer at the surface of the concrete. Preferably the slabs will be made of porous, asphalt impregnated concrete, and will be cast and impregnated at a central plant and shipped out to the jobs. By reason of their small size and light weight, however, the slabs may be handled and transported at comparatively low cost; and in a single shipment, sufficient slabs may be transported to protect a large number of piles.

Two different methods may be used in applying the slabs to the pile. In accordance with one method, the slabs are first arranged as a permanent form into which the body or concrete core of the pile is cast, the slabs having surface irregularities or key recesses into which the concrete flows, so that when the concrete sets, the slabs will have in effect become integrated with the body of the pile. In applying the slabs by the sec ond method, the body of the pile is first cast, and the precast slabs applied and bonded to the body by grout poured into key recesses within both the slabs and the body. Both of these methods may be used in forming different parts of the same pile, or the entire pile structure may be cast in accordance with either one of the methods.

The advantages and desirable departures from past practice made possible by the invention, include many additional features which would require considerable space to set out at length. It is believed that a full understanding of the objects and features mentioned above, as well as all the additional aspects and details of the invention, can most readily be given by proceeding directly to a description of certain typical and illustrative embodiments of the invention. For this purpose reference is had to the accompanying drawings, in which:

Fig. 1 is a perspective showing the arrangement of form slabs and braces used in casting the pile, some of the slabs being removed to show more clearly their shapes and relative positions;

Fig. 2 is a transverse sectional View showing the slabs and braces in the aspect of Fig. 1, after the slab form has been filled with concrete;

Fig. 3 is a perspective showing the cast pile after removal from the studs;

Fig. t is a fragmentary section taken in the vertical plane of line il of Fig. 3;

Fig. 5 is a plan of one of the top slabs in Figs. 1 and 2, inverted to show the key recesses;

Fig. 6 is a section on line 55-45 of Fig. 5;

Fig. 7 is a view, partly in section, showing the top portion of a driven pile supporting a floor structure and having subsequently applied protective slabs keyed to its upper extent;

Fig. 8 is an enlarged section on line 8--8 of Fig. 7;

Fig. 9 is a front elevational View showing the protective slabs applied to sheet piling;

Fig. 10 a vertical section on line Iii-16 of Fig. 9;

Fig. 11 is a horizontal section on line ll-H of Fig. 9;'

Fig. 12 is an elevation showing a further variational form of the invention; and

Fig. 13 is an enlarged section on line iii-l3 of Fig. 12.

The form of the invention shown in Figs. 1 to 8 inclusive may best be explained by first describing the method whereby a section of the pile is cast in a form composed of protective slabs, and then the procedure followed in applying slabs to the top portion of the pile after the latter has been driven. Reference is first made to Figs. 1 and 2 for the purpose of describing the sequence of operations in building up the slab form and finally filling it with concrete in casting the intermediate section of the pile. First I lay a suitable platform if] on which is erected a series of brace structures ll comprising uprights i2, cross pieces i3 and diagonal braces i=3. A series of bottom slabs l5 are then laid end to end upon the platform [0, and two courses of slabs it placed upon the bottom diagonal braces M- with their inner edges engaging slabs i5. 1 have shown the angularly placed slab-s if: each to have two elongated key recesses 15a with undercut sides and ends for the purpose of illustrating that if desired, not only the ends but the sides of the slab recesses may be undercut.

Fig. 5 illustrates the shape of the bottom slabs I5, as well as those in the top course hereinafter described, although the latter are provided with certain openings not present in the bottom slabs, as will later appear. It may be stated first that all the slabs will be precast and formed of a suitable waterproof material or composition resistant to attack and disintegration by acids, alkalies, and other deteriorating agencies. Preferably the slabs are made of concrete impregnated with waterproofing material such as asphalt, the concrete having sufficient porosity to 'be thoroughly impregnated throughout the interior of the slab. In this connection, reference is made to my c0- pending application on Protective slabs for concrete, Ser. No. 667,251, filed Apr. 21, 1933, for a more complete description of the advantages and characteristics of slabs of this general type. It will sufiice to observe here that the slabs may be made of any suitable waterproofing material resistant to deterioration, though I find asphalt impregnated concrete to be particularly well suited for my purposes.

Each slab i5 is rectangular in shape, of substantially uniform thickness, and has one or more key recesses l'l, three here being shown as typical, having undercut or dove-tailed ends [8, and

sides l9 which are beveled inwardly toward the base of the recesses. As will later appear, these recesses serve to form keys which securely bond the slab to the concrete body of the pile. The recesses are entirely contained within the slab so that the joint edges beyond the recesses are of the full thickness of the slab. In impregnating the slabs, the latter are immersed for a time in a bath of hot asphalt and then removed when the asphalt has fully permeated the pores. The impregnated slabs are stood on end to cool and dry, and in order to insure complete drainage of asphalt from the key recesses I1, I cast drain notches Ila. within the undercut ends it of the recesses.

As shown in Fig. 2, the adjoining edges of slabs l5 and R6 are beveled to provide upwardly opening wedge-shaped joint spaces 29. Similarly shaped joint spaces are formed at the ends of the slabs, corresponding to the later described joints illustrated in Fig. 4. As soon as slabs l5 and it are laid, joint spaces 26 and the similar joint spaces between the ends of the slabs are filled with hot asphalt which, by reason of its high temperature, has a tendency to melt the impregnating asphalt in the pores of the concrete at the edges of the slab. The result is that the joint filling asphalt, when cooled and hardened, will have become substantially integrated with the asphalt with which the slabs are impregnated. There is thus formed a joint that is thoroughly water tight and resistant to frost, acids, alkalies and other such deteriorating agencies. For further details concerning this type of joint, see Patent No. 1,953,920, granted to me April 10, 1934, on Protected concrete structures.

After laying the three lowermosts course of slabs, I then place the side slabs which are shaped similar to the bottom slabs 55, except that they have peripheral tongues extending along one side and end, and grooves within the remaining side and end. Tongue and groove joints 23 are formed between slabs l5 and the top angularly extending edges of the former having grooves 2 which receive tongues 25 on the lower edges of slabs 22. The joints at 23 are sealed with asphalt by first filling grooves M- with hot asphalt and then placing slabs 22. It may be mentioned that the joints between abutting ends of successive side slabs 22 will also be of the tongue and i groovetype, and will be filled with hot asphalt after the slabs have been placed, by pouring the joints from the top.

Before slabs 26 are positioned, the reenforcing steel is put into place. Slabs 26 are next put in place and held in the positions illustrated by temporary spreaders, not shown, placed between the upper ends of the slabs to keep them in place while the concrete is being poured. Asphalt filled tongue and groove joints similar to the previously described joints connect slabs 22 and 26 along their adjacent horizontally extending edges. The end. joints between successive slabs 26 will however be similar to the later mentioned joints at 28, see Fig. 4, in order that they may be poured from above.

All except the top slabs 29 having been placed and the joints cooled, concrete St is now poured into the interior space enclosed by the slabs and around suitable previously placed reenforcement 33!. Preferably the concrete will be tamped, vibrated or otherwise compacted into the slab form in order to exclude air and to secure the desired denseness. The concrete mixture may be proportioned to give great strength when set, and

to have high density withoutsubstantial porosity.

When the space within the slab form has been filled to a point near the top, slabs 29 are then laid in place and bedded until their top surfaces 29a are flush with the beveled top surfaces 23a. of slabs 26.

These top slabs 29 will be tamped firmly in place to compact the concrete beneath, and then, in order to insure that the joint recesses I within the slabs will be entirely filled with concrete, grout is poured or forced under a slight pressure into the key recesses through holes 33 cast within the slabs. Air and surplus grout are at the same time displaced through another set of holes 34, there being, as illustrated in Fig. 5, inlet and outlet holes extending through the slab into each key recess. The adjacent edges of slabs 26 and 29 are beveled to form wedge-shaped joint spaces at 35, and the abutting ends of successive slabs 29 are beveled to form similar joint spaces as indicated at 28 in Fig. 4. After the top slabs have become bedded with their key recesses completely filled with grout, holes 33, 34 and joint spaces 28 and 35 are cleaned out, allowed to dry, and then filled with hot asphalt. After the concrete has set for a period, the brace structures l l are removed.

At the same time the intermediate portion of the pile is being cast within permanent slabs as described, end portions of the pile extending beyond the slabs are also cast. As shown in Fig. 3, the driven end 31 of the pile is a solid concrete continuation of the concrete core 30 enclosed within the slabs, and has a cross sectional configuration conforming to the polygonal outer surface shape of the slab assembly. As shown in Fig. 4, the end slabs adjacent the driven end of the pile bear against shoulders 38 and form with the end 31, continuous smooth surfaces. If desired, asphalt filled joints may be formed at 38a between the end slabs and the driven end section of the pile. I

In casting the opposite solid concrete end 39 of the pile, longitudinally extending key recesses 40 having undercut sides 4|, see Fig. 8, are formed in the surfaces of the concrete, the lower ends of the recesses being closed by inwardly beveled shoulders 42, see Fig. 3. Recesses 40 may be cast by pouring the concrete around correspondingly shaped form boards which may be withdrawn endwise from the recesses after the concrete has set sufiiciently to hold its shape. I have not undertaken to illustrate forms to be used in casting the two end portions 3'! and 39 of the pile, since the building of forms to cast these portions of the pile in the shapes illustrated requires no special skill.

After the concrete has set and hardened, the pile is ready for driving in an upright position with end section 39 at the top. By reason of the fact that initially the protective slabs are not ap plied to the uppermost section 39 of the pile, the pile driver blows are not transmitted directly to the slabs, but alone to the concrete core. Although as the pile is being driven, shearing stresses between the concrete core and the permanent form slabs may be set up due to the inertia of the slabs, any cleavage whatsoever at the joints formed by the slab key recesses is prevented by the transverse shoulders, for example undercut shoulders I8 in Fig. 6, bearing against the concrete filling the recesses. In effect, the permanent slab form has become integratedwith the body of the pile, and has substantially the same strength.

The piles ordinarily will be driven to a depth such that the intermediate section to which the slabs are applied will extend above and below the limits of rise and fall of the water level. Ex-

perience has shown that where the piles are driven in sea water beds, it is within these limits that the pile is subjected to greatest deterioration by reason of the alternate submergence and exposure to air. It is readilyapparent that by reason of the integrated protective slab structure and the waterproof joints between the slabs, the concrete body of the pile is rendered entirely immune to attack.

Since the final depth to which a pile will be driven cannot be definitely ascertained in advance due to unknown conditions in the soil and formation into which the pile is driven, it is necessary to adjust the height of the driven pile to suit the level of the structure which it is to support, either by cutting off or adding to its upper end. The present pile structure lends itself particularly to height adjustment after driving, and to final application of slabs in order that the pile may be protected throughout its entire extent above the water level. When the pile is driven, slabs 43 and H, see Fig. 8, are placed around the top section 39, these slabs having self-contained under-cut key recesses 45 and 46 similar to the key recesses lSa in the previously described permanent form slabs 16. As illustrated, 1

the slab recesses come directly opposite the undercut key recesses 41! cast in the body of the pile, so that concrete poured into the recess forms a double key bonding the slabs to the body. The slabs have tongue and groove joints 4'! along their vertically extending edges, and if desired, similar joints may be formed between these slabs and the upper end of the intermediateslab section, and between vertically successive slabs applied to the top section 40 of the pile.

In applying slabs 43 and 44, all the joints 4? may be filled by pouring hot asphalt into the joint spaces from their upper ends after the slabs have been arranged about the pile as shown in Fig. 8, or the sleeve formed by the slabs may first be made in sections by joining two or more of the slabs before applying them to the pile. After the joints have hardened, grout is poured into the upper ends of the body key recesses ll] and caused to fiow down into and fully occupy the slab key recesses. Upon hardening, the grout forms keys 48 which securely bond the slabs to the concrete body of the pile.

In cases where it is necessary to extend the pile above the upper end of section 4! slabs 43 and M1 may be built up to the desired height as a sleeve form, within which additional reenforcement steel may be placed and concrete poured. In this case complete sleeve sections may be formed of the slabs before being placed on the pile, and these sections placed one upon the other, with sealed joints between, until the desired height has been reached.

In Fig. 7 I show a protected floor structure supported on the upper end of the pile after the height of the latter has been adjusted as previously explained. A concrete beam form comprising a series of side slabs 50 and bottom slabs 5| is built on a row of piles with the bottom slabs 5| resting upon their upper ends. These beam form slabs are similar in all respects to the previously described slabs applied to the pile, both as to waterproof characteristics and shape. The pile reenforcement 52 may be extended up into the beam form, and asphalt filled tongue and groove joints provided at 53 between the bottom slabs 5| and the lower edges of side slab 50. Additional slabs 54 may be suitably supported and joined to slabs 50 by asphalt filled joints at 55, to form the bottom protective layer of a concrete floor. After the slabs have been arranged as described, concrete is poured into space 56 to form a horizontally extending beam, the fioor 51 being poured at the same time. In setting, the concrete becomes securely bonded to the slabs, which in turn form an integral continuous protective layer about the beam and the entire underside of the fioor.

In Figs. 9 to 11 I show a variational form of the invention in which the slabs are applied tothe surface of sheet piling composed of individual piles 58 driven edge to edge and forming a continuous wall. The piles are precast with tongues 59 and grooves (it which interfit when the piles are driven in place. The individual piles are also precast with the view to protecting the surface 6| of the wall most subject to disintegration, as for example because of exposure to sea water, by the application and bonding of protective slabs thereto. For this purpose the piles 58 are cast with vertically extending key recesses 62 having undercut sides and extending continuously within that portion of the pile extent that is to be protected.

The slabs 63 may be applied to the face 6| of the sheet piling wall in various manners. For example, the lowermost horizontal course 64 of the slabs may be supported in place, the end tongue and groove joints 65 filled with hot asphalt, and then the upper courses 56 and 6'! applied successively, the horizontal tongue and groove joints 68 and the vertical joints 65 being poured as the slab structure is built up to the level of the top 58a of the piling. After the several slab courses have been placed and the joints allowed to harden, grout is poured or forced down through key recesses 62 in the pile, completely filling these recesses and also the key recesses 69 in the slabs. After the grout sets, the slabs will have become bonded and keyed to the surface of the piling, forming a continuous waterproof protective layer. Ordinarily the slabs need he applied to only a sufficient vertical extent of the pile that the lower slab course will at all times be submerged beneath the level of the water to which the piling is exposed.

Instead of first building up the successive slab courses to the top of the piling and then pouring grout to fill the key recesses of all the slabs at once, if found necessary or for any reason desirable, the grout may be poured into the key recesses after each horizontal slab course is laid. Since in this case the grout will be poured at intervals to shallower depths, a better opportunity may be given to avoid forming air pockets within the recesses, since the air may more readily escape.

After the slabs have been applied to the face of the sheet piling wall as described, a waling may be cast on the top of the piling and protected by slab courses continuing upwardly from those previously applied to the piling. In casting the waling I first place one or more courses 10 of slabs on the previously laid courses, and connect the individual slabs with tongue and groove waterproof joints of the character previously described. These slab courses EB serve as permanent forms against which the concrete for the waling H is poured, other temporary forms being erected to cast the waling in the shape indicated.

Where it is desired to cast an individual waling to be applied to a wall or sheet piling, this waling can be precast within protective slabs and then mounted. Thus in Fig. 10, I show a waling l9 placed at or below the low'water level and attached to the piling by horizontal tie rods 33. The waling is precast by pouring concrete into slabs BI, 82, and 83, the top slabs 84 being applied last and the enclosed space finally filled by pouring or forcing in grout through apertures in these top slabs, as previously described with reference to Fig. 5. A protective closure 35 through which the tie rod is to extend, may be formed of smallsize slabs or of a single impregnated concrete tube, and placed in the position shown before the concrete 86 is poured. Waterproof tongue and groove joints are formed between the slabs encasing the waling, as shown, and also at 8? between the lowermost slab 64 and the top slab 84 of the waling.

Figs. 12 and 13 show a variational form of the invention in which an individual pile is entirely enclosed within a protective sleeve made up of slabs applied to the pile in essentially the same method as that just described with reference to the sheet piling. In Fig. 13 I show a precast square concrete pile 12 having longitudinally extending undercut key recesses 13 formed in each of its four surfaces. Protective slabs M applied to the faces of the pile have end key recesses 55 directly opposite the pile key ways '13, and have asphalt filled tongue and groove joints at T6 and I'd along their engaging vertically and horizontally extending edges. The lowermost slabs I la are supported on a shoulder 78 which may be cast integrally with or otherwise fastened to the pile. As in the forms of the invention shown in Figs. 8 and 11, the slabs "M are bonded to the surface of the pile by grout poured into recesses 13.

In all the previously described forms of the invention in which the slabs have been applied to driven piles, the latter have been precast with grout receiving recesses in their surfaces. I may state that it is readily possible and fully practical to apply the slabs to driven piles that have not been specifically cast to provide bonding irregularities, simply by forming such irregularities in the pile surface by the use of air drills or other suitable implements. The irregularities or grout receiving spaces so formed need not necessarily take the shape of undercut key ways such as I have shown in the cast piles, but they may be of any character or configuration that will enable a secure bond to be had between the slabs and the pile. As an alternative method of applying the slabs to piles that have not had bonding recesses formed in their surfaces, or to smooth surface piles I may apply coarse wire mesh, reenforcement materials or the like, to the pile, then place the slabs against the Wire mesh or reenforcement, and finally pour grout into the space between the slabs and the pile. In this case the reenforcement acts to bond the grout to the pile, instead of irregularities formed in the surface of the latter.

I claim:

1. The method that includes, driving a pile, then protecting the surface of said pile throughout a predetermined portion of its length by applying preformed waterproof slabs thereto in contact with said surface, both the inner surfaces of the slabs and outer surface of the pile having recesses formed therein, and bonding the slabs to the pile while in contact with said surface, by pouring grout into said recesses.

2. The method that includes, driving a pile, and

then protecting the surface of said pile throughout a predetermined portion of its length by applying preformed waterproof slabs thereto in contact with said surface, both the inner surfaces of the slabs and outer surface of the pile having recesses formed therein, sealing the joints between said slabs, and then cementing the slabs to the pile while in contact with said surface, by pouring grout into said recesses.

3. The method that includes, driving a pile comprising a lower section having an integral water proof sleeve and an upper unprotected section, and then protecting the surface of said upper section by applying preformed waterproof slabs to said surface and in contact therewith so that the slabs are supported on the upper end of said sleeve, both the inner surfaces of the slabs and outer surface of the pile having recesses formed therein, and pouring grout into said recesses to cement the slabs to the pile while in contact with said surface.

4. The method that includes, driving a pile comprising a lower section having an integral waterproof sleeve formed of impregnated concrete slabs,

and an upper unprotected section, and then protecting the surface of said upper section by applying preformed waterproof slabs thereto in contact with said surface directly above said sleeve, both the inner surfaces of the slabs and outer surface of the pile having recesses formed therein, sealing the joints between the last mentioned slabs, and pouring grout into said recesses to cement the slabs to the pile while in contact with said surface.

5: The method that includes, driving a pile comprising a lower section having an integral water-' proof sleeve and an upper unprotected section, and then protecting the surface of said upper section by applying preformed waterproof slabs thereto in contact with said surface and said sleeve, both the inner surfaces of the slabs and outer surface of the pile having recesses formed therein, sealing the joints between the last men- 'tioned slabs and between the slabs and the sleeve,

and pouring grout into said spaces with the slabs contacting said surface.

JOHN W. B. BLACKMAN.

Images