US2095989A - Building unit - Google Patents

Description

52'173 Search Roon Oct. 19, 1937. w w LlLLARD 2,095,989

BUILDING UNIT Filed March 9, 1934 Y 6 @f2 Y 3/ 305 NVENTUR ma" JU 110 Patented Oct. 19, 1937 UNITED STATES Search Roon PATENT OFFICE BUILDING UNIT William W. Lillard, Midland Park, N. J.

Application March 9, 1934, Serial No. 714,854

20 Claims.

The present invention relates generally to the art of masonry construction and more particularly to masonry building units heretofore usually made by filling bags or sackswith freshly mixed concrete and sewing up the mouths of the sacks. These units are usually placed in a structure while the concrete in the sacks is fully plastic. Many structures can be strongly and satisfactorily built of such units by Workmen who could not build like structures of building units such as ordinary cement blocks.

In practice, certain di'iculties have been encountered in making masonry building units by iilling cloth sacks with wet, freshly mixed concrete and then sewing up the mouths of the sacks. Wet cloth is hard to sew. Should more concrete be mixed and sacked up than is needed to complete a structure, or portion of a structure, the mouths of the sacks must be ripped open and the sacks thoroughly cleaned of the concrete or else the sacks will be spoiled. Also, in building structures like dams or piers in remote places, it is often expensive to transport to such jobs special machinery designed for quickly filling the sacks and sewing up their mouths.

It has been proposed to construct a pavement slab by filling a mattress-like sack with excelsior and. concrete ingredients made by mixing dry cement with sand and crushed rock or gravel such as is ordinarily employed in the making of commercial concrete and thereafter to move the slab to its site'and lower it into water. Ordinary commercial sand and crushed rock and gravel usually carries considerable amounts of moisture received from rain or other sources and sometimes large amounts of such moisture. Ordinary commercial sand is especially likely to be materially moist although it is termed dry sand in the trade; and such partlymoist commercial sand and crushed rock or gravel is called in the trade dry aggregate.

A building unit member comprising dry cement and such dry aggregate as noted above cannot be kept or transported more than a day or two with safety. At the end of such time or before, the cement very probably will begin either to set or to be slaked. In many cases, one or the other of these actions will begin within a few hours. In a short time thereafter, such setting or slaking will usually ruin the concrete ingredients for making concrete therefrom.

An object of the present invention is the provision of a concrete building unit which can be partially prepared and be safely kept for a considerable time, and thereafter be made completely ready for use by simply applying water to it at the site of the structure.

As is well known to those skilled in the art of concrete construction, the economical preparation of a quantity of high grade, permanent concrete for placement in a structure, either in forms or in sacks requires care, skill and experience. Another object of my invention is to provide method and means by which plastic units of ready-mixed high grade concrete may be obtained by those unskilled in the preparation of concrete.

In practicing my invention, I thoroughly dry the concrete aggregate, i. e. the sand and stone, and mix the same With cement without water. This mixture is then poured into sacks and the mouths of the sacks tightly closed. The Work of drying the aggregate, mixing the same with cement and sacking up the mixture can be done at some convenient place quite distant from the site of the structure where the sacks of cement are to be used. The sacks 'of dry concrete ingredients will be protected from moisture until they are at the site of the structure ready to be used. Water will then be applied tothe dry ingredients in the sacks.

I have found that if thoroughly dried concrete aggregate is mixed with dry cement and the mixture sacked up and kept in a dry condition several months and then Wet just before the sacks are put in place in a structure, good concrete masonry will be obtained.

It is a feature of the present invention to provide means for keeping the cement in such sacks of concrete ingredients in a live or active condition without increasing the thickness of the sack excessively. To this end, a sack made of relatively thin cloth may be soaked in paraffin or like material and all the excess paraffin removed before pourng the dry ingredients into the sacks.

Another object of the present invention is the provision of a plastic concrete building unit having embedded in it metallic reinforcement supported in a predetermined position relative to the upper and lowerfaces of the unit.

The present invention is a continuation in part of my copending application Serial Number 392,175 led September l2, 1929 asa division of my application for patent on improvements in the Art of masonry construction, Serial Number 236,483 filed November 29, 1927.

Referring to the accompanying drawing which forms a part of these specifications,

Figure 1 is a partial sectional view through two building units formed of sacks of concrete Figures 4 and 5 are top and side views, respectively, of a form of hollow building unit in which my invention may be embodied.

Figure 6 is an enlarged cross-section along the line 6-6 of Figure 4.

Figure 7 is a diagrammatic view illustrating how water may be advantageously introduced into the interior of a sack of dry concrete ingredients.

As is well known to those skilled in the art, to secure truly permanent concrete of substantially maximum strength a relatively small proportion of water should be incorporated with the mixture of solid ingredients' of concrete. The resultant mixture secured by adding such small amount of water usually leaves the freshly mixed concrete lacking in. plasticity to fill forms and containers satisfactorily without objectionably heavy tamping. It has been found advantageous to add an extra amount of water to the solid ingredients of concrete to secure the desired plasticity, and to remove such extra water after the plastic concrete mixture is placed.

The following statements pertinent to my invention were made by a well known expert in concrete matters and appeared in a book entitled Basic Principles of Concrete Mixing by Franklin R. McMillin, Director of Research, Portland Cement Association. Copyright 1929.

Pages 66 and 67 Methods of placing and treatment-These comments suggest the other lines along which improvement can be made. These are twonamely, first, the removal of excess water after the concrete is in place, at the same time consolidating the mass,

It can be readily seen that any method of placing which extracts water from the mix as it is being deposited, in such manner that the space occupied by the water is at once filled by the consolidated concrete accomplishes the desired end.

It will appear as the description proceeds how the desirable removal of excess water from a mass of freshly mixed, fully plastic concrete is obtained in carrying out my invention.

In practicing the present invention, the concrete aggregate may consist either of sand and crushed stone or of other materials such as socalled concrete gravel which usually includes sand, pebbles and larger rocks.

The concrete aggregate is rst thoroughly dried. This may be satisfactorily done in some cases by exposing thin layers of the aggregate to warm sunshine, or to dry winds or to both of these natural agencies. The drying out process may also be done artificially by the application of dry heat such as that from flame, or by spreading the aggregate on an artificially heated floor member.

The dryness of the sand may be tested by burying dry pieces of ordinary newsprint paper in the sand for an hour or more. If the sand is thoroughly dry, the pieces of paper will retain their usual crispness. If the sand is not fully dry, the pieces of paper will absorb enough moisture to be appreciably damp and will have lost some of their crispness. The dryness of gravel may be tested in a like manner to that described for testing sand. Also, crushed stone may be tested in a like manner to that described for testing sand. If however, the individual stones are moist all through, care should be taken to fully dry out such stones. Other suitable tests may be employed, if desired, to make sure the aggregate is substantially as dry as the cement.

When the concrete aggregate has been thoroughly dried it will be mixed with cement without any water whatever, or it may be stored in a dry closed bin. In the latter case, the aggregate should `be tested again for dryness just before it is mixed with the cement.

The mixing of the dry aggregate and cement can be done in a concrete mixing machine of any well known kind; the machine being ilrst made thoroughly dry. Also, the mixing can be done by hand. The mixing should be done in a. dry place, preferably in a closed building.

The hydraulic or Portland cement which is to be mixed with the dry aggregate will be in a normal, fully dry state, and preferably should be freshly ground and free of lumps.

After the dry aggregate and cement have been thoroughly mixed, in which condition the resultant mixture i. e. ingredients should have a uniform color throughout, the mixture may be poured into dry sacks II and the mouths of the latter tightly closed. Where it is desired that the building unit form water tight joints in a structure, the sacks I I should be fllled only about three-quarters full. In cases where the dry sacks of concrete cement ingredients I are to be kept in a dry inert condition, as in storage for several days before using, or are to be transported a long distance to the site of a structure where they are to be used, it is desirable that the sacks I I be made of flexible material which is substantially impervious to air at ordinary atmospheric pressure. 'This is desirable because air nearly always 'carries some moisture, and sometimes carries a relatively large amount of moisture.

Thick closely woven cloth which has a sulcien't imperviousness to damp air to be used for sacks for holding the dry concrete ingredients is objectionable in certain ways for practicing the present invention. Such sacksv are expensive. Also the walls of such sacks being relatively thick the use of these sacks leaves two objectionably thick lays of impermanent material between each two adjoining building units formed by the wetted concrete ingredients in the sacks.

I have found that a sack II made of thin, inexpensive cotton cloth such as that known as domestic or muslin in the cotton goods trade, when soaked in boiling paraffin, asphalt or tar and which has the excess paran or other material removed, provides a thin Wall sack I I for the dry cement ingredients I0 which is satisfactorily impervious to the passage of damp air. Furthermore, the walls of such sacks will not appreciably decay over long periods of time,

In some cases where the dry ingredients I0 are to be wet and placed in a structure not long after the dry concrete aggregate and cement are mixed, the sacks II for holding the dry concrete ingredients, may be satisfactorily made of thin untreated cotton cloth such as domestic, muslin or cheese cloth.

It can be seen that other containers than cloth sacks can often be used in carrying out the present invention. For example, a basket of closely woven reeds or withes, can be used in some cases as a container for the concrete ingredients without departing from the broad scope of my invention.

The mouths of the sacks II will preferably be tightly closed by sewing in a well known way but it will be understood that it is within the scope of the present invention to close the mouths of the sacks by any other means that will permit the sacks of concrete to be used satisfactorily as building umts. That is, the means of closing the sacks should permit the latter when properly lled with plastic concrete ingredients to lie end-to-end with close joints and without excessive impermanent material between two adjoining sacks in the same plane.

It will be understood that a mixture of dry concrete ingredients of the kind noted above may be kept in cheese cloth sacks for a considerable period of time if such sacks are properly protected from moisture. Such protection may be accomplished in a number of ways. For example, such cheese cloth sacks of dry concrete materials canbe kept in a dry, tightly closed bin. In other cases, each of such sacks may be inserted into a moisture proof bag and the mouth of the bag tightly closed. When the sacks of concrete materials are to be used, they will, of course, be removed from the moisture proof bags.

A cheese cloth sack of plastic concrete made by mixing a small, extra amount of water with the solid ingredients when placed on top of a large stone or another sack of plastic concrete will often be strongly bonded to the other building element because of the seepage of a quantity of thin paste or mortar through the relatively open mesh of the walls of the last placed cheese cloth sack.

In cases where the dry concrete ingredients I0 are encased in a sack Il which has not been saturated in paraffin, the ingredients may be wet by simply sprinkling the sack or pouring water on it. If the sack is very large or thick it should be kneaded a few times to insure that the cement in the center of the sacks will be wet. Water may be introduced into a paraillned sack for wetting the concrete ingredients by puncturing the walls of the sack in a plurality of places with small nails or other suitable pointed instruments, and immersing the sack in water a short time, or covering it closely with a cloth blanket and sprinkling water on the blanket.

In Figure 7 is illustrated an advantageous way of wetting the dry concrete ingredients in a sack. One or more slim hollow, pointed tube members 25 are shown connected with a source of water through flexible water hose 2B of a well known kind. These slim tube members 25 are each made with a plurality of small openings or perforations 21 in their sides, i. e. through their side walls. One or more of these tube members are inserted deep into a sack of dry concrete ingredients and water under a light pressure is conducted through the tubes and out of the perforations into the sack. By connecting the hose 26 with a pail 28 holding a predetermined amount of water, the amount of water incorporated with a known amount of solid contents of a sack Il' can be easily and accurately known. For reasons pointed out hereinafter, this is an advantage of importance.' Water introduced into the central portions of a sack of dry concrete ingredients as explained above will soon spread outwardly and wet all of the contents of the sack if the same is kneaded or rolled over a few times.

I have found in practice that when thoroughly dry concrete ingredients such as cement and sand and crushed stone are well mixed before being placed in a sack that moisture introduced through the sack walls will penetrate to the center of the sack much easier and quicker than it would under like conditions in a sack lled with Portland cement alone.

It is a feature of the present invention to provide means for enabling a building unit in the Search Room form of a sack of concrete to resist severe stresses which tend to cause transverse cracks in the unit. To this end, metallic reinforcing elements i2 are embedded in the sack. The reinforcing may be pliable steel netting I3 of wires I4 having roughened elements l5 of any suitable form. .The netting I3 may be arranged with depending spacer elements i6 which may be made by severing predetermined wires of the netting and bending a section of each severed wire down as illustrated in Figure 2. By providing a sufiicient number of properly positioned spacer elements I6 the reinforcing netting, at substantially all points, will be spaced a suitable distance above the bottom of a sack irrespective of the unevenness of the bottom. This is an important advantage since the bottom of a plastic building unit made in the form of a sack of freshly mixed concrete will often lie unevenly on the supporting surface below it, such as when the sack is lying on uneven bedrock.

In some cases, a second reinforcing netting element designated as 20 may be advantageously disposed in the sack of concrete li adjacent the upper surface thereof. The netting 20 may be supported a desired distance below the upper surface of the sack by a plurality of cords 2|. One end of each cord 2 l may extend outwardly through the upper wall of the sack and be formed with a knot 22 which enables the cord to hold the netting suspended a predetermined distance below the upper surface of the sack until the concrete sets.

It will be noted that each of the reinforcing elements l2 and 20 is wholly encased in one sack I0 and thus all parts of it are securely protected from corrosion after the cement has set.` Before the concrete ingredients in the sack have been wet there will be no danger of the reinforcing elements I2 and 20 rusting since the ingredients around the reinforcement will be entirely without moisture.

In Figures 4, 5 and 6 there is illustrated a hollow building unit 30 which may be made according to my invention. A cloth sack 30s of suitable shape for providing an opening 3| through a building unit shown as having a substantially rectangular cross-section is employed. The sack may be filled through a mouth or opening 32 preferably provided in an outer wall element 33 of the sack. The opening 32 will be closed by suitable means after a sumcient amount of the concrete ingredients have been put into the sack. Interiorly disposed wall elements 34 of the sack 30s prevent the concrete ingredients from closing the opening 3i. It can be readily seen that other forms of building units embodying my invention can be provided, if desired.

I have found that a cloth sack soaked in parafn serves very effectively for protecting Portland and like dry cements from moisture. Also, it is much easier to fully remove the cement from such a sack than it is from a usual cloth sack since little or no cement adheres to the interior faces of the sack walls. Furthermore, no dry cement infiltrates into the walls of a paraflined sack as it does into the walls of a cloth sack, and a little moisture coming in Contact with a paramned sack before or'after emptying it of cement will not cause it to become stiff and partially useless as often happens when a usual cloth cement sack is moistened.

In Figure 1 the sacks I I are shown as being fastened together by having tie rods I8 partly embedded in each sack. 'I'he functioning of these tie rods is set forth in my co-pending application Serial Number 335,651 filed January 29, 1929, now Patent Number 1,777,926. It can be seen by those skilled in the art that the sacks Il may be employed with other means than the tie rods I8 for fastening them together or with no additional fastening means whatever without departing from the scope of my invention. Often, enough of the paste-like mixture of the cement and sand will seep through the walls of two adjoining bags to bond them together.

It will be noted that building umts in the form of ready-mixed dry concrete ingredients can be advantageously used in many cases without employing the reinforcements l2 and 20. Such a use does not depart from the scope of my invention.

It is well known by those skilled in the use of concrete that too much water mixed with the solid ingredients of concrete results in an inferior product. It is also known, as appears from the statement quoted above from the book Basic Principles of Concrete Mixing that it is desirable to remove excess water from a freshly prepared concrete mixture after it is placed. This desirable result is accomplished to a large extent in two ways in carrying out my invention. First, some of the excess water seeps through the thin cloth side walls of ordinary sacks. Second, the stones in a sack are ordinarily dry all the Way through before any water is introduced in the sack and these stones are therefore capable of absorbing much of the excess water in the mortar portion of the concrete, i. e. the mixture of cement and sand. It will be understood that by practicing my invention as explained hereinbefore water may be satisfactorily incorporated in a sack of solid concrete ingredients without putting in much excess water to remove. It can also be seen that by thoroughly mixing the dry cement and the equally dry sand and stone the cement is well distributed throughout the mass of a sack and one or more stones will nearly always be disposed in adjacent relation to each small portion of over-wet cement mortar.

It will be understood that the term thoroughly dry as employed in this specification and the subjoined claims in connection with concrete aggregate means aggregate substantially as dry as commercial, dry Portland cement before water is applied to it. It will also be understood that the term solid as used in the present specification and claims in connection with concrete ingredients means all of the non-liquid ingredients of concrete, including crushed stone or gravel, sand and powdered cement.

Certain of the advantages of my invention appear from the foregoing disclosure of the description. Other advantages arise from the provision of concrete building units from which excess water is automatically removed to a large extent. Other advantages arise from the provision of cement building units which after they have been wet and have begun to harden and dry out can be more satisfactorily wetted than concrete in forms to prevent too rapid drying out.

Variations may be resorted to within the-scope of the invention, and portions of the improvement may be used without others.

Having thus described my invention I claim:

1. As a new article of manufacture, a masonry building unit including a closed, thin wall, cloth sack, thoroughly dry, solid ingredients of concrete in said sack, said ingredients being well mixed, and means incorporated in the walls of said sack for increasing the imperviousness of said sack to damp air, the walls of said sack after the incorporation therein of said means being easily penetratable by small pointed instruments for introducing moisture into said sack for incorporation with said ingredients.

2. As a new article of manufacture, a masonry building unit including a closed sack, thoroughly dry, solid ingredients of concrete in said sack substantially filling it, said ingredients being well mixed, metallic reinforcing members enclosed in said sack, and means disposing said members in a predetermined position adjacent the upper and lower faces of said sack.

3. The method of wetting the contents of -a closed sack comprising a mixture of dry cement and dry concrete aggregate, said method including conducting water into the interior portions of said contents without wetting the exterior portions of said contents, and maintaining said sack in position so that said water may spread outwardly throughout said contents.

4. The method of incorporating water throughout the contents of a closed sack of dry, solid concrete ingredients, said method including wetting the external portions of said ingredients disposed adjacent the wall portions of said sack, and kneading said sack to bring the centrally disposed portions of said dry ingredients into better moisture-absorbing relation with the wetted outer portions of said ingredients, and thus more quickly wet all of the contents of said sack.

5. As a new article of manufacture, a masonry building unit including a closed sack, thoroughly dry, solid ingredients of concrete in said sack, substantially filling it, said ingredients being well mixed, metallic reinforcing members inclosed in said sack, and means disposing said members in predetermined positions adjacent the lower face of said sack.

6. As a new article of manufacture, a building unit including a closed cloth sack having an upper wall portion, thoroughly dry, well mixed, solid ingredients of concrete in said sack disposing said upper wall portion in an approximately horizontal plane when said sack is operatively positioned in a structure, metallic reinforcing members inclosed in said sack, and means fastened to said upper wall portion of said sack for supporting said reinforcing members in predetermined positions in the upper portion of said sack before said concrete ingredients have set and hardened about said reinforcing members.

7. As a new article of manufacture, a masonry building unit including a closed sack, said sack being sufficiently pliable that its lower face may t closely against an uneven surface, thoroughly dry, solid ingredients of concrete in said sack substantially filling it, said ingredients being well mixed, metallic reinforcing members inclosed in said sacks, and means disposing said members predetermined distances above the lower surface portions of said sacks irrespective of the unevenness of said lower surface.

8. As an article of manufacture, a masonry building unit including a closed sack containing well mixed, thoroughly dry, solid ingredients of concrete, and wire netting in said sack for reinforcing said concrete, parts of said netting being bent downwardly for engaging against the bottom of said sack and supporting the remaining portion of said netting in spaced relation to said sack bottom before said concrete hardens.

9. As a new article of manufacture, a masonry building unit including a closed sack having an upper wall portion, a lower wall portion and side wall portions joining said top and bottom wall portions, thoroughly dry, well mixed, solid ingredients of concrete in said sack approximately lling it, said sack including wall elements constructed to prevent said concrete ingredients reaching and filling a space centrally disposed relative to said side wall portions and extending from said top wall portion to said bottom wall portion, so that an opening through said unit from top to bottom is left when said sack is iilled with said concrete ingredients.

10. The method of wetting the contents of a closed sack containing a mixture of dry cement and dry concrete aggregate, said method including inserting a fluid-conducting member into an interior portion of said contents, passing a suitable uid through said member so as to wet said interior portion of said contents, and maintaining said sack in position so that said fluid may spread outwardly throughout said contents, whereby all of the fluid applied may be used without waste in wetting said contents.

11. The method of wetting the contents of a closed sack containing a mixture of dry cement and dry concrete aggregate, said method including inserting a water-conducting member into an interior portion of said contents passing water through said member so as to wet said interior portion of said contents, and kneading said sack for spreading said water outwardly throughout said contents.

12. A reinforcing means for use in the bottom portion of a sack having pliable wall elements inclosing dry concrete ingredients, said means including a wire netting device having a width and length materially less than the width and length, respectively, of said sack so that said netting device may be disposed in said sack along the bottom wall element thereof, said reinforcing means further including a plurality of downwardly extending wires of approximately equal lengths, the upper end portions of said wires being secured firmly to the netting of said device at spaced points thereon so as to support approximately all portions of said netting a desired distance above the bottom sack wall when the lower ends of said wires are disposed against the bottom sack wall.

13. As a new article of manufacture, a building unit including a dry, closed, water-permeable sack and thoroughly dry, solid ingredients of concrete in said sack, said ingredients being well mixed, said sack of concrete ingredients, after being wetted, being eiective to be readily lifted for placement intact in a structure ori a like unit, and dryness of said unit rendering it effective to be stored safely a considerable period of time before being wetted.

14. As a new article of manufacture, a masonry building unit including a closed cloth sack having top and bottom wall elements, solid ingredients of concrete in said sack substantially filling it, said ingredients being well mixed, metallic reinforcing means in said sack, and devices cooperating with said wall elements for disposing said reinforcing means short distances from said wall elements when said sack of concrete ingredients is in place in a structure.

15. As a new article of manufacture, a masonry building unit including a closed cloth sack havsexen Roon ing top and bottom wall elements, solid, well mixed ingredients of concrete in said sack, concrete reinforcing means in said sack, and means cooperating with said wall elements for disposing said reinforcing means in predetermined spaced'relation to said sack wall elements and therebetween, when said sack of concrete ingredients is in place in a structure.

16. In a building unit of the class described, in combination, a closed, cloth sack; thoroughly dry, Well mixed, solid ingredients of concrete in said sack, said ingredients including dry aggregate and dry cement; and a quantity of water incorporated in said ingredients, said quantity being slightly in excess of the amount required to cause said dry cement in said ingredients to set and harden, whereby an increased plasticity of said unit is obtained, said dry aggregate being eiiective to absorb some of the excess of said water in said sack immediately, whereby the absorbed water becomes ineffective to cause voids in said unit.

17. In a building unit of the class described, in combination, a closed sack constructed of cloth readily permeable by water, well mixed, solid ingredients of concrete in said sack, and a quantity of water incorporated with said ingredients, said quantity being in excess of the amount required to cause said concrete ingredients to set and harden, whereby greater plasticity of said unit is provided, said permeable cloth being irrimediately eifective after the incorporation of said water to permit a large proportion of the excess water in said concrete ingredients to escape from said sack, said cloth being also effective to prevent the escape of an appreciable amount of said solid concrete ingredients before or after they become wet by the incorporation of said water.

18. The method of preparing a concrete building unit including iilling a sack with dry concrete ingredients which consist of thoroughly dry concrete aggregates and dry cement, closing the mouth of said sack, and incorporating an amount of water in said ingredients which is in excess of the amount of water required to cause said dry cement in said sack to set and harden, whereby increased plasticity of the concrete in said sack is thereby obtained, said dry aggregate being effective to absorb some of the excess of said water immediately whereby the absorbed water becomes ineffective to cause voids in said unit.

19. A building unit including an outer envelope sack element having walls impervious to damp air, an inner sack element having walls of thin, loosely woven material permeable by damp air and moisture, thoroughly dry, well mixed, solid ingredients of concrete in said inner sack substantially lling it, the mouth of said inner sack being permanently closed, and means for closing the mouth of said outer envelope element in an airtight manner to enclose therein said lled sack, said inner lled sack and its contents being readily removable intact in a thoroughly dry condition from said outer envelope element.

20. The structure described in claim 19, characterized by metallic reinforcing means disposed within said inner sack, and devices for disposing said reinforcing means in spaced relation to the top and bottom walls of said inner sack, said metallic means and said devices being formed so that they are unlikely to puncture the walls of said inner and said outer sacks.

WILLIAM W. LILLARD.

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