A method and apparatus for the de-aeration of concrete by engaging rebars

Abstract

A rebar connector for aerating concrete that can be used with a rotating apparatus such as a drill. The connector includes and outer body with an aperture that accommodates a rebar. An attachment assembly is designed to couple the rebar to a vibration source, such as a drill, thereby transmitting vibration from the source to the rebar causing the concrete to be deaerated.

Description

A method and apparatus forthe de-aeration of concrete by engaging rebarsFIELD OFTHE INVENTION

[0001] The present invention relates to an apparatus adapted to engage a rebar to vibrate concrete. In particular, it relates to a rebar connector which at one end is adapted to engage a rebar, and at the other end adapted to be engaged by a rotating means, such as a motorised drill, the rebar connector vibrating the rebar when the rotating means is operated.BACKGROUND TO THE INVENTION

[0002] In the construction industry, it is common and in fact a requirement for concrete to be reinforced by an arrangement of vertically protruding bars, commonly referred to as reinforcing bars, or rebars, to improve the strength of structures. This arrangement is common, for example, when constructing concrete walls, but is also common when laying foundations of buildings, floors, footpaths, and the like.

[0003] Rebars aid in providing a reinforcing structure to the concrete, improvingthe tensile strength and overall durability of the concrete. Commonly, wet concrete is poured into an area that houses rebars until the concrete is at a desired level. However, after pouring it is common for the wet concrete to comprise a significant amount of air voids within the concrete, which, when the concrete hardens, produces undesirable areas of decreased strength.

[0004] At times, vibrating means are used to vibrate the poured concrete mixture to remove the air pockets, as well as aid in evenly settling wet concrete. Whilst this may be a useful method when dealing with an open flat surface it is difficult to do when one is dealing with cavities filed with concrete.

[0005] In the case of cavities, such as walls, workers can physically grab the rebars to shake or otherwise manually vibrate them in an attempt to de-aerate the concrete and eliminate or significantly reduce the presence the air voids, air pockets and entrapped air in the fresh cementitious fixture. However, this method of de-aerating concrete is not very successful.

[0006] There is therefore a need for a practical, convenient, and affordable solution to aid in de-aerating concrete around rebars. It is therefore an aspect of the present invention to overcome or ameliorate a problem of the prior art, or at least provide the public with a useful alternative.SUMMARY OF THE INVENTION

[0007] In a first aspect, the invention provides a rebar connector, comprising: an elongate outer body; a first aperture on one end of the elongate outer body, the aperture extending into an internal structure adapted to receive rebar; an attachment assembly on the other end of the elongate body adapted to be installed onto a vibration source; wherein the rebar connector is adapted to transmit a vibration from the vibration source to the rebar.

[0008] In an embodiment, the first aperture and attachment assembly are offset from an axial midline of the outer body.

[0009] In an embodiment, the internal structure comprises three compartments of different diameters.

[0010] In an embodiment, the attachment assembly is a square drive drill attachment.

[0011] In an embodiment, the attachment assembly is a slotted drive drill attachment.

[0012] In an embodiment, the elongate outer body is cylindrical.

[0013] In a second aspect, the invention provides for a method for vibrating rebar, the method comprising: pouring wet concrete around rebar; attaching one end of the rebar connector of any of the previous claims to the rebar; attaching the other end of the connector to a vibration source; activating the vibration source to transmit a vibrational energy through the connector and in turn to the rebar; wherein the vibrating rebar in turn vibrates the surrounding concrete.

[0014] It should be noted that any one of the aspects mentioned above may include any of the features of any of the other aspects mentioned above and may include any of the features of any of the embodiments described below as appropriate.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows.

[0016] Figure 1 illustrates a front perspective view of a rebar connector according to apreferred embodiment of the invention;

[0017] Figure 2 illustrates a side cross-sectional view of the rebar connector ofFigure 1 ;

[0018] Figure 3 illustrates a rear perspective view of the rebar connector ofFigure 1 ;

[0019] Figure 4 illustrates a front perspective view of a rebar connector according to a second preferred embodiment of the invention; and

[0020] Figure 5 illustrates a side cross-sectional view according to the second preferred embodiment of the invention as illustrated in Figure 4.DETAILED DESCRIPTION OFTHE INVENTION

[0021] The following detailed description of the invention refers to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Dimensions of certain parts shown in the drawings may have been modified and / or exaggerated for the purposes of clarity or illustration.

[0022] The present disclosure relates to a rebar connector, adapted at one end to engage a rebar, and adapted at the other end to fit onto mechanical means to rotate vibrate or shake the rebar.

[0023] Certain embodiments relate to the rebar connector.

[0024] Typically the rebar connector comprises a substantially cylindrical outer body.However, the rebar connector is not to be limited to a cylindrical outer body, and other elongate body shapes may instead be used such as but not limited to rectangular, hexagonal, and the like.

[0025] In certain embodiments, the rebar connector is manufactured from metal. In certain embodiments, the rebar connector is manufactured from a metal moulding process but may be produced using other techniques. Procedures of manufacturing items made from metal are commonly known in the art.

[0026] Typically the rebar connector comprises an aperture at one end adapted to engage the connector with a rebar. In certain embodiments, the aperture comprises a tiered structure adapted to allow the connector to be secured onto rebars of differing diameters. In certain embodiments, the tiered structure comprises three tiers.

[0027] Typically the rebar connector further comprises a coupling adapted to secure the connector to a vibration source. The vibration source may be but is not limited to a common drill, rattle gun, or impact wrench. The vibration source may comprise a square drive system, or may for example comprise a slotted drive system.

[0028] Rattle guns or impact wrenches are commonly used on construction sites. These operate on a mechanism that stores energy in a rotating mass, the rattle gun then releases this energy in rapid, controlled bursts. The repetitive and forceful impacts delivered by a rattle gun serve to transmit vibrational and rotational energy through the rebar connector and into the connected rebar, thereby acting to de-aerate the surrounding concrete. Those skilled in the art would appreciate that drills, rattle guns, and impact wrenches commonly share standardised apertures for fitting tool bits. Such apertures, or fittings, include but are not limited to square drive systems and slotted drive systems.

[0029] In certain embodiments, the rebar connector may comprise an aperture located substantially proximate the vibration source coupling. Such an aperture may function as a ‘washout aperture’, adapted to discharge or effuse excess liquid that may build up within the connector. The aperture may also function to discharge debris, such as dust, dirt, or other material, to prevent any buildup affecting the performance of the connector.

[0030] A preferred embodiment of the invention is shown in Figures 1-3. The rebar connector 10 is comprises a substantially cylindrical body 12, a front aperture 14 adapted to engage a vibration source, and a rear aperture 16 adapted to engage a rebar. The front aperture 14 may also be referred to as an attachment assembly, as the invention is not limited to using an aperture to connect to vibration sources.

[0031] Rear aperture 16 as shown in the Figures extends into the cylindrical body 16 as a tiered cylindrical structure, comprising a plurality of cylindrical compartments of different radii. The cylindrical structure comprises a first compartment 20, tapering into a second compartment 22, in turn tapering into a third compartment 24, which tapers into an end cap 26. The compartments are provided in varying sizes to allow for the rebar connector 10 to securely affix to rebars of varying sizes. It should be noted that the invention is not limited to comprising three internal compartments to secure rebar, but rather even one or any plurality of internal compartments may instead be used.

[0032] Front aperture 14 as shown in the Figures extends into the cylindrical body 16 as an attachment compartment 18, adapted to be affixed onto a square drive system. A user would be able to affix the front aperture 14 onto a drill with a square drive attachment, then affix the rearaperture 16 onto a rebar around which wet concrete has been poured. The user may then operate the drill, thereby vibrating the rebar connector 10, which in turn rotates or vibrates the rebar which it is connected to. The rotating or vibrating rebar thereby aids in de-aerating concrete and minimising any air pockets or voids that are present within the poured concrete. The attachment compartment 18 may comprise oval structures 36 which aid in engaging a square drive drill. Those skilled in the art would appreciate that such structures are commonly found on square drive drill attachments. It would also be appreciated to those skilled in the art that ‘rotating’ or ‘vibrating’ the rebar may often be used interchangeably, both functioning to induce repeated movement of the rebar which aids in dispersing and de-aerating voids within wet concrete.

[0033] A second preferred embodiment of the invention is illustrated in Figures 4-5. In this embodiment, the rebar connector 10 comprises at one end a rear aperture 16 adapted to engage the rebar, and at the other end comprises a substantially cylindrical protruding surface 30 adapted to be fitted into a slotted drive system drill. Those skilled in the art would appreciate that slotted drive system (SDS) drills are common knowledge in the art, and readily employed alongside square drive drills. These two drills are commonly found on construction sites and are capable of providing sufficient power de-aerate concrete.

[0034] The protrusion 30 may comprise a plurality of notched surfaces 32 of size approximately one third the length of the protrusion 30 and located substantially proximate its distal end. The protrusion may also comprise a plurality of notches 34 which extend part -way lengthwise from the distal end of protrusion 30. The notches 32, 34 facilitate installation onto slotted drive system drills, with their arrangement standard and commonly used in the art. The present invention offers the advantage of compatibility with conventional equipment fittings commonly utilised on construction sites. It eliminates the need for specialized equipment, custom-made machinery, or similar requirements.

[0035] The connector 10 may comprise an aperture 38 located adjacent the protrusion 30, adapted to function as a ‘washout hole’. This allows liquid concrete or other debris to effuse through the connector 10, thereby preventing any buildup that may adversely affect the performance of the connector 10. In an embodiment, the aperture 38 may be approximately 1 cm or less in diameter and may be machined into the connector 10 during manufacture. It should be noted that the presence of a washout hole or aperture 38 is not limited to being present on the second preferred embodiment and is not limited to be proximate the protrusion 30. Any suitable location for the washout hole for any embodiment of the invention as one skilled in the art would conceive may be appropriate.

[0036] A preferred method of de-aerating concrete will now be made clear to the reader. Although the following method describes utilising the rebar connector for dispersing concrete poured into Besser blocks, also known as concrete blocks, the invention is not to be limited to this application.

[0037] To lay the concrete blocks, a layer of mortar is applied on the foundation or slab where the first course of blocks will be placed. The blocks are then positioned on the mortar bed, ensuring they are level and aligned correctly according to the building plan. Mortar is applied between each block and along the vertical joints as additional rows of blocks are stacked.

[0038] Before reaching the desired height with the concrete blocks, horizontal and vertical reinforcement bars (rebar) are inserted into the hollow cores of the blocks. Rebar is cut to appropriate lengths and bent as necessary to fit within the block cores. In particular, vertical rebar is positioned within the core of the concrete blocks.

[0039] Once the concrete blocks are stacked to the desired height and the rebar is in place, wet concrete is poured from directly above into each core of the locks. The wet concrete mixture is poured directly into the hollow cores of the concrete blocks, filling them completely. While the concrete remains in its wet state, the user will affix the rear end 16 of the rebar connector 10 onto the rebar, opting for a connector suited for use with an available rattle gun.

[0040] The user will then attach the other end of the rebar connector 10 to a rattle gun that is compatible with the chosen connector. The rattle gun will be activated, thereby transmitting a rotation or vibrational energy through the connector 10 into the rebar, acting to rotate and vibrate the rebar embedded within wet concrete. This process thereby causes the concrete to vibrate, de- aerating the concrete and removing or reducing the presence of air bubbles and voids. This also acts to settle and distribute the wet concrete evenly within the desired area. Furthermore, vibrations caused by contact of the vertical rebar with horizontal rebar components during operation of the rattle gun additional aids the concrete in settling evenly.

[0041] It should be noted that while the rattle gun acts primarily to rotate the vertical rebar, when the vertical rebar encounters obstructions such as cross sections of rebar or particularly dense concrete or hardening concrete, rotational motion may be significantly dampened, prompting the rattle gun to primarily vibrate the vertical rebar from its hammering action.

[0042] Once the concrete has been adequately de-aerated and dispersed, the rebar connector and vibration source assembly can simply be moved onto the next rebar in sequence. This processefficiently eliminates air voids without requiring additional heavy machinery or specialised equipment, providing a straightforward and user-friendly solution.

[0043] In another preferred embodiment of the invention illustrated in Figure 6, the front aperture 14 is not coaxial with the longitudinal axis M of the rebar connector 10. Instead, the midpoint m of the front aperture 14 is shifted to be parallel and adjacent to axis M. It should be noted that the distance of the shift between midpoint m and axis M in Figure 6 has been illustrated for demonstrational purposes, with the shift being approximately 0.5 mm in length.

[0044] The shifted non-coaxial alignment of midpoint m causes the vertical rebar affixed to the connector 10 to be rotated in an oblique circular motion, differing from the conventional radial pattern. This approach enables the rebar to traverse a wider area within the concrete, maximising contact with the material and increasing probability of striking horizontally laid rebar. Consequently, a larger section of concrete is affected by the rotating rebar, and the vertical rebar is able to transmit additional vibration throughout the settling concrete leading to enhanced settling and deaeration ability.

[0045] The reader shall now appreciate the described methods and apparatus for vibrating concrete.LISTOF COMPONENTS

[0046] The drawings include the following integers.10 rebar connector12 body14 front aperture16 rear aperture18 attachment compartment20 first compartment22 second compartment24 third compartment30 protrusion32 notch34 notch36 oval structure38 washout apertureM longitudinal axis m midpoint of front aperture

[0047] Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field.

[0048] In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.

Claims

CLAIMS1. A rebar connector, comprising: a. an elongate outer body; b. a first aperture on one end of the elongate outer body, the aperture extending into an internal structure adapted to receive rebar; c. an attachment assembly on the other end of the elongate body adapted to be installed onto a vibration source; d. wherein the rebar connector is adapted to transmit a vibration from the vibration source to the rebar.

2. The rebar connector as in claim 1 , wherein the first aperture and attachment assembly are offset from an axial midline of the outer body.

3. The rebar connector as in claim 1 , wherein the internal structure comprises three compartments of different diameters.

4. The rebar connector as in claim 1 , wherein the attachment assembly is a square drive drill attachment.

5. The rebar connector as in claim 1 , wherein the attachment assembly is a slotted drive drill attachment.

6. The rebar connector as in claim 1 , wherein the elongate outer body is cylindrical.

7. A method for vibrating rebar, the method comprising: a. pouring wet concrete around rebar; b. attaching one end of the rebar connector of any of the previous claims to the rebar; c. attaching the other end of the connector to a vibration source; d. activating the vibration source to transmit a vibrational energy through the connector and in turn to the rebar; e. wherein the vibrating rebar in turn vibrates the surrounding concrete.

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