The present invention relates to exterior wall structures of residential, commercial or other buildings.
An exterior wall structure of a residential, commercial or other building often comprises an inner wall and an outer wall that are separated from each other so as to define a cavity therebetween. The cavity contributes to impeding moisture intrusion into the inner wall, equalizing pressure on either side of the outer wall, and insulating the exterior wall structure.
The outer wall typically comprises masonry units (e.g., bricks or concrete blocks) stacked and arranged into courses (rows) with mortar holding the masonry units together and filling their interfaces. The inner wall is usually linked to the outer wall by wall ties (e.g., corrugated wall ties) that are individually fastened to the inner wall and anchored in the mortar of the outer wall.
During construction of this type of exterior wall structure, it is not uncommon for excess mortar to bridge the outer wall and the inner wall and/or fall and clog weep holes of the wall structure that are provided for water drainage. This detrimentally affects the exterior wall structure's ability to impede moisture intrusion and allow pressure equalization.
These detrimental effects may be encountered whenever mortar is used to hold and fill interfaces of the masonry units of the outer wall. In particular, this applies when the masonry units are concrete blocks with a natural stone appearance that are used to provide a natural and aesthetic look to the exterior wall structure. For production considerations, the concrete blocks are typically cast in such a way that their height is oriented generally vertically during casting. This casting process often results in the concrete blocks having significantly different heights, thereby requiring mortar to compensate for differences in height of the concrete blocks when they are placed in the outer wall. Furthermore, in order to have their natural stone appearance, the concrete blocks may be subjected after casting to a mechanical artificial aging/weathering process (e.g., tumbling, object impacting, etc.) to realize desired natural stone characteristics. This process can damage lateral surfaces of the concrete blocks which can end up forming gaps in the interfaces of the concrete blocks when placed in the outer wall, thereby requiring mortar to fill these gaps.
There is therefore a need for improvements in exterior wall structures with inner and outer walls separated by a cavity.
As embodied and broadly described herein, the invention provides a system for interconnecting an outer wall and an inner wall of an exterior wall structure, the outer wall and the inner wall being separated from each other to define a cavity therebetween, the outer wall comprising a plurality of concrete blocks. The system comprises a plurality of elongated structural members, each elongated structural member being adapted to be fastened to the inner wall. The system also comprises a plurality of connecting elements, each connecting element being adapted to be connected to a given one of the elongated structural elements and to a given one of the concrete blocks. Each of the elongated structural members is adapted to be connected to plural ones of the concrete blocks via plural ones of the connecting elements.
The invention also provides a system for use in constructing an exterior wall structure, the exterior wall structure comprising an inner wall. The system comprises a plurality of concrete blocks adapted to be stacked to erect an outer wall of the exterior wall structure, the outer wall and the inner wall intended to be separated from each other to define a cavity therebetween. The system also comprises a plurality of elongated structural members, each elongated structural member being adapted to be fastened to the inner wall. The system also comprises a plurality of connecting elements, each connecting element being adapted to be connected to a given one of the elongated structural elements and to a given one of the concrete blocks. Each of the elongated structural members is adapted to be connected to plural ones of the concrete blocks via plural ones of the connecting elements.
The invention also provides an exterior wall structure. The exterior wall structure comprises an inner wall and an outer wall comprising a plurality of concrete blocks. The inner wall and the outer wall are separated from each other to define a cavity therebetween. The exterior wall structure also comprises a plurality of elongated structural members, each elongated structural member being fastened to the inner wall. The exterior wall structure also comprises a plurality of connecting elements, each connecting element being connected to a given one of the elongated structural elements and to a given one of the concrete blocks. Each of the elongated structural members is connected to plural ones of the concrete blocks via plural ones of the connecting elements.
The invention also provides a method for use in constructing an exterior wall structure, the exterior wall structure comprising an inner wall. The method comprises securing at least one elongated structural member to the inner wall. The method also comprises placing a plurality of concrete blocks horizontally adjacent to each other to form a course. The method further comprises, for each of the concrete blocks, connecting each of at least one connecting element to the concrete block and to one of the at least one elongated structural member secured to the inner wall in alignment with the course.
The invention also provides a plurality of dry-cast concrete blocks for use in constructing an outer wall of an exterior wall structure, the exterior wall structure comprising an inner wall, the outer wall and the inner wall intended to be separated to define a cavity therebetween. Each of the dry-cast concrete blocks comprises: a front surface comprising at least one portion having a cast texture with a natural stone appearance; a rear surface defining with the front surface a thickness of the dry-cast concrete block; two lateral surfaces defining a height of the dry-cast concrete block; and two lateral surfaces defining a width of the dry-cast concrete block. A difference in height between different ones of the dry-cast concrete blocks is less than about 1 mm.
These and other aspects of the invention will now become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying drawings.
A detailed description of embodiments of the invention is provided below, by way of example only, with reference to the accompanying drawings, in which:
It is to be expressly understood that the description and drawings are only for the purpose of illustrating certain embodiments of the invention and are an aid for understanding. They are not intended to be a definition of the limits of the invention.
The cavity 17 forms an air space between the inner wall 11 and the outer wall 15 and may have any suitable width (e.g., about 25 mm, 50 mm or any other suitable width). The cavity 17 contributes to impeding moisture intrusion into the inner wall 11, equalizing pressure on either side of the outer wall 15, and insulating the wall structure 10.
With additional reference to
The outer wall 15 comprises a plurality of concrete blocks 121-12N. The concrete blocks 121-12N are stacked and arranged into a plurality of courses (rows). Each course includes given ones of the concrete blocks 121-12N positioned horizontally adjacent to one another. For solidity considerations, the given ones of the concrete blocks 121-12N in one course are offset relative to the given ones of the concrete blocks 121-12N in an adjacent course.
As shown in
With additional reference to
The concrete block 12j is a dry-cast concrete block, i.e., it is made of no-slump concrete. No-slump concrete (also known as zero-slump concrete) can be viewed as concrete with a slump of 6 mm or less. It will be appreciated that various types of no-slump concrete are possible and may be used. It will also be appreciated that other types of concrete (e.g., measurable-slump concrete) may be used in other embodiments.
The concrete block 12j can be said to have a generally rectangular prism configuration with a front surface 141, a rear surface 142, and four lateral surfaces 143-146. The lateral surfaces 143 and 144 define a height of the concrete block 12j, the lateral surfaces 145 and 146 define a width of the concrete block 12j and the front surface 141 and the rear surface 142 define a thickness of the concrete block 12j.
The front surface 141 is intended to be exposed when the concrete block 12j is placed in the outer wall 15. In this example, the front surface 141 comprises seven portions 201-207 with a cast texture having a natural stone appearance, i.e., an aged, worn, or weathered appearance that resembles natural stone. As described later on, this cast texture is realized during casting of the concrete block 12j and may be based on a natural stone's surface which has been used to produce a mold for casting the concrete block 12j. For ease of reference, the portions 201-207 of the front surface 141 and their cast texture with a natural stone appearance will hereinafter be referred to as the “natural stone-like surface portions” 201-207.
The natural stone-like surface portions 201-207 are separated from each other by depressions 301-305 of the front surface 141 that can serve as false joints. When the concrete block 12j is placed in the outer wall 15, the natural stone-like surface portions 201-207 results in an area of the outer wall 15 being perceivable as including several (in this case, seven) natural stones of different sizes and configurations.
Although the front surface 141 comprises a plurality of natural stone-like surface portions (in this case, seven), it is to be understood that, in other embodiments, any number of natural stone-like surface portions may be provided. For example, in
With additional reference to
The natural stone-like surface portion 20k has a visually discernible boundary 22. In cases where the natural stone-like surface portion 20k would be contiguous to a chamfered, rounded, or otherwise non-natural stone looking edge portion of the concrete block 12 (e.g., an edge portion serving as a joint), the boundary 22 of that natural stone-like surface portion would be considered to be configured such that the chamfered, rounded or otherwise non-natural stone looking edge portion is not part of that natural stone-like surface portion.
The natural stone-like surface portion 20k includes a pattern of cast relief elements 231-23M formed during casting of the concrete block 12j. This pattern of cast relief elements 231-23M includes a plurality of peaks and a plurality of valleys, which are sized so as to be visually distinguishable when the concrete block 12j is placed in the wall structure 10. It is to be understood that various other patterns of cast relief elements are possible.
The cast texture of the natural stone-like surface portion 20k defines a “surface level difference” ΔL, which refers to the normal distance between a maximum level Lmax of that surface portion and a minimum level Lmin of that surface portion. As shown in
In this example, the minimum level Lmin of the natural stone-like surface portion 20k is located at its boundary 22. Generally, the minimum level Lmin of a natural stone-like surface portion may be located anywhere on that surface portion, including not at its boundary. The maximum level Lmax of a natural stone-like surface portion may also be located anywhere on that surface portion, including at its boundary 22.
The surface level difference ΔL may be greater than 10 mm, for example, between 10 mm and 30 mm. For instance, in one embodiment, the surface level difference ΔL may be about 20 mm. This enables the natural stone-like surface portion 20k to exhibit desired natural stone appearance characteristics for a wall structure. It is generally contemplated that a surface level difference ΔL of greater than 4 mm achieves satisfactory results in terms of natural stone appearance of a surface portion of a concrete block since it enables presence of visually distinguishable cast texture features mimicking surface texture of natural stone.
It is to be noted that different ones of the natural stone-like surface portions 201-207 of the concrete block 12j may define a common or distinct surface level difference ΔL and may have common or distinct maximum levels Lmax and minimum levels Lmin.
Each of the cast relief elements 231-23M of the natural stone-like surface portion 20k reaches a respective level L that is the maximum level Lmax, the minimum level Lmin, or a level therebetween. In this embodiment, a plurality of the cast relief elements 231 . . . 23M are seen in
Also, in this embodiment, each of the cast relief elements 231 . . . 23M of the natural stone-like surface portion 20k that is a valley (e.g., the cast relief element 232) can be viewed as having a respective depth D, which refers to the normal distance between the maximum level Lmax of that surface portion and that valley's deepest point. Depending on the surface level difference ΔL, in some embodiments, the respective depth D of each of one or more valleys of the natural stone-like surface portion 20k may be greater than 4 mm, for example, between 4 mm and 10 mm. This may further enhance natural stone appearance characteristics exhibited by the natural stone-like surface portion 20k.
The natural stone-like surface portion 20k is capable of interacting with ambient light to create shadows that further contribute to its natural stone appearance. More particularly, as shown in
In this embodiment, the depression 303 of the front surface 141 that separates the natural stone-like surface portions 201 and 202 can be viewed as having a respective depth, which refers to the normal distance between the maximum level Lmax of either of these surface portions and that depression's deepest point. Similar comments apply in respect of each of the depressions 301, 302, 304 and 305 of the front surface 141. Depending on the surface level difference ΔL, in some embodiments, the respective depth of each of the depressions 301-305 may be at least 10 mm, for example, between 10 mm and 30 mm. For example, in a particular case, the respective depth of each of the depressions 301-305 may be about 20 mm. This may further enhance natural stone appearance characteristics exhibited by the natural stone-like surface portions 201-205 of the concrete block 12j.
Continuing with
Each of the lateral surfaces 143-146 of the concrete block 12 will normally face a lateral surface of another one of the concrete blocks 121-12N (except for certain ones of the concrete blocks 121-12N that are located at extremities of the outer wall 15). Since the natural stone-like surface portions 201-207 are realized during casting of the concrete block 12j without requiring any subsequent mechanical artificial aging/weathering process (e.g., tumbling, object impacting, etc.) that could otherwise damage the lateral surfaces 143-146, each of these lateral surfaces is relatively flat and smooth. These flatness characteristics of the concrete blocks 121-12N are such that any gap which may exist between lateral surfaces of adjacent ones of the concrete blocks 121-12N can be viewed as being negligible. As a result, lateral surfaces of adjacent ones of the concrete blocks 121-12N form interfaces that can prevent water from easily passing between these concrete blocks and reaching the cavity 17.
In addition, and as further discussed below, the concrete block 12j is cast with its thickness oriented generally vertically, i.e., with its height and width oriented generally horizontally. This casting process helps to render negligible any difference in height between different ones of the concrete blocks 121-12N and to render negligible any difference in width between different ones of the concrete blocks 121-12N. For example, the difference in height between different ones of the concrete blocks 121-12N may be less than about 1 mm, and in some cases less than about 0.5 mm. Similar comments apply with respect to the difference in width between different ones of the concrete blocks 121-12N. The negligible difference in height between adjacent ones of the concrete blocks 121-12N is such that no mortar is required to compensate for it when these concrete blocks are placed in the outer wall 15. The negligible difference in width between different ones of the concrete blocks 121-12N enables accurate alignment of one or more of the grooves 371-373 of each of these concrete blocks with one or more of the grooves 371-373 of other ones of these concrete blocks when they are stacked on one another to form the outer wall 15.
Flatness characteristics and height tolerances of the concrete blocks 121-12N thus enable the outer wall 15 to be built without requiring mortar to hold these concrete blocks together or fill their interface. As mentioned above, not having to use mortar to hold the concrete blocks 121-12N together or fill their interface allows the cavity 17 to be free of mortar, which contributes to impeding moisture intrusion in the inner wall 11 and promoting pressure equalization between either side of the outer wall 15.
With reference now to
The elongated structural members 521-52P are disposed substantially horizontally on the inner wall 11 so as to be aligned with the courses of concrete blocks 121 . . . 12N. More particularly, each of the elongated structural members 521-52P is disposed on the inner wall 11 so as to be aligned with given ones of the concrete blocks 12l-12N forming a course and is connected to these concrete blocks via certain ones of the connecting elements 541-54T. Thus, each of the elongated structural members 521-52P is connected to plural ones of the concrete blocks 121-12N that are part of a course via plural ones of the connecting elements 541-54T. In addition, a particular one of the elongated structural members 521-52P may be disposed on the inner wall 11 so as to be proximate to the lateral surface 143 of each of the concrete blocks 121-12N forming a first course and to the lateral surface 144 of each of the concrete blocks 121-12N forming a second course immediately above the first course. This allows each of the connecting elements 541-54T that is connected to the particular one of the elongated structural members 521-52P to be connected to one of the concrete blocks 121-12N forming the first course and one of the concrete blocks 121-12N forming the second course. Also, in some cases, two or more of the elongated structural members 521-52P may be disposed on the inner wall 11 so as to be aligned with given ones of the concrete blocks 121-12N forming a course and may be connected to these concrete blocks via certain ones of the connecting elements 541-54T. It will thus be appreciated that the elongated structural members 521-52P and the connecting elements 541-54T cooperate to interconnect the inner wall 11 and the outer wall 15 at various points that are distributed in the wall structure 10. They also cooperate to interconnect individual ones of the concrete blocks 121-12N, thereby enhancing strength and solidity of the outer wall 15.
Referring additionally to
In this embodiment, the elongated structural member 52g comprises a first portion 57 and a second portion 59 angled relative to the first portion 57. In this case, the angle is approximately a right angle such that the elongated structural member 52g has an L-shaped configuration. The elongated structural member 52g may be made of metallic material (e.g., galvanized steel) and has a length that facilitates its transportation, handling and installation on the inner wall 11. For example, it may have a length of at least 1 m (e.g., about 10 ft or 3.048 m).
The first portion 57 is adapted to be fastened to the inner wall 11. In this embodiment, this is achieved by providing the first portion 57 with a plurality of apertures 60 adapted to receive fasteners that are used to fasten the elongated structural member 52g to the inner wall 11 (e.g., to the frame 19 of the inner wall 11). The fasteners may be screws, nails, or any other suitable fasteners. The apertures 60 are sized to accommodate the fasteners they are intended to receive (e.g., they may have a diameter of about 7/32 in or 5.56 mm). The apertures 60 are longitudinally distributed on the first portion 57 and spaced from each other so as to facilitate securing of the elongated structural member 52g to the inner wall 11. For example, adjacent ones of the apertures 60 may be spaced by a distance of at least 0.2 m (e.g., about 16 in or 0.406 m). When the elongated structural member 52g is fastened to the inner wall 11, the fasteners in the apertures 60 and the first portion 57 lying against the inner wall 11 cooperate to plug holes in the inner wall 11 that receive the fasteners, thereby preventing air and water infiltration into the inner wall 11 via these holes and promoting pressure equalization between either side of the outer wall 15.
The second portion 59 is adapted to be connected to individual ones of the connecting elements 541-54T. In this embodiment, this is achieved by providing the second portion 59 with a series of apertures 62 each adapted to receive a portion of one of the connecting elements 541-54T. Each of the apertures 62 is sized to accommodate the portion of the one of the connecting elements 541-54T it is intended to receive (e.g., it may have a diameter of about 7/32 in or 5.56 mm). The apertures 62 are longitudinally distributed on the second portion 59 and spaced from each other so as to enable individual ones of the connecting elements 541-54T to be connected to the elongated structural member 52g at different locations. This allows an individual one of the connecting elements 541-54T to be connected to the elongated structural member 52g at a location where it registers with one of the grooves 371-373 of a given one of the concrete blocks 121-12N in order to interconnect that concrete block and that elongated structural member. For instance, adjacent ones of the apertures 62 may be spaced by a distance of at least 7 mm (e.g., about ⅜ in or 9.525 mm). The second portion 59 has a width that is such that it does not reach the outer wall 15 when the elongated structural member 52g is secured to the inner wall 11 (e.g., about 0.625 in or 15.875 mm), thereby not bridging the cavity 17.
While in this embodiment each of the elongated structural members 521-52P has a certain configuration, it is to be understood that each of the elongated structural members 521-52P may have various other configurations in other embodiments. For example, each of the elongated structural members 521-52P may have a C-shaped configuration including two portions, each similar to the second portion 59 of the elongated structural member 52g with its series of apertures 62, such that a portion of one of the connecting elements 541-54T can be received in apertures of these two portions.
With additional reference to
In this embodiment, the connecting element 54b comprises a first portion 61 for connection to one of the elongated structural members 521-52P and a second portion 63 for connection to one of the concrete blocks 121-12N. In this example, the connecting element 54b comprises a rod bent to form the first portion 61 and the second portion 63. The rod may have a circular cross-section (e.g., with a diameter of about 4.75 mm) and may be made of metallic material (e.g., galvanized steel). This bent configuration allows economic production of the connecting elements 541-54T and facilitates their installation. The connecting element 54b may have any suitable dimensions (e.g., in this case, it may have an overall height of about 3 in or 76.2 mm, an overall width of about 2.25 in or 57.15 mm, and an overall depth of about 1.27 in or 32.26 mm).
The first portion 61 is adapted to be connected to a given one of the elongated structural members 521-52P. In this case, the first portion 61 is configured so as to be insertable into one of the apertures 62 of the given one of the elongated structural members 521-52P. When the first portion 61 is inserted into one of the apertures 62 of the given one of the elongated structural members 521-52P, the connecting element 54b is connected to that elongated structural member.
The second portion 63 is adapted to be connected to a given one of the concrete blocks 121-12N. In this case, the second portion 63 is configured so as to fit and be retained in one of the grooves 371-373 of the given one of the concrete blocks 121-12N. To that end, the second portion 63 comprises a first part 65 and a second part 67 that can be pressed and displaced towards each other to allow the second portion 63 to be positioned in one of the grooves 371-373 of the given one of the concrete blocks 121-12N. When the second portion 63 is positioned in one of the grooves 371-373 of the given one of the concrete blocks 121-12N, the second portion 63 engages that groove and is retained therein, thereby anchoring the connecting element 54b to that concrete block. The connecting element 54b is thus connected to the given one of the concrete blocks 121-12N.
While in this embodiment each of the connecting elements 541-54T has a certain configuration, it is to be understood that each of the connecting elements 541-54T may have various other configurations in other embodiments. In particular, the connecting elements 541-54T may be connected to the elongated structural members 521-52P and to given ones of the concrete blocks 121-12N in various other ways in other embodiments.
By virtue of their cooperation, the elongated structural members 521-52P and the connecting elements 541-54T therefore interconnect the inner wall 11 and the outer wall 15 at various points.
It will thus be appreciated that the wall structure 10, and particularly the outer wall 15 and the connection system 50, present several desirable features.
For example, in this embodiment, natural stone-like surface portions of the concrete blocks 121 . . . 12N (such as the natural stone-like surface portions 201-207 of the concrete block 12j) contribute to providing a natural and aesthetic look to the outer wall 15.
In addition, the natural stone appearance of each of the concrete blocks 121 . . . 12N is realized during casting of these concrete blocks, without requiring any subsequent mechanical artificial aging/weathering process (e.g., tumbling, object impacting, etc.). Also, since they are made of no-slump concrete, production time for the concrete blocks 121 . . . 12N may be significantly less than that required for wet-cast concrete blocks. Concrete blocks such as the concrete blocks 121 . . . 12N may therefore be mass-produced with high efficiency. An example of implementation of a process for manufacturing concrete blocks such as the concrete blocks 121 . . . 12N will be presented later on.
Furthermore, owing to this casting process, any difference in height and width between different ones of the concrete blocks 121-12N is negligible and lateral surfaces of adjacent ones of the concrete blocks 121-12N form interfaces that can prevent water from easily passing between these concrete blocks and reaching the cavity 17. This enables the outer wall 15 to be built without requiring mortar to hold the concrete blocks 121-12N together or fill their interfaces, resulting in the cavity 17 being free of mortar. As mentioned above, this mortarless nature of the cavity 17 avoids mortar bridging the outer wall 15 and the inner wall 11 or falling and clogging the weep holes, thereby enabling the cavity 17 to impede moisture intrusion in the inner wall 11 and promote pressure equalization between either side of the outer wall 15.
Moreover, the connection system 50, through cooperation between the elongated structural members 521-52P and the connecting elements 541-54T, strengthens the wall structure 10 by interconnecting the inner wall 11 and the outer wall 15 at various points that are distributed in the wall structure 10. The elongated structural members 521-52P and the connecting elements 541-54T also cooperate to interconnect individual ones of the concrete blocks 121-12N, thereby enhancing strength and solidity of the outer wall 15. By being exposed to air in the cavity 17 and not being in contact with mortar, the elongated structural members 521-52P and the connecting elements 541-54T remain dry and are thus less prone to rusting then conventional wall ties.
Construction of the wall structure 10 can also be effected conveniently and efficiently. For instance, assuming that the inner wall 11 has been constructed using conventional methods, an example of a method for advancing construction of the wall structure 10 will now be described with reference to
At step 400, one or more of the elongated structural members 521-52P are secured to the inner wall 11. Each of the one or more of the elongated structural members 521-52P is secured to the inner wall 11 so as to be aligned with given ones of the concrete blocks 121-12N that will be placed to form a course of the outer wall 15. This is effected using knowledge of the height of the concrete blocks 121-12N. In this example, each of the one or more of the elongated structural members 521-52P is fastened to the inner wall 11 by using fasteners in its apertures 60.
At step 410, given ones of the concrete blocks 121-12N are placed horizontally adjacent to one each other so as to form a course.
At step 420, for each of the given ones of the concrete blocks 121-12N that have been placed to form the course, each of one or more of the connecting elements 541-54T is connected to that concrete block and to one of the one or more of the elongated structural members 521-52P that have been secured to the inner wall 11 in alignment with the course. In this example, a given one of the connecting elements 541-54T is connected to a given one of concrete blocks 121-12N that has been placed to form the course and to a given one of the one or more of the elongated structural members 521-52P that have been secured to the inner wall 11 in alignment with the course by inserting its first portion 61 into one of the apertures 62 of that given elongated structural member and by positioning its second portion 63 in one of the grooves 371-373 of that given concrete block so as that it fits and is retained therein.
In this example, steps 400 to 420 are repeated to form each new course of concrete blocks in order to progressively erect the outer wall 15.
It will be appreciated that this method is presented for example purposes only as various modifications and enhancements are possible. For example, flashing, weep holes and other elements can be provided using conventional means during construction of the wall structure 10. As another example, as shown in
The concrete blocks 121-12N and the connection system 50 thus enable the outer wall 15 to be efficiently and conveniently constructed and connected to the inner wall 11. In particular, since no mortar is required to hold the concrete blocks 121-12N together or fill their interfaces, construction of the outer wall 15 is practically insensitive to weather conditions and does not require time to allow mortar to dry. Structural solidity of the outer wall 15 is immediate owing to the connection system 50. Installation of the connection system 50 is rapid and easy and requires no special skill.
Turning now to
At step 200, no-slump concrete is placed into a mold. To facilitate mass-production, in one embodiment, the mold has a plurality of cavities. In other embodiments, a plurality of molds each with a single cavity or each with a respective plurality of cavities may be used. To further facilitate mass-production, the mold may be located such that concrete blocks are placed on a production board when removed therefrom.
Each cavity of the mold is configured to form a respective concrete block comprising a surface with one or more natural stone-like surface portions (e.g., the front surface 141 of the concrete block 12j with its seven natural stone-like surface portions 201-207). To that end, each cavity is defined in part by a surface of the mold that includes at least one portion with a surface texture corresponding to the desired natural stone appearance (hereinafter referred to as “the at least one natural stone-like surface portion of the mold”). In embodiments directed to producing concrete blocks with a plurality of natural stone-like surface portions (such as those shown in
In order to closely simulate natural stone, in one embodiment, each given natural stone-like surface portion of the mold, and thus the corresponding natural stone-like surface portion of concrete blocks to be formed by the mold, is based on a natural stone's surface. In one example of implementation, data representative of at least a portion of the natural stone's surface is obtained, for instance, via three-dimensional scanning of the natural stone's surface. The obtained data may then be computer processed using software in order to generate data representative of the given natural stone-like surface portion of the mold. In some cases, this processing may include modifying the obtained data representative of at least a portion of the natural stone's surface to set the desired surface level difference ΔL′ and texture angles θ′ of the given natural stone-like surface portion. This processing may also ensure that the data representative of the at least one natural stone-like surface portion of the mold will result in the at least one corresponding natural stone-like surface portion of concrete blocks to be formed by the mold providing at least three points that are located relative to each other such that at least one other concrete block may be supported thereon in a stable manner.
As another possible consideration, in embodiments where individual ones of the cavities of the mold are intended to form concrete blocks of similar overall dimensions but with natural stone-like surface portions that have different configurations (e.g., different patterns of cast relief elements), these individual cavities may be designed to each have a common volume in order to facilitate production. In other words, a first cavity intended to form concrete blocks with natural stone-like surface portions having a first configuration may have a first volume, and a second cavity intended to form concrete blocks with natural stone-like surface portions having a second configuration different from the first configuration may have a second volume substantially corresponding to the first volume. This facilitates provision of substantially the same quantity of concrete into each cavity of the mold, which in turn facilitates efficient casting of concrete blocks in the mold and subsequent removal of the concrete blocks therefrom.
In embodiments where individual ones of the cavities of the mold are intended to form concrete blocks of significantly different overall dimensions and with natural stone-like surface portions that have different configurations (e.g., different patterns of cast relief elements), similar production benefits may be achieved by designing these individual cavities to each have a common volume per unit area.
Each cavity of the mold is configured such that a concrete block that is cast therein has its thickness oriented generally vertically, i.e., has its height and width oriented generally horizontally. This helps to render negligible any difference in height and width between different concrete blocks that are cast.
The mold may be manufactured via computer-aided manufacturing based on the data representative of each given natural stone-like surface portion of the mold. With no-slump concrete being used, the mold may be made of metal or other rigid material. There is no requirement for one or more portions of the mold to be made of elastomeric material (e.g., rubber), which is typically used in molds for casting wet-cast concrete blocks with a natural stone appearance.
Thus, during step 200, each cavity of the mold is filled with no-slump concrete in order to form a concrete block comprising a surface with one or more natural stone-like surface portions.
At step 202, the no-slump concrete in the mold is consolidated. Consolidation may include inducing vibration of the no-slump concrete in the mold so as to cause it to compact itself and closely conform to each cavity of the mold. A pre-vibration phase may be effected during step 200 to facilitate filling of the no-slump concrete in the mold and its eventual consolidation. Consolidation may also include application of pressure on the concrete in combination with its vibration. It will be appreciated that consolidation may be effected using various other techniques.
Upon completion of step 202, the no-slump concrete in each cavity of the mold has formed into a concrete block comprising a surface with one or more natural stone-like surface portions.
At step 204, the concrete block in each cavity of the mold is removed therefrom and continues on the production board. The concrete blocks may be directly stored for curing purposes. Since provision of a natural stone appearance is effected during casting, the concrete blocks do not require a subsequent mechanical artificial aging/weathering process (e.g., tumbling, object impacting, etc.) to impart them with such an appearance. Also, this absence of a mechanical artificial aging/weathering process that could otherwise damage lateral surfaces of the concrete blocks results in these lateral surfaces being relatively flat and smooth. In addition, with each concrete block having been cast with its height and width oriented generally horizontally, any difference in height and width between different concrete blocks is negligible.
The concrete blocks may directly be stacked or palletized in a stable manner since the at least one natural stone-like surface portion of each concrete block may have been configured to provide at least three points that are located relative to each other to ensure such stable supporting. With the concrete blocks being made of no-slump concrete, curing times are relatively short such that they are available for use within a short period of time (e.g., one day).
At step 206, each cavity of the mold is cleaned such that casting of new concrete blocks may be effected. In one embodiment, a cleaning unit uses a fluid to clean each cavity of the mold. The fluid may be a gas (e.g., compressed air) or a liquid whose flow relative to each cavity of the mold, and particularly each natural stone-like area of the mold, removes therefrom substantially any remaining no-slump concrete. Such a fluid-based cleaning action advantageously enables rapid cleaning of each cavity of the mold, thereby increasing production efficiency. In some cases, the cleaning unit may also use, in addition to the fluid, one or more brushes to clean each cavity of the mold, whereby the fluid-based cleaning action is combined with a brushing cleaning action. It will be appreciated that other embodiments may employ various other types of cleaning action.
In this example, the process returns to step 200 where a new production cycle begins. In some embodiments, utilization of no-slump concrete in combination with rapid cleaning of the mold and other elements of the process may enable a production cycle to take a relatively short period of time (e.g., 15 to 20 seconds per square meter of finished products in some cases).
Although various embodiments and examples have been presented, this was for the purpose of describing, but not limiting, the invention. Various modifications and enhancements will become apparent to those of ordinary skill in the art and are within the scope of the present invention, which is defined by the attached claims.