TECHNICAL FIELD

[0001] The present teachings relate to concrete elements and concrete structures, and more specifically, to means and methods of constructing reinforced concrete structures that exhibit strength and toughness to withstand ballistics and high explosive blast effects, including high-speed energy fragments from explosive weapons and kinetic energy projectiles.

BACKGROUND

[0002] Concrete and specifically reinforced concrete has been used for the past century as the main component for creating blast-resistant and projectile-resistant structures by military forces worldwide. Designs for concrete mix formulations are known in the art.

[0003] However, known structures, methods, and systems are limited in use to stationary buildings due to the mass, size, and/or thickness required for constructing the walls and roofs of such structures. When militaries require fortified structures in locations that are temporary and/or near combat zones, such as forward operating bases (FOBs), the fortified structures are usually constructed from much lighter materials than concrete. Typical structures include steel structures or wood structures, which are then supported by whatever earth or rocks that are available in the local area. Lately, deployable barrier systems, like the HESCO barrier (also known as HESCO MIL), has been used as a fast and easy way to create fortifications. The HESCOE barrier is made of a collapsible wire mesh container and fabric liner, which is filled with sand, soil or gravel. Nevertheless, roof reinforcements are still a challenge, and in general, supporting beams and columns must be used under sandbags or earth material cover. This method is usually very time and labor intensive and requires substantial materials and cost in order to be effective against threats of the modern battlefield. In many cases, these known methods are not suitable for road checkpoints, barracks for fastmoving troops, command and control units and similar mobile or semi-mobile activities. Alternative means, including armored steel and ballistic ceramics structures, also have disadvantages such as being expensive.

[0004] Past products developed by the US army and other military services concentrate on creating ultra-high strength concrete mixes, like that disclosed in US Patent No. 8,016,938. The reinforcement for such structures involves traditional reinforcement methods and designs, using conventional straight rebar steel configurations and concrete matrix usually augmented with steel or polymer fibers.

[0005] The threat profile and tactics of the current combat theater has changed dramatically over the past 25 years from large conventional armies to very light and very mobile forces. One of the preferred methods used in the current combat theater is arming light, fast vehicles (e.g., pickup trucks) with automatic cannons, such as 12.7 x 99 mm, 12.7 x 108 mm, 14.5 x 114 mm, 23 x 153 mm, the 30 x 165 mm, or the like. These “technicals” can be very effective against semi-mobile structures, especially if the structures are not heavily protected or are loosely armored, which is usually the case for mobile troops, with combatants engaging targets at ranges less than 1000 m at times. This is nevertheless well beyond the accurate and effective defensive fire of mobile troops, which are usually armed with rifles and medium machine guns. From such a distance, calibers from 14.5 to 30mm are highly destructive and effective especially when using armor piercing incendiary or high explosive projectiles, and substantial armoring is required to prevent the projectiles from perforating the defensive structures.

[0006] In constructing blast or projectile-resistant walls or structures, conventional reinforcement is used, employing straight steel rebar usually formed in a shape resembling either a square, rectangle, or in general formed at 90 degree angle cross sections, whereby concrete is cast into the steel matrix. This configuration is extremely heavy, requires large quantities of steel, and involves a construction method that is expensive, time-consuming and labor-intensive. Alternatively, or in addition thereto, ultra-high strength concrete using steel fibers may be used in order to increase the flexural and tensile strength of the structural element and to lessen cracking and micro cracking effects created by the impacts of the high energy projectiles or blasts.

[0007] There has been a recent trend to remove the steel rebar completely from the concrete elements in order to minimize the disadvantages related to weight, time and cost, and replace that with a matrix of steel fibers. However, this approach can only be used in small-sized elements with short spans and low load bearing capacity. Additionally, the use of large quantities of steel fibers is disadvantageous in that it renders the matrix less resistant to armor piercing incendiary projectiles when compared to high density cementitious material. This approach also requires the use of specialty ultra- high strength concrete mix, usually above 180 MPa in compressive strength, which may require specialty curing techniques using high temperature curing chambers in order to achieve the required cohesion and strength. This system, although effective in some applications, is economically prohibitive in large scale and as such has not achieved any substantial acceptance in the field.

[0008] Thus, there exists a need for improved concrete elements and structures, as well as girders and reinforcement elements for improved concrete elements, that overcome the above drawbacks while possessing ballistic-resistant and/or blast-resistant characteristics.

SUMMARY

[0009] The needs set forth herein as well as further and other needs and advantages are addressed by the present embodiments, which illustrate solutions and advantages described below. [0010] It is an object of the present teachings to provide a concrete element or structure that exhibits improved strength (e.g., compressive and/or tensile) and toughness for withstanding the effects of ballistics and explosives, as well as a girder(s) and an arrangement of girders for reinforcing such concrete element or structure.

[0011] It is another object of the present teachings to provide a ballistic- resistant and blast-resistant concrete element or structure that minimizes perforation, and more preferably withstands complete perforation, by kinetic energy projectiles and high-speed, high-energy explosive fragments. There are various configurations of kinetic energy projectiles and high-speed, high- energy explosive fragments, such as API (armor-piercing incendiary) projectiles, HE (high-explosive) projectiles that may be used with vehicles equipped with auto cannons and direct mortar fire. The present teachings similarly provide a girder(s) and an arrangement of girders that reinforce and support such ballistic-resistant and blast-resistant concrete element.

[0012] It is another object of the present teachings to provide a ballistic-resistant and blast-resistant concrete element or structure that resists cracking due to exposure of projectile and/or explosive impacts, which typically occurs in prior art concrete structures. The present teachings similarly provide a girder(s) and an arrangement of girders that reinforce and support such ballistic-resistant and blast-resistant concrete element.

[0013] It is a further object of the present teachings to provide a ballistic-resistant and blast-resistant concrete element or structure, as well as a girder(s) and an arrangement of girders, that requires less construction time, is less labor-intensive, and involves reduced materials and costs.

[0014] It is also an object of the present teachings to provide a method of making a ballistic-resistant and blast-resistant concrete element or structure that achieves the above identified objectives. [0015] These and other objects of the present teachings are achieved by providing a lattice girder, and more specifically a triangular profile lattice girder. Herein, a triangular profile lattice girder refers to a lattice girder formed of cords and trusses with a triangular profile which advantageously provides structural reinforcement. The lattice girder according to the present teachings is produced with two primary longitudinal chords (e.g., wires, bars, rods) at the bottom (or top) and one secondary longitudinal chord at the top (bottom) spatially distanced from one another, which are connected (e.g., welded) together by truss beams or stiffening elements (e.g., wires, bars, rods) extending between the secondary longitudinal chord and each of the primary longitudinal chords. The triangular profile lattice girder is highly efficient in providing load bearing support capacity to structures when used in an independent steel element or as part of a reinforced concrete steel matrix, such as walls, roof slabs and floor slabs, and usually in conjunction with light steel mesh. The lattice girder of the present teachings has high load bearing capacity and mechanical efficiency in relation to its weight and cost. Triangular profile lattice girders according to the present teachings may be made on high speed automatic bending and welding machines, making them extremely low cost to manufacture. They can also accommodate different size configurations, which are only limited by the number of chords and/or truss beams.

[0016] Objects of the present teachings are also achieved by providing a reinforced concrete structural element, which comprises: a first lattice girder having a triangular profile, the first lattice girder having at least one triangular cavity; a second lattice girder having a triangular profile, the second lattice girder having a size smaller than a size of the first lattice girder; a section of the second lattice girder being positioned through the triangular cavity so that the second lattice girder is transverse to the first lattice girder; wherein the positioning of the second lattice girder through the triangular cavity of the first lattice girder forms a lattice girder matrix that is designed to provide support and reinforcement to a concrete matrix in an x-axis, a y-axis, a z-axis, and one or more additional axes/directions.

[0017] The first lattice girder and the second lattice girder may each comprise: three rebar chords that are spaced apart from each other and substantially parallel with each other in a triangular shape; and a plurality of truss beams connected to the rebar chords. One pair of the truss beams of the first lattice girder which are longitudinally adjacent and one of the rebar chords of the first lattice girder form the triangular cavity. A cross-sectional area defined between the rebar chords of the second lattice girder is smaller than a cross-sectional area defined by the rebar chords of the first lattice girder.

[0018] Objects of the present teachings are also achieved by an architectural structure or building, which comprises two or more reinforced concrete structural elements. Each reinforced structural element includes: a first lattice girder having a triangular profile, the first lattice girder having at least one triangular cavity; a second lattice girder having a triangular profile, the second lattice girder having a size smaller than a size of the first lattice girder; a section of the second lattice girder being positioned through the triangular cavity so that the second lattice girder is transverse to the first lattice girder; and a concrete matrix embedding the first and second lattice girders. The positioning of the second lattice girder through the triangular cavity of the first lattice girder forms a lattice girder matrix that is designed to provide support and reinforcement to the concrete matrix in an x-axis, a y- axis, a z-axis, and one or more additional axes/directions. Multiple fasteners attach the two or more reinforced concrete structural elements to one another. The reinforced concrete structural elements strengthen the architectural structure or building to be resistant to explosive blasts and/or impacts of projectiles. [0019] Objects of the present teachings are also achieved by a method of concrete reinforcement, comprising the steps of: (i) providing a first lattice girder having a triangular profile, the first lattice girder having at least one triangular cavity; (ii) providing a second lattice girder having a triangular profile, the second lattice girder having a size smaller than a size of the first lattice girder; and (iii) positioning a section of the second lattice girder through the triangular cavity so that the second lattice girder is transverse to the first lattice girder, wherein the step of positioning the second lattice girder through the triangular cavity of the first lattice girder forms a lattice girder matrix that is designed to provide support and reinforcement to a concrete matrix in an x- axis, a y-axis, a z-axis, and one or more additional axes/directions. The step of positioning the second lattice girder through the triangular cavity of the first lattice girder includes verifying a cross-sectional area defined between the rebar chords of the second lattice girder is smaller than a cross-sectional area defined by the rebar chords of the first lattice girder.

[0020] Other features and aspects of the present teachings will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example the features in accordance with embodiments of the present teachings. The summary is not intended to limit the scope of the present teachings, which is defined by the claims included herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a right-side isometric view of an exemplary triangular- profile lattice girder reinforcement according to the present teachings.

[0022] FIG. 2 is a left-side isometric view of the exemplary triangular- profile lattice girder reinforcement of FIG. 1 .

[0023] FIG. 3A is partial cutaway view of a structural element (e.g., wall) that utilizes a matrix arrangement of the triangular-profile lattice girder reinforcement of FIG. 1 . FIG. 3B is an enlarged view of a section of the matrix arrangement indicated in FIG. 3A.

[0024] FIG. 4 is a partial cutaway view showing multiple structural elements (e.g., walls, floor, roof) each utilizing a matrix arrangement of the triangular-profile lattice girder reinforcement of FIG. 1 .

[0025] FIGS. 5A-5B are flowcharts showing a method of concrete reinforcement and more specifically, a method of creating concrete components/elements for constructing a structure or building, such as that shown in FIGS. 3 and 4.

[0026] It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

DETAILED DESCRIPTION

[0027] The present teachings are described more fully hereinafter with reference to the accompanying drawings, in which the present embodiments are shown. The following description illustrates the present teachings by way of example, not by way of limitation of the principles of the present teachings.

[0028] The present teachings have been described in language more or less specific as to structural features. It is to be understood, however, that the present teachings are not limited to the specific features shown and described, since the product herein disclosed comprises preferred forms of putting the present teachings into effect.

[0029] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. [0030] The present teachings provide, in various embodiments, concrete elements such as wall panels, beams, columns, roof slabs, floor slabs, or any other concrete structural element, that are used to create blastresistant and/or projectile-resistant (ballistic-resistant) structures either mobile, semi-permanently or permanently constructed using a new and improved method of reinforcement.

[0031] By using different diameter sizes of steel rebar, smooth or ribbed, a triangular profile lattice girder is formed in multiple sizes of that triangular profile. A steel matrix in any shape or design required is then created by placing a small (second) triangular lattice girder inside a large (first) triangular lattice girder along its complete longitudinal axis and preferably in every triangular cavity that the large lattice girder provides. Note, the terms “small” and “large”, and variations thereof, are intended to indicate differences in the relative sizes (e.g., cross-sectional areas defined by respective longitudinal chords) of the first and second girders, and for example, that the first triangular lattice girder is larger than the second triangular lattice girder, or the second triangular lattice girder is smaller than the first triangular girder. Accordingly, multiple smaller lattice girders can be welded, tied or allowed to float freely inside the cavity(ies) of the larger lattice girder. This configuration creates a steel weave matrix pattern in multiple directions and axes that exceed the x, y and z axes. Concrete is then placed inside that matrix to create a structurally reinforced concrete element. The steel weave matrix will act as, form, and provide a multidirectional skeleton to bond and hold the concrete matrix together in multiple diametric directions and axes, and to resist cracking when subjected to a high energy blast and/or an impact by a kinetic energy projectile.

[0032] Depending on the blast and impact resistance level required, the thickness of the concrete element can be adjusted accordingly and is in a range of 10cm-30cm, although not limited thereto, in thickness for a wall or roof panel for example. In some embodiments, other ranges of thickness may be 20cm-30cm, 20cm-40cm, 30cm-40cm, or 20cm-50cm.

[0033] By using this type of reinforcement, the structural elements may be made with regular high strength concrete of 100-120 MPa in compressive strength, without fiber reinforcement or with fiber reinforcement of any quantity or material. In some embodiments, the structural elements may be made with ultra-high strength concrete of up to 140-160 MPa, which allows the structural elements to be lighter in weight and smaller in thickness, while providing the same or better advantages over other methods used to construct ballistic concrete protection.

[0034] The triangular profile of the lattice girder reinforcement may be made from ribbed or smooth steel rebar rods that can vary in diameter from 4mm to 16mm. The arrangement of triangular profile lattice girder reinforcement according to the present teachings can be adapted in any configuration which the designer requires dependent on the design of the structural element.

[0035] An embodiment of the present teachings, configured appropriately, may be used to construct mobile armored ballistic bunkers, such bunkers can be made using concrete elements of different sizes to construct, as well as structures that can be transported separately, bolted together and assembled in the field, and subsequently unbolted, disassembled and transported elsewhere when no longer needed. The structures may be made to serve as, for example but not limited to, barracks, bathrooms, kitchens, dining areas, offices, command and control centers, checkpoints, guard houses, guard towers, equipment storage, explosive material stores, explosion-proof offices, equipment housings, and any structure that requires explosion blast or kinetic projectile impact resistance.

[0036] Another embodiment of the present teachings incorporates fine basalt fiber in the concrete matrix mix, wherein the basalt fiber further increases the cohesiveness of the concrete mix and lessen the effect of micro cracking that would occur due to the effect of an explosive blast and/or impact of a projectile. The amount of basalt fiber may be in the range of 1 -10 kg per cubic meter of concrete mix.

[0037] Another embodiment of the present teachings utilizes in the concrete matrix coarse aggregate in the size range of 10mm-40mm as the main component in the formation of the concrete mix. The total quantity of the coarse aggregate in the concrete mix shall not be less than 40% of the total concrete mix weight; in other words, the total quantity of coarse aggregate is greater than or equal to 40% of the concrete mix weight. The coarse aggregate may preferably be constituted from crushed rock that has a compressive strength of more than 110 MPa and preferably more than 150 MPa, such as but not limited to limestone, granite, or feldspar.

[0038] Referring to FIG. 1 , an isometric view of a concrete reinforcement 10, and more specifically a triangular profile lattice girder reinforcement, is shown. The triangular profile lattice girder reinforcement comprises at least one first lattice girder 1 and at least one second lattice girder 2 disposed transverse relative to the at least one first girder 1 . The first girder 1 is composed of two primary longitudinal chords 6a, 6b, one secondary longitudinal chord 7 disposed spatially apart from the primary longitudinal chords and substantially parallel to the primary longitudinal chords, and a plurality of truss beams 8 that are connected to the longitudinal chords. Each truss beam 8 extends between one of the primary longitudinal chords 6a, 6b and the secondary longitudinal chord 7. In particular, each truss beam is orientated non-perpendicular to the chords with which the truss beam is connected. The truss beams are configured to form triangular cavities 9 with the chords, and in particular, each pair of adjacent truss beams in the longitudinal direction is oriented with one of the chords 6a, 6b, or 7 to provide a triangle shaped opening. [0039] The second girder 2 has a configuration similar to the first girder 1 . That is, the second girder 2 has two primary longitudinal chords 6a, 6b, one secondary longitudinal chord 7 disposed spatially apart from the primary longitudinal chords and substantially parallel to the primary longitudinal chords, and a plurality of truss beams 8 that are connected to and extend between the longitudinal chords. Each truss beam of the second girder 2 is orientated non-perpendicular to the chords and are configured to form triangular cavities 9 with the chords. However, the second girder 2 is smaller than the first girder 1 . As shown in FIG. 1 , the spatial distance between each of the primary longitudinal chords and the secondary longitudinal chord of the second girder 2 is less than the spatial distance between each of the primary longitudinal chords and the secondary longitudinal chord of the first girder 1 . In addition, or alternatively, the spatial distance between the two primary longitudinal chords of the second girder 2 is less than the spatial distance between the two primary longitudinal chords of the first girder 1 . In essence, the cross-sectional area defined between the longitudinal chords 6a, 6b, and 7 of the second girder 2 is smaller than the cross-sectional area defined between the longitudinal chords 6a, 6b, and 7 of the first girder 1 .

[0040] For both the first girder 1 and the second girder 2, the primary longitudinal chords 6a, 6b have the same diameter as the secondary longitudinal chord 7. However, in some embodiments, the diameters may differ, such that the diameter of the primary longitudinal chords is greater or less than the diameter of the secondary longitudinal chord. In some embodiments, the diameters of the longitudinal chords 6a, 6b, and 7 may differ between the first girder 1 and the second girder 2. For example, the diameters of the primary longitudinal chords of the second girder 2 may be greater or less than the primary longitudinal chords of the first girder 1 , and/or the diameter of the secondary longitudinal chord of the second girder 2 may be greater or less than the secondary longitudinal chord of the first girder 1 . It is understood by those of ordinary skill in the art that any combination(s) of chord diameters within a given girder and/or between the first and second girders may be utilized to achieve the concrete reinforcement according to the present teachings. Exemplary diameters of the chords may be within the range of 6mm and 50mm.

[0041] Since the second girder 2 is smaller than the first girder 1 , the second girder is feed through one of the plurality of triangular cavities of the first girder 1 so that the second girder is positioned transversely within a portion of the first girder 1 , as shown in FIG. 1 . In some embodiments, the second girder 2 intersects the first girder 1 at an oblique angle, for example between 60 and 90 degrees. In preferred embodiments, the first girder and the second girder are perpendicular to one another. By way of the smaller configuration of the second triangular profile lattice girder relative to the first triangular profile lattice girder and the joining/union of the first and second girders, the matrix arrangement of the girders provides increased load bearing capacity and helps increase the compressive and tensile strength and toughness of the concrete matrix (see FIGS. 3A-3B and 4). In some embodiments, the smaller girder 2 is not physically connected to the larger girder 1 so that the smaller girder 2 is adapted to float freely inside the triangular cavity of the larger girder 1 . In other embodiments, the smaller girder is connected to the larger girder with wire ties, such as rebar loop ties, as is well known in the art. In yet other embodiments, the smaller girder is welded to the larger girder at points along the triangular cavity such that the weld joints inhibit relative movement between the smaller and larger girders. Other fastening mechanisms, as is well known in the art, may be used to connect the first and second girders. This arrangement of first and second girders, as described above, creates a weave matrix pattern in multiple directions and axes that exceed the x, y, and z axes.

[0042] For both the first girder 1 and the second girder 2, the primary and secondary longitudinal chords are made of steel, and preferably smooth rebar or ribbed rebar. The truss beams 8 of both girders may be similarly made of steel, and preferably smooth rebar or ribbed rebar. In some embodiments, the truss beams 8 are connected to the primary and secondary longitudinal chords, 6a, 6b, 7 by weld joints.

[0043] As shown in FIG. 1 , the triangular profile lattice girder reinforcement 10 may comprise a plurality of second triangular profile lattice girders 2, 3, 4. Preferably, each of the second girders has the same configuration, i.e., girder size, chord diameters, angles between truss beams and longitudinal chords, etc. However, in some embodiments, the second girders may differ in configuration, in one or more aspects. The triangular profile lattice girder reinforcement 10 may also comprise a plurality of first triangular profile lattice girders 1 . Although this is not shown, a person of ordinary skill in the art would be able to readily understand and visualize the concrete reinforcement 10 having multiple first girders 1 , each having a triangular cavity through which the second girder 2 is feed and positioned in a transverse orientation. If multiple second girders are present, then each first girder has other cavity openings through which the second girders 3 and 4 are positioned in transverse orientation. In preferred embodiments, the multiple first girders are parallel with each other, and/or the second girders are parallel with each other.

[0044] FIG. 2 is an isometric view of the concrete reinforcement 10 from a different point of view. As shown in FIG. 2 (as well as in FIG. 1 ), the plurality of second girders 2, 3, 4 are positioned in successive triangular cavities 9 of the first girder 1 . The orientation of each successive triangular cavity switches between being upright (apex above base) and being inverted (base above apex). As such, the second girders 2 and 4 are in an upright position (i.e., where the secondary longitudinal chord 7 is above the primary longitudinal chords 6a, 6b), whereas the second girder 3 is in an inverted position (i.e., where the secondary longitudinal chord 7 is below the primary longitudinal chords 6a, 6b). This also holds true when there are multiple first girders 1 . By way of this arrangement, the girders provide increased load bearing capacity and helps increase the compressive and tensile strength and toughness of the concrete matrix.

[0045] FIG. 3A shows an exemplary concrete element (e.g., wall) reinforced by the triangular profile lattice girder reinforcement 10. In particular, the triangular profile lattice girder reinforcement 10 includes a plurality of first girders 1 and a plurality of second girders 2, 3, 4 organized in a full weave matrix arrangement, as shown in FIG. 3B. The triangular profile lattice girder reinforcement matrix 10 reinforces the concrete matrix 20, thereby imparting increased load bearing capacity and increased compressive and tensile strength and toughness of the concrete matrix. The concrete element may further comprise a fastener 22, for example a steel anchor and bolt, to releasably attach different structural elements (e.g., roof slabs, floor slab) together for assembly, and thereafter disassembly. In some embodiments, the concrete matrix includes basalt fiber. The amount of basalt fiber may be in a range of 1 -10 kg per cubic meter of concrete mix.

[0046] FIG. 4 shows a structure or building incorporating the triangular profile lattice girder reinforcement 10. Specifically, reference number 30 indicates one instance of the triangular profile lattice girder reinforcement in a full weave matrix arrangement supporting a concrete matrix 31 to form a wall. Reference number 32 indicates one instance of the triangular profile lattice girder reinforcement in a full weave matrix arrangement supporting a concrete matrix 33 to form a roof. A plurality of fasteners 34, such as anchors and bolts 52, may be used to releasably connect the roof to the wall, as well as the wall to a floor 40. This allows for easy assembly and disassembly. Reference number 35 indicates the concrete matrix of another wall. FIG. 4 also show a floor 40 comprising the triangular profile lattice girder reinforcement 42 in a full weave matrix arrangement supporting a concrete matrix 44. In some embodiments, the floor may further comprise a wire mesh 50 (e.g., steel mesh) layered on top of the triangular profile lattice girder reinforcement matrix 42 and embedded within the concrete matrix 44 to provide additional reinforcement and support to the concrete matrix.

[0047] The present teachings also provide a method of concrete reinforcement, as illustrated in FIG. 5A. The method includes the steps of providing one or more first (large) triangular profile lattice girders 1 and one or more second (small) triangular profile lattice girders 2 (step 100) and building a framework or providing a mold configured to receive a concrete matrix (step 102). In some embodiments, the step of building a framework may precede the step of providing the first and second girders. Thereafter, the method comprises the step of positioning the one or more first girders 1 in the framework (step 104). In the situation where there are multiple first girders 1 , the girders 1 are positioned parallel to one another. For each second girder that is needed to construct a structural element, insert the second girder 2 through a triangular cavity 9 of each of the one or more first girders 1 , so that the second girder is positioned transversely within the one or more first girders (step 106). The step of positioning the second girder 2 through the triangular cavity further includes a step of verifying a cross-sectional area defined between the rebar chords of the second lattice girder is smaller than a cross-sectional area defined by the rebar chords of the first lattice girder.

[0048] Once positioning of the girders 1 and 2 is completed, they may be connected to each other (step 108). However, step 108 is optional, such that the girders are not physically connected to each other (i.e. , the second girders are left to float freely within the respective triangular cavities of the first girder). In step 110, a concrete matrix - which may or may not include basalt fiber - is poured into the framework (or mold) in order to embed the first and second girders. The concrete matrix is then cured, wherein the first and second girders serve as a skeleton and structural reinforcement for the concrete matrix (step 112). At step 114, once the concrete matrix has completely cured, the structural element (e.g., wall, roof slab, floor slab) has finished being created. [0049] Referring to FIG. 5B, the method may comprise additional steps towards constructing a structure or building involving a plurality of structural elements or components. For example, after initially performing steps 100- 114, which are collectively referred to as step 200, it is determined whether other structural elements must be created before the structure or building can be constructed (step 202). If yes, then step 200 is repeated. If no, then step 204 is performed, wherein the structural elements/components (e.g., walls, floor, roof) are assembled using fasteners (e.g., anchors and bolts). In step 206, the construction of the building is completed. After a period of time, if there is no need for the building in the current location, the structural elements may be disassembled (step 208) and transported to a new site (step 210). The structural elements may then be assembled again to create the same structure as before, or alternatively a different structure, at the new site (step 212). Steps 208-212 can be repeated as often as necessary. Note, instead of step 212, the structural elements may be stored for future use when the need arises for constructing a building at a particular location.

[0050] Although the present teachings as described above are suitable for site cast concrete structures, the present teachings may also be applicable to precast concrete. That is, precast concrete is poured into a mold with the triangular profile lattice girder reinforcement matrix 10. It is then cured in a controlled environment, usually a plant. Once finished, the precast concrete may be transported to a construction site and assembled with other structural pieces.

[0051] It should be understood to a person of ordinary skill in the art that different configurations of the lattice girder reinforcement are possible. For example, the arrangement and order of components of the lattice girder reinforcement may differ from those described in the above written description and figures without departing from the scope and spirit of the present teachings. [0052] While the present teachings have been described above in terms of specific embodiments, it is to be understood that they are not limited to those disclosed embodiments. Many modifications and other embodiments will come to mind to those skilled in the art to which this pertains, and which are intended to be and are covered by both this disclosure and the appended claims. For example, in some instances, one or more features disclosed in connection with one embodiment can be used alone or in combination with one or more features of one or more other embodiments. It is intended that the scope of the present teachings should be determined by proper interpretation and construction of any claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.