CN118043525A - Rear Zhang Pengzhang concrete slab with fibers - Google Patents
Rear Zhang Pengzhang concrete slab with fibers Download PDFInfo
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- CN118043525A CN118043525A CN202280066082.2A CN202280066082A CN118043525A CN 118043525 A CN118043525 A CN 118043525A CN 202280066082 A CN202280066082 A CN 202280066082A CN 118043525 A CN118043525 A CN 118043525A
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- 229910000831 Steel Inorganic materials 0.000 claims abstract description 98
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- 229910052804 chromium Inorganic materials 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
- E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
- E04B5/32—Floor structures wholly cast in situ with or without form units or reinforcements
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
- E04B5/43—Floor structures of extraordinary design; Features relating to the elastic stability; Floor structures specially designed for resting on columns only, e.g. mushroom floors
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
- E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
- E04C2/04—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres
- E04C2/06—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of concrete or other stone-like material; of asbestos cement; of cement and other mineral fibres reinforced
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
- E04C2/44—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the purpose
- E04C2/50—Self-supporting slabs specially adapted for making floors ceilings, or roofs, e.g. able to be loaded
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/20—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members
- E04C3/26—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members prestressed
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
- E04C5/012—Discrete reinforcing elements, e.g. fibres
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
- E04C5/073—Discrete reinforcing elements, e.g. fibres
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Reinforcement Elements For Buildings (AREA)
Abstract
The invention relates to a concrete slab comprising concrete and a combined reinforcement of rear Zhang Gang strands and fibres, the rear Zhang Gang strands having a diameter in the range 5mm to 20mm and a tensile strength higher than 1700MPa, the fibres being steel fibres and being used in an amount in the range 10kg/m 3 to 75kg/m 3 or coarse synthetic fibres and being used in an amount in the range 1.5kg/m 3 to 9.0kg/m 3, wherein the concrete is expanded concrete.
Description
Technical Field
The invention relates to a concrete slab comprising expanded concrete and a combined reinforcement of rear Zhang Gang strands and fibres.
Background
Post-tensioned concrete is a variant of prestressed concrete in which tendons, i.e. the rear Zhang Gang strands, are tensioned after the surrounding concrete structure has been cast and hardened. This is a practice known in the civil engineering field since the middle of the twentieth century.
Steel fiber reinforced concrete is concrete in which short steel wires dispersed in the concrete provide reinforcement. US-se:Sup>A-1,633,219 discloses reinforcing concrete pipes with steel wires. Other prior art publications US-A-3,429,094, US-A-3,500,728 and US-A-3,808,085 reflect the initial work done by Batelle Development Corporation. NV Bekaert SA et al further improves and industrializes steel fibers by providing anchor ends at both ends of the steel wire, see U.S. Pat. No. 3, 3,900,667. Another related improvement is disclosed in US-se:Sup>A-4,284,667, which relates to the introduction of glued steel fibres to mitigate the miscibility problem in concrete. Flattening the curved anchoring end of the steel fiber increases the anchoring of the steel fiber in the concrete as disclosed in EP-B1-0851957. The supply of steel fibres in chain packs is disclosed in EP-B1-1383634.
Both reinforcement techniques, post-tensioned concrete and fiber reinforced concrete (e.g. steel fiber reinforced concrete), exist not only as such but also in combination. The purpose is to combine the advantages of the two reinforcement types to obtain the reinforced concrete slab with high efficiency and reliability.
Prior art concrete panels having a composite reinforcement of both rear Zhang Jiaoxian and fibers suffer from excessive or complex designs. In order to remain safe and meet the specification requirements, the amount of steel fibers is often so high that problems such as balling occur during mixing of the steel fibers in the uncured concrete, although solutions exist in the prior art. Alternatively, or in addition, the distance between two adjacent post-tensioned strands or the distance between two adjacent post Zhang Jiaoxian bundles cannot exceed a certain maximum spacing, resulting in a significant amount of labor being required in installing post Zhang Jiaoxian, attaching the anchor, and applying tension. In a further prior art embodiment, the composition of the concrete is such that shrinkage during curing is limited, i.e. for example a low shrinkage concrete or a compensating shrinkage concrete composition may be selected.
Examples of complex designs of concrete slabs reinforced by both rear Zhang Gang strands and steel fibers are disclosed in NZ-a-220693. The prior art concrete slab comprises a lower skin with steel fibres and an upper skin, the middle core having post-tensioned tendons.
Thus, expanded concrete is also known in the art. However, the use of expanded concrete may lead to crack formation due to expansion and/or local or global over-expansion.
The invention may thus allow, in particular during curing, for simplified installation of the panel, reduced risk of crack formation, reduced size or opening of joints, reduced influence of shrinkage and/or cooling, to achieve load-bearing capacity and/or to help resist bending stresses, simplified panel design, in particular for example reduced number of post Zhang Gang strands. In addition, the present invention may increase the span of the slab and/or reduce the thickness of the slab and/or the present invention may help reduce the amount of concrete for a given slab thickness or a given span. Furthermore, the present invention may allow for easier and/or faster installation. In addition, the present invention may allow the panels to be structural panels, which may, for example, contribute to the structural integrity of a building. The present invention may also help to increase the ability of the structure to bend, deflect, shear, punch shear, structural integrity, temperature resistance, and/or shrink resistance. The invention allows, inter alia, to combine improved shear or impact resistance properties with improved bending capabilities, for example.
Disclosure of Invention
The general aspect of the present invention is to avoid the drawbacks of the prior art.
Another general aspect of the present invention is to avoid over-design and/or simplify installation.
Another aspect of the present invention is to provide a rear Zhang Jiaoxian and fibrous composite reinforcement to efficiently and effectively reinforce a concrete slab of expanded concrete. Yet another aspect of the present invention is to provide a rear Zhang Jiaoxian of an expanded concrete slab and a fibrous composite reinforcement. Thereby, the tendon or the rear Zhang Gang strand is post-tensioned, which means that tension is applied to the tendon or the rear Zhang Gang strand only after casting of the concrete, and/or the tendon or the rear Zhang Gang strand may also be kept in place, for example, once the concrete has been completely cured/hardened. Accordingly, tendons or rear Zhang Gang strands may be installed in the field and/or may be installed before or after casting. The tendon or rear Zhang Gang strand may comprise an anchoring system that may specifically attach the tendon or rear Zhang Gang strand to the cast concrete of the panel, and/or the pipe or jacket according to the present invention. This is particularly helpful, for example, in achieving larger panels, in facilitating continuity, in facilitating safety, in facilitating camber, in minimizing prestress losses (especially due to creep), in increasing freedom with respect to possible shapes, and in facilitating pleated construction of tendons or rear Zhang Gang strands. In contrast, pretensioning is mainly used for off-site cast prefabricated elements whose tendons are fixed to the formwork and tensioned before any concrete is cast. Thus, the dimensions of the prefabricated elements obtained by pretensioning are rather limited, since the use of templates or moulds is highly required, so that a floor panel may often require a plurality of prefabricated elements.
According to the present invention there is provided a concrete panel comprising concrete and a rear Zhang Gang strand and fibre composite reinforcement,
The rear Zhang Gang strand has a diameter in the range of 5mm to 20mm,
The tensile strength is higher than 1700MPa,
The fibers are steel fibers and are used in an amount ranging from 10kg/m 3 to 75kg/m 3, or coarse synthetic fibers and are used in an amount ranging from 1.5kg/m 3 to 9.0kg/m 3,
Wherein the concrete is an expanded concrete. The invention may also relate to a method of obtaining a panel according to the invention.
The tendon or rear Zhang Gang strand has a diameter in the range 5mm to 20mm, for example 6mm to 20mm, for example 6.5mm to 18.0mm, for example 13mm to <18.0mm. The tensile strength of the rear Zhang Gang strand is higher than 1700MPa, for example higher than 1800MPa, for example higher than 1900MPa, for example higher than 2000MPa, preferably between 1800MPa and 4000 MPa. The rear Zhang Gang strand may also have a maximum breaking load, for example, of more than 190kN, for example more than 195kN, for example more than 200kN, for example more than 220kN, preferably between 195kN and 350 kN. According to the invention, a tensile stress of between 5% and 15% of the final stress can be applied to the rear Zhang Gang strands within the first 24 hours after casting the plate. The concrete is an expanded concrete and the tensile stress applied between 5% and 15% of the final stress in the rear Zhang Gang strands within the first 24 hours after casting the slab may thus for example allow compensating for shrinkage and/or curing, in particular during curing. It may in particular allow expansion of the concrete to increase the compressive stress and thereby in particular for example reduce the risk of crack formation and/or simplify the installation, as it may no longer be necessary for the staff to have to be returned to site for (initial) post-tensioning operations after casting for example 2 to 5 days. In contrast, according to the invention, a tensile stress of between 5% and 15% of the final stress can be exerted on the rear Zhang Gang strands within the first 24 hours after casting the plate by the staff already at the casting site. The fibers can thereby help to resist bending stresses which are present in particular, for example, already after casting. This may significantly simplify the installation. In one embodiment of the invention, the length of the plate may especially be between 50m and 250m, preferably between 75m and 200 m. The invention is therefore particularly useful for long panels and/or seamless floors, as the invention may improve their dimensional stability and/or facilitate less seam opening between such long panels, especially during curing and/or after more than 28 days. This may be due to the compressive stress applied to counteract the expansion of the concrete, thereby contributing to an increase in dimensional stability of the panel.
The tendons or the rear Zhang Gang strands may be bonded or unbonded. In addition, the steel strands may preferably be present, for example, in the form of bundles. The invention may thus, inter alia, allow for a reduction in the amount of post Zhang Gang strands, for example.
In particular in view of use as a post Zhang Gang strand, the steel strand preferably has a low relaxation behavior, i.e. a high yield point at 0.1% elongation. The yield point at 0.1% can be considered the maximum elastic limit. Below the yield point, the rear Zhang Jiaoxian will remain in the elastic mode. Above the yield point, the post-tensioned strand may begin to elongate in plastic mode, i.e., irreversibly elongate. Preferably, the ratio of yield strength R p0.1 to tensile strength R m is higher than 0.75. Thus, the final stress may be a tensile stress of, for example, between 1000MPa and 3000MPa, preferably between 1500MPa and 2500 MPa.
After 1000 hours, the low relaxed Zhang Gang strand may have a relaxation loss of no more than 2.5% when the initial load reaches 70% of the specified minimum breaking strength of the post-tensioned strand, or the low relaxed Zhang Gang strand may have a relaxation loss of no more than 3.5% when the initial load reaches 80% of the specified minimum breaking strength of the post-tensioned strand.
The fibres may be steel fibres and may be used in an amount ranging for example from 10kg/m 3 to 45kg/m 3, preferably from 10kg/m 3 to 40kg/m 3, or ≡25kg/m 3 to 75kg/m 3, preferably >40kg/m 3 to 60 or 65kg/m 3, further preferably from 15kg/m 3 to 40kg/m 3, further preferably from >20kg/m 3 to <40kg/m 3, preferably from 15kg/m 3 to 35kg/m 3, preferably from 20kg/m 3 to 30kg/m 3 or from 10kg/m 3 to <30kg/m 3, or further preferably from 10kg/m 3 to 27kg/m 3. In one embodiment, the amount of steel fibers used according to the invention may for example preferably be less than or equal to 1.2 times, preferably 1.0 times, further preferably >0 to 1.1 times the amount or level of steel used and recommended for the steel bars or rebars to be replaced, and/or the amount or level of steel fibers may be less than or equal to 1.2 times, preferably 1 time, further preferably >0 to 1.1 times the recommended amount or level for the steel bars or rebars to be replaced. Thus, lower to moderate amounts may be particularly preferred to improve the uniform distribution of the fibers and/or to reduce and/or delay crack formation and/or to reduce the risk of fiber ball formation (i.e. by fiber entanglement, especially at high amounts) that may lead to defects, especially surface defects. Thus, lower amounts of fiber are preferred in the present invention, especially to reduce and/or delay crack formation under severe conditions, especially in the present invention where tension is generated not only by shrinkage but also by expansion and shrinkage during curing, for example.
The fibres may be coarse synthetic fibres and are used in an amount ranging from 1.5kg/m 3 to 9kg/m 3, for example from 2.5kg/m 3 to 7kg/m 3, for example from 3.5kg/m 3 to 5.0g/m 3.
The fibres are present in all parts of the concrete slab, i.e. the concrete slab is preferably an integral slab and the fibres are substantially evenly or uniformly distributed in the concrete slab. Thus, substantially uniform may mean, for example, that in addition to a very thin (preferably below 10mm, further preferably below 6 mm) upper skin layer, the upper skin layer is applied to provide a flat and wear-resistant surface to the plate and avoid fiber protrusion. This may in particular help for example to improve the die cutting shear. This means that the panel according to the invention thus comprises in particular no areas or parts of lower density, in particular no aggregation and/or aeration parts and/or no polymer-based insulation material, even more preferably no aggregation and/or aeration blocks and/or no polymer-based insulation material, which blocks and/or insulation material have a lower density (in particular compared to cast concrete). In an embodiment, the plate may preferably be cast in one or more steps, preferably in one step. The concrete slab in the sense of the invention can thus also be cast and/or completely cast, for example, also preferably during the day and/or once, whereby, in particular, the use or assembly of blocks or other concrete parts is not involved, for example. The concrete slab in the sense of the invention may also for example comprise only fibres and rear Zhang Gang strands as reinforcing elements, which may especially for example mean that the slab may be free of any other reinforcing elements, in particular other metal or steel reinforcing elements than fibres and rear Zhang Gang strands, in particular free of steel bars or rods, meshes, rods etc. The concrete slab in the sense of the invention comprises fibers and rear Zhang Gang strands. The concrete slab in the sense of the present invention may comprise a slipsheet, in particular e.g. a perforated slipsheet. On the other hand, the concrete slab in the sense of the invention may further for example be without a vapour barrier, in particular on the basis of the concrete slab, such that the slab preferably does not comprise a vapour barrier.
The fibre amount of 10kg/m 3 to 40kg/m 3 in the case of steel fibres and 1.5kg/m 3 to 9kg/m 3 in the case of crude synthetic fibres is low to medium compared to the prior art amounts of more than 40kg/m 3 or more than 9kg/m 3. Such low to moderate amounts may, for example, further allow the fibers to integrate in the concrete in a more uniform manner and promote mixing of the fibers in the concrete. In embodiments of the invention, the fibres may for example have a length of 10mm to 100mm, more preferably >10mm to 70mm, still more preferably >11mm and <65mm. This may also help for example good anchoring of the fibres in the concrete and/or limit crack size and/or allow self-repair. This may further contribute to the fibers being particularly useful in e.g. structural applications, wherein the fibers may contribute to the panel strength, in particular e.g. to resist bending and/or shear forces.
The concrete or expanded concrete may preferably have a characteristic compression cube strength or equivalent cylinder strength of 25N/mm 2 or more, preferably 28N/mm 2 or more, further preferably 30N/mm 2 or more. Thus, an expanded concrete in the sense of the present invention may also be, for example, a shrinkage-compensating concrete, which expands by approximately the same amount when cured as the concrete shrinks when cured. However, the expanded concrete in the sense of the present invention may preferably be an expanded concrete, also referred to as an easy-to-expand or self-expanding concrete, comprising a chemical agent that expands the concrete upon curing beyond the shrinkage of the concrete upon curing, such that the (overall) size of the concrete expansion upon curing of the concrete is at least >0%. This may allow the concrete slab according to the invention to be slightly self-tensioning due to its expansion, for example to reduce the risk of crack formation and/or to simplify installation, as it is no longer necessary for the staff to have to return to the site to perform the (initial) post-tensioning operation after casting, for example 2 to 5 days. More preferably, the concrete may be conventional concrete, wherein the strength of the conventional concrete is equal to or higher than the strength of the concrete of the C20/25 strength class defined in EN206 or equivalent national specification requirements, and less than or equal to the strength of the concrete of the C50/60 strength class defined in EN 206. These types of concrete are widely used. For the avoidance of doubt, self-compacting concrete is considered conventional concrete. In a preferred embodiment, the panel does not contain any further reinforcing elements other than steel fibres and rear Zhang Gang strands, such as steel bars or steel mesh or steel wire mesh, in particular there may be no steel bars at both the top and bottom, further preferably, for example, there may even be no steel bars at any support. The panel according to the invention can therefore be used particularly advantageously as a structural panel, in particular for example to contribute to the structural integrity of a building. Thus, the concrete slab according to the invention may especially have a thickness of, for example, between 4cm and 75cm, preferably between 5cm and 65cm, further preferably between 10cm and 55cm, further preferably between >10cm and <40cm, and/or have a width greater than the thickness and a length greater than the thickness. In one embodiment, the concrete slab according to the invention may in particular have a contour such as a cuboid. In one embodiment, the concrete slab according to the invention may, for example, have a cubic or cuboid profile, in particular, whereby preferably the total section modulus of inertia can be obtained according to the formula b.h 3/12, where "b" is the slab width and "h" is the slab thickness. In one embodiment, the panel according to the invention may be a panel wherein the compressive stress under the first stress is for example between 0.5N/mm 2 and 7N/mm 2, further preferably between 1N/mm 2 and 5N/mm 2, or between 5N/mm 2 and 100N/mm 2, preferably between 10N/mm 2 and 75N/mm 2, further preferably between 15N/mm 2 and 50N/mm 2.
In one embodiment of the invention, the expanded concrete may contain one or more of the following additives: caO, mgO, caSO 4 or any other additive that causes expansion of the concrete during curing of the concrete. Such additives may also be referred to as expansion admixtures or shrinkage reducers. In one embodiment of the invention, the expanded concrete may contain one or more of the following additives: caO, mgO, caSO 4 or any other additive that causes expansion of the concrete during curing of the concrete, the amount of these additives being between 5kg/m 3 and 35kg/m 3 of the concrete or of the expanded concrete, preferably for example between 10kg/m 3 and 30kg/m 3 of the concrete or of the expanded concrete, further preferably between 15kg/m 3 and 25kg/m 3 of the concrete or of the expanded concrete. The expanded concrete may be obtained, for example, using limestone and clay on the one hand and limestone, calcium sulfate and bauxite on the other hand, whereby, in particular, for example, sulfoaluminates may be formed, the volume of which may expand when exposed to water and the concrete cures. Thus, an expanded concrete in the sense of the present invention is preferably not a concrete comprising only expanded material, in particular for example expanded clay, but may for example be expanded overall by at least >0%, in particular when the concrete is cured. This may allow the concrete slab according to the invention to be slightly self-tensioning due to its expansion, for example to reduce the risk of crack formation and/or to simplify installation, as it may no longer be necessary for the staff to have to be returned to site for (initial) post-tensioning operations after casting, for example for 2 to 5 days.
In an embodiment of the invention, the plate or plate may expand, for example, between-5% and 5%, preferably between-2.5% and more preferably between-2.5% and 2.5% during the first 168 hours of curing, further preferably between-1.5% and 1.5%, further preferably between-0% and >0% during the first 168 hours of curing, further preferably between-0.5% and 1.5%, further preferably between-0.5% and > 0.5% during the first 168 hours of curing, further preferably between-0.1% and 0.1% during the first 168 hours of curing, further preferably between-0.07% and 0.07% or > 0.04% during the first 168 hours of curing, further preferably between-0.05% and < 0.07% and 0.05% during the first 168 hours of curing, further preferably between-0.0.04% and 0.0.0% during the first 168 hours of curing, further preferably between-0.05% and 0.04% during the first 168 hours of curing. In one embodiment, the tensile stress in the strands of the panel may be, for example, between 50MPa and 900MPa during the first 168 hours of curing, preferably between 100MPa and 650MPa during the first 168 hours of curing. Thus, the tensile stress mentioned above is a total tensile stress preferably corresponding to, for example, an initial tensile stress and an additional tensile stress related to the expansion of the elongated strand. This may further help to allow the concrete slab according to the invention to be slightly self-tensioned due to its expansion, in particular when the dimensions of the slab expand >0%, for example, thus reducing the risk of crack formation and/or simplifying installation, as it may no longer be necessary for the staff to have to be returned to site for (initial) post-tensioning operations after casting, for example 2 to 5 days.
In a preferred embodiment of the invention, the fibers are steel fibers and have a straight middle portion and anchored ends at both ends. The steel fibers may thereby particularly contribute to good dispersion in and/or good compatibility with concrete, for example. The use of steel fibers alone or in particular in combination with post-tensioning, where compression may be applied, may also help, for example, limit crack size and/or allow self-healing. Furthermore, the use of steel fibers may also help to form irregular cracks, delay moisture propagation, for example, and thus help to improve the durability of the panel. The steel fibers may also have a high tensile strength and/or a high modulus of elasticity and/or a high shear resistance, which may make the steel fibers particularly suitable for e.g. structural applications, wherein the steel fibers may contribute to the plate strength, especially e.g. against bending stresses and/or shear forces.
Most preferably, the tensile strength of the intermediate portion is above 1400MPa, preferably above 1500MPa, preferably above 1600MPa, preferably above 1700MPa, further preferably above 1900MPa, even further preferably above 2000MPa, even further preferably above 2200MPa, preferably between 1400MPa and 3500 MPa.
Preferably, the anchor ends each comprise three or four bending sections. Examples of such steel fibers are disclosed in EP-B1-2652221 and EP-B1-2652222. These steel fibers may be particularly useful in view of their good dosage/performance ratio, especially in combination with post-tensioning as in the present invention, so that they may contribute to achieving good performance at relatively moderate dosages, especially with respect to crack control, for example.
In an embodiment of the invention, the plate may rest on the ground or on at least two supports. In embodiments of the invention, the support may be a part of the foundation, preferably below the slab, and/or away from the foundation, or preferably the support may not be a part of the foundation. If the supports are part of a building foundation they may preferably be in contact with soil or the ground. On the other hand, in case the support is not part of the building foundation, the panels may preferably be so-called overhead panels, which may especially be part of a multi-storey building above or below ground. Thereby, the elevated plate and/or its support may preferably not be in contact with the soil or the ground, preferably the elevated plate (as compared to a plate laid on the ground) may thus also not be supported evenly along the plate, but rather precisely at the support. Thus, it is particularly advantageous that the panel according to the invention can be used as or act as a structural panel, in particular for example contributing to the structural integrity and structural resistance of a building. In contrast, the panels laid on the ground do not act as, for example, structural panels. Thus, the plate according to the invention may preferably be a high frame plate, for example as a structural plate.
In embodiments of the invention, the support may be a concrete support, a masonry support, a steel support or a support of composite concrete, masonry and/or steel.
In an embodiment of the invention, the support may comprise a column, a wall, a pile or a beam or any combination thereof or any other element acting as a vertical support, wherein further such a support may be in particular a point support, a linear support or a zone support.
In the present invention, the rear Zhang Gang strands may be pleated, i.e. they are positioned, for example, to relieve as much as possible of the tensile stress in the concrete, so that above the supports they are located in the upper half of the concrete slab and between the supports they are located in the lower half of the concrete slab.
In embodiments of the present invention, the rear Zhang Gang strands may be of a ribbon-ribbon steel strand construction or a ribbon-distributed steel strand construction or a construction resulting from any combination thereof, and/or the rear Zhang Gang strands may be arranged in any construction, preferably without any maximum and/or minimum spacing requirements, and/or the rear Zhang Gang strands may be used for bonded or unbonded rear tensioning, and/or the anchors for the rear Zhang Gang strands may be designed as described in, for example, patent application US 63/052,283, in order to reduce bursting behind the rear tensioning anchors during or after rear tensioning, and/or wherein the fibers are substantially evenly or uniformly distributed in the panel. The ribbon-like or ribbon-like configuration of the steel strands may thus allow the retention plate to be less affected by the steel strands, allowing for greater design freedom or safe drilling through the plate, for example. Thus, post-bond tensioning may use bonding strands that may be bonded to the concrete of the panel, for example, using cement paste, so that the integrity of the anchoring structure may be maintained by bonding even in the event of a problem. Alternatively, the unbonded post-tensioned strands may be provided with plastic cloth and not attached to the concrete of the panel.
The supports may be arranged in a regular rectangular pattern or quadrilateral shape, wherein a set of four supports or a set of four supports form a quadrilateral shape. The concrete slab comprises straight areas at the support, which connect the support in both directions (i.e. in the length direction and width direction) by the shortest distance between those areas of the concrete slab above the support. The width of the straight region may vary between 0% and 80%, for example between 5% and 50% of the maximum cross-sectional dimension in the width direction of the plate between the two supports. The rear Zhang Gang strands are present in bundles in these straight regions. The presence of post-tensioned steel strands in the straight regions is commonly referred to as a banding pattern. The rear Zhang Gang strands may or may not be outside of the straight region.
In one embodiment, the support may be arranged to form a regular rectangular pattern or quadrilateral shape, the concrete slab comprising straight areas connecting the support in both directions (i.e. longitudinal and transverse) by means of a shortest distance, the post-tensioned steel strands being present only in closely spaced arrangement in said straight areas, wherein, for example, in a so-called ribbon-ribbon configuration, the maximum distance between the strands may not exceed 0.8m, and/or the support may be arranged to form a regular rectangular pattern or quadrilateral shape, the concrete slab comprising straight areas connecting the support in both directions (i.e. longitudinal and transverse) by means of a shortest distance, the post-tensioned steel strands in any or both directions being present in and/or outside said straight areas with a larger spacing, for example, in a so-called distributed or ribbon-distributed configuration, the maximum distance between the strands may exceed 1.5m. Thus, the bundles may be closely spaced arrangements wherein two or more individual strands may be arranged in close proximity to each other to form a bundle, whereby preferably the maximum distance between individual strands of the bundle may be <0.8m, further preferably <0.25m. Because individual strands may be rarely used, but may be used more frequently as part of a bundle, strands and bundles may be used interchangeably (or as synonyms) in the present invention. The ribbon-distributed configuration is thereby achieved by arranging the strands in a closely spaced arrangement in one direction (e.g., transverse) and in another, large spacing arrangement in the other direction (e.g., longitudinal). Thus, the strands or strands bundles may be arranged in particular, for example, in an arrangement selected from: a bi-directional distribution arrangement, a unidirectional tape and unidirectional hybrid arrangement, wherein the hybrid arrangement comprises strands or bundles in a tape and distribution arrangement, a bi-directional tape arrangement, a unidirectional tape and unidirectional hybrid arrangement, wherein the hybrid arrangement comprises strands or bundles in a tape and distribution arrangement, a bi-directional hybrid arrangement, wherein the hybrid arrangement comprises strands or bundles in a tape and distribution arrangement.
In one embodiment, the plate and any support may be permanently fully connected such that the plate cannot be freely moved from its support, permanently fully disconnected such that the plate can be freely moved, partially connected such that the plate is partially freely moved in some direction or temporarily disconnected such that the plate is at least temporarily free to move until connected in place. Thus, disconnection or partial connection may allow for, for example, a reduction in shortening the restraining force that may occur upon shrinkage and may result in large cracks. For example, for very stiff or very long plates, such as due to shrinkage of the concrete, due to elastic shortening in connection with post-tensioning, due to creep of the concrete or due to temperature changes, such plates are particularly susceptible to shortening restraining forces, and thus disconnection or partial connection may be particularly useful. On the other hand, the connection may help to support higher loads, especially for example seismic loads.
In one embodiment, the span of a plate of a given thickness is increased by between 5% and 50%, preferably between 10% or 40%, or between 15% and 35%, further preferably at least 5%, 15%, 20%, 25% or 30%, compared to a plate of the same plate thickness but without fibers and rear Zhang Gang strands, and/or the thickness of a plate of a given span between two supports is reduced by between 5% and 50%, preferably between 10% or 40%, or between 15% and 35%, further preferably at least 5%, 15%, 20%, 25% or 30%, compared to a plate of the same span but without fibers and rear Zhang Gang strands.
In one embodiment, the amount of concrete for a given thickness or span may be reduced by between 5% and 50%, preferably between 10% or 40%, or between 15% and 35%, more preferably at least 5%, 15%, 20%, 25% or 30%, compared to a panel without fibers and rear Zhang Gang strands.
In one embodiment, the present invention, particularly the combination of, for example, rear Zhang Gang strands and fibers, may help to increase the structural ability to bend, deflect, shear, punching shear, temperature and/or shrink resistance as compared to a panel without steel fibers and/or steel strands. Thus, the present invention can in particular facilitate increasing the die cutting shear by, for example, 10% to 100%, preferably 20% to 60%, compared to embodiments not according to the present invention. The combination may replace partly or entirely any other form of steel reinforcement and/or partly or entirely excessive thickening measures at the support, such as a drop-in cover or a drop-in panel.
The invention further comprises a method of obtaining a concrete slab according to the invention, comprising:
casting a concrete slab comprising concrete and a rear Zhang Gang strand and fiber composite reinforcement,
The rear Zhang Gang strand has a diameter in the range of 5mm to 20mm,
The tensile strength is higher than 1700MPa,
The fibers are steel fibers and are used in an amount ranging from 10kg/m 3 to 75kg/m 3, or coarse synthetic fibers and are used in an amount ranging from 1.5kg/m 3 to 9.0kg/m 3,
Wherein the concrete is an expanded concrete, and
-Applying a tensile stress in the rear Zhang Gang strands of between 5% and 15% of the final stress within the first 24 hours after casting the panel.
Detailed Description
Explanation of the principles of the invention
Concrete is a very brittle material that is difficult to resist tensile stresses in order to avoid or at least reduce the presence of tensile stresses.
Fig. 1 shows a schematic longitudinal cross section of a panel (1) according to the invention with expanded concrete (2) and rear Zhang Gang strands (3) (fibers not shown in this schematic view), the panel having a length (4) and a thickness (5), whereby the rear Zhang Gang strands (3) exert a compressive stress (6, arrows) and the expanded concrete (2) expands as indicated by the arrows (7).
In some embodiments, the rear Zhang Gang strands may also be disposed in the middle of the panel.
However, no location can ensure that there is no tensile stress at all. In the context of the present invention, the rear Zhang Gang strand can therefore be specifically designed, for example, to absorb and compensate for tensile stresses which occur during the hardening and shrinkage of concrete in addition to the applied load. The rear Zhang Gang strand may, for example, have a sufficiently high tensile strength, i.e. above 1700MPa or even above 1800 MPa.
The fibres are mixed as uniformly as possible in the concrete so that the fibres can preferably be present over the whole volume of the panel and can withstand tensile stresses caused by various loads.
In a second embodiment of the invention, a concrete slab is formed on a support. A slipsheet may or may not be present between the support and the plate.
Rear Zhang Gang stranded wire
A typical rear Zhang Gang strand may have, for example, a 1+6 structure, in which one core wire and six layers of wires wound around the core wire. In one embodiment, the rear Zhang Gang strands may be in non-compacted form.
In an alternative preferred embodiment, the rear Zhang Gang strands may be in compacted form. In this compacted form, the six-layer wire no longer has a circular cross section, but a cross section in the form of a trapezoid with rounded edges. The compacted Zhang Gang strands have fewer voids and a higher steel content per cross-sectional area.
As described above, the rear Zhang Gang strands may have a high yield point, i.e., a high yield force at 0.1% elongation. The ratio of the yield force F p0.1 to the breaking force F m is higher than 75%, preferably higher than 80%, for example higher than 85%.
Typical steel compositions for the post Zhang Gang strand are a minimum carbon content of 0.65%, a manganese content ranging from 0.20% to 0.80%, a silicon content ranging from 0.10% to 0.40%, a maximum sulphur content of 0.03%, a maximum phosphorus content of 0.30%, the balance being iron, all percentages being by weight. Most preferably, the carbon content is higher than 0.75%, for example higher than 0.80%. The content of other elements such as copper or chromium may not exceed 0.40%.
All steel wires may be provided with a metal coating, such as zinc or zinc-aluminium alloy. Zinc aluminum coatings have better overall corrosion resistance than zinc. Zinc aluminum coatings have a temperature resistance compared to zinc. In contrast to zinc, zinc-aluminum alloys do not flake off when exposed to high temperatures.
The zinc aluminum coating may have an aluminum content ranging from 2% to 12% by weight, for example, an aluminum content ranging from 3% to 11%.
The preferred components are located near the eutectoid site: al is about 5%. The zinc alloy coating may also have a wetting agent, such as lanthanum or cerium, in an amount of less than 0.1% of the zinc alloy. The remainder of the coating is zinc and unavoidable impurities.
Another preferred composition contains about 10% aluminum. This increased amount of aluminum provides better corrosion protection than eutectoid compositions having about 5% aluminum.
Other elements such as silicon (Si) and magnesium (Mg) may be added to the zinc-aluminum coating. In order to optimize the corrosion resistance, particularly good alloys contain 2% to 10% aluminum and 0.2% to 3.0% magnesium, the remainder being zinc. For example 5% Al, 0.5% Mg, the remainder being Zn.
An example of a rear Zhang Gang strand is as follows:
-diameter 15.2mm;
-steel section 166mm 2;
modulus of elasticity: 196000MPa;
-breaking load F m: 338000N;
Yield force F p0.1: 299021N;
-tensile strength R m 2033MPa.
Steel fiber
Steel fibers suitable for use in the present invention typically have a middle portion with a diameter D in the range of 0.30mm to 1.30mm (e.g., 0.50mm to 1.1 mm). The length of the steel fibers is l, and thus the aspect ratio l/D ranges from 40 to 100.
Preferably, the steel fibers have ends that improve anchoring in the concrete. These ends may be in the form of bent sections, flat sections, undulations or thickened sections. Most preferably, the end portions are in the form of three or more bending sections. In one embodiment, the steel fibers may be glued.
Fig. 2 shows a preferred embodiment of the steel fibre (8). The steel fibers (8) have a straight middle portion (9). One end of the middle part (9) is provided with three bending sections (10), (11) and (12). The other end of the intermediate portion (9) also has three bending sections (10 '), (11 ') and (12 '). The bending sections (10), (10') form an angle (a) with respect to the line forming the extension of the intermediate section (9). The bending sections (11, 11 ') form an angle (b) with respect to a line forming the extension of the bending sections (10, 10'). The bending sections (12), (12 ') form an angle (c) with respect to the bending sections (11), (11').
The length l of the steel fibres (8) may be in the range between 50mm and 75mm and is typically 60mm.
The diameter of the steel fibers may be between 0.80mm and 1.20 mm. Typical values are 0.90mm or 1.05mm.
The length of the bending sections (10), (10 '), (11 '), (12) and (12 ') may range between 2.0mm and 5.0 mm. Typical values are 3.2mm, 3.4mm or 3.7mm.
The angles (a), (b) and (c) may be in the range between 20 ° and 50 °, for example between 24 ° and 47 °.
The steel fibers may or may not be provided with a corrosion resistant coating such as zinc or zinc-aluminum alloy.
In a particularly preferred embodiment of the steel fibre, the intermediate portion has four bending sections at each end.
In another particularly preferred embodiment of the steel fibre, the maximum load elongation of the intermediate portion is higher than 4%, for example higher than 5%, for example higher than 5.5%. Steel fibers with such high elongation at maximum load are useful in structural applications such as pile floors, overhead systems, and structural wall systems.
Coarse synthetic fiber
Examples of coarse synthetic fibers may be selected from carbon fibers, glass fibers, basalt fibers or other non-steel based fibers, such as fibers based on polyolefins (e.g. polypropylene or polyethylene) or based on other thermoplastics.
Example
Length of panel or distance between two seams: 100m
Distance between two strands: 2m
Plate thickness: 160mm
Initial stress applied during the first 24 hours:
10% = 186MPa of final stress 1860MPa
Strand size: 15.2mm (area 140mm 2)
Tension applied to the strand: 186N/mm 2*140mm2 = 26.040N
Compressive stress exerted on concrete: tensile force exerted on the strand = 26040/concrete cross section = 2000mm x 140mm = 0.09N/mm 2
When the panel expands 0.5mm/m within 7 days or 168 hours and the length of the panel is 100m, the panel expands 50mm within 7 days.
Initial stress applied to the strands was 186N/mm 2
The additional stress resulting from expansion of 50mm resulted in elongation of the steel and was calculated as follows:
additional stress = tensile strength of steel strand (200000N/mm 2) ×expansion (50 mm)/plate length (100000 mm) = 200000N/mm 2*50mm/100000mm＝100N/mm2
Thus, the total stress after 7 days is the initial stress (186 MPa or N/mm 2) +additional stress (100N/mm 2) =186+100=total tensile stress 286N/mm 2 in post-Zhang Jiaoxian after 7 days.
Claims (15)
1. A concrete slab comprising concrete and a rear Zhang Gang strand and fiber composite reinforcement,
The rear Zhang Gang strand has a diameter in the range of 5mm to 20mm,
The tensile strength is higher than 1700MPa,
The fibers are steel fibers and are used in an amount ranging from 10kg/m 3 to 75kg/m 3, or coarse synthetic fibers and are used in an amount ranging from 1.5kg/m 3 to 9.0kg/m 3,
Wherein the concrete is an expanded concrete.
2. The concrete slab of claim 1,
Wherein a tensile stress of between 5% and 15% of the final stress can be applied by the rear Zhang Gang strands within the first 24 hours after casting the panel, and/or wherein the concrete has a characteristic compressive cube strength of 25N/mm 2 or higher, preferably 28N/mm 2 or higher, further preferably 30N/mm 2 or higher, and/or wherein the compressive stress at the first pressurization is between 0.5N/mm 2 and 7N/mm 2, further preferably between 1N/mm 2 and 5N/mm 2, or between 5N/mm 2 and 100N/mm 2, preferably between 10N/mm 2 and 75N/mm 2, further preferably between 15N/mm 2 and 50N/mm 2, and/or wherein the expanded concrete can comprise one or more additives selected from the group consisting of: caO, mgO, caSO 4 or any other additive capable of causing expansion of the concrete during curing of said concrete, and/or wherein
The expanded concrete can comprise one or more additives selected from the group consisting of: caO, mgO, caSO 4 or any other additive capable of causing expansion of the concrete during curing of said concrete, said additive being in an amount between 5kg/m 3 and 35kg/m 3 of the concrete or of the expanded concrete, preferably between 10kg/m 3 and 30kg/m 3 of the concrete or of the expanded concrete, further preferably between 15kg/m 3 and 25kg/m 3 of the concrete or of the expanded concrete, and/or wherein the dimensions of said panel or said panel are expanded between-5% and 5% during the first 168 hours of curing, preferably between 0% or >0% and 5% during the first 168 hours of curing, further preferably between-2.5% and >0% during the first 168 hours of curing, further preferably between 0% or >0% and 2.5% during the first 168 hours of curing, further preferably between-1.5% and 1.5% during the first 168 hours of curing, further preferably between-0% and 0.07% and 0% during the first 168 hours of curing, further preferably between 0% and 0.07% and 0% and 0% 0.5% during the first 168 hours of curing, further preferably between-0% and 0.07% and 0% and > 0.5% during the first 168 hours of curing, further preferably between-0% and 0.5% between 0% and 0% 5% during the first 168 hours of curing, it is further preferred that between 0% or >0% and 0.05% expansion during the first 168 hours of curing, it is further preferred that between > 0.05% and <0.05% expansion during the first 168 hours of curing, it is further preferred that between-0.04% and 0.04% expansion during the first 168 hours of curing, it is further preferred that between > 0.04% or >0% and <0.04% expansion during the first 168 hours of curing, and/or wherein the tensile stress in the strands of the sheet is between 50MPa and 900MPa during the first 168 hours of curing, preferably between 100MPa and 650MPa during the first 168 hours of curing, and/or wherein the sheet does not comprise any further reinforcing elements, such as steel bars or steel mesh, other than steel fibers and rear Zhang Gang strands, and/or wherein the sheet is cast in one or more steps.
3. The concrete slab of claim 1 or claim 2,
Wherein the fibers are steel fibers, and/or wherein the fibers are glued, and/or wherein the coarse synthetic fibers can be selected from carbon fibers, glass fibers, basalt fibers or other non-steel based fibers, preferably polyolefin fibers, further preferably polypropylene fibers or polyethylene fibers, and/or wherein the amount of steel fibers is in the range of 10kg/m 3 to 45kg/m 3, preferably 10kg/m 3 to 40kg/m 3, or ≡25 to 75kg/m 3, preferably >40kg/m 3 to 60kg/m 3 or 65kg/m 3, further preferably 15kg/m 3 to 40kg/m 3, further preferably >20kg/m 3 to <40kg/m 3, preferably 15kg/m 3 to 35kg/m 3, preferably 20kg/m 3 to 30kg/m 3 or 10kg/m 3 to < 30kg/m 3 or further preferably 10kg/m 3 to 27kg/m 3, and wherein the amount of steel used is equal to or less than 1.1 times, preferably equal to or more than 1.1 times the amount of steel used, and preferably equal to 2 times the amount of steel bars used, and preferably equal to or less than 1 times the amount of steel bars used.
4. The concrete slab of any one of the preceding claims,
Wherein the steel fibers comprise a straight intermediate portion having a tensile strength above 1400MPa, preferably above 1500MPa, preferably above 1600MPa, preferably above 1700MPa, further preferably above 1900MPa, even further preferably above 2000MPa, even further preferably above 2200MPa, preferably between 1400MPa and 3500 MPa.
5. The concrete slab of any one of the preceding claims,
Wherein the steel fiber comprises anchoring ends at both ends,
The anchoring ends each comprise three or four bending sections, and/or
Wherein the elongation capacity of the steel fibers is between 2.5% and 12%, preferably at least 2.5%, preferably at least 3.5%, further preferably at least 4.5%, even more preferably at least 5.5%, and/or
Wherein the slab comprising steel fibre concrete is strain hardened when bent.
6. The concrete slab of any one of the preceding claims,
Wherein the steel fibres are used in the panel in an amount in the range of ≡25kg/m 3 to 60kg/m 3 or 65kg/m 3, preferably 20kg/m 3 to 30kg/m 3, or >40kg/m 3 to 60kg/m 3 or 65kg/m 3, and/or wherein the fibres have a length of 10mm to 100mm, more preferably >10mm to 70mm, even more preferably >11mm and <65mm.
7. The concrete slab of any one of the preceding claims,
Wherein the support is a concrete support, a masonry support, a steel support or a support of combined concrete, masonry and/or steel, and/or
Wherein the support is part of the foundation, or preferably the support is not part of the foundation, and/or wherein the concrete slab has a uniform average density, and/or wherein the concrete slab is cast once and/or fully cast throughout the day, and/or wherein the concrete slab comprises only fibres and rear Zhang Gang strands as reinforcing elements, and/or wherein the concrete slab has no vapour barrier, and/or wherein the thickness of the concrete slab is for example between 4cm and 75cm, preferably between 5cm and 65cm, further preferably between 10cm and 55cm, further preferably between >10cm and <40cm, and/or the concrete slab has a width greater than the thickness and/or a length greater than the thickness.
8. A concrete slab according to any one of the preceding claims, wherein the support may comprise a column, a wall, a pile or a beam or any combination thereof or any other element acting as a vertical support, wherein further such a support may in particular be a point support, a linear support or a zone support, and/or wherein tension is applied to the rear Zhang Gang strands only after the concrete has been cast and once the concrete has fully cured/hardened, the rear Zhang Gang strands remain in place, and/or wherein the tensile strength of the rear Zhang Gang strands is higher than 1800MPa, preferably higher than 1900MPa, preferably higher than 2000MPa, further preferably between 1800MPa and 4000MPa, and/or wherein the maximum breaking load of the rear Zhang Gang strands is higher than 190kN, preferably higher than 195kN, preferably higher than 200kN, further preferably between 195kN and 350kN, and/or wherein the rear Zhang Gang comprises an anchoring system and/or a pipe or sheath.
9. The concrete slab of any one of the preceding claims,
Wherein the concrete slab further comprises a plastic slipsheet between the concrete slab and the support, in particular at the contact point between the slab and the support, or there is no plastic slipsheet between the slab and the support.
10. The concrete slab of any one of the preceding claims,
-Wherein the rear Zhang Gang strand is of a ribbon-ribbon strand construction or a ribbon-distributed strand construction or a construction resulting from any combination thereof, and/or
Wherein the rear Zhang Gang strands can be arranged in any configuration, preferably without any maximum and/or minimum spacing requirements,
-Wherein the rear Zhang Gang strand is used for bonded or unbonded post-tensioning, and/or
Wherein the anchor for the post Zhang Gang strand is designed to reduce bursting behind the post-tensioned anchor during or after post-tensioning, and/or
-Wherein the fibres are substantially uniformly or homogeneously distributed in the plate.
11. The concrete slab of any one of the preceding claims,
Wherein the plate and the support are permanently fully connected such that the plate cannot be freely moved from its support, or permanently fully disconnected such that the plate is freely moved, or partially connected such that the plate is partially freely moved or temporarily disconnected in certain directions such that the plate is at least temporarily freely moved.
12. The concrete slab of any one of the preceding claims,
-The support members are arranged to form a regular rectangular pattern or quadrilateral shape, the concrete slab comprising straight areas connecting the support members by a shortest distance in two directions, longitudinal and transverse, the post-tensioned steel strands being present in a closely spaced arrangement only in the straight areas, wherein the maximum distance between the strands does not exceed 1.5m, and/or
-The support is arranged to form a regular rectangular pattern or quadrilateral shape, the concrete slab comprising straight areas connecting the support by a shortest distance in two directions, longitudinal and transverse, wherein post-tensioned steel strands in one direction are present outside the straight areas with a large spacing, wherein the maximum distance between the strands exceeds 1.5m.
13. The concrete slab of any one of the preceding claims,
Wherein the span of the panel of a given thickness between two supports is increased by between 5% and 50%, preferably between 10% and 40% or between 15% and 35%, further preferably by at least 5%, 15%, 20%, 25% or 30%, and/or compared to a panel of the same panel thickness but without fibres and rear Zhang Gang strands
Wherein the thickness of the panel at a given span between two supports is reduced by between 5% and 50%, preferably between 10% and 40% or between 15% and 35%, more preferably by at least 5%, 15%, 20%, 25% or 30%, and/or compared to a panel having the same span but without fibers and rear Zhang Gang strands
The amount of concrete can be reduced by between 5% and 50%, preferably between 10% and 40%, or between 15% and 35%, more preferably at least 5%, 15%, 20%, 25% or 30%, and/or for a given panel thickness or a given span compared to a panel without fibers and rear Zhang Gang strands
The combination of the rear Zhang Gang strands and the fibers increases the structural capacity of bending, deflection, shearing, punching, structural integrity, temperature resistance, and/or shrinkage resistance as compared to a panel without steel fibers and/or steel strands.
14. A method of obtaining a concrete slab according to any one of claims 1 to 13.
15. The method of claim 14, comprising:
Casting a concrete slab comprising concrete and a rear Zhang Gang strand and fiber composite reinforcement,
The rear Zhang Gang strand has a diameter in the range of 5mm to 20mm,
The tensile strength is higher than 1700MPa,
The fibers are steel fibers and are used in an amount ranging from 10kg/m 3 to 75kg/m 3, or coarse synthetic fibers and are used in an amount ranging from 1.5kg/m 3 to 9.0kg/m 3,
Wherein the concrete is an expanded concrete, and
-Applying a tensile stress in the rear Zhang Gang strand of between 5% and 15% of the final stress within the first 24 hours after casting the panel.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP21250006.0 | 2021-09-29 | ||
| EP21250006 | 2021-09-29 | ||
| PCT/EP2022/077114 WO2023052502A1 (en) | 2021-09-29 | 2022-09-29 | Post-tensioned expanding concrete with fibers for slabs |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118043525A true CN118043525A (en) | 2024-05-14 |
Family
ID=78179342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280066082.2A Pending CN118043525A (en) | 2021-09-29 | 2022-09-29 | Rear Zhang Pengzhang concrete slab with fibers |
Country Status (5)
| Country | Link |
|---|---|
| CN (1) | CN118043525A (en) |
| AU (1) | AU2022354113A1 (en) |
| CO (1) | CO2024004802A2 (en) |
| IL (1) | IL311779A (en) |
| WO (1) | WO2023052502A1 (en) |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1633219A (en) | 1926-12-17 | 1927-06-21 | George C Martin | Method of forming pipe |
| US3429094A (en) | 1965-07-07 | 1969-02-25 | Battelle Development Corp | Two-phase concrete and steel material |
| US3500728A (en) | 1966-11-08 | 1970-03-17 | Battelle Development Corp | Concrete construction and roadways |
| US3900667A (en) | 1969-09-12 | 1975-08-19 | Bekaert Sa Nv | Reinforcing wire element and materials reinforced therewith |
| BE791262A (en) | 1971-11-11 | 1973-03-01 | Battelle Development Corp | IMPROVEMENTS IN CONCRETE CONSTRUCTION ELEMENTS |
| NL173433C (en) | 1973-04-16 | Bekaert Sa Nv | ||
| BE1009638A3 (en) | 1995-09-19 | 1997-06-03 | Bekaert Sa Nv | STEEL WIRE ELEMENT FOR MIXING IN POST-CURING MATERIALS. |
| MY118701A (en) * | 1997-02-12 | 2005-01-31 | Bekaert Sa Nv | Combination reinforcement for floor on piles |
| EP0964113A1 (en) * | 1998-06-11 | 1999-12-15 | N.V. Bekaert S.A. | Combination reinforcement for floor on piles |
| BE1014155A3 (en) | 2001-05-04 | 2003-05-06 | Bekaert Sa Nv | METHOD FOR DOSING OF REINFORCING FIBRE IN THE MANUFACTURE OF APPLIED THEREBY vibrated and CHAIN BOX. |
| BE1021496B1 (en) | 2010-12-15 | 2015-12-03 | Nv Bekaert Sa | STEEL FIBER FOR ARMING CONCRETE OR MORTAR, WITH AN ANCHORING END WITH AT LEAST TWO CURVED SECTIONS |
| BE1021498B1 (en) | 2010-12-15 | 2015-12-03 | Nv Bekaert Sa | STEEL FIBER FOR ARMING CONCRETE OR MORTAR, WITH AN ANCHORING END WITH AT LEAST THREE STRAIGHT SECTIONS |
| US9909307B2 (en) * | 2015-04-23 | 2018-03-06 | Hughes General Contractors | Joint-free concrete |
| RU2643055C1 (en) * | 2016-11-02 | 2018-01-30 | Экокон Технолоджис ДМСС | Three-layer bearing panel manufacturing method |
| CN113250364A (en) * | 2020-04-02 | 2021-08-13 | 中国铁路设计集团有限公司 | Large-span underground structure hollow box type steel reinforced concrete beam slab and manufacturing method thereof |
-
2022
- 2022-09-29 AU AU2022354113A patent/AU2022354113A1/en active Pending
- 2022-09-29 CN CN202280066082.2A patent/CN118043525A/en active Pending
- 2022-09-29 WO PCT/EP2022/077114 patent/WO2023052502A1/en active Application Filing
- 2022-09-29 IL IL311779A patent/IL311779A/en unknown
-
2024
- 2024-04-17 CO CONC2024/0004802A patent/CO2024004802A2/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| IL311779A (en) | 2024-05-01 |
| AU2022354113A1 (en) | 2024-03-28 |
| CO2024004802A2 (en) | 2024-04-18 |
| WO2023052502A1 (en) | 2023-04-06 |
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