UHPC (Ultra High Performance Concrete) rib prestress laminated slab

Abstract

The invention relates to the field of concrete laminated slabs, in particular to a UHPC rib prestressed laminated slab which comprises a concrete substrate, UHPC reinforcing ribs and prestressed reinforcements. The concrete base plate comprises a bottom layer, a cavity layer located above the bottom layer and a top layer located above the cavity layer, and a cavity extending in the span direction of the concrete base plate is formed in the cavity layer. The UHPC reinforcing ribs are connected to the upper portion of the top layer in an extending mode in the span direction, and the compressive strength of a concrete material adopted by the UHPC reinforcing ribs is larger than that of a concrete material adopted by the concrete base plate. Prestressed steel bars are embedded in the bottom layer in the span direction in an extending mode. According to the UHPC rib prestress laminated slab, the self weight can be fully reduced, the bending resistance, shearing resistance and anti-cracking capacity can be guaranteed, and the requirements for structural safety and light weight can be met at the same time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building engineering, and particularly relates to a UHPC rib prestressed composite slab. BACKGROUND

[0002] In the development process of building industrialization and green construction technology, the fabricated concrete system has been widely used in floor slab structures of residential buildings, public buildings and industrial plants due to high on-site construction efficiency, less wet work and easy control of component quality. The composite slab as the core stressed component of the fabricated floor slab has become the core direction of industry technology optimization.

[0003] However, the concrete composite slab in the related art often needs to be thick and heavy, which is not convenient for carrying and assembling to the construction site. If the concrete slab is reduced in weight by setting a cavity and reducing the thickness, the bending and shearing resistance and crack prevention ability of the reduced concrete slab are weakened, and the structural safety and lightweight requirements cannot be considered. SUMMARY

[0004] The purpose of the present application is to provide a UHPC rib prestressed composite slab which not only has low self-weight, but also has guaranteed bending and shearing resistance and crack prevention ability, and can consider the structural safety and lightweight requirements.

[0005] The UHPC rib prestressed composite slab of the present application comprises: a concrete base plate comprising a bottom layer, a cavity layer located above the bottom layer and a top layer located above the cavity layer; wherein the cavity layer is provided with a cavity extending along the span direction of the concrete base plate; a UHPC reinforcing rib connected above the top layer in the span direction, wherein the compressive strength of the concrete material used in the UHPC reinforcing rib is greater than the compressive strength of the concrete material used in the concrete base plate; and a prestressed steel bar buried in the bottom layer in the span direction.

[0006] According to some embodiments of the present application, the concrete base plate is provided with a splicing part for splicing in concave-convex matching.

[0007] According to some embodiments of the present application, the width of the splicing part gradually changes in the direction away from the concrete base plate.

[0008] According to some embodiments of the present application, the splicing part further comprises at least one of the following arrangements: (1) the upper and lower surfaces of the splicing part are flush with the upper and lower surfaces of the concrete base plate, and the width of the splicing part gradually decreases along the recessed / protruding direction of the splicing part; (2) the upper and lower surfaces of the splicing part are flush with the upper and lower surfaces of the concrete base plate, and the width of the splicing part gradually increases along the recessed / protruding direction of the splicing part; (3) the splicing part comprises a splicing groove recessed inward from the side surface, a splicing protrusion protruding outward from the side surface and spaced from the splicing groove, and a flat side part connected between the splicing groove and the splicing protrusion.

[0009] According to some embodiments of the present application, further comprising: a plurality of pre-buried lifting members fixed at the top layer at intervals to form a lifting area between the plurality of pre-buried lifting members.

[0010] According to some embodiments of the present application, the pre-buried lifting member further comprises at least one of the following arrangements: (1) implemented as a lifting steel reinforcement framework extending along the span direction; (2) comprising: an upper lifting steel reinforcement extending along the span direction; and a plurality of lower lifting steel reinforcement frameworks arranged at intervals along the extension direction of the upper lifting steel reinforcement, and each lower lifting steel reinforcement framework comprises a plurality of lower lifting steel reinforcements, the top ends of the plurality of lower lifting steel reinforcements are close to each other and fixed to the upper lifting steel reinforcement, and the bottom ends of the plurality of lower lifting steel reinforcements are away from each other and anchored to the top layer.

[0011] According to some embodiments of the present application, further comprising: a connecting steel reinforcement framework fixed between the UHPC reinforcing rib and the top layer.

[0012] According to some embodiments of the present application, the connecting steel reinforcement framework comprises: an upper connecting steel reinforcement extending along the span direction and fixedly connected to the bottom surface of the UHPC reinforcing rib; and a plurality of lower connecting steel reinforcement frameworks arranged at intervals along the extension direction of the upper connecting steel reinforcement, and each lower connecting steel reinforcement framework comprises a plurality of lower connecting steel reinforcements, the top ends of the plurality of lower connecting steel reinforcements are close to each other and fixed to the upper connecting steel reinforcement, and the bottom ends of the plurality of lower connecting steel reinforcements are away from each other and anchored to the top layer.

[0013] According to some embodiments of the present application, further comprising: at least one layer of steel mesh laid between the UHPC reinforcing rib and the top layer, and comprising a plurality of stress steel reinforcements passing through the connecting steel reinforcement framework; and / or at least another layer of steel mesh laid above the UHPC reinforcing rib.

[0014] According to some embodiments of the present application, the cavities are a plurality of cavities arranged at intervals to form a plurality of partition parts; and the prestressed steel reinforcements are a plurality of prestressed steel reinforcements corresponding to the plurality of partition parts one by one.

[0015] Advantages The UHPC rib prestressed composite slab of the present application is combined with the UHPC rib and the concrete base plate with built-in prestressed steel bars, which not only relies on the high strength and high toughness characteristics of the UHPC to guarantee the bending and shearing resistance of the composite slab, but also cooperates with the low-thickness bottom layer with prestressed steel bars to realize the self-weight reduction through the cavity formed by the concrete base plate, and the anti-cracking and anti-deflection capacity under large span can be guaranteed, which takes into account the structural safety and lightweight requirements.

[0016] (2) The UHPC rib prestressed composite slab of the present application has a width that gradually changes and a splicing part for concave-convex matching, which not only facilitates splicing, reduces the probability of splicing misalignment and is conducive to improving the bonding strength after splicing, but also forms a zigzag-shaped splicing joint that can form multiple turns, which is conducive to improving the integrity and impermeability of the joint part and eliminating the cracks and leakage hidden dangers that are prone to occur in traditional flat joints.

[0017] (3) The UHPC rib prestressed composite slab of the present application uses a hoisting steel framework as a pre-embedded hoisting part, which not only facilitates the UHPC rib prestressed composite slab, but also can be post-poured in the post-poured concrete layer to enhance the strength of the UHPC rib prestressed composite slab. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the UHPC rib prestressed composite slab of an embodiment of the present application.

[0019] Figure 2 is a top view of the UHPC rib prestressed composite slab of an embodiment of the present application.

[0020] Figure 3 is a side view of the UHPC rib prestressed composite slab of an embodiment of the present application.

[0021] Figure 4 is a schematic diagram of the UHPC rib prestressed composite slab of an embodiment of the present application when spliced with other concrete slabs.

[0022] Figure 5 is a side view of the UHPC rib prestressed composite slab of another embodiment of the present application.

[0023] REFERENCE NUMERALS: UHPC rib prestressed composite slab 100; concrete base plate 11; bottom layer 111; cavity layer 112; cavity 1121; separation part 1122; top layer 113; splicing part 114; splicing groove 1141; splicing convex part 1142; flat side part 1143; UHPC reinforcing rib 12; connecting steel framework 121; upper connecting steel 1211; lower connecting steel 1212; prestressed steel bar 13; Pre-buried hanging piece 14; upper hanging steel bar 141; lower hanging steel bar 142; Lower steel mesh 15; first lower stress steel bar 151; second lower stress steel bar 152; Upper steel mesh 16; first upper stress steel bar 161; second upper stress steel bar 162; Other concrete slab 900. DETAILED DESCRIPTION

[0024] The advantages and effects of the present application can be easily understood by those skilled in the art from the messages disclosed in the present application. The present application can also be implemented or applied by means of other different embodiments or modules, and the details in the present application can be modified or changed according to different viewpoints and application modules without departing from the spirit of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0025] The embodiments of the present application will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement the present application. The present application can be embodied in various different forms, and is not limited to the embodiments described herein.

[0026] In the description of the present application, the expressions of "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that the specific features, structures, materials or characteristics expressed in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics expressed can be combined in any one or a group of embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples expressed in the present application and the features of the different embodiments or examples without conflict.

[0027] In addition, the terms "first", "second" are only used for the purpose of expression, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a group" is two or more, unless otherwise specifically limited.

[0028] In order to clearly illustrate the present application, the devices irrelevant to the description are omitted, and the same or similar constituent elements throughout the description are assigned the same reference numerals.

[0029] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0030] While the terms first, second, etc., are used in some examples herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, module, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, modules, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0031] The technical terms used herein are for reference only to specific embodiments and are not intended to limit the scope of this application. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in the specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0032] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the message of the present invention, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0033] Concrete slab components in related technologies are often thick and heavy, making them inconvenient to transport and assemble to the construction site. Furthermore, when concrete slabs are made lighter by creating cavities and reducing their thickness, their bending and shear strength and crack resistance are weakened, making it impossible to balance structural safety and lightweight requirements.

[0034] Therefore, the UHPC ribbed prestressed composite slab of this application not only significantly reduces its self-weight but also ensures its bending and shear strength and crack resistance, thus balancing structural safety and lightweight requirements. It is understood that the UHPC ribbed prestressed composite slab described in this application is a prefabricated composite slab, manufactured in a factory and transported to the construction site to simplify construction procedures.

[0035] Figure 1 This is a structural schematic diagram of the UHPC ribbed prestressed composite slab according to an embodiment of this application. Figure 2 This is a top view of the UHPC ribbed prestressed composite slab according to an embodiment of this application. Figure 3 This is a side view of a UHPC ribbed prestressed composite slab according to an embodiment of this application.

[0036] See Figures 1 to 3 The UHPC rib prestressed composite slab 100 of this application embodiment includes a concrete substrate 11, UHPC reinforcing ribs 12 and prestressed steel bars 13.

[0037] Optionally, the concrete substrate 11 is a common concrete substrate 11 (NC substrate), which is precast using common concrete and serves as a foundation component. As an example, the common concrete is implemented as a concrete material with a compressive strength of 30~60MPa.

[0038] The concrete substrate 11 includes a bottom layer 111, a cavity layer 112 above the bottom layer 111, and a top layer 113 above the cavity layer 112. The cavity layer 112 contains a cavity 1121 extending along a first span direction of the concrete substrate 11. The cavity 1121 can significantly reduce the component's self-weight, reduce its own load, and save concrete material.

[0039] Optionally, there are multiple cavities 1121, and the multiple cavities 1121 are distributed at equal intervals along the second span direction of the concrete substrate 11 to achieve a sufficient reduction in self-weight.

[0040] Optionally, one of the first span direction and the second span direction is a shorter span direction (lateral) and the other is a longer span direction (longitudinal). Preferably, the first span direction is a shorter span direction and the second span direction is a longer span direction. It should be noted that when the UHPC rib prestressed composite slab 100 is used as a floor slab, it is necessary to ensure that the floor slab deflection is small under the design vertical load. Under the same vertical load, the deflection in the shorter span direction is smaller and the bending stiffness is higher. The cavity 1121 is arranged in the shorter span direction and is continuous, which can reduce the weakening of the overall stiffness. Moreover, the volume of a single cavity 1121 is small, and the purpose of weight reduction is achieved by utilizing the small cavity volume, thus avoiding excessive weakening of the bearing capacity. Of course, it is understood that in this application, the first span direction can also be a longer span direction and the second span direction can be a shorter span direction, which is also within the scope of protection of this application.

[0041] It is worth mentioning that the cavity 1121 not only serves to reduce weight but can also be filled with lightweight thermal and sound insulation materials. These materials fill the cavity 1121 to form a thermal and sound insulation section. For example, the thermal and sound insulation materials can be functional materials such as glass wool, extruded polystyrene board, or polyurethane foam. These functional materials provide thermal insulation, sound insulation, and are lightweight. Their placement within the cavity 1121 integrates the weight reduction, thermal insulation, and sound insulation functions of the UHPC ribbed prestressed composite slab 100, eliminating the need for an additional thermal and sound insulation layer and simplifying the construction process. Furthermore, the through-hole cavity 1121 facilitates the filling of lightweight and thermally insulating functional materials.

[0042] Optionally, the roughness of the upper surface of the top layer 113 is not less than 4 mm. The relatively large roughness of the upper surface of the top layer 113 ensures that when a post-cast concrete layer is poured on the upper surface of the top layer 113 at the construction site, the post-cast concrete layer can be firmly bonded to the concrete substrate 11, which helps to ensure the bonding strength between the two.

[0043] The UHPC reinforcing rib 12 extends along the first span direction and connects to the top layer 113. The compressive strength of the concrete used for the UHPC reinforcing rib 12 is higher than that of the concrete used for the concrete substrate 11. For example, the UHPC reinforcing rib 12 is a concrete reinforcing rib, precast using ultra-high performance concrete (UHPC) with a compressive strength greater than 100 MPa. The UHPC reinforcing rib 12, as the main load-bearing rib system, undertakes bending and shear resistance, thereby enhancing the bending and shear resistance of the concrete substrate 11. Thus, the concrete substrate 11 and the UHPC reinforcing rib 12 adopt a "UHPC+NC" dual-material compatibility design, enabling the UHPC rib prestressed composite slab 100 to both rely on high-strength, high-toughness ribs to ensure bending and shear resistance, and reduce the redundant use of UHPC material through the ordinary concrete substrate 11, balancing cost and performance.

[0044] Optionally, the cross-sectional shape of the UHPC reinforcing rib 12 is rectangular, and the width and height of the rectangular cross-section are determined according to the design span and load of the composite slab.

[0045] Optionally, a connecting steel reinforcement skeleton 121 is further provided between the UHPC reinforcing rib 12 and the top layer 113. The upper end of the connecting steel reinforcement skeleton 121 is cast and fixed to the UHPC reinforcing rib 12, and the lower end is anchored in a pre-set steel reinforcement anchoring groove in the concrete substrate 11. Thus, the connecting steel reinforcement skeleton 121 strengthens the interlayer connection between the UHPC reinforcing rib 12 and the concrete substrate 11, preventing interlayer delamination damage. At the same time, compared with the method where the UHPC reinforcing rib 12 is directly integrally formed on the concrete substrate 11, the above method allows for a gap between the UHPC reinforcing rib 12 and the top layer 113, thereby facilitating subsequent construction processes between the UHPC reinforcing rib 12 and the top layer 113, such as arranging steel bars between the UHPC reinforcing rib 12 and the top layer 113 to form a steel mesh.

[0046] As an example, there are multiple UHPC reinforcing ribs 12, which are spaced apart along the second span direction. There are also multiple connecting rebar frames 121, each corresponding to one of the UHPC reinforcing ribs 12. Each connecting rebar frame 121 includes an upper connecting rebar 1211 and multiple lower connecting rebar frames. The upper connecting rebar 1211 extends along the first span direction and is fixedly connected to the bottom surface of the UHPC reinforcing rib 12. The multiple lower connecting rebar frames are spaced apart along the extension direction of the upper connecting rebar 1211, and each lower connecting rebar frame includes multiple lower connecting rebars 1212. The top ends of the multiple lower connecting rebars 1212 are close to each other and fixed to the upper connecting rebar 1211, while their bottom ends are anchored away from each other to the top layer 113.

[0047] The prestressed steel bars 13 are embedded in the bottom layer 111 extending along the first span direction. The prestressed steel bars 13 can pre-apply compressive stress to the bottom layer 111, so that when the bottom layer 111 of the concrete substrate 11 is under tension, it can counteract tensile stress, increasing the stiffness of the concrete substrate 11. This makes the bottom layer 111 less prone to cracking even with a small thickness, which is beneficial for reducing the self-weight of the concrete substrate 11 while ensuring the anti-deflection and anti-cracking capabilities of the concrete substrate 11 under large spans. Therefore, the concrete substrate 11 of this application not only has its self-weight significantly reduced, but also its bending and shear strength, anti-deflection capabilities, and anti-cracking capabilities are guaranteed, thus balancing structural safety and lightweight requirements.

[0048] Optionally, there are multiple cavities 1121, which are spaced apart to form multiple partitions 1122 spaced along the second span direction. There are multiple prestressed steel bars 13, each corresponding to one of the partitions 1122. Thus, the partitions 1122 form a protective layer for the prestressed steel bars 13, which helps protect the internal prestressed steel bars 13, preventing them from corroding and detaching due to the thin upper layer.

[0049] Optionally, the prestressed steel bar 13 extends out of the bottom layer 111 to form an anchorage portion outside the concrete substrate 11 for anchoring to other concrete components.

[0050] It should be noted that in related technologies, the treatment of splicing joints between two concrete slabs includes both integral joints and separate joints, both of which have significant technical shortcomings. Integral joints require the reinforcing steel bars within the concrete slab to extend beyond the slab side, and are then connected on-site by binding or welding before the concrete is poured. This structure necessitates additional consideration for steel bar processing during the prefabrication stage, and the extended steel bars are prone to deformation during transportation and hoisting, requiring on-site correction, significantly increasing construction procedures and costs, and reducing construction efficiency. Separate joints only transfer shear force by arranging additional steel bars in the post-poured area, but their joint integrity is poor, making them prone to cracking under vertical loads or temperature shrinkage.

[0051] Figure 4 This is a schematic diagram illustrating the splicing of the UHPC ribbed prestressed composite slab 100 with other concrete slabs 900 according to an embodiment of this application. (See attached diagram.) Figure 3 and Figure 4 The concrete substrate 11 of this application has a splicing portion 114 on its side for interlocking with other concrete slabs 900. The other concrete slabs 900 can be the UHPC rib prestressed composite slab of this application, or ordinary concrete slabs that are suitable for splicing. Therefore, the concrete substrate 11 can be spliced ​​with other concrete slabs 900 through the splicing portion 114, facilitating the alignment and splicing of the concrete substrate 11 with the other concrete slabs 900, and reducing the distance between the concrete substrate 11 and the other concrete slabs 900 along the span direction (e.g., ...). Figure 4 The probability of misalignment during splicing (as shown in the front-to-back direction). Furthermore, due to the interlocking mechanism of the splicing part 114, after splicing, the joint between the concrete substrate 11 and other concrete slabs 900 is not a straight line in the span direction of the slab, but rather a zigzag line with multiple bends (the joint shape is as shown in the diagram). Figure 4 As shown by the dashed line, compared to straight joints, the twisted and extended zigzag joints have a more tortuous path and a longer extension path, which helps to improve the shear and crack resistance of the joint between two concrete slabs. They also increase the length and resistance of the water penetration path, thus helping to solve the potential cracking and leakage problems at the joints of concrete slabs.

[0052] Optionally, the width of the splicing portion 114 gradually changes along the direction away from the concrete substrate 11. For example, it gradually increases or gradually decreases. Therefore, compared to the insufficient bonding strength between the joint formed by a rectangular right-angle splicing portion and the panel interface, this application effectively improves the interface bonding strength when splicing two concrete panels. This is mainly because the outer surface of the concrete panel is rough, and the splicing surface (side and end faces for splicing) of the splicing portion 114 is also rough. Due to the gradual change in width of the splicing portion 114, the surface area of ​​the rough splicing surface of the splicing portion 114 for splicing is also large during splicing. This results in a high bonding strength and friction between the concrete substrate 11 and other concrete panels 900 during splicing, which helps reduce the probability of joint width expansion after bonding and improves the crack resistance and impermeability after bonding.

[0053] As an example, the angle of inclination of the splicing side formed by the gradual change in width of the splicing part 114 is 45 degrees. However, it is understood that the angle of inclination of the splicing side is not limited to this, for example, it can also be 30 degrees, 60 degrees, etc. The height (depth) and width of the splicing part 114 are designed according to the stress requirements of the joint, so that the splicing side forms the required angle of inclination.

[0054] Optionally, when the concrete substrate 11 is joined with other concrete slabs 900, the joint between the concrete substrate 11 and the other concrete slabs 900 is filled with adhesive filler (not shown in the figure) to increase the bonding strength between the concrete substrate 11 and the other concrete slabs 900. As an example, the adhesive filler can be formed by injection using ultra-high performance concrete grout (UHPC grout). However, it is understood that when the concrete substrate 11 is joined with other concrete slabs 900 in this application, the adhesive filler may not be used, and this is also within the scope of protection of this application.

[0055] In some examples, the splicing portion 114 includes a splicing groove 1141 recessed inward from the side of the concrete substrate 11, a splicing protrusion 1142 protruding outward from the side and spaced from the splicing groove 1141, and a flat side portion 1143 connecting the splicing groove 1141 and the splicing protrusion 1142. This results in a joint with multiple bends (eight bends) after splicing, and a greater distance between the bottom of the splicing groove 1141 and the top of the splicing protrusion 1142, which helps to increase the path length of the joint, thereby improving the crack resistance and impermeability of the joint.

[0056] In some examples, the upper and lower surfaces of the splicing portion 114 are flush with the upper and lower surfaces of the concrete substrate 11, and the width of the splicing portion 114 gradually decreases along the concave / convex direction of the splicing portion; that is, along the convex direction, the width of the splicing protrusion 1142 gradually decreases, and along the concave direction, the width of the splicing groove 1141 gradually decreases. Therefore, when splicing with other concrete slabs 900, the other concrete slabs 900 can gradually approach the concrete substrate 11 from its horizontal side or from above the concrete substrate 11 and gradually fit into the concrete substrate 11, thereby achieving alignment and splicing with the concrete substrate 11. Furthermore, since the upper and lower surfaces of the splicing part 114 are flush with the upper and lower surfaces of the concrete substrate 11, the joint formed after splicing is straight through the thickness direction of the concrete substrate 11. This facilitates the injection of adhesive grout at the joint so that the injected adhesive grout flows and penetrates the thickness direction of the concrete substrate 11, ensuring the filling effect of the adhesive filler.

[0057] In other examples, the upper and lower surfaces of the splicing portion 114 are flush with the upper and lower surfaces of the concrete substrate 11, and the width of the splicing portion 114 gradually increases along the concave / convex direction. That is, along the convex direction, the width of the splicing protrusion 1142 gradually increases, and along the concave direction, the width of the splicing groove 1141 gradually increases. Therefore, when splicing with other concrete slabs 900, the other concrete slabs 900 can gradually approach the concrete substrate 11 from above and gradually fit into the concrete substrate 11, thereby achieving alignment and splicing with the concrete substrate 11. Furthermore, after embedding, because the width of the splicing portion 114 at its maximum concave / convex point is the largest, the spliced ​​concrete substrate 11 cannot be horizontally moved out of the other concrete slabs 900. For example, the width of the opening of the splicing groove 1141 is smaller than the width of the bottom wall of the deepest recess, preventing other concrete slabs 900 from horizontally moving out of the opening of the splicing groove 1141. This design helps prevent other concrete slabs 900 from horizontally moving away from the concrete substrate 11 during subsequent construction processes (such as pouring concrete or laying reinforcing bars), thus reducing the probability of the joint width widening after bonding and improving the crack resistance and impermeability after bonding.

[0058] Optionally, the UHPC rib prestressed composite slab 100 further includes a plurality of embedded lifting members 14. The plurality of embedded lifting members 14 are fixed to the top layer 113 at intervals to form a lifting area between them. Thus, during the transportation of the UHPC rib prestressed composite slab 100 from the factory to the construction site, when hoisting the UHPC rib prestressed composite slab 100 onto or from a transport vehicle to the construction site, multiple lifting ropes can be connected to the plurality of embedded lifting members 14 respectively, forming a lifting area between them, facilitating the hoisting and transportation of the UHPC rib prestressed composite slab 100.

[0059] As an example, the embedded lifting member 14 includes a lifting steel reinforcement cage. Thus, when the UHPC rib prestressed composite slab 100 is on the construction site, and concrete is subsequently poured on top of the UHPC rib prestressed composite slab 100 to form a post-cast concrete layer, the lifting steel reinforcement cage is cast inside the post-cast concrete layer, which helps to strengthen the flexural strength of the final concrete slab. However, it is understood that the embedded lifting member 14 in this embodiment is not limited to this, and the embedded lifting member 14 may also be an embedded lifting ring or an embedded lifting hook.

[0060] As an example, the hoisting steel reinforcement cage includes upper hoisting steel bars 141 and a plurality of lower hoisting steel bar frames. The upper hoisting steel bars 141 extend along the first span direction. The plurality of lower hoisting steel bar frames are spaced apart along the extension direction of the upper hoisting steel bars 141, and each lower hoisting steel bar frame includes a plurality of lower hoisting steel bars 142. The top ends of the plurality of lower hoisting steel bars 142 are close to each other and fixed to the upper hoisting steel bars 141, while the bottom ends are far apart from each other and anchored to the top layer 113.

[0061] Figure 5 This is a structural schematic diagram of a UHPC ribbed prestressed composite slab 100 according to another embodiment of this application. (See also...) Figure 5 The UHPC ribbed prestressed composite slab 100 further includes at least one layer of reinforcing mesh, namely a lower reinforcing mesh 15. The lower reinforcing mesh 15 is laid between the UHPC reinforcing ribs 12 and the top layer 113, and includes multiple first lower reinforcing bars 151 that pass through the connecting reinforcing bar skeleton 121 and extend along the second span, and multiple second lower reinforcing bars 152 that extend along the first span direction and intersect with the multiple first lower reinforcing bars 151. Thus, through the bidirectional reinforcing mesh, the UHPC ribbed prestressed composite slab 100 is formed as a bidirectional composite slab to adapt to situations where the floor slab needs to be subjected to bidirectional forces, such as large-span residential, office, and commercial buildings.

[0062] Optionally, the UHPC rib prestressed composite slab 100 further includes at least another layer of reinforcing mesh, namely an upper reinforcing mesh 16. The upper reinforcing mesh 16 is laid above the UHPC reinforcing rib 12 and includes multiple first upper reinforcing bars 161 extending along the second span and multiple second upper reinforcing bars 162 extending along the first span direction and intersecting with the multiple first upper reinforcing bars 161. This arrangement enhances the bidirectional load-bearing performance of the UHPC rib prestressed composite slab 100. Of course, as part of the UHPC rib prestressed composite slab 100, the first and second reinforcing meshes are laid in the factory. However, the UHPC rib prestressed composite slab 100 of this application may also exclude the first and second reinforcing meshes, and the first and second reinforcing meshes may also be laid on the construction site.

[0063] As an example, the fabrication and on-site construction of the UHPC ribbed prestressed composite slab according to this application embodiment includes the following steps: Fabrication of UHPC reinforcing ribs: A standardized steel mold is used, with the inner contour dimensions of the mold conforming to the rectangular cross-section design requirements. During fabrication, one end of the connecting steel reinforcement cage is inserted into the pre-drilled hole in the mold, and the other end is fixed to the mold. Next, ultra-high performance concrete is poured into the mold and compacted using a high-frequency vibrator (50Hz) until the surface is covered with slurry. After covering with plastic film and allowing to cure for 2 hours, the concrete is demolded and placed in a 90℃ steam curing chamber for 8 hours.

[0064] Concrete substrate fabrication: A combined steel mold is used, with a rectangular hollow core mold. Prestressed steel strands are arranged along the length of the slab, and clamp-type anchors are installed at both ends. A limiting plate is installed at the tensioning end. Then, ordinary concrete is poured in layers to the design elevation, vibrated to compact, and the surface is leveled. The 45° splice section on the side of the slab is formed simultaneously, covered and water-cured for 14 days, and anchoring grooves for connecting the reinforcing steel skeleton are reserved on the slab surface.

[0065] (3) Fixing between UHPC reinforcing ribs and concrete substrates: After the UHPC reinforcing ribs and concrete substrates are prefabricated, they are transported by flatbed truck. The UHPC reinforcing ribs are stacked vertically (with wooden blocks between layers), and the concrete substrates are stacked horizontally (with the support point 1 / 4 span from the end). The connecting steel reinforcement skeleton of the UHPC reinforcing ribs is inserted into the anchoring groove of the concrete substrate, and the gap is filled with non-shrink cement mortar.

[0066] (4) Use a truck crane for hoisting. The hoisting point is set at 1 / 4 span from the end of the plate (determined by calculation). Keep it horizontal during hoisting.

[0067] (5) Upon arrival at the construction site, the prestressed steel bars of the UHPC ribbed prestressed composite slab are installed onto the precast beams. The trapezoidal splices of two adjacent concrete substrates are aligned and spliced, with the joint width controlled at 30±5mm and the straightness deviation of the joint ≤5mm. Temporary supports are used for fixation. Then, the adhesive grout is prepared, stirred evenly, and injected into one side of the joint between the two concrete substrates through a grouting funnel. The injection is stopped when the grout overflows fully from the other side. After the compressive strength of the joint grout reaches the required level, the cavity is filled with thermal insulation material.

[0068] (6) At least two layers of bidirectional steel mesh are arranged above the concrete substrate, wherein at least one layer of steel mesh is arranged between the UHPC reinforcing rib and the top layer of the concrete substrate, and at least one layer of steel mesh is arranged above the UHPC reinforcing rib, and the steel mesh layer is tied to the upper connecting steel bar of the connecting steel bar skeleton to ensure the position of the steel bar.

[0069] (7) After the steel mesh is laid, a post-cast concrete layer higher than the UHPC reinforcing rib is poured on site above the concrete substrate to form a post-cast concrete layer with steel mesh embedded inside.

[0070] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the protection scope of this application.

Claims

1. A UHPC rib prestressed composite slab, characterized in that, The application relates to a concrete base plate, which comprises a bottom layer, a cavity layer above the bottom layer and a top layer above the cavity layer; wherein the cavity layer is provided with cavities extending along the span direction of the concrete base plate; a UHPC reinforcing rib is connected above the top layer along the span direction, wherein the compressive strength of the concrete material of the UHPC reinforcing rib is greater than that of the concrete material of the concrete base plate; and a prestressed steel bar is embedded in the bottom layer along the span direction. The side surface of the concrete base plate is provided with a splicing part for concave-convex splicing. The width of the splicing part gradually changes in the direction away from the concrete base plate. The splicing part further comprises at least one of the following settings: (1) the upper and lower surfaces of the splicing part are flush with the upper and lower surfaces of the concrete base plate, and the width of the splicing part gradually decreases along the concave / convex direction of the splicing part; (2) the upper and lower surfaces of the splicing part are flush with the upper and lower surfaces of the concrete base plate, and the width of the splicing part gradually increases along the concave / convex direction of the splicing part; (3) the splicing part comprises a splicing groove recessed inward from the side surface, a splicing convex part protruding outward from the side surface and spaced from the splicing groove, and a flat side part connected between the splicing groove and the splicing convex part.

2. The UHPC rib prestressed composite slab according to claim 1, characterized in that, Further comprising: a plurality of embedded lifting parts fixed at the top layer and spaced from each other to form a lifting area between the embedded lifting parts.

3. The UHPC rib prestressed composite slab according to claim 2, characterized in that, The embedded lifting part further comprises at least one of the following settings: (1) is implemented as a lifting steel framework extending along the span direction; (2) comprises an upper lifting steel bar extending along the span direction and a plurality of lower lifting steel frameworks spaced along the extension direction of the upper lifting steel bar, and each lower lifting steel framework comprises a plurality of lower lifting steel bars, the top ends of which are close to each other and fixed to the upper lifting steel bar, and the bottom ends of which are away from each other and anchored to the top layer.

4. The UHPC rib prestressed composite slab according to claim 2, characterized in that, Further comprising: a connecting steel framework fixed between the UHPC reinforcing rib and the top layer. The connecting steel framework comprises: an upper connecting steel bar extending along the span direction and fixedly connected to the bottom surface of the UHPC reinforcing rib; and a plurality of lower connecting steel frameworks spaced along the extension direction of the upper connecting steel bar, and each lower connecting steel framework comprises a plurality of lower connecting steel bars, the top ends of which are close to each other and fixed to the upper connecting steel bar, and the bottom ends of which are away from each other and anchored to the top layer. Further comprising: at least one layer of steel mesh laid between the UHPC reinforcing rib and the top layer, and comprising a plurality of stress steel bars passing through the connecting steel framework; and / or at least another layer of steel mesh laid above the UHPC reinforcing rib. The cavities are a plurality of cavities spaced to form a plurality of partition parts; and the prestressed steel bars are a plurality of prestressed steel bars corresponding to the plurality of partition parts.

5. The UHPC rib prestressed composite slab of claim 1, wherein, ​ ​ 6. The UHPC rib prestressed composite slab according to claim 5, characterized in that, ​ ​ ​ 7. The UHPC rib prestressed composite slab of claim 1, wherein, ​ ​ 8. The UHPC rib prestressed composite slab according to claim 7, characterized in that, ​ ​ ​ 9. The UHPC rib prestressed composite slab according to claim 7, characterized in that, ​ ​ ​ ​ 10. The UHPC rib prestressed composite slab of claim 1, wherein, ​

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