LP floor slab structure

Abstract

The utility model discloses an LP floor slab structure, which relates to the technical field of building construction structures and comprises distributed steel bars, connecting clamping pieces, pressure-bearing ribs, a bottom die and an LP slab. The distributed steel bars and the connecting clamping pieces are welded to form a steel bar clamping piece truss, and the pressure-bearing ribs are arranged on the steel bar clamping piece truss and arranged on the distributed steel bars away from the bottom die. The bottom die is mounted at the bottoms of the distributed steel bars and connected with the connecting clamping pieces; the LP plate is arranged outside the steel bar clamping piece truss in a surrounding mode, the LP plate is located on the bottom die, and the pressure bearing rib is wrapped with the LP plate. According to the floor slab structure, support-free construction of a construction site is achieved, that is, a traditional supporting system is not needed in the construction process, and the use cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of building construction structures, in particular to an LP floor structure. Background Art

[0002] LP stands for light-duty precast, which means "lightweight prefabrication" or "lightweight assembly component technology". It is a prefabricated assembly process with integrated formwork (double-sided disassembly-free), integrated steel bars, and integrated insulation. Through the optimization and innovation of materials, processes, procedures, and methods, the steel bars, insulation, and formwork of the building body are assembled into building components in the factory, assembled into a steel bar formwork skeleton on site, and poured in one-time concrete. LP floor slabs are also prefabricated floor slabs. As an important part of prefabricated buildings, prefabricated floor slabs are the most widely used structural components in prefabricated buildings. They mainly appear in the form of steel truss floor slabs and steel truss composite slabs, which are suitable for steel structures and PC structures respectively. Among them, PC stands for Precast Concrete, which is the abbreviation of prefabricated concrete structure.

[0003] From the initial steel structure, steel beam and steel column engineering production, on-site prefabricated construction solves the problem of formwork-free, reduced or no support in the steel structure system, and adopts corrugated steel plates and steel truss floor decks. With the vigorous promotion of building industrialization, the large-scale application of prefabricated concrete structures characterized by standardized parts, prefabricated construction, and factory production, various floor slabs using ordinary steel bars and prestressed steel bars have been launched one after another. The mainstream floor slabs include: steel truss composite floor slabs, SP slabs (prestressed hollow floor slabs), PK slabs (PK prestressed concrete composite slabs), double T slabs (prefabricated reinforced concrete load-bearing components combined with slabs and beams), etc.

[0004] However, all the above-mentioned prefabricated panels have various disadvantages. For example, during the hoisting, transportation and post-pour of concrete, the prefabricated bottom slab concrete is prone to cracking and excessive deflection. Prestressed composite slabs use prestressing technology, which can effectively solve the problem of slab cracking, but there are problems such as the difficulty in controlling the back supply of the slab span caused by the application of prestress. Prestressed hollow slabs and prestressed double T slabs require a larger shelving length and are mainly suitable for large-span frame structures.

[0005] Therefore, it is necessary to design a LP formwork-free and support-free floor structure that can solve the above-mentioned existing problems. Utility Model Content

[0006] In order to solve the problems in the prior art, the utility model provides a LP floor structure.

[0007] In order to achieve the purpose of the utility model, the technical solution adopted by the utility model is as follows:

[0008] A LP floor structure comprises distributed steel bars, connecting clips, pressure-bearing ribs, bottom formwork and LP plates; the distributed steel bars and the connecting clips are welded to form a steel bar card truss, the pressure-bearing ribs are arranged on the steel bar card truss, and the pressure-bearing ribs are arranged on the distributed steel bars away from the bottom formwork, the pressure-bearing ribs are wrapped with LP plates on the outside, and concrete is poured inside the wrapped ribs; the bottom formwork is installed at the bottom of the distributed steel bars, and the bottom formwork is connected to the connecting clips; the LP plate is surrounded by the outside of the steel bar card truss.

[0009] Based on the above technical solution, further, the distribution steel bars include upper steel bars and lower steel bars, and both the upper steel bars and the lower steel bars are composed of steel bars that are staggered horizontally and vertically.

[0010] Based on the above technical solution, further, there are several connecting cards, and one end of the connecting card is connected to the upper steel bar, and the other end is connected to the lower steel bar; and several connecting cards are evenly spaced between the upper steel bar and the lower steel bar.

[0011] Based on the above technical solution, further, the horizontally and vertically staggered steel bars include force-bearing bars and distribution bars; when the horizontally arranged steel bars are force-bearing bars, the longitudinally arranged steel bars are distribution bars; when the horizontally arranged steel bars are distribution bars, the longitudinally arranged steel bars are force-bearing bars.

[0012] Based on the above technical solution, further, the height of the connecting card is 85mm-160mm.

[0013] Based on the above technical solution, further, the width of the LP plate is 1000mm-3000mm, preferably 1300mm, the length of the LP plate is 1000mm-4200mm, preferably 3100mm, and the thickness of the LP plate is 100mm-160mm, preferably 130mm.

[0014] Based on the above technical solution, further, the pressure-bearing ribs are concrete pressure-bearing ribs.

[0015] Based on the above technical solution, further, the bottom mold is a high ductility concrete bottom mold, and the height of the bottom mold is 12mm-15mm, preferably 12mm.

[0016] Compared with the prior art, the beneficial effects of the present invention are specifically embodied in:

[0017] (1) The floor structure provided by the utility model realizes the support-free construction on the construction site, that is, the traditional support system is no longer needed during the construction process, thus saving the use cost.

[0018] (2) The support-free structure of the utility model is composed of distributed steel bars, connecting cards, pressure-bearing ribs, bottom molds and LP plates, which can ensure a more efficient installation and save a lot of labor costs. At the same time, there is no need to wait for the demolding process, which reduces labor costs and correspondingly reduces the burden of on-site management, further improving construction efficiency. It also reduces the labor demand for scaffolding and formwork during the construction process.

[0019] (3) The LP support-free slab of the utility model is light in weight, and the thickness of the prefabricated LP floor bottom formwork is only 12mm-15mm thick, about 50 kilograms per square meter, which can effectively improve the efficiency of production, transportation and installation. In addition, the LP support-free floor can have reinforcement on one side or no reinforcement, and the slabs can be arranged in a close-fitting manner, reducing the process of on-site formwork support and improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a top view of the structure of the utility model;

[0021] Figure 2 It is a side view from the first perspective of the structure of the utility model;

[0022] Figure 3 A side view of the structure of the utility model from a second perspective;

[0023] Figure numerals: 1. distribution steel bars; 2. connection cards; 3. pressure-bearing ribs; 4. bottom formwork; 5. LP plate. DETAILED DESCRIPTION

[0024] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific implementations. The technical features of each implementation of the present invention can be combined accordingly without conflicting with each other.

[0025] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed below. The technical features in each embodiment of the utility model can be combined accordingly without conflicting with each other.

[0026] In the description of the present utility model, it is necessary to understand that when an element is considered to be "connected" to another element, it can be directly connected to another element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0027] Example

[0028] Combination Figure 1-Figure 3 As shown, this embodiment provides a LP floor structure, including distribution steel bars 1, connecting cards 2, pressure ribs 3, bottom molds 4 and LP plates 5; the distribution steel bars 1 and the connecting cards 2 are welded to form a steel bar card truss, the pressure ribs 3 are arranged on the steel bar card truss, and the pressure ribs 3 are arranged on the distribution steel bars 1 away from the bottom mold 4, the pressure ribs 3 are wrapped with LP plates 5 on the outside, and concrete is poured inside the wrapping; the bottom mold 4 is installed at the bottom of the distribution steel bars 1, and the bottom mold 4 is connected to the connecting cards 2; the LP plate 5 is surrounded by the outside of the steel bar card truss.

[0029] In this embodiment, the distribution steel bars 1 include upper steel bars and lower steel bars, and both the upper steel bars and the lower steel bars are composed of steel bars staggered horizontally and vertically. There are a plurality of connecting cards 2, and one end of the connecting card 2 is connected to the upper steel bars, and the other end is connected to the lower steel bars; and a plurality of connecting cards 2 are arranged at equal intervals between the upper steel bars and the lower steel bars. The steel bars staggered horizontally and vertically include force-bearing bars and distribution bars; when the transversely arranged steel bars are force-bearing bars, the longitudinally arranged steel bars are distribution bars; when the transversely arranged steel bars are distribution bars, the longitudinally arranged steel bars are force-bearing bars. When there are beam devices on the outside of both sides, the force-bearing bars and the distribution bars must at least extend into the beams, and do not need to extend out at the joints of the two LP floor slabs. The height of the connecting card 2 is 85mm-160mm, preferably 115mm-130mm. The width of the LP plate 5 is 1000mm-3000mm, preferably 1300mm; the length of the LP plate 5 is 1000mm-4200mm, preferably 3100mm, and the thickness of the LP plate 5 is 100mm-160mm, preferably 130mm. The pressure-bearing rib 3 is a concrete pressure-bearing rib. The bottom mold 4 is a high-ductility concrete bottom mold, and the height of the bottom mold 4 is 12mm-15mm, preferably 12mm.

[0030] Based on this structure, in order to test the performance of the entire LP unremovable and unsupported floor structure, relevant bearing capacity experiments were carried out. The basic parameters of the floor are as follows: the length of LP plate 5 is 3100mm, the width of LP plate 5 is 1300mm, the thickness of LP plate 5 is 130mm, the stress reinforcement is C10@200 steel truss, the skeleton distribution reinforcement is C8@200, the height of the steel truss connection card 2 is 115mm, and the net distance of the stress reinforcement is 80mm. The stress reinforcement extends 475mm out of the bottom formwork, the plate is set aside for 75mm, the clear span of the plate is 3100mm, and the bottom formwork is 12mm thick high ductility concrete.

[0031] Experimental conditions: During the test, the formwork-free and support-free LP floor is placed on the test bench. The test bench uses a steel material table with a height of 900mm from the ground and a net distance of 3100mm between the two supports. A 0.5mm thick steel plate is laid on the upper surface of the formwork-free and support-free LP floor. After the floor is erected, a horizontal line is fixed on both sides of the floor, about 100mm away from the thin steel plate, to measure the deformation of the floor under load.

[0032] Experimental requirements: Before loading, use a precision caliper to measure the initial distance between the horizontal line and the thin steel plate on the upper surface of the LP floor, and then load evenly on the thin steel plate. The initial load is 100KN / m 2 The total load is 403KN. After loading, the deformation of the LP floor is measured. After 30 minutes, the deformation is measured again. After the initial loading, the deformation is measured at 25KN / m each time. 2 The load is gradually increased in one level (total load of each level is 100KN). The deformation of the steel skeleton is measured immediately after loading, and then measured again after an interval of 30 minutes. When the total deformation of the floor slab reaches 15mm, the loading is stopped, and the uniformly distributed load value on the LP floor slab is calculated to obtain the bearing capacity of the LP floor slab under normal use; then the loading is continued, each time at 50KN / m 2 Load (the total amount of each load is 200KN), and measure the deformation value of the LP floor after loading until the LP floor is destroyed. After the LP floor is destroyed, the total load-bearing data of the LP floor is summarized and statistically analyzed, an experimental report is made, relevant calculations are performed, and experimental conclusions are drawn.

[0033] The test process is as follows: the supports of the unsupported floor are made of aerated concrete blocks with a length, width and height of 600×300×200 placed side by side on the workshop floor, and 1600×90×45 wooden beams are laid on the blocks to ensure that the block supports are evenly stressed. In order to prevent the wooden beams from being compressed and deformed, 50×50 square steel pipes are added to the wooden beams, and the floor is placed on the square steel pipes with a length of 10mm.

[0034] Test load: Floor self-weight:

[0035] Bottom mold 40.012×2100=25.2KN / m 2 ,

[0036] Compression rib 0.2×0.025×2×2100 / 1.3=16.15KN / m 2 ,

[0037] Steel skeleton (14×0.617+1.3×10×0.395+0.036×10×7) / 1.3=12.53KN / m 2 , total deadweight: 53.88KN / m 2 .

[0038] Loading is divided into initial loading and graded loading. Initial loading is the first loading at the beginning of the test, and the loading amount is 100KN / m 2 Measure the floor deformation immediately after loading, let it stand for 30 minutes and measure the floor deformation again, then load it step by step according to the requirements of graded loading. The load of graded loading is 25KN / m each time when the total deformation is less than 15mm. 2 , when the deformation exceeds 15mm, press 50KN / m 2 Load, measure deformation immediately after each loading, let stand for 30 minutes and then measure deformation again. The test measurement data are as follows:

[0039] Table 1 is the deformation record of 130mm thick steel bar card truss

[0040]

[0041]

[0042]

[0043]

[0044] It should be noted that in Table 1, the initial load is 100KN / m 2 The total load is 403KN. The deformation is measured again after 30 minutes. After the initial loading, the deformation is measured at 25KN / m each time. 2 Load one level at a time (total load of each level is 100KN), and measure again after 30 minutes until the total deformation of the floor reaches 15mm, then stop loading. Then continue loading, each time at 50KN / m 2 Load (the total amount of each load is 200KN), and measure the deformation value of the floor slab after loading until the floor slab is destroyed.

[0045] Table 2 is the deformation record of 130mm thick steel bar card truss

[0046]

[0047]

[0048]

[0049]

[0050] It should be noted that in Table 2, the initial load is 100KN / m 2 (Total load is 403KN), and measure the deformation again after 30 minutes; after the initial loading, press 25KN / m each time 2Load one level at a time (total load of each level is 100KN), and measure again after 30 minutes until the total deformation of the floor reaches 15mm, then stop loading. Then continue loading, each time at 50KN / m 2 Load (the total amount of each load is 200KN), and measure the deformation value of the floor slab after loading until the floor slab is destroyed.

[0051] From the above test data, cracks appeared when the LP floor deformation was about 9mm. At this time, the curvature of the LP floor was 2.9 / 1000, and the cracks appeared between the ribs of the LP board 5. When the LP floor deformation was 15mm, the load value was 350KN / m 2 (excluding deadweight), including deadweight, the load value is 400KN / m 2 The ultimate bearing capacity at the time of failure is 688KN / m 2 , the load value including deadweight is 740KN / m 2 .

[0052] During the test, different conditions can be set for the experiment, such as the initial load (150KN / m 2 ), load is 475KN / m 2 Or load is 650KN / m 2 I won’t show too much here.

[0053] Description of failure mode: Load reaches 450KN / m 2 When the load reaches 550KN / m 2 When the load is 600KN / m 2 When the load reaches 650KN / m 2 When the load reaches 688KN / m 2 When the test floor slab was in operation, a sound was heard, and then the concrete of the pressure rib 3 was broken at a position 400 mm away from the support at the set position, and the floor slab collapsed.

[0054] Analysis of test results: The formwork-free and support-free LP floor structure uses steel trusses as the main load-bearing components, supplemented by pressure-bearing ribs 3 to bear the pressure in the upper compression zone of the floor. During the test, all loads act on the upper surface of the floor steel trusses. The load is the upper chord compression for the steel trusses. When the load is large enough, the steel trusses will lose their bearing capacity due to out-of-plane instability. During the test, when the load reaches 550KN / m 2When the truss tilts out of the plane, it is a manifestation of instability. In the actual engineering practice, the concrete poured by the formwork-free and support-free LP floor acts on the bottom formwork 4 of the floor. The force is manifested as the tension of the lower chord of the steel truss. Only the effect of the construction load is the compression of the upper chord of the truss. According to the value of the load specification, the construction load is 100KN / m 2 Consideration will not have any impact on the stability of the steel truss.

[0055] Performance requirements for bottom formwork 4: Under the conditions of floor slab curvature permitted by the specification (L / 250), no cracks will appear in the bottom formwork 4 concrete.

[0056] The above is only an implementation method of the utility model, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. A LP floor structure, characterized in that: Including distribution steel bars, connection cards, pressure ribs, bottom formwork and LP plates; The distribution steel bars and the connection cards are welded to form a steel bar card truss, the pressure-bearing ribs are arranged on the steel bar card truss, and the pressure-bearing ribs are arranged on the distribution steel bars away from the bottom form; The bottom formwork is installed at the bottom of the distribution steel bars, and the bottom formwork is connected to the connection card; The LP plate is arranged around the outside of the steel bar card truss, and the LP plate is located on the bottom formwork, and the outside of the pressure-bearing rib is wrapped with the LP plate.

2. The LP floor structure according to claim 1, characterized in that: The distribution steel bars include upper steel bars and lower steel bars, and both the upper steel bars and the lower steel bars are composed of steel bars that are staggered horizontally and vertically.

3. The LP floor structure according to claim 2, characterized in that: There are a plurality of connection cards, one end of which is connected to the upper steel bar, and the other end of which is connected to the lower steel bar; and the plurality of connection cards are arranged between the upper steel bar and the lower steel bar at equal intervals.

4. The LP floor structure according to claim 2, characterized in that: The horizontal and vertical staggered steel bars include force-bearing bars and distribution bars; when the horizontally arranged steel bars are force-bearing bars, the longitudinally arranged steel bars are distribution bars; when the horizontally arranged steel bars are distribution bars, the longitudinally arranged steel bars are force-bearing bars.

5. The LP floor structure according to claim 1, characterized in that: The height of the connection card is 85mm-160mm.

6. The LP floor structure according to claim 1, characterized in that: The width of the LP plate is 1000mm-3000mm, the length of the LP plate is 1000mm-4200mm, and the thickness of the LP plate is 100mm-160mm.

7. The LP floor structure according to claim 1, characterized in that: The pressure-bearing ribs are concrete pressure-bearing ribs.

8. The LP floor structure according to claim 1, characterized in that: The bottom mold is a high ductility concrete bottom mold, and the height of the bottom mold is 12mm-15mm.

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