Lightweight concrete stair

Abstract

The utility model relates to the technical field of prefabricated stairs, and discloses a lightweight concrete stair which comprises a lower platform located at the bottom end and an upper platform located at the top end, the upper platform and the lower platform are connected through a plurality of sets of L-shaped fold line beams, and each fold line beam comprises a kick plate which is horizontally arranged. The pedal is perpendicular to the kick plate; ladder beams are arranged on the two sides of the kick plate and the pedals; according to the utility model, the use amount of steel bars can be effectively reduced, the weight of the prefabricated stair is further greatly reduced and the cost is saved on the premise of meeting the bearing capacity and normal use conditions of the stair, and the self weight is light and materials are saved; meanwhile, the prefabricated staircase combined by the broken line beams is reasonable in structure, and the mechanical property is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of prefabricated stairs, in particular to a light concrete staircase. Background Art

[0002] At present, most of the existing buildings in my country use cast-in-place reinforced concrete stairs, but their defects are also very obvious. This is because the construction site not only requires a large number of formwork, but also requires on-site tying of steel bars and pouring of concrete. This results in a long construction period, high labor intensity, serious environmental pollution and resource consumption, and it is difficult to guarantee quality.

[0003] Prefabricated reinforced concrete stairs are produced in a standardized manner in the factory, then transported to the construction site, and then hoisted and spliced. Prefabricated assembly construction has a short construction period, low time cost, little interference to the construction site, and low requirements for on-site construction conditions. It is the development trend of construction. However, the existing prefabricated staircase atlas and standard reinforced concrete stairs in my country have a large self-weight and consume a lot of materials, resulting in a high cost. In addition, the large size makes adjustment inflexible, which reduces the efficiency of hoisting construction and increases the complexity of the process. Utility Model Content

[0004] The purpose of the utility model is to provide a lightweight concrete staircase, which can effectively reduce the amount of steel bars used. Under the premise of meeting the bearing capacity of the stairs and normal use conditions, the weight of the prefabricated stairs can be further greatly reduced, saving costs. It has a light weight and saves materials. At the same time, the prefabricated staircase composed of broken line beams has a reasonable structure and its mechanical properties are guaranteed.

[0005] The utility model adopts the following technical solutions:

[0006] A lightweight concrete staircase comprises a lower platform at the bottom and an upper platform at the top, wherein the upper platform and the lower platform are connected by a plurality of groups of L-shaped broken line beams, wherein the broken line beams comprise a horizontally arranged kick plate and a pedal arranged perpendicular to the kick plate; ladder beams are arranged on both sides of the kick plate and the pedal.

[0007] Preferably, ultra-high-strength steel bars are provided at the bottom of the ladder beam on each side along the extension direction of the stairs.

[0008] Preferably, the ladder beam is a solid beam body with a rectangular cross section.

[0009] Preferably, horizontal distribution ribs are provided inside the pedal.

[0010] Preferably, three horizontal distribution bars are provided, and ends of the horizontal distribution bars extend into the steel bar skeleton of the ladder beam.

[0011] Preferably, an anti-slip groove is provided at the top of the pedal.

[0012] Preferably, the kick plate is a 3-8 mm thick steel plate.

[0013] Preferably, both the upper platform and the lower platform are provided with assembly holes.

[0014] Preferably, the ladder beams at both ends are provided with hanging nails, and the hanging nails are connected with hanging rings.

[0015] Preferably, the ladder beam on which the hanging nail is provided is provided with hanging point reinforcement ribs.

[0016] Compared with the prior art, the beneficial effects of the utility model are as follows: the utility model greatly reduces the weight of the prefabricated assembled stairs from the perspective of cross-sectional form and structural measures, without reducing its bearing capacity and rigidity; the traditional plate-type stairs are changed into stairs composed of L-shaped broken line beams, so that the force of the stairs is changed from the stair treads to the stair beams on both sides, which greatly ensures the stability of the structure.

[0017] In addition, the utility model enhances the structural strength of the stairs by adopting a structural form of a combination of ultra-high-strength steel bars and ultra-high-performance concrete (UHPC). Due to the high compressive and tensile properties of UHPC materials, the amount of steel bars used in the present invention can be reduced by about 30% compared to ordinary concrete stairs, so a small amount of horizontally distributed steel bars are arranged in the compression zone of the pedals to further improve the compression resistance of the compression zone. At the same time, ultra-high-strength steel bars are arranged in the ladder beams on both sides of the stairs to improve the ultimate bearing capacity of the stairs and ensure the safety of the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present application;

[0019] Figure 2 A top view of an embodiment of the present application;

[0020] Figure 3 for Figure 2 Middle AA section view;

[0021] Figure 4 for Figure 2 Middle BB cross section;

[0022] Figure 5 for Figure 2 Section 1-1. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the present invention in conjunction with the accompanying drawings and embodiments:

[0024] like Figures 1 to 5As shown, a lightweight concrete staircase described in the utility model comprises a lower platform 1 at the bottom and an upper platform 2 at the top, and the upper platform 2 is connected to the lower platform 1 by a plurality of groups of L-shaped broken line beams, wherein each group of broken line beams comprises a horizontally arranged kick plate 3 and a pedal 4 arranged vertically with the kick plate 3, and the ends of the adjacent kick plates 3 and the pedals 4 in contact are fixedly connected; ladder beams 5 are arranged on both sides of the kick plates 3 and the pedals 4. Among them, the upper platform 2, the lower platform 1, the pedals 4 and the ladder beams 5 are all cast by ultra-high performance concrete (UHPC), which has the advantages of high strength, good toughness, corrosion resistance, good durability, low later maintenance cost, etc., and has good economic benefits and safety.

[0025] Furthermore, in this embodiment, ultra-high strength steel bars 6 are provided at the bottom of each ladder beam 5 along the extension direction of the stairs, and two ultra-high strength steel bars 6 are provided on each side to improve the ultimate bearing capacity of the stairs and ensure the safety of the components. In addition, the ladder beam 5 in this embodiment is a solid beam body with a rectangular cross-section, and a steel bar skeleton is provided inside to ensure its structural strength. Horizontal distribution bars 7 are provided in the pedal 4, and three horizontal distribution bars 7 are provided, and the end of each horizontal distribution bar 7 extends into the steel bar skeleton of the ladder beam 5 to improve the integrity of the entire staircase structure after the ultra-high performance concrete is poured and enhance its structural strength; wherein, the top of the pedal 4 is preferably provided with an anti-slip groove to prevent pedestrians from slipping when stepping on it.

[0026] In this embodiment, the kick plate 3 is made of 3-8 mm thick steel plate, preferably 5 mm thick steel plate, which can ensure the structural strength without significantly increasing the overall mass of the stairs. In addition, both the upper platform 2 and the lower platform 1 are provided with assembly holes 10 to facilitate the subsequent connection and fixation with the installation position; the ladder beams 5 at both ends are provided with hanging nails 8, and the hanging nails 8 are connected with hanging rings. The setting of the hanging rings is used to lift the entire cast stairs. The hanging nails 8 are preferably set at the middle and lower parts and the middle and upper parts of the stairs to ensure the uniformity of the force of the entire staircase during lifting; wherein, the ladder beams 5 where the hanging nails 8 are set are provided with hanging point reinforcement ribs 9, and the hanging point reinforcement ribs 9 are cast integrally with the steel skeleton in the ladder beams 5 to enhance the structural strength at the hanging point during lifting and ensure the stable lifting of the stairs.

[0027] During the construction of the utility model, the ultra-high performance concrete (UHPC) is first prepared, specifically including: placing the prepared dry mix on a scale, weighing the corresponding weight of the dry mix and the corresponding amount of water accurately to 1g; using a planetary mixer with a frequency of 50Hz, stirring for 60S, and then slowly adding water while stirring for more than 1200S; and obtaining the ultra-high performance concrete (UHPC) after continuous mixing.

[0028] Secondly, in the prefabrication factory, the formwork is supported, the steel bars are tied, and the horizontal distribution bars 7 of the stair treads 4 are extended into the steel skeleton of the ladder beams 5 on both sides. The stress-bearing steel bars of the ladder beams 5 on both sides are effectively anchored and connected with the stress-bearing steel bars of the upper platform 2 and the lower platform 1. Before the UHPC concrete is put into the mold, special equipment should be used to measure the working properties of the concrete such as temperature, slump, air content, water-cement ratio and water seepage rate. Only concrete with the performance of the mixture meeting the design or mix ratio requirements can be poured into the mold. The temperature of the concrete entering the mold should generally be controlled at 5-30℃, and the free fall height during concrete pouring should not be greater than 2m. When it is greater than 2m, chutes, string tubes, funnels and other equipment should be used to assist in conveying concrete to ensure that the concrete does not stratify and segregate. The pouring of concrete should be carried out in a layered and continuous manner, and the interval time should not exceed 90min. The temperature difference between the newly poured concrete and the adjacent hardened concrete or rock and soil medium during pouring should not be greater than 15℃. After pouring, spray a layer of water mist on the surface of UHPC, and then cover it with a curing film for moisturizing curing. The moisturizing curing should be no less than 48 hours. After the moisturizing curing is completed, steam curing is carried out under high temperature conditions above 95°C.

[0029] Finally, the stairs are hoisted to the corresponding installation position, and the assembly holes 10 on the upper platform 2 and the lower platform 1 are assembled and connected one by one with the assembly holes reserved on the building platform plate through bolts, and then ultra-high performance concrete slurry is poured into the assembly holes 10 and the holes for installing the hanging nails for sealing and connection. The installation of the entire staircase is completed, and the whole process is convenient and quick.

[0030] The utility model adopts a structural form of ultra-high-strength steel bars 6 combined with ultra-high performance concrete (UHPC), which greatly ensures the stability of the stairs. Due to the high compressive and tensile properties of UHPC materials, the utility model can reduce the amount of steel bars by about 30% compared with ordinary concrete stairs, so a small amount of horizontal distribution bars 7 are arranged in the compression zone of the steps, which can further improve the compression resistance of the compression zone while not significantly increasing the weight of the stairs; in addition, a total of 4 ultra-high-strength steel bars 6 are arranged in the ladder beams 5 on both sides of the stairs, which further improves the ultimate bearing capacity of the stairs and ensures the safety of the components.

Claims

1. A lightweight concrete staircase, characterized in that: It includes a lower platform at the bottom and an upper platform at the top, wherein the upper platform and the lower platform are connected by a plurality of groups of L-shaped fold line beams, wherein the fold line beams include a horizontally arranged kick plate and a pedal arranged perpendicular to the kick plate; ladder beams are arranged on both sides of the kick plate and the pedal.

2. The lightweight concrete staircase according to claim 1, characterized in that: The bottom of the ladder beam on each side is provided with ultra-high-strength steel bars along the extension direction of the stairs.

3. The lightweight concrete staircase according to claim 1, characterized in that: The ladder beam is a solid beam body with a rectangular cross section.

4. The lightweight concrete staircase according to claim 1, characterized in that: Horizontal distribution ribs are arranged inside the pedal.

5. The lightweight concrete staircase according to claim 4, characterized in that: Three horizontal distribution bars are provided, and the ends of the horizontal distribution bars extend into the steel bar skeleton of the ladder beam.

6. The lightweight concrete staircase according to claim 1, characterized in that: The top of the pedal is provided with an anti-skid groove.

7. The lightweight concrete staircase according to claim 1, characterized in that: The kick plate is a 3-8 mm thick steel plate.

8. The lightweight concrete staircase according to claim 1, characterized in that: The upper platform and the lower platform are both provided with assembly holes.

9. The lightweight concrete staircase according to claim 1, characterized in that: Hanging nails are arranged on the ladder beams at both ends, and hanging rings are connected to the hanging nails.

10. The lightweight concrete staircase according to claim 9, characterized in that: The ladder beam on which the hanging nails are provided is provided with hanging point reinforcement ribs.

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