1. A method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure is characterized by comprising the following steps:

when a steel ladder in a high-rise concrete structure (4) is reconstructed, firstly, a step plate, a platform plate and a railing on the steel ladder are dismantled, and a steel ladder beam (1) is reserved;

erecting a template by taking the steel ladder beam (1) as a positioning foundation, pouring concrete of the cantilever concrete ladder beam (2) to form the cantilever concrete ladder beam (2) taking the steel ladder beam (1) as an inner support, and pouring concrete of a concrete platform plate (6) between the cantilever concrete ladder beams (2) at two sides;

and step three, after the concrete reaches the design strength, erecting the precast concrete stairs between the concrete platform plates (6) and installing the handrails.

2. The method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure according to claim 1, wherein: the periphery of the steel ladder beam (1) is provided with longitudinal bars (3) implanted into a high-rise concrete structure (4), the other ends of the longitudinal bars (3) are fixedly welded with the steel ladder beam (1), and when concrete of the cantilever concrete ladder beam (2) is poured, the concrete completely covers the longitudinal bars (3), so that the thickness of a protective layer of the longitudinal bars (3) is ensured to meet requirements.

3. The method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure according to claim 1, wherein: the cantilever concrete ladder beam (2) is of a variable cross-section structure with the cross-sectional area linearly reduced from a fixed end to a free end.

Background

The steel structure stair structure has the advantages of convenience and rapidness in construction, relatively low manufacturing cost and the like, and is widely applied to civil and architectural engineering. When the cantilever steel ladder is arranged in a high-rise concrete structure (such as a hydropower station concrete dam and a reinforced concrete frame structure house), fixing parts such as bolts are embedded in the concrete structure, and then the steel ladder is connected with the concrete structure through steel ladder beams. However, the steel surface layer gradually generates oxidation along with the passage of time, a serious corrosion phenomenon can occur, and certain potential safety hazards can exist in the walking process of personnel. In addition, the daily maintenance of the steel ladder is relatively labor and material consuming.

In the face of the situation, steel materials are partially replaced again to prolong the service life, and the steel ladder is partially processed in a mode of transforming the steel ladder into a more firm and durable concrete stair. In the transformation process of the steel ladder, the problem of dismantling the steel ladder beam is troublesome. Because the steel ladder distributes in the concrete structure outside, is in the state of encorbelmenting, need utilize equipment to demolish steel ladder roof beam one by one to need to accomplish the steel ladder roof beam and demolish the superficial layer defect processing at position, the process is more, and the space is limited, and the high altitude construction degree of difficulty is great. The removed steel ladder beam is also required to be transported out by matching with a hoisting system, the entrance condition of large-scale construction mechanical equipment is limited, and the construction cost is higher; in addition, the steel ladder after being dismantled is difficult to recycle.

Disclosure of Invention

The invention aims to provide a method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure, which has the advantages of simple structure, convenience in construction, good stability, safety and reliability, and overcomes the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure comprises the following steps:

when a steel ladder in a high-rise concrete structure is reconstructed, firstly, a step plate, a platform plate and a railing on the steel ladder are dismantled, and a steel ladder beam is reserved;

erecting a template by taking the steel ladder beams as a positioning foundation, pouring concrete of the cantilever concrete ladder beams to form cantilever concrete ladder beams taking the steel ladder beams as inner supports, and pouring concrete of a concrete platform plate between the cantilever concrete ladder beams on two sides;

and step three, after the concrete reaches the design strength, erecting the precast concrete stairs between the concrete platform plates and installing the handrails.

In the method, the longitudinal bars implanted into the high-rise concrete structure are arranged on the periphery of the steel ladder beam, the other ends of the longitudinal bars are fixedly welded with the steel ladder beam, and when the concrete of the cantilever concrete ladder beam is poured, the concrete completely covers the longitudinal bars, so that the thickness of a protective layer of the longitudinal bars is ensured to meet the requirement.

In the method, the cantilever concrete ladder beam is of a variable cross-section structure with the cross-section area linearly reduced from the fixed end to the free end.

Due to the adoption of the technical scheme, the invention has the following advantages: according to the invention, the original steel ladder beam is not required to be dismantled, and the concrete stair is arranged on the basis of the original steel ladder beam, so that the problem of high dismantling difficulty of the steel ladder beam under the condition of incomplete construction conditions outside the concrete structure is solved. Meanwhile, the longitudinal upper steel ladder beam and the concrete can longitudinally jointly bear bending moment and shearing force, and the transverse upper steel ladder beam can replace the structural action of distribution ribs without additionally configuring reinforcing steel bars, so that the transverse upper steel ladder beam has a considerable effect on the reduction of engineering quantity. Therefore, the improved concrete stair has the advantages of good appearance quality, safety, reliability, easiness in construction, easiness in formwork erection and positioning and the like.

Drawings

FIG. 1 is a perspective view of a schematic of the structure of the present invention;

fig. 2 is a cross-sectional view of a schematic of the structure of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention comprises the following steps: referring to fig. 1 and 2, a method for transforming a steel ladder into a concrete ladder in a high-rise concrete structure includes the following steps:

firstly, when a steel ladder in a high-rise concrete structure 4 is reconstructed, firstly, a step plate, a platform plate and a railing on the steel ladder are dismantled, and a steel ladder beam 1 is reserved;

erecting a template by taking the steel ladder beam 1 as a positioning foundation, pouring concrete of the cantilever concrete ladder beam 2 to form the cantilever concrete ladder beam 2 taking the steel ladder beam 1 as an inner support, and pouring concrete of a concrete platform plate 6 between the cantilever concrete ladder beams 2 at two sides;

and step three, after the concrete reaches the design strength, erecting the precast concrete stairs between the concrete platform plates 6 and installing the railings.

In the method, the longitudinal bar 3 embedded in the high-rise concrete structure 4 is arranged on the periphery of the steel ladder beam 1, the other end of the longitudinal bar 3 is welded and fixed with the steel ladder beam 1, and when the concrete of the cantilever concrete ladder beam 2 is poured, the concrete completely covers the longitudinal bar 3, so that the thickness of a protective layer of the longitudinal bar 3 is ensured to meet the requirement.

In the method, the cantilever concrete ladder beam 2 is of a variable cross-section structure with the cross-section area linearly reduced from the fixed end to the free end.

In conclusion, the original steel ladder beam 1 does not need to be dismantled, the concrete stair is arranged on the basis of the original steel ladder beam 1, and the problem that the steel ladder beam is difficult to dismantle under the condition that the construction condition of the outer side of the concrete structure is incomplete is solved. Meanwhile, the longitudinal upper steel ladder beam 1 can be longitudinally combined with concrete to bear bending moment and shearing force, and the transverse upper steel ladder beam can replace the structural action of distribution ribs without additionally configuring reinforcing steel bars, so that the transverse upper steel ladder beam has a considerable effect on reduction of engineering quantity. Therefore, the improved concrete stair has the advantages of good appearance quality, safety, reliability, easiness in construction, easiness in formwork erection and positioning and the like.