A construction method for underpinning a hollow floor slab to a cast-in-place floor slab

Abstract

The invention relates to a construction method for underpinning a hollow floor to a cast-in-place floor. The construction method includes the following steps: S1, setting a protective net under the hollow floor to be removed; S2, dismantling the hollow floor Carry out demolition, and add a wall unloading support frame in the middle part of the gap between the supporting parts at both ends of the original hollow floor slab; The wall unloading support frame; S4, install steel bars between the two wall unloading support frames corresponding to the load-bearing horizontal wall, and then install steel bars between the two wall unloading support frames corresponding to the longitudinal wall; S5, support formwork ; S6, fastening with steel wires at the interlaced parts of the reinforcing bars; S7, pouring concrete into a cast-in-place floor slab; the present invention replaces the original hollow floor slab that does not meet the function of use after transformation with a cast-in-place slab to achieve the effect of reinforcement and transformation Purpose.

Description

technical field [0001] The invention belongs to the technical field of construction engineering reinforcement and transformation, and in particular relates to a construction method for underpinning a hollow floor to a cast-in-place floor. Background technique [0002] At present, the construction methods used for direct reinforcement of hollow floor slabs that do not meet the new use requirements are: such as enlarging the section method, bonding steel method, pasting carbon fiber cloth method, etc. [0003] The basic idea of ​​enlarging the section method is to increase the section of the floor slab on the top of the hollow slab to increase the bearing capacity and rigidity; The floor is jointly stressed to meet the new use requirements; the basic idea of ​​the paste carbon cloth method is to paste the carbon fiber cloth on the surface of the hollow floor through structural glue, so that the carbon fiber cloth and the original hollow floor are jointly stressed to meet the n...

AI Technical Summary

Problems solved by technology

[0005] (1) The net height of the floor is reduced, and the comfort of the room is reduced;

[0006] (2) The durability of the floor slab is not improved;

[0007] (3) Integrity is poor

[0009] (1) Limitation 1: The code stipulates that after the reinforcement of reinforced concrete structural members, the increase in the flexural bearing capacity of the front section should not exceed 40%;

[0010] (2) Limitation 2: The code stipulates that the concrete strength level of the reinforced concrete structural members shall not be lower than C15, and the positive tensile bond strength of the concrete surface shall not be lower than 1.5MPa; due to the long service life of the hollow floor , its strength index often fails to meet the specification requirements;

[0011] (3) The requirements for the anchorage length at the end are relatively strict. In actual engineering, due to the limitation of the plate end support, the anchorage length is difficult to meet;

[0013] (5) Due to the long service life of the hollow floor slab, the carbonized layer on the surface is relatively thick, and the carbonized layer is often not fully polished when pasting the steel plate and carbon cloth, and the pasting quality is difficult to guarantee;

[0015] (7) Poor durability and poor aesthetics

[0016] In addition, in order to meet the new requirements for use, when it is necessary to open more and larger openings on the hollow floor and increase the load, it is difficult to meet the requirements of the above reinforcement methods.

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