Taking advantage of the characteristics of light weight, high strength, large bearing capacity and good seismic performance of profiled steel plate, the traditional formwork support system is cancelled. The designed steel plate rib, as a permanent formwork of concrete floor slab in engineering, plays the role of replacing the steel bar at the bottom of the slab in the use stage, which is not only convenient for construction and saves costs, but also has concrete bond strength with concrete and improves the bearing capacity of the structure.

The construction of multi-storey and high-rise steel structures usually adopts one column, two floors or three floors, and the construction speed is faster. With the increase of structural height, profiled steel plate can be used as the operating platform during construction to ensure construction safety.

application area

This construction method is suitable for composite structural engineering of steel structure and concrete floor, especially for buildings with high floors and large areas, which are not suitable for erection of full-house scaffolding system.

Construction preparation work

Materials and machines

labour organization

In the construction of profiled steel sheet, operators are required to have high technical level and be able to work in multiple groups at the same time. The types of work that need to be configured are: riveter, welder, gas welder, rigger, surveyor and mechanic.

Cao Zuo Jian

The body frame structure has been welded and qualified by ultrasonic inspection.

After the welding of the main frame structure is completed, re-examine the verticality deviation of the column.

Before the upper beam is installed, the profiled steel plate should be placed on the lower beam. If the profiled steel plate is hoisted after the installation of the secondary beam is completed, it will inevitably lead to oblique delivery, which will easily damage the steel plate and even cause danger.

construction sequence

Plane construction sequence

With the installation sequence of the main structure, profiled steel plates will be laid. As long as they meet the construction conditions, they can start from their respective units.

Internal structure order

In order to ensure the safety of the construction personnel of the upper steel column, the upper laminated steel plate of the column should be laid first, and then the lower laminated steel plate should be laid.

method of erection

Preparation before installation:

Be familiar with the drawings carefully, and understand the typesetting distribution, size control requirements and position relationship of profiled steel plates on steel beams.

Before installation, check the flatness of the steel beam and the integrity of the steel beam, carefully clean up the sundries on the top surface of the steel beam, and check whether there is anti-corrosion technology on the surface of the steel beam. If there is, the anticorrosive surface must be polished off.

Comprehensively measure the flatness of the steel beam surface, set out the steel beam surface according to the layout of profiled steel plate and building axis survey, and make measurement marks.

Installation of profiled steel plate:

Hanging and laying

The profiled steel plate shall be provided by the designated manufacturer. When the company supplies, the profiled steel plates are transported to the site in bundles with the installation unit as the unit, each piece.

Bundles of profiled steel plates shall be neatly stacked in the laying order according to the layout provided by the factory.

Before hoisting profiled steel plate, the plate type, size, number and position shall be checked respectively according to the design and construction drawing, and after the ingredients are confirmed to be correct.

With the installation sequence and progress of the main structure, it will be hoisted to each construction section and piled up. Stacking should be dispersed into strips. When lifting profiled steel plate on the beam, lower it slowly to avoid rough lifting action.

In order to protect the profiled steel plate from deformation during lifting, a soft sling should be used or rubber or steel plate should be added at the corner where the steel wire rope contacts the steel plate.

Use stow-wood, but it must be tied firmly. Beware of slipping, and the profiled steel plate slides obliquely and hurts people. For overweight and super-long plates, lifting points should be added or hangers should be used to prevent deformation or damage during lifting.

When profiled steel plates are piled up in bundles, they should span multiple steel beams. When a single span is placed between two beams, attention should be paid to the width of support at both ends to avoid falling accidents caused by dumping.

Before installing profiled steel plate, the position line of profiled steel plate laying should be marked on the beam. When laying profiled steel plates, rough installation should be carried out first to ensure that the corrugations are aligned and the steel bars can pass through the "groove". After the plates are hoisted in place, they will be put in place one by one along the laying direction, starting from the pop-up laying line of steel beams. After reaching the control line, the plate joint should be adjusted appropriately.

Schematic diagram of profiled steel plate hoisting:

When the wind speed is greater than or equal to 6m/s, construction is prohibited, and the removed profiled steel plates should be re-bundled, otherwise the profiled steel plates are likely to be blown by strong winds, causing safety accidents or damaging the profiled steel plates.

Laying of irregular panels: according to the arrangement of steel beams on site, set out the center line of steel beams, pre-assemble profiled steel plates on the platform on the ground, then set out control lines, and then typeset and cut according to the width of profiled steel plates.

Fixed; unchangeable

The lap length of profiled steel plate should meet the design requirements. In general, the lap length between the edge end and the supporting steel beam is not less than 50mm, and the edge lap between plates adopts "concave-convex buckle". In order to prevent the steel plate from being separated due to stress, the side lap joint should be fixed with fastening clips or spot welded, with the maximum spacing of 900 mm ... See the details of profiled steel plate fixing and inserting plate structure for details.

Any unfixed profiled steel plate may be blown away or slipped by strong wind, resulting in an accident.

Welding and stud welding of profiled steel plate

In the process of laying profiled steel plate, the center line of the supporting steel beam completely covered by profiled steel plate should be marked on the profiled steel plate, so that the stud welding can be in place accurately.

Formulate strict storage regulations for stud solder and stack it correctly as required.

Before welding, strictly check whether the gap between profiled steel plate and steel beam is controlled within 65438±0mm, and ensure that the welding place is dry.

According to the diameter of the stud, the appropriate welding process parameters are selected. Six studs are directly punched on the 80x 80mm 16Mn steel plate with the thickness ≥ 16 mm. After the appearance inspection of the weld is qualified, the sample is cold-bent for 30 degrees, and after the original axis of the stud is bent for 30 degrees, the welded part is qualified without cracks.

Before formal large-area welding, stud welding process should be evaluated. According to the requirements of relevant parameters in the process evaluation report, the welder shall be urged by special personnel to try welding before going to work, and the parameters shall be adjusted according to the welding effect. After a period of records, it is necessary to synthesize the adjusted parameters, list a table, and make technical disclosure to each welder one by one.

For the through studs encountered in the actual construction process, the thickness of profiled steel plate, the galvanized layer on the surface and the gap between steel plate and steel beam should be fully considered, and the profiled steel plate should be placed on the specimen before each construction, and the construction should be carried out after adjusting the process parameters. The first 10 nail in construction, after passing the 30 bending test, will be constructed normally.

After the laid profiled steel plate is straightened, in order to prevent it from slipping off the steel beam or being lifted by strong wind, it should be spot-welded firmly or fixed with studs in time. Spot welding or plug welding is used between profiled steel plate and supporting steel beam, and the average maximum spacing of welding spots is 300 mm. Spot welding shall be carried out at each groove, and the welding shall be firm (the diameter of the welding spot shall not be less than10 mm); Carry out side spot welding every 900 mm

Spot welding is fixed by manual arc welding, and spot welding is carried out by DC welder. If the welding current of the stud is too large, which causes the pressed steel plate to burn through and loosen, the spot welding should be done next to the stud.

Edge closing method of profiled steel plate

When the profiled steel plate edge beam or laying is discontinuous:

When the slab is continuously laid on the beam:

End seal of profiled steel plate

After the profiled steel plate is laid and welded in place, it is necessary to seal the gap between the corner and the peak of the profiled steel plate in order to prevent slurry leakage during concrete construction. This treatment method can be sealed by matching plug or PVC tape plugging. Details are as follows:

On-site cutting

After the profiled steel plate is positioned, the cutting line pops up and cuts along the line. The location of the cutting line should refer to the plan and layout, and check; If the profiled steel plate is damaged due to wrong cutting, the plate type and length shall be recorded, and the supplier shall be informed to supplement it in time; On-site corners, column edges and reinforcing plates need to be cut. In principle, electric shear and plasma gas cutting technology are preferred in wire cutting, and the method of destroying the strength of base metal cannot be used. Oxyacetylene cutting is strictly prohibited.

General holes should be chiseled as far as possible after concrete pouring. If the pre-opening perpendicular to the plate rib direction is harmful to the groove rib of profiled steel plate, it must be reinforced according to the regulations. For details of reinforcement measures, please refer to the construction details of opening reinforcement. (6) Opening reinforcement description:

Rectangular openings with circular aperture, 800 mm and below, or any size of 800 mm and below can be enclosed by formwork first, and holes can be opened only after the concrete pouring of the floor slab is completed and reaches more than 75% of the design strength.

According to the reinforcement method of reinforced concrete structure (see structural design for details), steel bars are set around corners and holes.

When the diameter of the opening or any size is greater than 800 mm, a surrounding beam should be added around the opening. As shown in the figure, the reinforcement measures of profiled steel plate opening ≥ 800 mm

quality management

Quality control measures

Establish a comprehensive quality consciousness and implement "whoever produces, who manages quality;" Who is responsible for construction and quality; Who operates, who guarantees the quality "principle, the project quality post responsibility system.

Technical disclosure system: adhere to the principle of ensuring construction quality with technical progress, and the technical department will prepare targeted quality technical disclosure to guide construction operations.

Inspection system for components entering the site: the profiled steel plates entering the site must be inspected according to the requirements of national specifications, and all unqualified materials will leave the site.

Install in strict accordance with the typesetting diagram. When the typesetting diagram is inconsistent with the installation object, consult with the technical department in time.

Establish a three-inspection system. Implement and adhere to the system of self-inspection, mutual inspection and handover inspection, and make written records.

Before handover and acceptance, carefully check whether there are any omissions in the installation process, and repair, correct or replace the impact deformation and damage caused in the construction process.

Check whether there is slurry leakage and other gaps are not blocked.

Quality control standard

For the construction quality standard of profiled steel plate processing and installation, refer to Code for Acceptance of Construction Quality of Steel Structure Engineering (GB50205-200 1).

The entry acceptance of profiled steel sheet mainly depends on whether there are cracks in the bottom plate and whether the galvanized layer has quality defects such as cracks, peeling and scratches visible to the naked eye.

The dimensional deviation data of profiled steel plate are as follows: wave distance deviation 2.0mm wave height deviation 1.5mm (section height ≤ 70 mm); The lateral bending deviation is 20mm (length ≤7m).

The allowable deviation of on-site processing and manufacturing of profiled steel plate is as follows:

The installation of profiled steel plates should be straight, and the ribs between two adjacent steel plates must be connected, and the deviation should be controlled within 5mm to ensure the beautiful effect of the finished surface at the bottom of profiled steel plates.

Visual inspection of studs. The welded welding nail should have extruded molten metal (extrusion leg) around its root, but the vertical surface of the extrusion leg of the welding nail can not be fused, and the horizontal surface can overflow, sometimes allowing a small number of small shrinkage cracks or defects on the extrusion top surface that are radial or perpendicular to the straight line of the welding nail.

Quality standard for appearance inspection of studs

Check the bending (knocking) of the stud. After the appearance inspection is qualified, 65438 0% of the total number of bolts shall be selected for bending inspection, and the head of the bolt shall be struck with a hammer to bend it, deviating from the original vertical position by 30 degrees, and the weld at the root of the bolt shall be tested to be qualified without cracks and fractures.

Special repair measures must be taken where misplaced abandoned holes are reserved.

safety measure

Before laying profiled steel plates, conduct safety education for construction personnel to improve safety awareness. Generally, the laying sequence of profiled steel plates is loose laying, adjustment and riveting. Before laying, a horizontal safety net should be laid under the profiled steel plate in advance.

The lifting weight of profiled steel plate should not be too large. In this process, there must be a special person to command and operate carefully to avoid material damage, deformation and scrap due to operational errors.

The stacking and stacking of profiled steel plates should not be too high, and should be used in coordination with cranes to avoid falling and injuring people due to high stacking.

Riveting personnel should rivet the adjusted profiled steel plate in time, and require the plate laying to be synchronized with riveting. Missing riveting and springboard riveting are not allowed to prevent the board from slipping due to missing riveting and prevent people from stepping down.

During the construction of profiled steel plate, wires and cables should be suspended by insulation measures to avoid electric shock and personal injury caused by leakage.

The edge safety protection of the left hole must be handled in time, and the hole should be closed in time after the profiled steel plate is laid, with guardrails and obvious signs.

When laying profiled steel plates, irrelevant personnel are prohibited from entering the construction site and walking under the construction layer of profiled steel plates.

It is forbidden to throw anything at high altitude, and the articles are fastened with ropes. It is forbidden to install profiled steel plates when the wind reaches level 5 and rainy days.

Pay attention to the wind direction when installing the movable profiled steel plate, and the construction personnel should move horizontally when moving the profiled steel plate to avoid the windward operation on the surface of the medium-pressure steel plate during construction.

Environmental protection measures

Profiled steel plates must be placed horizontally, and temporary shielding measures (such as linoleum paper and sacks) should be taken to avoid glare effect, which will affect the walking construction of construction workers and the working life of surrounding residents. Speed up the steel bar binding, and the glare effect will be weakened to some extent after the steel bar binding is completed.

Reliable shielding measures should be taken during construction to avoid light pollution caused by light leakage of welding arc.

Handle with care during installation, and do not knock the profiled steel plate during construction at night, so as to avoid noise and reduce noise pollution.

benefit analysis

Because profiled steel plate is used as the formwork for pouring concrete, a large number of wooden formwork and its supports are saved. On the one hand, it saves a lot of wood, and because of the lack of forest resources in China, the price of wood is also very high. Therefore, it is of great significance to our country, on the other hand, it also saves all or part of the template support.

Because the profiled steel plate is very light, it is very convenient to pile up, transport and install, which not only saves a lot of labor, but also reduces the workload on site and improves the construction conditions of workers.

In the application stage, profiled steel plate can also replace tensile steel bars due to the interaction with concrete. Therefore, the production and installation of steel bars are reduced.

Because the profiled steel plate is directly supported on the steel beam as a template for pouring concrete, it provides a broad working platform for various types of work, so pouring concrete and other types of work can be carried out in multiple layers, which greatly speeds up the construction progress and shortens the construction period. This is especially significant for large high-rise and super-high-rise buildings.

Convenient for laying communication, electricity, heating and other pipelines. Moreover, materials such as heat preservation, sound insulation, heat insulation and vibration isolation can be laid to improve the working performance of the floor. Compared with wooden formwork, the possibility of fire in the construction of profiled steel composite floor is reduced.

Engineering application example

This method has been applied in the clean coal project of Yanmei Lantian Clean Energy Co., Ltd. The desulfurization additive factory-coarse powder workshop and the vertical mill and hammer crushing workshop of pulverized coal preparation system are multi-storey and high-rise steel frame structures, with the total consumption of profiled steel plates of about 6000m2 and the average consumption of single layer of 600 m2. The laying period of each laminated steel plate is about 1 day. At present, the construction of profiled steel plate composite floor has been completed. After on-site inspection, it was found that the bottom profiled steel plate. After special construction acceptance and comprehensive evaluation, the construction quality meets the design requirements, and all quality evaluation indexes are qualified.

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