Development of Job Instruction for Installation of Reinforced Concrete Frame of One-Storey Industrial Building

Contents

Introduction

1 Scope

2 General provisions

3 Organization and procedure of works execution

3.1 Justification of installation method

3.2 Preparatory works

3.3 Main works

3.4 Final works

4 Requirements for quality of works

5 Requirements for logistical resources

5.1 Specification of mounting elements

5.2 Bill of Quantities

5.3 Calculation and selection of lifting mechanisms

5.4 List of process accessories, tools, equipment and accessories

5.5 List of machines and process equipment

5.6 List of materials and articles

6 Safety and Health

7 Technical and economic indicators

7.1 Calculation of labor costs and wages

7.2 Calculation of technical and economic indicators

List of literature used

Introduction

The main document regulating the sequence, methods of execution of construction processes and the use of mechanization tools is the process chart. It is developed on the basis of the study of standard technological charts and best practices of domestic and foreign construction.

In this course design, it is required to draw up a process plan for the installation of the prefabricated framework of a one-story industrial building.

Installation of building structures is a leading technological process in the construction of the country as in the production industry. This is facilitated by a developed industry for the production of structures from prefabricated railway elements, the presence of effective mechanization tools, in-line work, etc. Installation of structures largely determines the structure of object flows, the overall pace of construction of the facility, the order and methods of other work.

The Job Instruction shall describe the methods of works performance ensuring improvement of technological processes, reduction of construction cost and labor intensity, product quality improvement. It is necessary to justify the selected installation method, as well as give detailed explanations on the technological processes, including graphically - in the form of diagrams and figures.

The student receives initial data at the first practical lesson, the development of the TC is carried out during the course of the discipline "Construction Production Technology." Thus, the project allows you to consolidate the student's knowledge in this discipline, contributes to the qualitative study of other disciplines of the department "Technology and organization of construction production, and also helps in writing a diploma project.

1 application area

Process for which developed

process sheet is installation of prefabricated frame of one-storey industrial building. This routing is intended for new construction.

The mounted building is a one-story industrial structure. The building is frame, the frame consists of prefabricated reinforced concrete and metal elements.

The building consists of three spans:

• I - span 30m, pitch of columns 6m, height from floor to bottom of rafter structure is 9.6m

• II- span 30m, pitch of columns 12m, height from floor to bottom of rafter structure is 10.8m

• III - span 24m, pitch of columns 6m, height from floor to bottom of rafter structure is 9.6m

Each span is equipped with a bridge crane with a lifting capacity of 20t.

The length of the building in each span is 156m.

The diagram of the building is presented on the form with the task, as well as in the graphic part of the course work.

The following assemblies are used in the processes:

items:

• Crane columns extreme 5K 965; Series 1.424.15, Issue 1

• Crane columns extreme 3K 1088; Series 1.424.15, Issue 2

• Crane beams BK63A1UK; Series 1.424.15, Issue 2

• Crane beams BK123A1UK; Series 1.424.15, Issue 2

• Rafter trusses FB24U14A1U; series 1.4633, issue 4

• Rafter trusses SPS 302.55; GOST 23119-78

• PG6A1UT coating plates; GOST 22701.3-77

• Coating plates 2PG121A1UT; series 1.465.1 - 7/84, issue 1

• Wall panels of PC 12.12.2511; KZHI25

The scope of installation is 1843.2 m ³.

This routing is not linked to any calendar

timeline and designed for normal conditions. It is worth considering that the performance of work in winter makes some adjustments to

construction process.

At negative temperatures precast reinforced concrete elements

are stored in warehouses on high linings and measures are taken to prevent icing of surfaces. Before installation, the joined surfaces of the elements are cleaned from snow and ice with scrapers, brushes, and hot air. When performing installation work, the most vulnerable place is the joint of prefabricated reinforced concrete structures.

During winterization of butt joints

measures must be taken to prevent freezing of concrete in the joint until it reaches strength, the values ​ ​ of which depend on the type of structure and the timing of its commissioning.

Sealing of joints is performed by one of the following methods:

heat-free - concrete with anti-frost additives, heating - conventional concrete with heat treatment. Under certain conditions, a combined method is also used - concrete with anti-frost additives and subsequent heat treatment.

Combined method involves addition to concrete

mixture of sodium nitrite (not exceeding 10% of cement weight) to reduce freezing temperature. After filling of joint concrete is subjected to heat treatment.

Electrical heating is mainly used for column joints

with glass-type foundations and wall panels. When electroheating the joints of columns with foundations, round reinforcement bars with a diameter of 6... 8 mm are lowered into the laid mixture, which serve as electrodes. The distance between the rod electrodes is taken so that local concrete overheats are excluded (20... 25cm). All open surfaces of heated joints are covered with vlago and steam-proof material, insulated with sawdust, slag, and mineral plate mats.

The combined method makes it possible to abandon the heating of docked

elements before concreting, start heating at any time, convenient for installation works, use unheated aggregates for concrete mix preparation.

Concrete mixture with addition of sodium nitrite retains

electric conductivity at negative temperatures, which makes it possible to apply electric heating.

Presence of negative ambient air temperatures imposes

certain restrictions on the process of sealing joints. So, sealing of joints mastics is allowed at temperatures not lower than 20 wasps. Polyisobutylene mastic for better adhesion to concrete should be preheated to 110... 120 ° C.

Otherwise, the process of sealing joints in winter conditions

flows in the same way as in summer.

Winter time has less impact on technology

installation of metal structures than reinforced concrete. Basically, the installation of metal structures in winter is carried out with the same machines, devices and methods as in summer. The main specific feature of the joint arrangement is the imposition of restrictions on welding operations - welding cannot be carried out at a temperature below 30 ° C.

2 general provisions

All sections of Job Instruction are developed according to:

• MDS 1229.2006 "Methodological Recommendations for Development and Execution of Job Instruction";

• SNiP 12.012004 "Construction Organization";

• SNiP 3.03.0187 "Bearing and enclosing structures";

• SNiP 12032001 "Occupational Safety in Construction" (Part 1);

• SNiP 12042002 "Occupational Safety in Construction" (Part 2).

3 organization and technology of works execution

3.1 Justification of installation method

During installation of the frame of this one-story industrial

The building uses a combined installation method. This method is a combination of differentiated and complex installation methods. The building is divided into three grips corresponding to the spans of the building. Installation of columns and crane beams is carried out in a differentiated manner, work is carried out on grips with ensuring production flow. Elements are also unloaded by grips immediately prior to installation. Installation of rafter trusses, slabs and wall panels by integrated method is carried out.

Application of the combined method, division of the building by grips and

well-thought-out movement of workers in the facility with maximum combination of individual operations and observance of rhythmicity and continuity allows to achieve short construction terms without attracting extra labor.

3.2 Preparatory works

Before starting the installation of the building frame, it is necessary to:

• Organize transport access routes to the facility

• Complete construction of building foundations

• Establish the necessary communications

• Build temporary fencing for construction area with warning signs

• Inspect, install and accept the necessary mounting mechanisms, accessories and equipment

All prefabricated elements entering the construction site shall be thoroughly inspected:

• all parts shall be marked at manufacturers.

It is necessary to check geometric shapes, rectilinear edges and faces, correct arrangement of embedded parts, mounting loops, reinforcement outlets;

• parts with cracks, deformations and other defects are subject to

returning to the plant.

Before lifting and moving the prefabricated elements to the installation area:

• clean the element, from dirt;

• apply the main risks and check, presence of marks of support places

elements;

• check the correctness and reliability of slinging.

Layout of the work site, including: building breakdown

grips, cranes movement and parking schemes, etc. - see graphic part.

Work is carried out in the open air, under normal conditions

construction.

3.3 Main works

Main works include installation of prefabricated units directly

elements (columns, crane beams, rafter trusses, coating plates and wall panels), including their slinging, alignment and temporary attachment, as well as related work (welding and anti-corrosion coating device, grouting of columns and pouring of seams of coating plates).

All work flow diagrams on the construction site, slings

elements, as well as temporary anchoring schemes - see the graphic part.

1) Reinforced concrete columns

Columns shall be installed in a differentiated manner. We install the columns with the MKG25 crane as part of the link: crane driver 6p - 1 person, installers: 6p - 1 person, 4p - 3 people, 3p - 1 person. Simultaneously with the installation, operations are carried out to terminate the joints of the columns, which are carried out by installers 3p and 4p from the same link. The installation of the columns is carried out in 2 shifts. For more information, see the graphic.

Reinforced concrete columns at the facility are laid out on wooden

liners in the area of the installation crane. Lining thickness shall be not less than 25 mm. Layout should be performed so that the crane from the installation parking can set the columns to the design position without changing the boom departure (see graphic part)

Each column must be inspected so that it does not have deformations, damages, cracks, shells, chips, exposed reinforcement, concrete strains; check the geometric dimensions of the column, the presence of a mounting hole, the correct installation of steel embedded parts.

The columns are stroked and then installed by means of a mounting crane into the foundation sleeves on a leveling concrete layer with a thickness of 20 mm, combining axial hairlines in the lower part of the columns with axial hairlines on the foundation. Then columns verticality is checked by means of two theodolites. Theodolites are located at right angles to the digital and letter axes of buildings .

The columns are temporarily attached and adjusted vertically using inventory wedge inserts and inventory retainers. The inventory retainers are removed after the final installation of the column in the design position, and the inserts are dismantled after pouring the seam and reaching 70% of the design strength with concrete.

Termination of the joint is performed manually with fine-grained concrete mixture immediately after installation of the column. Concrete mixture poured into joint is compacted with the help of vibrators. During filling of the joint, a special fence is installed on wedge inserts, which is removed after filling.

2) Crane beams

Installation of crane beams is carried out by differentiated method. A comprehensive team consisting of: crane driver 6p - 1 person, structural installers: 6p - 1 person, 4p - 3 people, 3p - 1 person, electric welders 6p - 2 people works at the installation. Install crane beams using MKG25 crane. Works on installation of crane beams, welding and anticorrosion processes are carried out in 2 shifts.

Crane beams shall be installed after all columns within the first grip have been installed and when the concrete at the junction between the column and the walls of the foundation shell has gained at least 70% of the design strength, which is reflected in the work schedule (see graphic part). Before installation of reinforced concrete crane beams it is necessary to perform geodetic check of elevations of support platforms of crane cantilevers of columns.

Inventory stairs must be installed on the columns in order to organize a workplace for installers and welders. The place where the beam will be installed must be cleaned of debris and dust with metal brushes.

The beam is raised above the design elevation by 50 cm, and then with the help of braces it is brought to a position close to the design one. During installation of crane beams, hairlines on the lower end faces of the beams must coincide with hairlines on the column consoles. Temporary attachment of the beam is carried out using a string and a screw tie to adjust the beams.

After the beams are laid on the column cantilever and temporarily fixed with tubing, they are adjusted by the height elevations. Axes of crane beams are adjusted with theodolite installed along axis of the first crane beam on a special bracket.

After alignment, mounting ladders are hung on the beams, with the help of which welders weld embedded parts of columns to the upper shelves of the beams, as well as welding along the lower belt of the crane beam. The height of the weld leg is 10 mm. Then weld is coated with anticorrosion composition.

As long as the welders permanently secure one beam, the installers begin to prepare for the installation of the next beam in order to save time.

3) Installation of rafters and slabs

Installation of trusses and coating plates is performed by a complex team. The crew includes: crane driver 6p - 1 person, installers: 6p - 1 person, 4p - 3 people, 3p - 1 person, as well as electric welders 6p - 2 people. SCG 63/100 crane is used. Installation of rafter trusses is carried out by the main lifting, and coating plates - by auxiliary lifting (goose).

We begin to install trusses and coating plates after installation of all crane beams on the first grip. Work on installation of trusses and slabs is performed by a complex method, which provides for installation and final fixation of all structural elements of one building cell.

On the first and second gripper, metal trusses are also pre-assembled, which is carried out on special stands in the crane area. Pre-assembly is carried out by the same installers who directly install trusses and plates.

For metal trusses it is necessary to perform temporary reinforcement during lifting and installation (see graphic part).

Trusses and cover plates are mounted with their preliminary laying in the area of the installation crane. Before starting installation it is necessary to equip trusses with safety rope and braces. A steel handrail is also attached to the upper belt of the truss, which serves as a support for the installers. Trusses should be installed in the design position, combining axial hairlines on their ends with hairlines on the supporting surfaces of the columns. Then embedded parts of elements are joined by welding, anticorrosion coating is applied. Stability of trusses during installation is ensured by means of roof conductor-spacer. Temporary attachment can be removed only after installation and final welding of embedded parts of one plate. The first two at the end of the truss building are fixed with braces, which are fixed to the attachment anchors, and with two spacers with a length corresponding to the pitch of the columns. Further installation is carried out using a roof conductor.

Storage of plates is performed by stacks in area of action of mounting crane. In a span with a length of 24 m, two stacks of plates of 4 plates in each are arranged, and in spans of 30 m - two stacks of 5 plates in each. Slabs are laid by marking on upper belts of trusses in order to ensure their design position in plan of rafter structure.

The first coating plate is welded in four support units, the rest in at least three units.

When laying plates in each cell, one installer is located on a plate laid in an adjacent cell, the second - on a ladder platform hung on a column. In the future, both installers switch to the newly laid plate for receiving and laying the next one. Extreme slabs shall be equipped with an inventory fence structure.

After placing the plates on the middle plate, a roof conductor is mounted for temporary attachment of the next truss.

4) Pouring of slab seams

After all the columns in the building are installed, two people

from the team that mounted the columns - one installer 4p and 3p each - remain on the object in order to begin pouring the seams of the coating plates after a while. The beginning of filling is provided so that when entering the third grip, the work on installation of trusses and coating plates is completed.

The seams are previously cleaned of debris and dirt. Fill Seams

is carried out with the help of a pneumatic supercharger, which through a pipeline supplies under pressure fine-grained concrete mixture to the seams of the coating slabs. Workers must monitor the pouring process, smooth the surface of the seam, and seal the pouring mixture with a vibrator.

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