Course project on concreting technology of foundation structures: "Design of concrete works technology"

Contents

Table of contents

1 Introduction

2. Design Task

3. Scope of application of task list

4. Define Scope of Work

5. Layout diagrams of monolithic structures formwork

6. Technology and organization of construction

6.1 Preparatory works

6.2 Reinforcement works

6.3. Formwork

6.4. Concrete Mix Feed

6.5. Concrete laying and compaction

6.6. Concrete Care

6.7. Wall Structure Flattening

7. Production Costing of Work

8. Work Schedule

9. Quality Control and Acceptance

10. Site Health & Safety

11. Technical and economic indicators

LIST OF LITERATURE

1 Introduction

Concrete and reinforced concrete works are one of the main types of construction. In the total cost of material resources consumed in capital construction, the cost of concrete and reinforced concrete works is about 25%.

The main areas of improvement of capital construction are reducing the time and cost of construction, as well as reducing labor costs. This is achieved by improving the organization of construction, using advanced technology for the construction of buildings and structures and complex mechanization of processes.

The course project on concreting technology of foundation structures is designed to expand and consolidate theoretical knowledge in terms of designing the technology for the production of reinforcement, formwork and concrete works, as well as acquire skills in the independent use of reference, regulatory and special literature.

Scope of application of task list

This process sheet was developed for concreting the walls of the basement with a thickness of 400mm, and a height of 3.0m, in the city of Novosibirsk..

This TC is designed for new construction, within the city. Reinforcement of wall structures - with spatial frames and flat grids; joints of rebar grids and frames are made overlapping by welding.

The Job Instruction provides for the construction of a monolithic reinforced concrete wall using a unified disassembly formwork "PERI TRIO," enlarged into formwork panels.

Loading and unloading operations, reinforcement and formwork are carried out by an automobile crane with a lifting capacity of 6.3 tons.

This JI uses B25 grade concrete delivered from the plant at a distance of less than 10 km to the construction site.

Technology and organization of construction

Complex process of erection of monolithic structure consists of processes of formwork arrangement, installation of reinforcement products, laying and compaction of concrete mixture, disassembly of formwork and care of concrete.

The following procedure of works execution is provided by this Technical Instruction:

Reinforcement works:

- Preparation of reinforcement bars of required length;

- Transportation of reinforcement products, fixators, embedded parts, penetrators, PCBs - tubes to the laying area;

- Installation of vertical individual reinforcement bars with wire joints;

- Arrangement of layout base of horizontal guide rods;

- Installation of horizontal separate reinforcement bars with elm joints by wire and U-shaped reinforcement elements for fixing two vertical grids to each other;

- Installation of reinforcement rods according to the working design;

- Installation of embedded parts, penetrators, channels and junction boxes for electrical wiring;

- Arrangement of process seam with fixation of mesh-slave between two vertical bars of reinforcement;

Formwork:

- Marking of the base for formwork shields, for the pitch of braces;

- Transportation of formwork to the installation area;

- Treatment of formwork panels with antiagdesion lubricant;

- Installation of the first panel of formwork (corner) with its attachment with a straightening brace;

- Installation of subsequent formwork panels with their fixation between co-formations and installation of braces;

- Installation of intermediate braces;

- Installation of opposite formwork panels with their attachment to the previously installed panels by weights;

- Alignment of wall formwork panels with their adjustment to design position;

- Top wall elevation leader;

- Arrangement of scaffolding for finding people at the top of the formwork .

Concrete works:

- Acceptance of concrete mixture into the hopper;

- Concrete mix supply to concreting zone;

- Laying of concrete mixture with compaction by depth vibrator;

- Leveling of concrete mix by beacon elevations;

- Smoothing of concrete mixture;

- Cleaning of receiving bin, tools, tooling from concrete.

Decompression:

- Removal of canopies, their cleaning, folding and storage on sub-bottoms for further transportation to a new grip (in winter time);

- Removal and storage of attachment elements: locks, brakes;

- removal of braces;

- Removal and storage of formwork panels;

6.1 Preparatory works

1. Before commencing work, it is necessary to:

- complete the work on the construction of the floor slab of the underlying floor, moreover, the strength of the concrete slab should be at least 50% of the design;

- Places of works on construction of cast-in-situ walls shall be exempted from equipment, accessories, construction material not used;

- clean the foundation on which the reinforcement works will be carried out from debris

6.2 Reinforcement works

Before fittings are installed, it is necessary to:

- carefully check compliance of formwork with design dimensions and quality of its execution;

- make the certificate of formwork acceptance;

- prepare rigging equipment, tools and electric welding equipment for operation;

- clean the valves from rust;

- close openings in floors with wooden shields or install temporary fencing.

Flat frames and grids are transported in packages. Spatial frames are reinforced with wooden anchorages to avoid deformation during transportation. Reinforcement bars are transported connected into packs, embedded parts - in boxes. Reinforcement frames and grids are attached to vehicles by means of surface twists or braces.

Reinforcement bars received on the construction site are laid on racks in closed warehouses sorted by grades, diameters, lengths, and the nets are stored rolled up in a vertical position. Flat grids and frames shall lie on liners and pro-masonry with stacks in the crane area. The height of the stack shall not exceed 1.5 m.

Flat and spatial frames weighing up to 50 kg are fed to the installation place with a crane in packs and installed manually. Individual rods are supplied to the installation place by bundles, the mesh - using a crossbeam of three pieces.

Places of their location are marked on formwork before installation of reinforcement frames with chalk. For temporary attachment of reinforcement frames to the formwork, strubcins are used.

Temporary fixation of frames in vertical direction, alignment of curved outlets of reinforcement and establishment of axial displacement of welded rods are carried out by strubcins. After installation and alignment of frames, horizontal rods are tied to them one by one using wire twists.

To form protective layer between reinforcement and formwork fixators are installed with spacing for walls of 1-1.2 m, floors - 0.8-1.0 m.

6.3. Formwork

1. Before commencing work, it is necessary to:

finish rebar works;

clean the base on which the opa-dump elements will be installed from garbage.

2. As a formwork, it is proposed to use large-panel formwork.

3. Work on the installation of the formwork begins with the marking of the base for the formwork panels and the pitch of the braces. The drawing is carried out by two workers .

At this time, the workers apply antiagdesion lubricant to the formwork shields.

4. Workers carry out transportation of formwork elements with the help of crane and self-building load-bearing clamps, then preliminary assembly of corner panels of formwork is carried out .

5. After installation of corner elements or extreme panels, they are fixed by means of drawing brace. Next, ordinary rectilinear shields are installed and fixed using straightening locks, as well as straightening braces.

To ensure the stability of the formwork and its perception of horizontal loads, the remaining braces are arranged.

6.5. Concrete laying and compaction

Before concrete works start, it is necessary to:

complete work on installation of reinforcement, reinforcement shall be rigidly fixed to ensure its design position during concreting;

- to inspect the works on installation of formwork and reinforcement of walls with execution of the corresponding act.

Concrete mixture shall be supplied to the laying area:

- concrete pump with characteristics for this object (concrete distribution boom);

Section of workers is used to lay concrete mix in structure by controlling flexible tip of concrete pump boom as wall structure volume is filled.

And then the worker performs layer-by-layer compaction of the concrete mixture with the help of a depth vibrator and subsequent alignment of the concrete mixture with cell marks.

6.6. Concrete care.

1. In the initial hardening period, concrete must be protected against precipitation or moisture loss (cover with a moisture-intensive material), subsequently maintain a temperature-moisture regime with the creation of conditions that ensure its strength increase (humidification or watering). The need for watering is determined visually when inspecting the state of concrete.

When performing works over 25 0С:

Care for freshly laid concrete should be started immediately after the concrete mixture is laid and carried out until, as a rule, 70% of the design strength is achieved, and with the corresponding justification - 50%.

When concrete reaches a strength of 0.5 MPa, its subsequent care should consist in ensuring the wet state of the surface by means of the device of moisture-intensive coating and its moistening, holding the open surfaces of concrete under a layer of water, continuous spraying of moisture over the surface of structures. At the same time, periodic watering of open surfaces of hardening concrete and reinforced concrete structures is not allowed.

6.7. Wall Structure Flattening

1. In summer time, smelting should be carried out with a strength of at least 1.5 MPa, in winter time with a strength of at least 40% of the design.

The decision to open the structure is made by the work manufacturer on the basis of the conclusion of the construction laboratory on the strength of concrete of the structure. The conclusion is given based on the results of testing of test samples of cubes stored in natural and normal conditions, as well as the results of testing the strength of concrete using non-destructive control methods, for example, an IPSMg4 device, or a Koshkarov hammer in specially leveled areas on the upper face of the slab to be erected.

After flattening, the walls are covered with PVC film until concrete strength is 50% of the design one or daily watering is carried out.

Production Costing of Work

The basis for compiling the calculation of labor costs is the bill of quantities of work and the compendium of HESB aggregated norms [6] or the compendium of HSE [8] in terms of determining the normative labor intensity of the work .

When developing a comprehensive PDP for the construction of a part of the building, the list of works in the production calculation is compiled according to the enlarged indicators presented in the HESB [6] based on the entire building or standard floor .

When compiling the Job Instruction for concreting a separate structure of the building, the calculation of labor costs contains a detailed description of the works and can be compiled in accordance with ENi R [8].

The calculation is presented in Annex No. 1.

Quality Control and Acceptance

Production quality control shall include:

- incoming control of design and estimate documentation, structures, products, materials and semi-finished products;

- operational control of individual construction processes or production

operations and acceptance control of construction and installation works.

At all stages of construction, in order to verify the effectiveness of the previously carried out production control, special services or commissions specially created for this purpose should selectively carry out inspection.

Incoming inspection shall be carried out in a specially designated room (area) equipped with the necessary means of control, testing and office equipment, as well as meeting the requirements without danger of work.

Workplaces and personnel performing incoming control shall be certified in accordance with the established procedure.

Based on the results of production and inspection quality control of CIW, measures should be developed to eliminate the identified defects.

Measuring instruments and test equipment used in input control are selected in accordance with the requirements of regulatory technical documentation (NTD) for controlled products and PR 50.2.00294 "Procedure for state metrological supervision of the release, condition and use of measuring instruments, certified measurement methods, standards and compliance with metrological rules and norms." If the metrological means and control methods differ from those specified in the NTD, the consumer agrees on the technical characteristics of the used means and control methods with the supplier or the customer's representative office.

As-built documentation is text and graphic materials reflecting actual execution of design solutions and actual position of capital construction facilities and their elements in the construction process as the works defined in the design documentation are completed. As-built documentation shall be maintained by the constructor and shall include:

- certificates of inspection of the geodetic basis of the capital construction facility;

- acts of separation of axes of the capital construction facility on the ground;

- acts of inspection of works that have an impact on the safety of the capital construction facility and, in accordance with the construction technology, control over the execution of which cannot be carried out after performing other works (hidden works), are drawn up by acts of inspection of hidden works;

- acts of inspection of building structures, elimination of defects identified during construction control in which it is impossible without disassembly or damage of other building structures and sections of engineering and technical support networks (responsible structures), are executed by acts of inspection of critical structures;

- acts of inspection of sections of engineering support networks, elimination of defects identified during construction control in which it is impossible without disassembly or damage of other building structures and sections of engineering support networks, are executed by acts of inspection of sections of engineering support networks;

- as-built geodetic diagrams;

- as-built diagrams and profiles of engineering and technical support network sections;

- acts of testing and testing of technical devices;

- results of examinations, inspections, laboratory and other researches of the performed works which are carried out in the course of construction control;

- documents confirming quality control of used construction materials (products);

- other documents reflecting actual execution of design solutions.

Proposals for quality control of construction and installation works.

Quality control of construction and installation works shall be carried out by special services of construction organizations equipped with technical means in order to ensure the necessary completeness and reliability of control results, as well as by production units of contractors (executors) in the order of self-control during construction production.

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