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Kazan State University of Architecture and Civil Engineering
Department of Technology, Organization and Mechanization of Construction
on production practice
discipline: Technology of production processes
Completed
3rd year correspondence student
Levin Leonid Sergeevich
No. of credits books 11-12-052
Kazan 2015
foundation pit pile building plaster
3. Breakdown of the axes of the pile fields. Driving driven piles
5. Grillage devices
12. Installation work (installation of floor slabs, columns, beams, trusses)
13. Installation of roofs made of roll and sheet materials
14. Production of glass works
15. Plastering works
16. Production of facing works using facing tiles
17. Production of facing works using polymer and metal lath materials
18. Performance of works when installing suspended and stretch ceilings
19. Production of painting works with the use of water-glue and water-based paints
20. Production of painting works using oil and enamel paints
21. Production of wallpaper works
22. Performance of work when installing wooden floors
23. Performance of work when installing a monolithic floor
24. Production of works when installing tiled floors
25. Performance of work when installing floors with roll coatings
26. Production of works when installing engineering equipment systems in buildings
1. Technology of production of geodetic works
Geodetic work in construction (geodetic support of construction) is a complex of measurements, calculations and constructions in drawings and nature, ensuring the correct and accurate placement of buildings and structures, as well as the construction of their structural and planning elements in accordance with the geometric parameters of the project and the requirements of regulatory documents.
Geodetic works are part of process of construction design and production, their content and technological sequence are determined by the stages and technology of the main production.
The following stages of the production of geodetic works can be distinguished:
1) Geodetic works when constructing a foundation pit.
The main tasks at this stage of construction are:
Detailed breakdown of the pit contour;
Control of the depth of the excavation pit;
Calculation of the volume of earthworks;
Executive survey of the pit.
Source documents:
center drawing or site topographic plan;
pPGR requirements for the main characteristics of the pit in plan and height.
2) Planned marking
Performed by a tacheometer and tape measure.
Carry out and fix on the ground the main axes of the structure
Set aside from the main axes of the building the distance to the lower contour of the bottom of the pit (lower edge. Data on the deposited distances are indicated in the PPGR and can be 0.5 h 1.0 m.
Calculate and plot the distance from the lower contour to the upper contour of the pit
In modern times, the upper edge of the pit is taken out. Then it is fixed with reinforcement with a signal tape. When excavating, the reinforcement should remain. Geodetic control of the depth of the excavation using a sight or level, if the depth of the excavation is up to 2 m.
2. Opening of pits for building foundations
Construction and installation work and, first of all, the construction of the underground part of buildings and structures, is associated with the implementation of significant volumes of earthworks. Excavation are classified as the most difficult and laborious types construction workscarried out in difficult conditions and largely dependent on natural and climatic factors. Therefore, one of the tasks facing designers, technologists, builders is the development and implementation of methods and technologies that help reduce the volume of earthworks at the construction site.
Excavation work refers to the complex of works of the zero cycle, which includes: a fragment of pits and trenches, arrangement of drainages, strengthening and preparation of foundations for a building, erection of foundations and walls, ceilings, tunnels, backfilling, soil in the sinuses between foundations and slopes of excavations and Other works of the zero cycle are considered completed after the arrangement of the underground part of the building with all communications and elements underground structures.
Excavation work is one of the most difficult and laborious types of construction work. They are performed different methods, divided into four groups: mechanical, hydraulic, explosive and manual. In addition, in some cases, to increase bearing capacity the soil is rammed, developed by drilling.
The result of excavation is an earthen structure, which is an engineering structure built from the ground into soil mass or erected on the surface of the ground. Earthen structures are divided by:
in relation to the soil surface - excavations, embankments, underground workings, backfilling;
by service life - permanent and temporary;
functional purpose - pits, trenches, pits, wells, dumps, dams, dams, roadbeds, tunnels, planning sites, mine workings;
in terms of geometric parameters and spatial form - deep, shallow, extended, concentrated, simple, complex, etc.
To temporary earthworks include excavations torn off during the construction of foundations for residential and industrial buildings, bridges, dams, trenches for laying water, sewer, gas and other networks, embankments for temporary roads and dams.
Recesses more than 3 m wide are called ditches, narrower recesses for strip foundations or communications networks are called trenches, and recesses for free-standing foundations or pillars are called pits. These structures have a bottom and side surfaces, inclined slopes or vertical walls. Excavations developed to extract the soil that is missing for construction are called reserves; embankments into which excess soil is dumped - by cavaliers or dumps. Places for dumping construction and other waste are called landfills, and places where sand, crushed stone and others are mined building materials - quarries. Excavations closed from the surface of the earth and arranged for the laying of transport and communication tunnels are called underground workings. Excavations have a bottom and sloping slopes, after the installation of underground structures (or the underground part of structures), backfilling of the sinuses is performed - filling the space between the structure and the slopes of the pit with soil.
3. Breakdown of the axes of the pile fields. Driving pile driving
The position of the main axes is periodically checked by tying them with precise geodetic instruments to the baseline. The layout of the main axes must be retained for the entire duration of the work.
To break down the vertical positions (marks of the pile heads, the bottom of the grillage), a constant benchmark is laid near the structure. The benchmark must be tied to the state leveling marks with a precision level. The absolute mark of the benchmark must be represented on it with indelible paint. Like leading signs, the bench mark is installed in places where any ground movement cannot occur.
Stakeout and fixing of the main axes, as well as the installation of the benchmark, must be done by a qualified surveyor. You can stake out the pile field with or without cast-off.
Layout of the pile field with a castoff device. Before the start of the breakdown, at a distance of at least 3 m from the main axes of the building, an inventory or non-inventory cast-off with a height of 1-1.5 m is arranged. buildings with the help of a theodolite transfer the main axes of the building. Intermediate axes corresponding to individual sections of the pile field breakdown are applied to the strip using a measuring tape. The position of the main and intermediate axes on the strip is fixed with nails or clamps. Between the points of the axes of the pile field put out on the cast-off, a soft steel wire with a diameter of 1-1.5 mm is pulled, which fixes the position of the axes of the building transferred to the terrain. The points of intersection of the axes are demolished using a plumb line to the planned surface of the site and fixed with metal pins or wooden rings.
The breakdown of the locations of the piles between the center lines fixed on the ground along the main and intermediate axes is carried out at each site with a measuring tape.
Laying out a pile field without a castoff device. The pile axes are laid out without a castoff device using a theodolite and a steel measuring tape in the following sequence:
a) according to the available control points, they clarify the correct position of the main axes of the structure on the ground;
b) using a theodolite and a measuring metal tape, the locations of the piles are broken down along the main axes (this work must be completed before pile driving);
Driving pile driving
Driven piles are driven into the ground by impacts, vibration, indentation and a combination of these methods.
On the construction site, pile storage areas should be located closer to the pile driving path so that the pile can be lifted by the pile head without a crane. The movement of the pile driver should be as straight as possible with the minimum number of turns.
The most widespread method is the impact method of driving piles. According to this method, various hammers are used to drive the piles - mechanical, steam-air and diesel hammers, which are mounted on copra or mobile pile rigs.
The pile driving process consists of the following operations: moving the pile driving unit to the pile driving site, pulling, lifting, aligning and installing the pile, and then driving to the design mark or a given failure.
For large volumes of piling work and the use of piles with a length of more than 12 m, universal tower-type pile drivers are used, installed on trolleys, moving along rails. These pile drivers have a large carrying capacity and a significant dead weight.
The most widespread in industrial and civil construction are self-propelled piling installations based on cranes, excavators, tractors and cars.
Such installations have great maneuverability and are used for driving piles with a length of 3-10 m. Pile-driving installations allow you to pull and lift the pile, to put the head of the pile in the headrest.
The efficiency of pile driving depends on the right choice pile hammer, namely from the correct determination of the ratio of its mass and the mass of the pile. This also takes into account the type of soil into which the pile is immersed. The mass of the striking part of a free-falling hammer when driving a 12 m long pile into dense soils should be equal to 1.5 times the mass of a pile with a cap, and when driving into soils of average density, 1.25 of this mass.
Steam hammers are available in single and double action.
4. The device is boring rammed piles
Rammed piles are arranged in place of their design position by placing (packing) concrete mixture or sand (soil) into cavities (wells) formed in the soil. Piles are often made with a widened bottom - the fifth. Broadening is obtained by drilling out the soil with special drills, expanding the soil with reinforced tamping of the concrete mixture in the lower part of the well, or blasting an explosive charge.
Depending on the methods of creating a cavity in the soil and the methods of laying and compaction of the packing material, piles are subdivided into bored, pneumatic, vibration-rammed, frequency-rammed, sand and soil-concrete.
Bored piles. The salient feature of the device technology bored piles is preliminary drilling of wells to a given level and the subsequent formation of the pile shaft.
Depending on the soil conditions, bored piles are arranged in one of the following three ways: without fixing the walls of the wells (dry method), with the use of clay solution to prevent the collapse of the walls of the well, with casing the wells.
The dry method is applicable in stable soils (subsidence and clayey of solid, semi-solid and refractory consistency), which can hold the walls of the well. The technology for installing such piles is as follows. Using rotary drilling methods (auger string or bucket drill), a well of the required diameter and a given depth is drilled in the ground. Upon reaching the design mark, if necessary, the lower part of the well is expanded with the help of special expanders attached to the drill rod and included in the drilling rig kit. The principle of the expander is as follows: the pressure transmitted through the rod opens the joint system of the expander blades; when the rod rotates, the knives cut off the soil falling into the bucket located under the expander. For 4 ... 5 operations of cutting and extracting soil, an expanded cavity with a diameter of up to 1.6 m is formed. After the well is accepted in the prescribed manner, if necessary, a reinforcing cage is mounted in it and concreted by the method of a vertically moving pipe.
Concrete pipes used in construction, as a rule, consist of separate sections and have joints that allow you to quickly and reliably connect the pipes. The concrete mixture is fed into the receiving hopper directly from the mixer or using a special hopper. As the concrete mix is \u200b\u200blaid, the concrete-cast pipe is removed from the well. In the well, the concrete mix is \u200b\u200bcompacted using vibrators mounted on the receiving funnel of the concrete cast pipe. At the end of the concreting of the well, the pile head is molded in a special inventory conductor and protected with a heater in winter. Using this technology, bored piles are most often made with a diameter of 400, 500, 600, 1000 and 1200 mm and a length of up to 30 m.
A clay solution to keep the walls of wells from collapsing is used when installing bored piles in unstable watered soils. In this case, the wells are drilled in a rotary way.
However, when driving through rocky interlayers, replaceable percussion-type working bodies (grabs, chisels) are used. The mud enters the well through a hollow drill rod. Due to the hydrostatic pressure exerted by this solution, the density of which is 1.2 ... 1.3 g / cm, piles are arranged without casing. Clay solution is prepared at the work site mainly from bentonite clays, and while drilling it is injected into the well. Rising up the borehole along its walls, the clay slurry enters the sump, from where it is returned by the pump to the drill rod for further circulation. Then a reinforcement cage is installed in the well. The concrete mix is \u200b\u200bfed using a vibrating bunker with a concrete-cast pipe, which is lowered into the well. The vibrated concrete mixture, entering the well, displaces the clay solution. As the well is filled with concrete mixture, the concrete pump is removed.
Installation of bored piles with casing of the borehole walls is possible in any geological and hydrogeological conditions.
Special pipes can be left in the ground or removed from boreholes during the piling process (inventory pipes). Casing sections are usually connected with specially designed joints or by welding. Casing pipes are immersed in the process of drilling a well with hydraulic jacks, as well as by driving the pipe into the ground or vibrating. Drilling wells special installations rotational or impact method.
After cleaning the bottom hole and installing the reinforcement cage in the well, the well is concreted using the vertically movable pipe (VTP) method. As the well is filled with concrete, the inventory casing is removed. At the same time, a special system of jacks, mounted on the installation, imparts a reciprocating and semi-rotating movement to the casing pipe, additionally compacting the concrete mixture. At the end of the concreting of the well, the pile head is formed in a special inventory conductor.
For the device of broadening in the bases of piles, as a rule, an explosive method is used. To do this, a casing is installed in the drilled well so that its lower end does not reach the bottom of the well by 1.2 ... 1.5 m, that is, it is outside the range of the camouflage explosion. An explosive charge of the calculated mass is lowered into the casing pipe to the bottom of the well and the conductors are removed from the detonator to the blasting machine. The pipe is filled with concrete mixture and an explosion is made. The explosive energy compacts the soil and creates a spherical cavity, which is immediately filled with concrete from the casing. The well is finally filled in as described above.
In our country, bored piles are made with a diameter of 880 ... 1200 mm, a length of up to 35 m. For the installation of bored piles, cast concrete is used with a cone draft of 16 ... 20 cm.
5. The device of grillages
The design of the grillage and the technology of its device are adopted depending on the type of piles. Grillages combine a group of piles into one structure and distribute the loads from the structure to them. They are most often a continuous tape along the entire outline of the building in plan, including the internal walls. When using reinforced concrete piles, the grillages can be made of monolithic and prefabricated reinforced concrete. Depending on the type of building or structure, grillages are divided into high and low. When driven piles, the heads of which, after driving, may be at different elevations, before the installation of the grillage, it is necessary to perform laborious operations to align the pile heads. To do this, it is necessary to cut (cut) the concrete of the piles to a certain level, cut or bend their reinforcement.
Pile cutting. Wooden piles and sheet piles are cut with mechanical or electric saws, steel piles - with an autogenous or gas cutter, in reinforced concrete piles the concrete of the heads is usually destroyed using pneumatic jackhammers. It is more effective for these purposes to use punches - installations for cutting the heads of piles, consisting of a rigid closed bed, lowered and clamped on the pile, a movable frame, removable teeth and a hydraulic jack with a piston. The installation kit includes several pairs of punches for piles with different cross-sectional dimensions. The maximum working force is 200 tons, the working stroke is from 10 to 50 cm, the productivity of the installation is 15 ... 20 piles per hour.
When piles are immersed, sometimes they deviate in plan, with a multi-row or cluster arrangement of piles, these deviations do not cause complications when installing grillages. If there is a single-row arrangement of piles and part of the section of individual piles goes beyond the boundaries of the future grillage, then in this case it is necessary to arrange a monolithic one.
When preparing the heads of rammed piles for the device of prefabricated grillages, check the upper surface against the level and, if necessary, level the supporting surface of the piles using a concrete mixture or cement mortar. The beams of the reinforced concrete grillage themselves are installed on a leveling bed of sand or slag, starting from the corner of the building, and perform assembly work strictly on seizures. The elements of the prefabricated grillage are connected to prefabricated short piles by welding with homogeneous joints.
6. Erection of foundations and foundation walls or columns of buildings
Preparatory processes. Before starting the construction of foundations, it is necessary:
organize the drainage of surface water from the site;
to lay the necessary driveways and access roads for transport and construction equipment;
prepare storage areas, formwork assemblies, enlargement of reinforcement meshes and frames, deliver assembly equipment and accessories;
deliver formwork kits to the warehouse, reinforcement mesh and frames;
perform the necessary sand, gravel, concrete preparation for foundations;
geodetic axis staking and position staking
foundations in accordance with the project;
mark the position of the working planes of the foundation formwork panels using a pier, pins, and other clamps;
check if device is correct concrete preparation and marking the position of the axes and elevations of the base of the foundations.
Cleaning the surface from dirt and debris.
When erecting monolithic walls the main attention should be paid to the manufacture of good-quality formwork, its reliable fastening and convenient rearrangement during the concreting process. Usually, the formwork is made on one wall or, even better, on the entire perimeter of the walls. Shields 2-4 m long and 50-80 cm high are knocked together from well-rounded and tightly fitted boards 30-40 mm thick and connected from the outside with upright bars with a section of 80x80 mm every 1-1.5 m. when installing the boards on the wall, they are connected at the bottom with metal ties with threaded bolts (after removing the formwork, the ties are knocked out), and at the top of the racks are fixed with the same ties or wooden plates with fixing cutouts.
The process of erecting a wall is as follows. First, one or two layers of roofing material are spread on the plinth and two rows of bricks are laid out on M25 mortar. After 2-3 days, the formwork is installed and concreting is started. Concrete is poured in layers of 15-25 cm.Each layer is first bayonetted with a metal rod (especially carefully at shields), then tamped with a wooden rammer, the next layer of concrete is poured, etc. The formwork is removed and rearranged no earlier than 3 days later, covering the concrete for all this time with roofing material.
Instead of formwork panels, you can use brickwork in a half-brick, which will then serve as a wall cladding. The walls are laid and the concrete is poured simultaneously. For better adhesion to concrete, after 4-6 rows in height and after 2-3 bricks along the length in thickness, the walls release bricks. Such a combined structure has the advantage that in this case there is no need to make expensive formwork.
Lightweight concrete is most often prepared from cement and coal slag. The composition of concrete with cement M300 (in parts by volume) 1:10 for external and interior walls and 1: 8 for thin partitions. When using M200 or M400 cement, the amount of slag is respectively reduced or increased by 2 parts. To improve the quality of concrete, it is advisable to sift the slag and divide it into two fractions: coarse (with grain sizes of 6-40 mm) and fine - up to 5 mm. There should be 1.5 times more coarse slag in the filler. First, both fractions, measured in the required volume, are mixed with each other and with cement, then water is gradually added, again thoroughly mixed until a homogeneous state and only then they begin to fill the walls. The prepared concrete should be used within an hour, therefore its volume should be accurately calculated and not prepared more than necessary. The plasticity of the concrete mass can be increased by adding 1 to 2 parts of lime to facilitate mixing and laying.
Erection of foundations. When erecting monolithic foundations first, their axes from the cast-off are transferred to the foundation pit, and then, based on these axes, the contour for placing the inner edges of the formwork is broken. In large foundations, the formwork is broken from the castoff. In this case, identical cast-off points are used and each contour point is obtained by the method of rectangular casement notch, fixing it with a peg or pin.
On small objects, the axes are demolished with the help of wires hung on the cast-off, on large ones - with theodolites installed above the cast-off points and oriented along their axes. If wires are used, the point of their intersection is demolished to the bottom of the excavation with a plumb line, and if the theodolite, it is determined on the basis of the intersection of the sections demolished to the bottom of the excavation. The bottom of the foundation, characteristic ledges and its top are controlled by a level from working benchmarks. The concrete pouring level mark is fixed with nails or a colored pencil on the inner wall of the formwork. Due to the shrinkage of the concrete, the level of the foundation decreases slightly, which is sometimes taken into account in the elevation of the supporting surface. In practice, most often the actual concrete elevation is somewhat lowered in order to then grout the base plate. This method is used in the construction of foundations for technological equipment and for columns with milled shoes.
When building strip foundations of walls, they additionally monitor the breakdown of the inputs to the building of underground utilities. At a certain level and according to the distance specified in the project, wooden plugs of a slightly larger diameter than the communication pipe are installed in the formwork. When concreting the foundation, holes remain in these places, to which the communication is subsequently brought.
After concreting the foundation, control measurements of the distances between the axes and leveling of the foundation surface are performed. As a result of measurements, an executive scheme is drawn up, in which deviations from the design data are shown.
7. Concrete work during the erection of monolithic foundations for building columns
Training. Before starting the construction of foundations, it is necessary:
Organize the drainage of surface water from the site;
Lay the necessary driveways and access roads for transport and construction equipment;
Prepare storage sites, formwork assemblies, enlargement of reinforcing meshes and frames, deliver assembly equipment and accessories;
Bring to the warehouse the formwork kits, reinforcing mesh and frames;
Perform the necessary sand, gravel, concrete preparation for foundations;
Make a geodetic breakdown of the axes and breakdown of the position of the foundations in accordance with the project;
Mark the position of the working planes of the foundation formwork panels using a mooring, pins, and other clamps;
Check the correctness of the device of concrete preparation and marking of the position of the axes and marks of the base of the foundations.
Acts for hidden works must be drawn up for the preparation device for foundations. The prepared foundation for the foundations must be accepted by the commission according to the act.
Before starting the installation of the large-panel formwork of walls and ceilings on the next working horizon, the following preparatory measures must be taken:
Leveling the floor surface;
Breakdown of axes and marking of the position of walls according to the project;
Drawing on the surface of the floor with paint marks that fix the position of the formwork;
Preparation of assembly equipment and working tools;
Cleaning the surface from dirt and debris, and in winter - additional snow and ice.
Formwork installation.
Control of the set of formwork delivered to the construction site should include: external visual inspection, check of completeness, quality of the materials used, welds, geometric dimensions of assembly units and elements, threaded connections, paints and varnishes, the presence of markings on products.
The elements of the formwork delivered to the construction site must be placed in the area of \u200b\u200bthe erection crane. They should be stored under a canopy, in the position in which the formwork elements were located during transportation, sorted by brands and standard sizes and under conditions that exclude mechanical damage. Formwork panels are stacked in stacks no more than 1.2 m high on wooden linings and gaskets, the rest of the fasteners must be stored in boxes. Before starting the installation of the formwork, the panels are pre-assembled into panels.
Foundation formwork is carried out in the following sequence:
The enlarged formwork panels of the lower step of the shoe are mounted and fixed;
The assembled box is installed strictly along the axes and the formwork of the lower step is fixed with metal pins to the base;
Risks are applied to the edges of the enlarged panels, indicating the position of the box of the second stage of the foundation;
In accordance with the risks, a pre-assembled box of the second stage of the foundation is installed;
According to the risks, they arrange a third stage box;
Risks are applied to the upper box, indicating the position of the column box;
Arrange the box for the column column;
Install and secure the liner formwork.
Installation wall formwork must be done in the following sequence:
Cleans shields and other elements from dirt and mortar;
Apply an anti-adhesive coating to the formwork;
Attach the scaffold brackets to the formwork panel;
Connect the formwork panels to each other into a single formwork panel using locks; three locks are installed in height in the corner and central zones;
The formwork panels are lifted from the assembly site using an assembly crane, fed to the installation site and installed close to the concrete plinth previously concreted;
Unfasten the formwork panels with struts;
Lay the working flooring on the scaffold brackets;
Ties on one side through holes in the shields and bushings located between the shields are pulled to the other side;
Tighten the screeds with nuts from one or both sides until the shields and the sleeve located between them are completely connected to each other, the length of which is equal to the thickness of the structure to be covered;
They check the reliability of fastening: formwork elements and the quality of its assembly.
Reinforcement of the structure. Reinforcement iron concrete structures it is desirable to carry out welded reinforcement cages and prefabricated meshes.
Reinforcement elements and finished meshes are delivered to the construction site and placed on the storage site. When accepting the reinforcement, meshes and frames delivered to the object, the conformity of the reinforcing bars and meshes to the project, the diameter and distance between the working bars of the frames and meshes are checked. Frame elements that require preliminary pre-assembly are brought to the assembly site. Reinforcement cages and meshes are assembled at the pre-assembly stand using the necessary conductors and all types of welding: contact, spot, electric arc, in some cases viscous. Reinforcement cages and meshes are assembled into packages and in this form are supplied to the work area with an assembly crane.
The reinforcement mesh of the foundation shoes is arranged in the formwork on the clamps, which provide a protective layer of concrete according to the project. The rest of the elements of the reinforcing cage of the foundation are installed and fastened by welding or knitting wire, subject to the required protective concrete layer.
In the process of installing reinforcement in the formwork of walls and floors, special attention is paid to ensuring the design dimensions of the thickness of the concrete cover, displacement of reinforcing bars when they are installed in the formwork, as well as when fabricating reinforcing cages and meshes on site.
To assess the deviation from the design values \u200b\u200bof the position of the axes and the verticality of the frames, geodetic instruments are used.
Reinforcement and formwork are interconnected. Depending on the location of the structure, you can first install the reinforcement, and then the formwork, into which the reinforcing mesh and frames are laid. In some cases, a part of the formwork is arranged, reinforcing cages are installed and fastened to it, the rest of the shuttering boards are attached and connected.
The assembled reinforcement must be securely fixed and protected from deformations and displacements during the process of concreting structures. Cross intersections of reinforcement bars, laid individually, at their intersections, must be fastened with a knitting wire or using special wire connecting clips. Design position reinforcing bars and meshes must be ensured by the correct installation of support devices, templates, clamps, spacers and supports. Reinforcement trims, wooden blocks, pieces of brick, crushed stone, gravel cannot be used as supports.
Acceptance of the assembled reinforcement, all butt joints must be carried out before the concrete mixture is laid and drawn up by an act on hidden works... The act should indicate possible deviations from the project, an assessment of the quality of the mounted fittings should be given.
After installing the reinforcement and formwork, checking the quality of the work performed, permission is given for the production of concrete work.
Concreting. Before starting work on placing the concrete mixture in the formwork of walls and floors, it is necessary to complete the installation of reinforcement and formwork within the grasp. Before placing the concrete mixture, it is necessary to check the quality of the installation and fastening of the formwork, as well as all structures and elements that are closed during the concreting process (reinforcement, embedded parts, etc.).
Before placing the concrete mix, you must:
Check the correct installation of reinforcement and formwork, installation and fastening of the clamps, which provide the required thickness of the concrete cover;
Accept according to the act all hidden structures and elements, access to which after concreting will be impossible;
Clean reinforcement and formwork from debris, dirt and rust. The work on the concreting of individual structures includes:
Acceptance of concrete mix and its supply to the work area;
Laying and compaction of concrete mix;
Maintenance of concrete in the process of gaining the required strength.
Concreting of a foundation with a sub-column is performed in two stages. At the first stage, all the steps of the foundation and the sub-column are concreted to the mark of the bottom of the liner, at the second - the upper part of the sub-column after the installation and fastening of the liner.
It is advisable to organize uninterrupted delivery of concrete mix to the facility using concrete mixer trucks. Concrete supply to the place of laying can be solved in several ways. When using buckets, they are installed on the unloading site, and after reloading the concrete mixture into them, they are alternately fed into the laying area, where they are unloaded directly into the concrete structure.
When concreting using an auto concrete pump, the radius of action of its distribution boom allows placing concrete mixture in the structure in the area of \u200b\u200bthe boom. The normal operation of the concrete pump can be ensured when pumping a concrete mixture of permitted mobility, which will facilitate the transportation of concrete over extreme distances and without delamination and the formation of plugs.
The concrete mix is \u200b\u200blaid in horizontal layers 0.3 ... 0.5 m thick, without breaks along the length and with a consistent laying direction in one direction in all layers.
Each layer is carefully compacted with vibrating heads (deep vibrators). When compacting the concrete mixture, it is not allowed to rest the vibrators on reinforcement, embedded parts, screw ties and other formwork elements.
When compacting the concrete mixture, the end of the working part of the vibrator should be immersed in the previously laid concrete layer by 5 ... 10 cm. The step of repositioning the vibrator should not exceed 1.5 of its radius of action.
Vibrating in one position should provide sufficient compaction, the main features of which are:
Stopping the settling of the laid concrete mixture;
The appearance of cement laitance on its surface;
Stopping the release of air bubbles on the surface.
When rearranging, the vibrator should be removed slowly and without turning it off, thereby allowing the void under the tip to be evenly filled with concrete mixture. The next layer of concrete must be laid before the concrete of the previous layer begins to set. The break between the laying of layers of concrete mix can be in the range of 40 minutes, but the next layer must be laid before the start of setting of the concrete mix.
After placing the concrete mixture in the formwork, it is necessary to create favorable temperature and humidity conditions for concrete hardening. The horizontal surfaces of the concreted structure are covered with wet burlap, tarpaulin, sawdust, roll materials for a period depending on climatic conditions and in accordance with the recommendations of the flow chart for these works.
8. Construction of monolithic foundations, platforms and floors
Substrate preparation, sub-base and screed installation
To prepare the base, the vegetative layer of soil is removed with a bulldozer and taken out for use on landscaping. Heavily and frozen soils, admixture of snow and ice must be removed and replaced sand bedding... The bases on non-stony soils are compacted with crushed stone or gravel with a size of 40 ... 60 mm in one layer, pressing it into the soil and pouring water at the same time. Before the device of the concrete underlying layer (preparation), it is necessary to erect underground part buildings, backfill the sinuses between the foundation and the excavation, plan and roll the soil.
Preparation for floors made of concrete grades M100 - M200 is laid at the design mark in separate strips using a set of concrete-laying machines. AT unheated premises after 10 ... 12 m in length and 5 ... 6 m in width, in preparation, through expansion joints with a width of 8 ... 10 mm are arranged, which are cut by machines equipped with abrasive discs. The grooves are filled with hot bitumen.
The underlying layer of prefabricated reinforced concrete slabs (6 x 3 x x 0.12 m) is arranged according to the finished sandy base... Plates are laid with a crane. Areas near the columns and walls are concreted in place.
The screed is a 15 ... 40 mm thick layer of fine-grained concrete, cement-sand mortar of grade 100 or asphalt concrete. The screed is arranged along the floor in order to level its surface or give it a design slope. If a layer of porous or non-rigid sound-insulating material is laid on the floor surface, the screed forms a crust that serves as the basis for the floor covering. A screed is used to close the pipelines placed on the floor surface, making it 10 ... 16 mm thicker than the pipe diameter.
Surface cement screeds for laying synthetic carpets, linoleum and PVC tiles, they are rubbed with a SO-89 machine with a capacity of 40 ... ... 50 m2 / h.
Under the coatings laid on bitumen mastic, the screeds are primed with a primer - a solution of bitumen in kerosene (composition 1: 2 or 1: 3), which is applied with a spray gun.
Device monolithic slab... When performing construction work, it is important to clearly follow technical requirements and the recommendations contained in the technological map for the construction of the foundation reinforced concrete slab. The duration of the structure's life will depend on the implementation of these recommendations. The construction of a reinforced concrete base is done on the first or basement floor, placing a monolithic slab there. Strengthening its strength characteristics allows the construction of such a base, which evenly distributes the loads relative to the slab under the foundation.
Such a technological map is developed for a project for the construction of an individual house or a building for foremen or foremen of construction organizations and can serve as a technological document. In the appendix, the technological map contains a detailed schematic image with the exact dimensions of the monolithic foundation printed on it. Routing describes the technology construction processes (reinforcement, formwork and concrete work); contains instructions on safety measures, discloses technical and economic indicators by type of work; gives an idea of \u200b\u200bthe equipment and tools used in the construction of a reinforced concrete monolithic slab; gives a calculation of the costs of installation and dismantling of various structures, describes the process of quality control of the processes performed.
The design of a reinforced concrete monolithic slab refers to one of the options for the construction of a shallow or unsubmerged foundation.
A shallow foundation is used for lightweight buildings, the installation of which is made of wood or foam concrete, small brick or frame buildings. It is advisable to use it on slightly heaving soil. Foundation slab shallow laying is laid in depth about 50-70 cm.
Heavy houses with bulky floor slabs are built on buried foundations. This type of foundation is used on heaving soils, as well as in the case when it is planned to equip a basement or basement in the house, for example, for a utility room or garage. The foundation is deepened 20-30 cm deeper than the soil freezing mark. Dwelling on such a design, it should be understood that its device will entail a large consumption of materials and labor costs.
What is a monolithic slab? This is a slab made of reinforced concrete, under which a cushion is laid from a layer of compacted rubble or sand 10-30 cm. The crushed stone cushion is placed on the mainland soil, in another way - the earth, which was not subjected to mechanical stress (loosening and digging).
Often a concrete slab is 20-40 cm thick. In addition to a monolithic slab, precast reinforced concrete from several slabs (for example, road slabs) is allowed. They provide for the installation of a concrete or cement leveling screed over the slabs.
However, a monolithic foundation, representing a device of one slab, is more reliable and durable in operation, since it has a high spatial rigidity, in comparison with a precast type foundation made of many slabs. In addition, the cost of the device and installation of a monolithic foundation on site is much cheaper than the purchase, delivery and installation using a crane of road slabs and the installation of a cement screed over them.
9. Concreting of monolithic floors
Basic instructions for concreting floors
The technological scheme was developed for concreting monolithic floors during the construction of a residential building. The concrete slabs are made using a movable formwork along the grips, after the execution of monolithic walls and columns to the bottom level of the slab. Before the start of concreting floors at each grip, it is necessary:
Provide measures for the safe conduct of work at height;
Install the formwork;
Install fittings, embedded parts and hollow cores for wiring;
All structures and their elements closed during the concreting process (prepared foundations of structures, reinforcement, embedded products and others), as well as the correct installation and fastening of the formwork and its supporting elements must be adopted in accordance with SNiP 3.01.01-85.
Before concreting, the surface of the wooden, plywood or metal formwork should be coated with emulsion lubricant, and the surface of the concrete, reinforced concrete and reinforced-cement formwork should be moistened. Clean the surface of previously laid concrete from the cement film and moisten or cover with cement mortar. Protective layer reinforcement is maintained using inventory plastic clamps, installed in a checkerboard pattern. To align the upper mark of the concrete slab, spatial clamps are installed or removable lighthouse rails are used, the top of which must correspond to the level of the concrete surface.
Concrete mix is \u200b\u200btransported to the facility by auto concrete trucks with concrete unloading into bunkers at the concrete receiving site. The concrete mixture is supplied to the floor structure in bunkers with a volume of 1.0 cubic meters. using a tower crane.
When concreting, walking on a reinforced floor is allowed only on boards with supports resting directly on the floor formwork. When unloading the concrete mixture from the bunker into the slab formwork, the distance between the lower edge of the bunker and the surface on which the concrete is laid should be no more than 1.0 m. The concrete mixture should be laid horizontally in layers 1.5-2 m wide of the same thickness without breaks, with a consistent direction stacking in one direction in all layers. Laying the next layer of concrete mixture is allowed before the beginning of the setting of the concrete of the previous layer. The duration of the break between the laying of adjacent layers of concrete mix without the formation of a working seam is established by the construction laboratory. When concreting flat slabs, working seams, in agreement with the design organization, are arranged anywhere along the wall axis. The surface of the working seam should be perpendicular to the surface of the slab, for which, at the intended points of interruption of concreting, slats are placed along the thickness of the slab. The resumption of concreting at the site of the working seam is allowed to be carried out when the concrete reaches a strength of at least 1.5 MPA and the removal of the cement film from the seam surface with a mechanical brush followed by watering. To compact the concrete mix, deep vibrators (IV-66, IV-47A) or surface vibrators (PV-1, PV-2) are used.
The concrete mix is \u200b\u200blaid in the structure in layers of 15 ... 30 cm with careful compaction of each layer. The most common way to compact concrete is by vibration. Internal (depth), external and surface vibrators are used at the construction site. Vibrators are powered by electric current (electric vibrators) or compressed air (pneumatic vibrators). In massive structures, concrete is placed using internal vibrators. Surface vibrators are used to compact concrete mixtures in floor slabs, floors and other similar structures. External vibrators are used for concreting densely reinforced thin-walled structures. The duration of vibration in each place of the vibrator installation depends on the plasticity (mobility) of the concrete mixture and is 30 ... 60 s. A sign of sufficient vibration is the cessation of concrete settling and the appearance of cement laitance on its surface. Excessive vibration of the concrete mix is \u200b\u200bharmful as it can lead to delamination of the concrete. The step of rearranging the internal vibrators is from 1 to 1.5 of their radius of action.
With a large supply of concrete to large arrays, packet (group) vibrators are used. Large structures are concreted in sections (blocks) with the device of working (construction) seams. Block dimensions in terms of no more than 50 ... 60 sq. M. and height up to 4 m.
The interrupted concreting can be resumed after the setting process in the previously laid concrete mixture ends and the concrete acquires a strength of at least 1.2 MPa, approximately 24-36 hours after the concrete was placed. For reliable adhesion of concrete in the working joint, the surface of the previously laid concrete is carefully processed: the upper film of the mortar is removed by notching and the coarse aggregate is exposed, blown with compressed air and washed with a stream of water, wiping with wire brushes, in the places where the reinforcement is released, the rods are cleaned from the solution.
During operation, it is not allowed to rest the vibrator on fittings and embedded parts of a monolithic structure. In places of direct installation of electrical boxes, do not perform vibration compaction.
The step of rearranging the deep vibrators should not exceed one and a half radius of its action, the surface vibrators are rearranged so that the vibrator platform in the new position overlaps the adjacent vibrated area by 50-100mm.
The duration of vibration at each position should ensure sufficient compaction of the concrete mixture, the main signs of which are the termination of its settling, the appearance of cement laitance on the surface and the termination of the release of air bubbles. In places where reinforcement, embedded products or formwork interfere with the proper compaction of the concrete mixture with vibrators, it should be additionally compacted with a bayonet. During and after concreting, it is necessary to take measures to prevent adhesion of formwork elements and temporary fasteners to concrete.
The adhesion of the concrete to the formwork increases over time, so the formwork must be removed as soon as the concrete has acquired the required strength. Stripping of the side surfaces of concrete structures is allowed after the concrete reaches strength, ensuring the safety of their corners and edges, which is observed when the concrete strength is at least 2.5 kg / sd sq., Achieved after 1 ... 6 days, depending on the grade of concrete, cement quality and temperature regime of concrete hardening.
Removal of the bearing formwork of reinforced concrete structures is allowed when the design strength of concrete is reached,%:
slabs and vaults with a span of up to 2 m 50
beams and purlins with a span of up to 8 m 70
slabs and vaults with a span of 2 ... 8 m 70
supporting structures with a span of more than 8 m 100
When performing work, it is necessary to be guided by the requirements of SNiP 3.03.01-87 "Bearing and enclosing structures", SNiP 12-03-2001, SNiP 12-04-2002 "Labor safety in construction" and SP 12-135-2003 "Labor safety in construction . Industry standard instructions on labor protection ".
10. Production of masonry in the construction of solid walls of buildings
Depending on the structural, operational and other features of the bearing and enclosing elements of buildings and structures, one can distinguish between continuous, lightweight masonry and masonry with facing.
Solid unreinforced brickwork It is used for the construction of walls, piers and pillars, partitions, for the installation of lintels and cornices and is made of solid single (250x 120x65 mm) and hollow (250 X X120X65 and 250x120x88 mm) bricks. Walls. The height of a free-standing wall depends on its thickness and massiveness of the masonry, as well as on the wind load and can reach 8 m. The average thickness of horizontal joints is 12, vertical joints - 10 mm (joints with a thickness of no more than 15 and no less than 10 mm are allowed).
To ensure the solidity of the masonry, they provide for the ligation of transverse and longitudinal vertical seams in a single or multi-row system. With a single-row system of dressing, butt and spoon rows alternate, with a multi-row system, several spoon rows are overlapped with one butt. The number of spoon rows depends on the type of brick and its thickness. When laying from solid single and hollow bricks with a thickness of 65 mm, a row of spoon bricks overlap with a butt row. This is called a six-row dressing. If the thickness of the brick is more than 65 mm, the tying of the spoon rows with the butt row is provided every 0.4 m (from the top of the lower to the bottom of the upper butt row). With a multi-row dressing system, the longitudinal vertical seams remain through to the entire height of the spoon rows, and the transverse ones in each row are tied.
The strength of multi-row masonry on solutions of grade below M25 is less than single-row, and on solutions of grade M25 and higher it is practically the same.
When laying solid brick walls according to a single-row ligation system, each vertical seam of the lower butt row should be covered with bricks of the upper spoon row.
11. Production of masonry during the construction of insulated walls of buildings
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22.09.2015 6:24
The construction process of any building can be divided into several stages. It is much more convenient for developers to carry out the process and produce it with high quality. The main stages of construction will be discussed in this article.
Algorithm
At first, specialists work on creating a building project, think over all the smallest details. At this stage, it is very important to think over the subtleties of the structure, what rooms will be there, how the lighting will be carried out and much more. Many experts call this stage the creation of building layouts (http://www.makety.ru/services/doma-zdaniya/). Architects approve their projects with other specialists and agree on all constructions.
After completing the creation of the layout, specialists carefully and thoroughly study the soil. It is also very important to study the earth in order to know what quality it is. Only after studying the soil, specialists begin to erect the foundation of the building. It is erected taking into account all the data obtained, the foundation must be suitable for a certain territory, soil.
After the construction of the foundation, the developer proceeds to the construction of the structure itself. It can take as long as you like, because it all depends on the number of floors, the building design itself... The simpler the project, the easier and faster it is to build a specific building. A wide variety of materials are required at this stage.
After the completion of construction, specialists carry out communications to the building. We are talking about heating systems, water supply, lighting. This can take a long time, because experts will take a long time to check the correctness of the installation of these systems. The building must be safe for everyone in it.
After carrying out the necessary systems, interior decoration, inspections, the building can be considered completed. The developer receives the necessary documents that can confirm the completion of the construction process. This is how buildings and structures are built.
Experts identify other stages of construction, describing the process in more detail, but many points are incomprehensible to inexperienced people. The main stages in this process are the ones listed above. It is most understandable not only for specialists, but also for inexperienced and ignorant people in this field.
In most wells, the water level ranges from one and a half to two meters, the lucky few can boast of a large one. Depending on the season and weather, this value fluctuates: in a dry summer, the water mirror in the well can drop to one meter. In such a situation, it is almost impossible to do without interruptions.
The geopolitical situation creates a favorable background for the development of domestic production, therefore investments in this sector are rightfully considered an interesting area of \u200b\u200bactivity. To create an effective company, you need your own sites - closer to the sales markets. At the moment, it is cheaper and faster to build a new structure than to spend money on the reconstruction of an old one.
All stages of construction of an industrial building can be completed in a few months or even weeks, if you choose the right work technology. In particular, metal structures that are suitable for our climate and are highly resistant have proven themselves well. Plants and factories, assembly shops, service stations and much more can be built on their basis.
Here are just the most important stages in the construction of industrial buildings:
Design work. The contours of the future building are created in a special program, and in some cases standard drawings can be used.
Geodetic works. Transferring design points to "real soil" is a long and difficult process that requires special equipment and experience.
Lead to the construction of utilities. The building will need at least water and electricity supply, and many structures also need natural gas and sewerage.
Arrangement of the foundation. The base of the structure will take on a key load, and therefore should take care of maximum strength and the endurance of the element.
Installation of walls and roofs. If frame technologies are used for construction, then the necessary technical units are created at the factory, and their final assembly is performed at the facility.
Installation of engineering networks. They are installed in walls, ceilings, as well as in technical tanks to ensure maximum protection of communications.
Outdoor and interior decoration building. When it comes to production facilities, the decoration should be simple, practical, and at the same time aesthetic.
Installation of production equipment and devices. Everything you need for productive work, including machines, sectional doors, lighting fixtures, security systems, is installed on site.
Commissioning works. If necessary, the correct operation of all elements of the structure is checked before putting it into operation.
Steel structures can also be used as a construction technology multi-storey buildings... However, until now in our country they have not received wide development, despite the availability and speed of construction. However, the possibilities frame technologies business owners appreciated: this is a practical and inexpensive way to acquire your own building for solving production problems.
