Reinforced concrete monolithic columns: manufacturing features

Modern construction relies heavily on monolithic columns made of reinforced concrete. These columns offer the stability and strength required to support constructions of any size, including enormous commercial projects and residential buildings. These columns are made using a mix of materials and methods that are intended to guarantee longevity and security.

The capacity of reinforced concrete monolithic columns to support heavy loads is one of their primary characteristics. The combination of steel reinforcement and concrete gives this strength. Steel performs better in tension than concrete does in compression. Together, these materials form a composite that is far stronger than either one would be on its own.

Formwork, also known as a mold, is created at the beginning of the manufacturing process to shape the column. After that, rebar—steel reinforcement bars—is inserted into this mold. To guarantee that it remains in place while the concrete is being poured, the rebar is carefully arranged and tied together. The column’s tensile strength comes from this rebar structure.

Concrete is poured into the mold after the rebar has been installed. For the concrete mixture to have the ideal ratio of workability to strength, it needs to be properly prepared. To ensure that the rebar is completely encased and to remove any air pockets, the concrete is vibrated after it has been poured. For the column to remain structurally sound, this step is essential.

The concrete needs to be properly cured after it has been poured and vibrated. In order to allow the concrete to reach its maximum strength, curing entails keeping it moist and at the proper temperature. The duration of this process varies from a few days to a few weeks, contingent upon the particular mixture and surrounding circumstances. For the column to last and to avoid cracks, proper curing is necessary.

The best qualities of steel and concrete are combined in the engineering marvel known as reinforced concrete monolithic columns. These columns are an essential component of contemporary construction because of the meticulous manufacturing process that guarantees they can withstand the enormous weight and stresses placed on them.

Feature	Description
Materials	Use steel rebar and concrete mix
Formwork	Set up sturdy molds to shape the column
Reinforcement	Place rebar inside the formwork for strength
Pouring Concrete	Pour concrete mix into the formwork carefully
Compacting	Vibrate the concrete to remove air pockets
Curing	Keep the concrete moist to strengthen it

Purpose and types

In addition to serving as a bearing, concrete columns can also serve as an open support for balconies, terraces, and bridges. They are also utilized insides as a decorative accent.

They can have sections that vary in length and in shape, such as square, rectangular, round, or figured sections. Additionally, prefabricated and monolithic concrete columns are classified based on the manufacturing process.

• Prefabricated ones are structures manufactured at a factory and assembled at the construction site. Their main advantages are speed of installation and low price. Their disadvantages include the complexity of transportation and installation, which require equipment.

• A monolithic concrete column is completely manufactured at the construction site by pouring concrete into molds with reinforcement. The advantage of this method is the ability to manufacture a higher quality and more reliable structural element. And the main disadvantage is the labor intensity of the process and the long period of hardening of the concrete mixture until the required strength is achieved.

The filling method is applied in private, civil, and industrial construction. In this instance, adhering to SNiP’s concrete column requirements is imperative.

As a point of reference. This is SNiP 3.03.01-87, "Bearing and enclosing structures," first of all. in addition to GOST 26633-91. Concrete with fine grains and a weight of 7473-94 GOST. mixtures for concrete.

Features of installation

They frequently use hand-poured concrete for columns in private construction. You must know how to do this task correctly in order to complete it quickly.

An overview of each step can be found here:

• Preparation of all necessary materials and tools. Everything that is needed should be at hand, since concreting of each element should be carried out continuously.
• Cleaning the surface from dirt and construction debris.
• Installation of formwork.
• Construction of a reinforcing frame.
• Pouring concrete into the columns in the formwork.
• Dismantling the formwork after the solution has dried and set.

Now, a detailed explanation of each step.

Tools and materials

The set of tools required will vary depending on whether you plan to use ready-made or homemade formwork. Universal removable panels come with all the fasteners, making work easier and faster.

You’ll need edged boards or plywood sheets, bars for supports and ties, and the following supplies and equipment for your DIY formwork:

• Building level;
• Building corner;
• Tape measure;
• Hammer;
• Screwdriver;
• Screws and nails.

Knitting wire and steel rods with a diameter of at least 1.2 cm are required for the reinforcement frame. A strong and efficient concrete mixer is essential if you choose to mix concrete by hand for concrete columns (recipe for the mixture will be provided below).

Suggestions. A deep vibrator is also highly desirable for tamping and sealing concrete mixtures. However, you can tamp with metal rods instead of needing it.

Requirements for the quality of materials

The quality of the materials used determines the structure’s strength, dependability, and durability in addition to technology compliance. This relates to the concrete mix first and foremost.

Kindly take note! For columns with a cross-section of 30 cm or more, SP 52-103-2007 states that the minimum class of concrete to use is B25 and the maximum class is B60.

Use these component proportions when mixing on your own to produce high-quality concrete M400 class B30:

• Cement M400 – 1 part;
• Sand – 1 part;
• Crushed stone or gravel – 2.5 parts.

Following mixing, an equal amount of water is added to the dry ingredients to create a homogenous mobile mixture.

Furthermore, fiber fiber, which strengthens the material, or plasticizing additives, which make styling easier, can be added to the composition. Fiber concrete columns are less likely to develop shrinkage cracks and are more resilient to outside forces.

Using a concrete pump to pump ready-made concrete into the formwork is a quicker and more efficient method for handling large volumes of work.

Every shipment of concrete mix to the customer needs to be accompanied by a passport bearing the following details:

• Document number;
• Name of the manufacturer;
• Date and time of dispatch;

This is of great importance! Delivery of concrete to the construction site must occur no later than ninety minutes following dispatch. It needs to be shielded from the sun, wind, and precipitation while being transported.

• Type of concrete mix;
• Compressive strength class;
• The largest filler fraction;
• Volume and type of additives;
• Manufacturer"s warranty obligations.

Prior to accepting concrete, the passport must be examined to ensure that there is no stratification and that the declared filler fractions are present.

Kindly take note! Before using, the stratified mixture has to be mixed. It is forbidden to add water to it if it becomes immobile! In accordance with GOST 1081-2002, you have the right to request a control check if you have any concerns about the concrete’s quality.

Installation of formwork

It is important to keep an eye on the structure’s level and the accuracy of the angles when erecting formwork. Spacers and screws affixed to four sides guarantee its dependability and robustness.

It is important to keep in mind that the technology used to construct columns permits the dropping of concrete mixture from a maximum height of five meters. If a higher structure is required, the formwork is only installed on three sides, progressively raising the fourth as concrete is poured into the form.

Reinforcement

The reinforcing frame is used in more than one situation, such as when they promote metal columns for aesthetic or fire safety purposes.

At least four rods that are vertically positioned and placed in the corners of the structure come together to form the frame. They are positioned in the formwork using a variety of supports, and they are joined amongst themselves with knitting wire.

The final scheme illustrates that there should be roughly 40 mm separating the formwork’s walls from the metal frame. Take into consideration building concrete columns by hand.

Bill with concrete

The following guidelines are necessary for the technology used in the production of reinforced concrete columns:

• The column can only be installed on a strong base or a buried foundation.

• Concreting should be carried out horizontal layers of one thickness, without tears. The direction of laying in all layers should be the same.
• Concreting of the lower layer is performed with a concrete mixture with a fine fraction of filler to a height of about 300 mm. Larger stones from the next batch of concrete dropped into the formwork are sunk into the fine-fraction mixture, forming a normal composition. As a result, there are no voids or cavities left in the lower part of the column.

• During laying, the mixture is tamped with a vibrator or metal rods. Air bubbles are “driven out” of it by tapping the formwork boards with a hammer.

• As the formwork is filled, the reinforcement cage is periodically leveled, maintaining the same distance between it and the walls of the form.

• Laying of the concrete mixture in the columns is carried out without interruption to the entire height of one floor.

Kindly take note. If necessary, working seams can only be placed at the top of the column, just below the floor beam abutment level, or at the bottom, close to the foundation.

• When laying concrete intermittently, the surface of the working joints must be strictly horizontal (or perpendicular to the axis of the column).
• Concreting can be continued after a break only after the concrete has reached a minimum strength of 1.5 MPa.

• The upper edge of the formwork must be 5-7 cm above the level of the laid concrete mixture.
• To secure the wall panel to the reinforced concrete column, embedded parts are installed in the body of the latter at a given height during pouring.

A metal corner is welded to the embedded portion prior to fastening the wall panel to the concrete column.

In an effort to create the ideal drying conditions—positive air temperature and normal humidity—the concrete is left in the formwork after it has been laid. To shield it from precipitation and sunlight, the exposed surface is periodically misted with water and covered with a film.

Dismantling of formwork

Only after the solution has solidified and attained the necessary strength properties can the formwork be removed.

The best way to determine strength indicators is to test working mixture samples in a laboratory. In private construction, the columns are poured and then dismantled about a month later.

Modern construction relies heavily on reinforced concrete monolithic columns because of their strength and longevity. They are essential for maintaining stability and supporting big structures. To get the best results, the manufacturing process involves a number of crucial steps that must be carefully followed. Every step affects the columns’ overall performance, from the careful selection of premium materials to the installation of exact formwork and appropriate curing.

The reinforcement is among the important elements. Strategically positioned steel bars within the concrete improve the column’s capacity to support weights and withstand different kinds of pressure. Concrete’s compressive strength and steel’s tensile strength are combined to create a material that benefits from both of their strengths. For the integrity of the column, these bars must be positioned and spaced correctly.

It is necessary to carefully design the concrete mix itself in order to satisfy certain structural requirements. This involves determining the appropriate ratios for aggregates, sand, water, and cement. The mix’s workability and consistency are essential to producing a solid, void-free column. Furthermore, a uniform structure and the avoidance of weak spots require a continuous and smooth pouring process.

After concrete is poured, it must be properly cured. This procedure aids in the concrete’s attainment of its maximum strength and calls for maintaining appropriate temperatures and moisture levels. Ignoring this step can cause cracks and shorten the column’s life. As a result, curing requires the same level of attention to detail as the other phases.

In summary, careful curing procedures, precise construction methods, and premium materials are all necessary for the successful manufacture of reinforced concrete monolithic columns. The interdependence of each step and the careful attention to detail guarantee that these columns will offer the durability and support required for any construction project. Builders can produce durable, dependable structures by comprehending and utilizing these manufacturing features.

Modern construction is not complete without reinforced concrete monolithic columns, which provide unparalleled strength and durability. The fundamentals of manufacturing are examined in this article, along with formwork design, material selection, and appropriate curing methods. Reinforced concrete columns are a dependable option for a range of construction needs because builders can guarantee the structural integrity and longevity of their projects by comprehending these crucial components.

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Pouring concrete columns

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