What is an armored belt under floor slabs and how to tie it?

Ensuring the stability and strength of a building is essential during construction. The armored belt, a reinforced concrete structure intended to distribute loads evenly and prevent wall cracks, is a crucial element in accomplishing this. However, what is an armored belt exactly, and why is it required beneath floor slabs?

Typically, the armored belt—also called a ring beam—is positioned on top of the walls, slightly below the floor slabs. It keeps the walls together, giving the slabs a strong base and assisting in preventing any movement or shifting that can jeopardize the structural integrity of the building. This reinforcement is especially crucial in seismically active areas and in places where settling may occur due to the properties of the soil.

Steel rebar is used in the installation of an armored belt, and it is subsequently covered in concrete. The building’s weight and any potential dynamic forces can be effectively supported by this combination because it offers both tensile and compressive strength. One of the most important steps in ensuring the belt works as intended is to properly tie the rebar.

Comprehending the function and structure of an armored belt can aid both builders and homeowners in acknowledging its significance in constructing secure and long-lasting structures. This post will go over the specifics of installing an armored belt beneath floor slabs, including the supplies required and the procedures for properly tying the rebar.

Armoured belt design

A unique reinforced concrete belt is built to balance the loads caused by the weight of the roof and interfloor panels on the end plane of the capital walls. It is also carried out when the monolithic foundation is poured.

The following actions must be taken in preparation for building a basement, interfloor, or foundation reinforced belt:

• think over the design features of the reinforced concrete reinforcement contour;
• select the optimal size of the reinforcement and decide on the height of the armored belt;
• purchase the building materials necessary for the construction of the armored belt.

The load-bearing capacity of the walls, for which porous blocks were used in their manufacture, as well as the current forces at floor level must be considered when choosing the design, dimensions, and materials to be used. If you are using lightweight floor slabs, you can use a less potent armored belt. In this instance, the width and wall thickness should match. Let’s delve deeper into the dimensions and features of the design.

What is the armored belt made of?

Building codes govern how the reinforced belt is designed. This power contour keeps the building box from deforming.

The reinforced belt is made from the following construction materials:

• Concrete solution with M400 labeling and above. The mixture is filled with a formwork frame, inside of which there is a reinforcement grid. After the concrete hardens, a force contour is formed around the perimeter of the load-bearing walls. The concrete mixture is made according to a standard recipe based on Portland cement, crushed stone and sand. It is important to carry out concreting in one go with further compaction of the concrete mass using vibration equipment. It is important to prevent the formation of air cavities inside the monolith;
• steel bars with a cross-sectional size of 0.8-1 cm. Corrugated reinforcement is cut into blanks of the required sizes, which are tied with knitting wire into a spatial frame. The structure consists of four longitudinally located rods connected by transverse rods. The diameter of the cross elements is 0.6 cm. A metal grill that increases the loading ability of a concrete massif has a square or rectangular cross -section in the transverse plane.

The formwork design determines which materials are used in its manufacture:

• wooden panels are used for collapsible formwork;
• fixed structure is made of polystyrene.

Making sure the formwork structure is tight and rigid is crucial.

Height and thickness of the reinforced belt

The following design documentation governs the reinforced belt’s dimensions:

• the height of the power contour is equal to its thickness when manufacturing a square section reinforced belt. For a rectangular structure, the height exceeds the width by 1.5-1.6 times;
• the thickness of the reinforced belt usually corresponds to the width of the load-bearing walls of the building. The construction technology allows for a reduced belt thickness, at the level of 0.7-0.8 wall thickness.

When the building project is being developed, the power contour’s dimensions are decided.

When it is necessary to strengthen building structures with a reinforced belt?

One responsible component of residential buildings is a reinforced belt that is positioned at various heights from the zero mark. The following issues are intended to be resolved by the reinforced belt:

• forming a level base for installing interfloor panels;
• smoothing out various types of loads created by roof beams;
• preventing cracking of load-bearing walls as a result of deformation of the frame;
• proportional distribution of loads acting on the end plane of the walls;
• reducing the likelihood of wall deformation under the influence of increased forces;
• reducing the impact of loads caused by gusts of wind;
• ensuring the stability of buildings constructed in conditions of sloping terrain;
• preserving the integrity of the frames of buildings constructed in seismically active areas;
• increasing the safety margin of building structures affected by the reaction of frost heaving of the soil.

The building’s stability is diminished by the lack of a reinforced belt installed on the upper story of load-bearing walls.

In the following cases, building a reinforced belt is required:

• when using cellular blocks for the construction of walls;
• when building houses in seismically active zones;
• when constructing buildings on problematic soils.

In some cases, such as when building capital walls with bricks and pouring the foundation below the freezing point of the earth, you can dispense with the need for a reinforced concrete belt. In other situations, a reinforced belt is a necessary component of the structure.

Reinforced belt under prefabricated and monolithic reinforced concrete floors

The necessity of an armored belt beneath floor slabs is undeniable. Many important functions are carried out by an armored belt built beneath floor panels:

• increases the load-bearing capacity of walls made of cellular blocks. After all, porous concrete is prone to deformation under increased load;
• proportionally distributes loads from the interfloor ceiling and roof to the walls. Local efforts can cause cracks to form;
• protects the building frame from cracking. The belt smooths out temperature fluctuations and increases the durability of the structure.

In the general power outline, reinforced edging—made of reinforced concrete—connects the building’s box and the floor slab.

Preparing to make a reinforced belt for slabs – building materials and tools

When organizing a separate production of armored cars that will be used to install the floor panels, get the building supplies ready:

• plywood, strict boards or sheet polystyrene for the assembly of formwork;
• Portland cement, gravel and small sand for the manufacture of concrete mixture;
• steel reinforcement and knitting wire for assembling the power frame;
• polyethylene film for sealing the formwork structure;
• Fasteners (screws, screws, nails) for the assembly of formwork.

The design documentation serves as the basis for determining the quantity of materials.

Additionally, specific tools and equipment will be needed to complete the task:

• concrete mixer that facilitates the preparation of a large volume of concrete mixture;
• grinder with a metal disc used for cutting steel reinforcement;
• manual hook for tying reinforcement or semi-automatic device;
• building level and plumb line, necessary for taking measurements.

A bending device will also be needed when using reinforcement bars with a larger diameter.

Technology for constructing a reinforced belt – main stages

The following series of events is enabled by the technology used in the production of an armored belt:

1. Preparation of blanks for assembling the formwork frame.
2. Assembling formwork from plywood sheets, wooden panels or sheet polystyrene.
3. Cutting reinforcement bars into blanks of appropriate sizes.
4. Assembling the power frame by connecting the rods using annealed wire.
5. Mixing the components intended for preparing the concrete solution.
6. Continuous filling of the formwork structure with mortar.
7. Removal of air inclusions using a deep or surface vibrator.
8. Maintaining the humidity of the concrete mass by periodic moistening.
9. Dismantling the formwork after the concrete solution has hardened.

After carefully studying the technology involved in creating an armored belt, completing every step on your own is simple.

What materials can be used for formwork?

Traditionally, formwork—from which a panel structure is constructed—is made of planed wood. Typically, the wooden edging has a height of 0.3 meters and a width that matches the wall thickness. The self-tapping screws are used to secure the boards. The formwork board’s side edging is fastened with threaded studs or strips. A level should be used to regulate the formwork’s upper plane’s horizontality. It’s critical to seal any cracks and firmly fasten the boards.

Formwork is made of the following materials in addition to boards:

• moisture-resistant plywood. Before filling the concrete, it is impregnated with waste oil to facilitate dismantling;
• extruded polystyrene. Polystyrene sheets are a component of heat-insulated formwork.

Depending on the specifications in the design documentation, each formwork structure manufacturer chooses a different type of material.

Installation of reinforcement

The steps involved in installing the reinforcement cage are as follows:

1. Cutting metal rods.
2. Laying rods along the formwork on pads.
3. Tying the lower tier elements with wire.
4. Installing transverse rods.
5. Fastening the upper tier elements to the vertical rods.

The floor elements can be fastened with steel wire or threaded studs once the reinforcement grid has been assembled.

How to pour concrete?

Concrete mortar preparation and pouring are done in the order listed below:

1. Prepare the concrete mixture in the required volume.
2. Perform continuous concreting.
3. Tam the concrete using reinforcement or vibrator.
4. Plan the surface of the concrete mass.
5. Lay a polyethylene film on the concrete.
6. Perform periodic moistening of the concrete surface.

Take down the formwork once the concrete has reached operational hardness. The dimensions of the formwork structure guarantee the thickness of the reinforced belt beneath the floor slabs.

Topic	Explanation
What is an armored belt under floor slabs?	An armored belt, also known as a reinforced concrete belt, is a horizontal layer of reinforced concrete that strengthens the structure of a building. It is typically placed under floor slabs to distribute the load evenly and prevent cracking or shifting.
How to tie an armored belt?	Tying an armored belt involves placing steel reinforcement bars (rebar) within a wooden or metal formwork, then pouring concrete over the rebar. The rebar should be tied together with wire at the intersections to ensure stability. Once the concrete is poured, it should be allowed to cure properly to achieve maximum strength.

Anyone working on construction projects must comprehend the function and design of an armored belt located beneath floor slabs. This belt of reinforced concrete ensures a building’s stability and longevity by providing crucial structural support. It increases the structure’s overall durability by distributing loads evenly and avoiding wall cracks.

In order to build an armored belt, rebar is positioned inside formwork along the walls, and concrete is then poured to form a continuous, solid belt. An essential step in ensuring the strength and integrity of the belt is correctly tying the rebar. Although this process may seem difficult, it is actually quite doable if best practices are followed and every detail is carefully considered.

An intelligent investment in a building’s resilience and safety is the installation of an armored belt beneath floor slabs. Your construction projects will succeed in the long run if you take the time to comprehend and apply this technique correctly. Building strong and dependable structures requires understanding the function of an armored belt, whether you are a professional builder or a do-it-yourself enthusiast.

A reinforced concrete beam known as an "armored belt" beneath floor slabs encircles the base of a building and offers vital stability and support. Its purpose is to evenly distribute loads so as to avoid cracks and maintain the structural integrity of the object. Correctly tying the armored belt improves the construction’s overall strength and durability by positioning steel reinforcement bars in a predetermined pattern and securing them to the floor slabs. This fundamental element is necessary to construct a sturdy and long-lasting structure.

Video on the topic

How to make a reinforced belt under floor slabs in a house made of aerated concrete. Part 1. Reinforcement frame.

Reinforced belt under floor slabs. Formwork, insulation, tying reinforcement.

Reinforcement of the reinforced belt under floor slabs

ARMOPOYAS. DEVICE AND PURPOSE

Reinforced belt under floor slabs / installation of formwork

8. Reinforced belt! Why do it, how not to make a mistake, when is it needed? Seismic belt! A house made of aerated concrete from A to Z!