Reinforced concrete lintels (RC, RC): technical characteristics, types

Of course! This is a brief and easy-to-read overview of reinforced concrete lintels:

Modern construction cannot exist without reinforced concrete lintels, which give vital support above windows, doors, and other openings in buildings. They create a structural element that can withstand heavy loads and a variety of environmental stresses by fusing the strength of concrete with the flexibility and durability of steel reinforcement. Because of these factors combined, reinforced concrete lintels are a common option for both commercial and residential building projects.

There are various benefits to using lintels made of reinforced concrete. They are appropriate for a variety of applications due to their extreme durability and ability to withstand tension and compression forces. Their ability to withstand fire and pests also gives buildings an additional degree of safety and durability. These lintels can also be customized by architects and engineers to meet unique building specifications and aesthetic preferences because they are available in a variety of sizes and shapes.

To accommodate various building requirements, there are several varieties of reinforced concrete lintels. Because precast lintels are produced in controlled settings, their strength and quality are always guaranteed. They are a practical choice for speedy installation because they come in standard sizes. Conversely, cast-in-place lintels are made to order on the construction site to meet specific structural requirements or architectural features. The advantages of each type of lintel vary, and choosing the best one depends on a number of variables, including project deadlines, environmental constraints, and load requirements.

For the benefit of builders and designers, it is essential to comprehend the technical properties of reinforced concrete lintels. Its performance is affected by various factors, including the proportion of steel reinforcement, the quality of concrete utilized, and the lintel’s dimensions. Construction experts can guarantee that lintels offer dependable support and improve the building’s structural integrity by choosing the right specifications.

Characteristic	Description
Strength	Reinforced concrete lintels are strong and can support heavy loads, making them ideal for construction projects.
Durability	These lintels are resistant to weather, fire, and corrosion, ensuring a long-lasting structural element.
Thermal Insulation	They provide good thermal insulation, helping maintain indoor temperature and energy efficiency.
Cost-Effective	Due to their durability and low maintenance needs, reinforced concrete lintels are cost-effective over time.
Types	There are several types, including precast, prestressed, and composite lintels, each serving different construction needs.
Installation	Reinforced concrete lintels are easy to install and can be customized to fit specific design requirements.

General characteristics

Parameters of products of this type, related to the RC product group, are regulated by GOST 948-84. Lintels are used in the construction of structures from masonry materials, most often – this is brick, but this type of material can also be used in the construction of walls from stone, concrete.

• concrete of different types (preference is given to heavy), for example, B15 and more; in terms of density, the best option is considered to be 2200-2500 kg / m³;
• reinforcement – stressed or non-stressed – in the second case, simple reinforcement is assumed; hot-rolled rods with an anti-corrosion coating are used, the recommended diameter is up to 0.6 cm.

The strength level fluctuates throughout the year between 70 and 90%. For instance, material with better qualities is utilized in the winter. He is exposed to aggressive factors during this time.

The following guidelines must be followed by concrete window and door jumpers:

• resistance to the formation of cracks;
• strength;
• sufficient stiffness;
• increased frost resistance;
• Inappropriateness to the formation of corrosion.

The quality of the materials used in production, the size of embedded elements, steel rods, the thickness of the concrete layer, and the deviation of this parameter from the reinforcement are some of the factors that determine how long the fertile fee will operate.

Constructive features

Because they are easily assembled, concrete jumpers for windows and doors can be built right on the construction site. However, a certain amount of material needs to be ordered in advance from the factory. This kind of furniture device:

• concrete, thanks to which the product is formed, determines the strength characteristics of lintels for window and door openings; the thickness of the concrete layer is regulated by GOST;
• steel rods (reinforcement): eliminate the risk of cracking of products, increase the strength of the finished structure;
• slinging elements: do not affect the main characteristics, the main function is to facilitate the transportation and installation of lintels.

Slinging holes are a 30 mm diameter substitute for the latter elements. As a result, product transportation is made easier. When loops are intended to be used for gripping, they are installed during the beam-production phase.

Selecting the appropriate content is essential. Products of this kind must therefore be able to endure exposure to temperatures as low as -40 °C. Lintels that are not reinforced during production cannot be used because they will not function properly and will eventually deform when subjected to tensile and tensile loads.

Products made of reinforced concrete are categorized according to their intended use and variations in configuration.

• block lintels (PB): the most common type of reinforced concrete products, characterized by a width of no more than 250 mm, such products differ from their analogues in configuration – they have the shape of a regular parallelepiped;
• slab (PP): this is the name of a small-sized block of reinforced concrete products that are assembled into a larger structure with a width of over 250 mm, in terms of external characteristics, such lintels resemble a slab;
• beam type, characterized by an L-shaped form, defined as PG: due to the recess (a quarter of the block is conventionally cut out), it becomes possible to install such products in areas where floor slabs will adjoin; due to the protrusion, the reliability of the joint of the structural elements increases;
• facade lintels (PF): extend beyond the facade of the object, have a quarter protrusion.

Slight slopes on the side and end sides are acceptable when producing slab and bar products. In this instance, the lower edge’s measurements may vary slightly from the upper edge’s: by up to 8 mm in width and up to 20 cm in length. Preference should be given to the stressed option if you intend to use PB and PP types of products, as in this instance, improved finished structure strength characteristics are observed.

Loads

Apart from prefabricated and cast, there exist lintels that vary in their ability to withstand the force exerted by the applied loads:

In the first instance, the products are utilized in the construction of low-rise buildings and are not subjected to large loads. Loads: 100, 200, 300, 400, and 800 kN/m on such lintels. Presumably, the roof, or upper portion of the structure, is applying pressure to the concrete product. Products that bear loads can tolerate the same weight as well as ceiling pressure. Here are the loads in kN/m: 2000, 2700, 3700, and 5200.

It has been observed that stacking two lintels on top of one another fails to produce the desired outcome, which is the strengthening of the structure. When two products are positioned above one another, their bearing capacity will be significantly less than that of a single jumper, which has the same dimensions as two products combined.

Other varieties of lintels exist as well:

• pencil;
• purlins;
• beams.

The first choice stands out due to its compact size—120 mm in thickness. The size of pencil gave rise to its name. When installing interior doors, it is only utilized inside the object to reinforce the upper portion of the opening. These products’ reinforced concrete can’t be used for anything else because they can’t support the weight of the ceiling or roof.

Large items that are intended to support loads are called purlins. The beam is identifiable by its substantial weight, which is indicated by the protrusion. Its primary objective is to support higher structures.

Pencils and both load-bearing and non-load-bearing lintels are used more frequently than others.

Dimensions

Products made of reinforced concrete have uniform dimensions, which makes manufacturing easier. Lintels made of reinforced concrete measurements:

• width of non-load-bearing structures: 120 and 250 mm;
• width of load-bearing products: 250 and 290 mm;
• standard height: 65, 90, 140 mm;
• length — in the range from 1030 to 3890 with a gradation of 260 and 130 mm;
• over the specified values, the length is 4410, 4800, 5960 mm.

The brickwork-compatible parameters make the structure’s installation easier. When making your selection, remember that the beam’s length should be at least 30 centimeters longer than the opening’s width. You can make your own lintels if there isn’t a suitable option available for purchase. But because this is a labor-intensive process, the products end up costing more.

In Moscow, completed beams range in price from 140 to 3800 rubles per piece. These products are adequate for daily use. Larger, more robust beams can cost as much as 30,000 rubles. The type of concrete affects the price as well.

Technological characteristics

There are two ways to produce something:

• manufacturing a beam separately from the structure where it will be used; a finished lintel is installed above the opening;
• the product is poured directly on the site of its future installation.

Every technique has unique challenges. For instance, creating a beam is not difficult in the first scenario. But, considering how to raise it is imperative, as the product’s main distinction is its substantial weight.

The strength and tightness of the formwork must be guaranteed when pouring the beam at an elevation. There shouldn’t be a flow of the solution between the boards. It’s also important to consider how the formwork will be removed once the concrete hardens. This method’s benefit is that the product doesn’t need to be transported. When a big beam needs to be made and no one else is available to help lift it, this option is selected.

• strength level, which allows classifying the products as load-bearing or non-load-bearing products, the first option is intended for transportation by crane due to its significant weight, the second is much lighter, so it can be lifted manually with assistants;
• the support length for load-bearing beams is 30 cm, for non-load-bearing beams the value of this parameter can be reduced to 15-20 cm;
• load-bearing lintels are divided into types: reinforced, cut;
• facade beams are longer than their counterparts;
• during transportation and storage, stacks of lintels are placed at a distance of at least 250 mm, dense material is placed in the gaps – such a measure is necessary to prevent deformation of the beams when falling.

Reinforced concrete lintels are crucial structural elements used in construction to support loads above openings like windows and doors. Known for their strength and durability, these lintels are made by embedding steel reinforcement within concrete, which enhances their ability to bear tension and compression forces. There are various types of reinforced concrete lintels, each suited for different applications and load requirements, such as precast, cast-in-place, and prefabricated lintels. Understanding the technical characteristics of these lintels, including their load-bearing capacity, resistance to environmental factors, and installation methods, is essential for selecting the right type for specific building projects. Whether for residential, commercial, or industrial use, reinforced concrete lintels provide a reliable solution for maintaining structural integrity.

Marking

The primary characteristics of the products are encoded in the designation of reinforced concrete products. Consequently, based on the marking, you can ascertain:

• standard size, which allows you to decipher what dimensions the beam is characterized by;
• designation of the product according to classification;
• length – if the value of this parameter is not an integer, it is rounded up to the nearest integer number of decimeters;
• design load (kN/m);
• reinforcement characteristics;
• information on slinging elements or holes;
• the possibility of using beams in special conditions.

Products made of reinforced concrete are labeled as follows (for example): 2PB 10-to-1-p. It is clear from the designation that the beam in question is a part of the bar products, as indicated by section No. 2, which measures 120 by 140 mm. Although 10 dm is a rounded estimate, 1030 mm is a more accurate measurement. The design allows for slinging loops, and the estimated load on the lintel is 1 kN/m.

How to make a lintel yourself

1. Creating a sketch of a bar and a form.
2. Polyethylene is placed in the finished form. This material has a smooth surface, does not belong to porous coatings, therefore it is easily separated from concrete during the extraction process.
3. Rods are prepared (diameter 10-12 mm), the length is determined by the dimensions of the beam.
4. A frame is created from reinforcement: you need to make a lattice of 4 longitudinal rods, they are connected with wire.
5. The metal structure is installed in the finished form, but from below it must be placed on pads, which will ensure the same distance from the frame to the upper and lower edges of the beam.
6. A solution is prepared (the ratio of components is standard).
7. The form is filled with concrete.
8. The structure is covered with polyethylene from above.
9. The concrete is periodically moistened.

The product can be taken out of the mold after it has hardened for one month.

Laying formwork, reinforcement

Formwork is performed by the molding structure. The boards are set up for this. Plywood, wood, and particle boards are acceptable, but metal is preferable if you intend to fill at a height. The framework needs to be reinforced. This means that you must make a mold whose walls are at least 20 mm thick.

Wood is fastened with nails, and metal is fastened with self-tapping screws. The lower shield is installed first (it extends beyond the opening); it is horizontal and supported by supports when the formwork is created in weight.

It is advised to insulate the lintel to minimize heat loss from the space. Materials for thermal insulation include expanded polystyrene, mineral wool, and polystyrene. 100 mm is the recommended thickness.

Pouring concrete

Concrete M200 or M250 is used to prepare the solution. Crushed stone, sand, and cement have a 2:5:1 ratio. Using a concrete mixer to combine the ingredients is preferable. This results in a homogeneous mixture. Air is removed from the solution by compacting it before mixing separately. Mortar is poured into the reinforcement cage container, which is positioned on the lower side of the formwork (atop supports as high as 200 mm).

Of course! This is the last paragraph of an article about lintels made of reinforced concrete:

Modern construction requires reinforced concrete lintels because they provide structures with strength and support. To ensure stability and longevity, they are made to disperse weight from above openings such as doors and windows. Because of their durability, they are perfect for both residential and commercial buildings, enabling designers and builders to produce inventive and safe designs.

Reinforced concrete lintels come in a variety of forms, each designed to satisfy particular specifications. Builders have many options, ranging from precast lintels for convenience and uniformity to custom-cast options for specific architectural needs. One of the main benefits of reinforced concrete lintels is their versatility, which allows them to be used in a variety of climates and environments.

Selecting the appropriate type of reinforced concrete lintels for a construction project requires an understanding of their technical specifications. To make sure the lintels function as intended, factors including load-bearing capacity, dimensions, and reinforcement details need to be carefully taken into account. To guarantee that the selected lintel satisfies safety requirements and design objectives, seeking advice from structural engineers or other qualified experts can be beneficial.

To sum up, reinforced concrete lintels are a necessity in the building sector since they offer vital support for a variety of structures. They are the material of choice for builders all over the world because of their capacity to combine strength and versatility. Reinforced concrete lintels will continue to be a vital component of dependable and safe building practices even as construction methods and materials advance.

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Video on the topic

Classification of reinforced concrete lintels – [© masterkladki]

reinforced concrete form for the manufacture of bar lintels 2PB

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