What is composite reinforcement for foundations: characteristics, installation technology, reviews

What it is?

These are smooth, periodic-profiled, non-metallic rods. They are created by impregnating both natural and synthetic fibers with a viscous polymer.

Classification

The primary source material divides non-metallic rods into three groups:

1. Fiberglass reinforcement (FRP) consists of fiberglass rods impregnated with thermosetting resins. The fibers create durable lengths that are tightly bound with a quick-hardening binder;
2. Basalt plastic products (BPP) – these are basalt fibers bonded with the same polymer resins as ASP. Composite rods are resistant to aggressive environments.
3. Carbon fiber length lengths (AUP) are the strongest, but also the most expensive material and are not used for knitting frames of monolithic foundations.

Specifications

The following indications are among the primary technical features of composite reinforcement:

• Tensile strength. Tensile strength is the most important characteristic of reinforcement as it experiences tensile loads in the foundation monolith. The tensile strength of composite rods is several times higher than their steel counterparts. This feature of polymer lengths is noticeable when, according to calculations, a composite ø 8 mm can replace steel rods ø 12 mm. Where rods are subject to deflection, steel products are used. The composite cannot withstand this type of deformation.
• Elastic modulus. The characteristic reflects the ability of the material to restore its shape after deformation from external forces. The higher this indicator, the less likely it is that microcracks will appear in the monolith mass. In this parameter, steel is superior to polymer. This applies to structures subject to bending. The modulus of elasticity of steel reinforcement is 200,000 MPa. For a composite it is 55,000 MPa. Therefore, instead of steel rods, almost 4 times more composite reinforcement will be required.
• Specific elongation. The parameter reflects the increase in the length of the rod after its rupture and is expressed as a percentage. To put it simply, the characteristic affects the cracking of the monolith. The higher its value, the greater the risk of destruction of the concrete structure. If the specific elongation for fiberglass and basalt is 2.2 – 2.5%, then for steel it can reach 25% (depending on the class of reinforcement).
• Density. Characterized by the specific gravity of the material. The greater the weight of one unit of volume of the rod, the stronger it is. The density of the composite is approximately 2 tons/m3, while for steel its value is 7.85 tons/m3 .
• Thermal conductivity. The ability of materials to transfer thermal energy to less heated bodies is called thermal conductivity. Reinforcement laid in the foundation with low thermal conductivity will prevent heat from escaping from the house. Thermal conductivity coefficient of the composite is 0.35, for steel – 46.
• Anti-corrosion resistance. In this regard, steel products are completely inferior to composite rods. Polymers are not subject to corrosion, but they lose their strength characteristics due to aging.
• Dielectric properties. In contrast to the high electrical conductivity of steel reinforcement, composite frames in a monolith do not interfere with transmitting electrical devices. Dielectric polymers do not interfere with the passage of radio signals due to the absence of their own electromagnetic fields.
• Weight. The total mass of the foundation depends on how much the material weighs. The use of a composite significantly reduces the pressure of the foundation on the soil base. Polymer material, unlike steel products, is transferred in small batches into the formwork manually. Transporting plastic rods is much easier than steel rods. Firstly, it is stored and transported in bays, and secondly, for transportation it is enough to use a small truck such as a Gazelle.

comparison table

The following table illustrates how much lighter a composite with steel reinforcement is:

Pros and cons of use

You must consider all the benefits and drawbacks of the polymer material in comparison to steel rods in order to assess the benefits and drawbacks of a composite.

The following are some benefits of polymer materials:

• Light weight allows you to manually manipulate large volumes of rods when knitting the foundation frame, which would require more effort from workers when installing a similar steel base.
• Composite reinforcement with a diameter of up to 6 mm is sold twisted into coils. This allows you to use even passenger cars for its transportation.
• Immunity to corrosion makes it possible to store composite products in any conditions. The only limitation is storage under a canopy for UV protection.
• The dielectric properties of the polymer contribute to the permeability of monolithic structures to radio signals. This does not interfere with the operation of radio-electronic devices.
• Low thermal conductivity of the frame increases the thermal insulation characteristics of monolithic concrete structures.
• The environmental friendliness of composite products lies in the absence of harmful fumes during their decomposition.

Take note! The primary benefit of composite products over steel ones is their more affordable cost.

Here is a comparison table for an illustration.

The following elements are among the composite’s drawbacks:

• The elasticity of the material does not allow the composite rod to bend – it immediately breaks. If it is necessary to perform complex reinforcement frame assemblies, polymer rods are combined with steel rods.
• Inability to use welding. The composite is destroyed by strong heating (above 1500 C). You can order fiberglass rods with metal ends at the factory to make it possible to weld the reinforcement into a single frame.
• When cutting rods, there is a danger of fine sharp dust getting into the respiratory and visual organs. The employee must work in a respirator and safety glasses.

Modern foundation reinforcement options include composite reinforcement, which offers improved corrosion resistance and durability over traditional steel rebars. This article examines its salient features, elaborating on its composition, which is both lightweight and sturdy, thereby enhancing construction efficiency and longevity. It discusses installation technology, highlighting its versatility in different foundation designs and ease of handling. Reviews from professionals in the field and users demonstrate how well it works in practical settings, highlighting the advantages it offers for strengthening concrete structures against external influences and structural stresses. Learn how composite reinforcement, with its cutting-edge materials and useful benefits, is revolutionizing foundation construction.

Rules for working with material

The following guidelines must be followed when working with polymer products:

• Handle and move composite rods while wearing gloves. To do this, it is better to use cotton gloves or mittens with a layer of latex coating applied to the back side.
• Coils with rods up to 10 mm in diameter are carried manually. And coils with a composite with a diameter of 12 mm or more are rolled around the territory. Do not allow reinforcement strands to fall from a height of more than 500 mm.
• Unwind the coil only in a vertical position. Remove the packaging elements and leave the rings to make it more convenient to cut the reinforcement into pieces of the required length.
• Cutting composite with a diameter of up to 8 mm using an angle machine. Larger rods are cut with a circular saw. The cutter must wear safety glasses and gloves.
• The reinforcement is knitted using steel wire and nylon clamps. How this is done – see below.

Assembling the frame and knitting elements

Installing a composite frame is not like installing a steel frame.

• The fundamental difference between the technology of knitting reinforced frames made of composite materials and the installation of steel reinforcement is that plastic rods cannot bend. Therefore, the joints of the parts of the polymer structure are the intersections of the rods at right angles.
• When constructing monolithic foundations, composite reinforcement is knitted with steel wire using a crochet hook, and a “reinforcement knitter” is also used – a special unit powered by a battery. In addition, plastic clips are used to fix the rods at intersections. To do this, the reinforcement is placed in the grooves and pressed on it by hand until it clicks.
• To maintain vertical distances between reinforcing mesh, special plastic racks are used. In addition, each column is also a reinforcing element of the frame.
• Automatic knitting machine reduces frame installation by five times. The productivity of the tool is expressed in the time spent on creating one reinforcement unit, it is equal to 0.98 seconds.
• In foundation formwork, it is sometimes economically feasible to connect polymer rods with nylon ties. Their price is so low that it practically does not affect the rise in price of a monolithic structure.

Are there any differences in the reinforcement of different types of foundations??

There are three types of monolithic foundations: slab, columnar, and strip. There are uniform reinforcement guidelines for all varieties of monolithic foundations. This primarily pertains to the typical spaces that exist between the reinforcement cage, the bottom, and the formwork.

Reviews

The buyer is constantly looking to eliminate any doubts he may have about a specific item. He frequently uses internet forums to accomplish this. Forums that address the benefits and drawbacks of composite reinforcement assist developers in selecting the best brand of polymer rods.

The following can be used to summarize a number of reviews posted on different forums by people who constructed monolithic structures, including foundations, using composite reinforcement:

• preference for composite reinforcement was given by developers whose basement was planned to become a living space;
• the choice in favor of polymer reinforcement was made with the aim of significantly reducing the pressure of the house on a weak soil foundation;
• in case of a large bending moment at the base of the foundation slab, a composite was chosen as reinforcement, the rods of which are 3 times more tensile than long steel bars;
• An attractive feature of polymer rods is their complete immunity to corrosion.

The pros and cons of using plastic reinforcement for tying reinforcement cages versus steel rods, as well as the sharing of experiences with using composites in home construction, are actively discussed in the following forums:

An overview of the foundation’s use of fiberglass reinforcement through video:

There are several benefits to using composite reinforcement for foundations over traditional steel reinforcement in construction projects. Composite rebars are made of materials like carbon fiber and fiberglass, which give them strength, resistance to corrosion, and electrical conductivity without sacrificing weight. Because of these characteristics, they are perfect for prolonging the lifespan and durability of concrete constructions, particularly in corrosive environments.

Although the installation of composite reinforcement is similar to that of steel rebars, specific techniques are needed because of the differences in their properties. To preserve the integrity of the rebars, contractors need to make sure they are handled and cut properly. Composite rebars have a high tensile strength despite being lighter, which lowers the overall weight of concrete components and adds to the structural stability of foundations.

When compared to traditional steel rebars, composite reinforcement is easier to work with, according to reviews from construction experts. They point out that handling steel is easier and poses fewer safety risks, which lowers labor costs and expedites construction schedules. Additionally, by lessening the environmental impact of steel production and preventing corrosion, composite rebars support sustainable building practices.

To sum up, composite reinforcement is a progressive method of improving foundation construction. In terms of longevity, security, and environmental sustainability, it provides significant advantages due to its exceptional resistance to corrosion, elevated tensile strength, and lightweight composition. Composite materials are expected to become more important in the future of infrastructure development as construction methods advance.

Video on the topic

Composite reinforcement or metal reinforcement? Which one to choose

STEEL or COMPOSITE reinforcement?

Pros and cons of composite reinforcement in the foundation. Composite or steel reinforcement in an armored belt?