Is it possible to use fiberglass reinforcement in the foundation? Fiberglass reinforcement for the foundation. Main characteristics and main disadvantage

Composite reinforcement refers to modern materials, designed to replace expensive rolled metal and provide greater resistance to the negative influence of external factors. After this type of polymer rod began to be produced in Russia in 2012, interest in it from builders began to increase every year.

Application glass plastic materials for reinforcement of monolithic concrete structures This is especially true in cases of possible exposure to moisture, since polymers are not susceptible to corrosion.

Plastic rods are used at individual development sites, during the construction of large buildings and structures, for coastal fortifications and highways. In private construction, it is used to make reinforcing frames for strip and slab foundations, and also to reinforce masonry made of foam concrete blocks.

The material from which plastic fittings are made is a polymer mixture of longitudinal fiberglass of increased strength and thermally resistant resin. Standard diameters of produced rods range from 4 to 32 mm. Maximum operating temperature 60˚C. Tensile strength 150 MPa.

Preparation of materials for assembling the reinforcing frame

To increase the overall strength of a concrete monolith, it is reinforced with a structure made of fiberglass reinforcement in the form of a flat mesh or spatial frame, which is assembled from round rods of variable or constant cross-section. The individual elements of such structures are connected to each other using binding wire, fixing clamps or a special gun.

Therefore, to knit a reinforcing frame you need to purchase:

• plastic fittings of designed diameters;
• tie wire or tie clamps.

Unlike traditional metal rods, fiberglass reinforcement is supplied in the form of a coiled coil.

Therefore, before starting to assemble the frame, it must be unwound and cut into pieces of the required length. Cutting is done with a hacksaw or other tool that does not allow the material to heat up. Marking cut locations on the surface can be easily done using an ordinary marker.

The binding wire must be round in cross-section and have a diameter of at least 1 mm to ensure the necessary strength of the connection and not burst when twisted. To quickly obtain pieces of wire of the length required for knitting, the entire rolled coil must be cut into 3 or 4 parts with a grinder.

To make the binding wire softer, it can be burned in a flame using a blowtorch or in a fire. Unburnt wire bends worse and does not always provide a tight grip on the joint. In addition, unprepared metal has less ductility and is more likely to break during operation.

Knitting with clamps.
General knitting pattern.

Wire tying tool

Using pliers for knitting is not very convenient. They do not provide the required connection coverage density and require a lot of effort. Therefore, steel wire is twisted onto reinforcing bars using special hooks or a knitting gun. Tool stores offer for sale two types of hooks designed for tying reinforcement:

• simple manual ones, which must be rotated all the time during operation;
• semi-automatic screw type, with a hook that rotates when you press the handle;
• plastic fasteners in the form of rings and vertical posts that fit onto the reinforcement.

Instead of buying a simple hook, you can make it yourself (for more details on how to do this -), bend it from a thick steel wire and sharpening the edge. In this case, you will have something to knit a project design from rods without purchasing a tool.

The method of using a knitting gun speeds up and simplifies the process, but this rather large tool may not provide access to certain places. In addition, such a tool leads to excessive wire consumption.

Plastic clamps are needed in order to fix the assembled reinforcement cage in the required spatial position inside the formwork before pouring concrete.

Technology of manual wire knitting of fiberglass reinforcement

In order for the reinforcement frame or mesh to take on the required spatial shape and not change it when pouring concrete, everything individual elements must be securely connected to each other. The most common way to do this is to use tie wire. Knitting is a simple and quick joining method that does not require high qualifications. In addition, fiberglass reinforcement simply cannot be connected by welding, and therefore this type of fastening is most suitable in this case.

The entire process of how to knit fiberglass reinforcement for a foundation can be divided into the following step-by-step steps:

1. the reinforcement rolled into a coil is unwound and cut into pieces of the designed length;
2. plastic clamps are put on the transverse rods of the lower reinforcing layer;
3. longitudinal rods are laid on the spaced transverse elements at a specified distance from each other;
4. at all intersections of the reinforcement, connections are made by twisting loops of knitting wire folded in half;
5. after assembling the bottom row, vertical reinforcing elements are tied to the intersections of the outer cells;
6. transverse sections are tied to the upper ends or to the middle of the vertical posts, depending on the design number of rows;
7. the next row of longitudinal reinforcement is laid and knitted;
8. the assembled frame is transferred and installed inside the formwork for the strip foundation.

The work can be greatly simplified if you combine fiberglass reinforcement with metal. You can prepare rectangular frames from steel rods in advance and then you will not need to perform separate knitting of vertical sections.

The nuances of knitting structures for pouring a slab foundation

Reinforcement of monolithic slab-type support bases is carried out in the form of one or two rows of meshes, depending on the design solution. Therefore, in this design, reinforcing bars are not considered as longitudinal and transverse. To raise the lower mesh above the waterproofing layer, plastic clamps are placed on the reinforcement every one and a half to two meters. This allows you to install the reinforcement cage strictly in a horizontal plane at a given height.

An important feature of assembling reinforcement for a slab foundation is that it is produced locally. This is necessary due to the large size of the structure and the impossibility of subsequent movement. Therefore, during knitting, you must be extremely careful not to step on the laid reinforcing bars and damage the structure.

In the Swedish and Finnish insulated slab (more about it in) it is necessary to provide for the intersection of the slab rods with the reinforcing frame of the side support strip. To do this, the rods are cut longer, placed on vertical side reinforcement frames and tied with wire.

The nuances of knitting fiberglass frames for strip foundations

Features of the assembly of reinforcement for strip foundations include the presence of lateral junctions, intersections and corners.

In places where the tapes meet under the internal walls, the connection of the perpendicular frame with the external one is made using bent U-shaped elements.
In the corners, the reinforcement is bent at a right angle or prepared L-shaped elements are tied. The overlap length of the connected rods must be at least 30 cm and at least 2 knits are performed in this area.

Fiberglass reinforcement should be bent very carefully, without using heat treatment. The elastic properties of plastic make the bending procedure quite difficult. Therefore, to assemble corners and junctions, it is recommended to buy prefabricated bent elements.

The intersections of fiberglass reinforcement under the strip foundation can be connected by straight sections or one of the intersecting structures can be assembled at the installation site.

The assembly of reinforcement cages can be carried out in an open place, away from the dug trench. Correct styling the already assembled structure provides a distance from the formwork walls and bottom of at least 25 mm.

Finally

Tying fiberglass reinforcement for the foundation is a technologically simple process that does not require special professional skills. Even an unprepared person can quickly learn it. You just need to practice a little.

The low weight of the material greatly simplifies the work, and the large length of the reinforcing rod in the coil allows you to cut rods of any required length. This reduces the number of joints, unlike steel materials.

You can see more details about how to properly knit fiberglass reinforcement in the following videos.

Video on the topic

The foundation is the foundation of a structure that supports the main load. For this reason, it needs to be built from durable materials with good wear and tear. Special attention It is worth paying attention to fasteners that will hold the structure and also protect it from premature destruction. The most suitable option is fiberglass reinforcement for the foundation. This is a new material that has recently become very popular. But first, it’s worth considering its advantages and important features.

Fiberglass reinforcement is a whole system of glued glass fibers. A polymer composition is used as a binder.

Typically, the reinforcement has the form of a rod, which has several constituent elements:

• main trunk It has a core that consists of parallel fibers. They are glued together using polymer resin. This ensures high structural strength;
• outer shell. The sheath fibers are wound around the AKS barrel in a spiral sequence. Sometimes sand spraying is used.

Advantages and disadvantages

Fiberglass reinforcement is an excellent option for strengthening the foundation. This material increases its strength, increases service life and allows it to withstand high loads.

If you are thinking which reinforcement is better - fiberglass or metal, it is worth considering important positive features of composite reinforcement over steel:

Do not forget about the disadvantages of composite products:

• Fiberglass reinforcement has a low modulus of elasticity and can be easily bent. During the construction of the foundation and paths, this drawback is not noticeable. But if the products are used in the construction of floors, then this nuance should not be missed; it is important to carry out all the necessary calculations;
• The products have an insufficient level of heat resistance. You should not combine fiberglass reinforcement with concrete mortar under strong temperature changes, otherwise it may completely lose its binding properties;
• fragility. Over time, composite products wear out and begin to deteriorate; exposure to an alkaline environment also has a huge impact on rapid wear. But manufacturers, in order to increase the service life of fiberglass reinforcement, began to add rare earth metals to its composition;
• not intended for welding.

Reinforcement calculation

When building a foundation with your own hands, it is important to correctly calculate necessary materials, including fiberglass reinforcement. The calculation must be carried out in accordance with the following important nuances:

• The correct determination of the base length parameters must be carried out. When taking measurements, it is necessary to take into account the length of the internal load-bearing partition;
• it is required to calculate the length of the reinforcing rods. It should be taken into account that the reinforcing elements will be placed in several tiers;
• you need to determine the number of places with connections. Composite products are joined not by welding, but by overlap. For this reason, 100 cm is added to the area of ​​each corner;
• Calculations must be carried out for transverse connections.

To understand exactly how the calculation of fiberglass reinforcement bars is performed, it is worth considering an example using the parameters of a house with a base size of 12x12 meters, which was made using tape technology.

During the calculation the following actions will be performed:

• the perimeter of the house is calculated. P = 2*(12+12) = 48 m;
• the total length of the reinforcement elements, which are stretched into two tiers of 4 edge bars, will be calculated as follows - D = 48 * 4 = 192 m.
• the number of jumpers must be calculated taking into account the minimum permissible run-up of 0.5 meters. In an example it looks like this, P = 48/0.5 = 96 pieces;
• Calculations of the perimeter of the frame (500x500 mm) must be carried out. Pk = (0.5+0.5)*2 = 2 m;
• calculations are made of the length of the reinforcing rings - Dk = 96 pcs * 2m = 192 m. In this case, trimming must be taken into account - 192 + 5% = 202 m;
• in the end you will need - 192 + 202 = 394 meters of product with the same profile;
• It is worth calculating the required number of clamps for knitting - X = 96 pcs * 4 = 384 pcs.

In order for the composite material to protect and strengthen the foundation, it is recommended to follow important recommendations when working with it:

• Rebar cutting is done using a hot torch or bolt cutter. Sawing polymer reinforcement products with any other devices causes the formation of harmful microscopic chips;
• bending of reinforcement is allowed only in the manufacture of structural reinforcement products. This process is performed using an electric hair dryer; this tool heats the bent area to 100-120 0 C, and then, after taking the required shape, everything is cooled;
• the fittings should be stored in a cool, dark place, protected from sunlight;
• When unwinding coils with rods, it is recommended to take into account the degree of elasticity of the composite material. To relieve its strong tension, one end of the reinforcement must be secured for some time to the coil body using a meter-long piece of chain.

How to reinforce a foundation with fiberglass reinforcement

Fiberglass reinforcement is often used for strip foundations. It strengthens it, enhances its strength. But in order for the reinforcement process to proceed correctly, it should be approached with all responsibility.

Preparation

When using composite products for the base, it is worth preparing the necessary tools for the job:

• to take the required measurements you will need a tape measure;
• Bulgarian. This tool is needed for fitting and cutting fiberglass rods;
• personal protective equipment;
• water level;
• plastic clamps. They are necessary to connect the rods.

At the preparatory stage, you need to dig a trench. It is carried out according to the data specified in the project of the future structure. Important features of earthworks include:

• After digging the trench, it is recommended to level and compact the bottom well;
• then sand is poured in the form of a layer, its thickness should be 10-15 cm;
• the layer is watered and thoroughly compacted;
• crushed stone is poured on top of the sand with the same thickness as sand and thoroughly compacted;
• As a result, a kind of cushion of sand and crushed stone is formed at the bottom.

It is important to do everything correctly. The bottom of the trench should be perfectly flat so that after laying the fiberglass reinforcement there are no distortions. This will require the use of a water level.

Construction of formwork

For a strip foundation, formwork is required; it gives it the required shape and protects it from distortions. It is made from boards that are connected in the form of shields. It is recommended to use nails and screws for fastening. The caps of fasteners should be located on the inside. Additionally, the structure should be strengthened with special spacers.

The surface of the formwork walls is covered with polyethylene film, which is attached using a construction stapler. The use of film is desirable; it will keep the boards clean and also prevent liquid from leaking out of the concrete mixture.

On the walls of the formwork it is necessary to mark the level to which the concrete solution will be poured. It will also serve as a guide when installing a frame made of fiberglass reinforcement. To get everything right, you should use a water level.

Features of the construction of a frame made of reinforcement

After installing the formwork, reinforcement must be carried out. When constructing a frame, the following important conditions should be observed:

After constructing the frame, the concrete mixture can be poured. It is recommended to pour the solution carefully; it should completely fill the space between the frame elements. Be sure to periodically pierce the concrete with a metal rod, this will eliminate air voids.

Despite the fact that reinforcement made of composite materials has been used in Europe, the USA and some other countries to strengthen concrete monolithic structures since the 70s of the last century, for us it is still a new and rarely used material. However, in recent years, thanks to the desire of private construction companies to introduce modern technologies into production, fiberglass reinforcement is becoming increasingly used.

Initially, fiberglass reinforcement, due to its high cost, was used only for monolithic structures subject to difficult operating conditions. But the gradual development of the chemical industry and the building materials industry has led to lower prices and increased availability of fiberglass.

The expansion of production and scope of application of reinforcement with composite reinforcement entailed the development and approval of GOST 31938-2012, which determines the manufacturing conditions, appearance, dimensions and procedure for laboratory testing of products of this type.

What is fiberglass reinforcement

Structurally, in cross section, it is a bundle of threads made of fiberglass, carbon fiber, basalt and some other polymers, coated on top with viscous resins. This structure provides tensile strength more than three times that of steel ( detailed comparison composite and metal reinforcement is given).

Classification

Depending on the type of raw materials used in the manufacture, PVC reinforcement for foundations is divided into:

• glass composite - ASC;
• carbon composite – AUK;
• basalt - ABK;
• combined – ACC.

In addition, polymer rods vary in cross-sectional diameter from 4 to 32 mm and appearance surface, which can be smooth, corrugated or powdered.

Deliveries are made in the form of rolled coils or straight cut rods up to 12 meters long.

Specifications

The structural structure of composite reinforcement for foundations makes it a unique building material that is used for the construction of especially critical monolithic concrete structures. The main technical indicators include:

• lower tensile strength for ASC 800 MPa, AUK 1400 MPa, ABK 1200 MPa;
• ultimate strength during compression testing for all types - not less than 300 MPa;
• transverse shear resistance for ASK is not less than 150 MPa, AUK 350 MPa, ABK 250 MPa;
• the average specific gravity of composite reinforcement is 1900 kg/m 3 ;
• The maximum operating temperature is 60˚C.

When comparing elasticity indicators, it should be noted that carbon fiber reinforcement is more than 2 times higher than fiberglass and 1.5 times higher than composite basalt reinforcement.

Weight of plastic fittings.

Cost of fiberglass rod

The price of polymer reinforcing materials depends on the structure and components in the composition. The design of the composite rod consists of a longitudinal set of glass fibers bonded together with epoxy resin. The surface can remain smooth, have a rough powder, or be wrapped in a spiral with a special glass roving. The latter method allows you to obtain a ribbed surface that will provide more reliable adhesion to concrete.

Unlike rolled metal, which in most cases is sold by weight, the price of fiberglass reinforcement is always determined per linear meter. This often leads to the misconception that composite materials cost much more per ton than steel.

It is necessary to understand that with a diameter of 12 mm, one ton of metal will contain 1100 meters of rod, and plastic - 12500 meters. In addition, the high strength of fiberglass reinforcement allows the use of smaller diameters under the same installation conditions. These conditions show that the cost of polymers will not be higher, but lower, than that of rolled metal. A study of the price lists of manufacturing companies showed that the price of the most popular diameters 4-8 mm is in the range 8.50-27.20 rub/m.

Pros and cons of using fiberglass

Experts consider the main advantages of composite reinforcement to be:

• resistance to corrosion and many aggressive chemicals;
• high strength, exceeding similar indicators for metal;
• durability, increasing the service life of the structure by 2-3 times;
• low specific weight, facilitating loading and transportation;
• simple calculation of fiberglass reinforcement for the foundation;
• possibility of use at negative temperatures down to -60˚C;
• environmental friendliness of the components used;
• accessibility and cost-effectiveness of use;
• no restriction on rod length during installation due to supplies in coils;
• dielectric and antimagnetic properties.

A serious disadvantage of composite reinforcement is its reduced strength during fracture testing. Where metal rods simply bend, fiberglass can break, weakening the reliability of the structure. Therefore, such polymers are not used in the installation and production of load-bearing elements and floors, which limits their use and is a disadvantage.

The maximum heating temperature does not allow the use of plastic reinforcement with the potential for prolonged exposure to an open flame. In the event of a fire, such concrete monoliths will be identified as damaged and must be replaced.

Comparing the pros and cons of fiberglass reinforcement, we can confidently conclude that these materials can and should be used to create reliable and durable monolithic structures.

Scope of application

Fiberglass is an excellent material for installing any type of foundation. Composite reinforcement is used not only in industrial, but also in private construction. Especially if there is a possibility of high lifting groundwater and on marshy soils. This material is indispensable when performing work to strengthen banks, during the construction of hydraulic structures and at sites with possible exposure to aggressive substances.

Good results are obtained if plastic reinforcement is used to strengthen road surfaces in areas with high humidity and in permafrost conditions. A rod with a diameter of 4 mm is used for reinforcing masonry made of foam concrete and aerated concrete blocks, as well as floors in industrial and commercial facilities.

Experts also recognize the advantage of composite reinforcement as the ability to effectively combine traditional steel rods and composite plastic materials. With the help of steel, the corners and junctions of the walls are strengthened, and all spans are reinforced with plastic. This allows you to speed up the assembly of the frame without compromising the quality of the structure and expand the areas of application of materials.

Foundation reinforcement technology

Thanks to the reduced weight of plastic reinforcement and the ability to use rods of any length, assembling a reinforcing frame is much easier than using metal rods. The increased strength of polymer reinforcement for foundation materials allows the use of a smaller cross-section.

For example, steel reinforcement with a diameter of 12 mm, often used for installing foundations in private construction, is replaced with 8 mm plastic, and 10 mm rods with 7 mm polymer.
A calculation table that will help you determine exactly what diameter can be used in each individual case.

Technological production process installation work using plastic reinforcement for the foundation is carried out in several stages, as shown in the video at the end of the article:

1. installation of formwork;
2. marking the concrete pouring level;
3. assembly of the reinforcing frame;
4. removal of formwork.

Installation of the formwork structure when reinforcing a strip foundation with fiberglass reinforcement must be carried out in accordance with the design to ensure the exact configuration and dimensions of the foundation elements. When made of wooden boards, chipboard or plywood, it is recommended to wrap the panels in glassine. This will save the material and reuse it.

After this, marks must be made on the inside of the enclosing elements using a water level top level future monolith. They will allow you to navigate when pouring concrete and ensure its even distribution.

Assembly of the reinforcing frame

The layout of the reinforcement and the dimensions between individual rods are always indicated in the project. If you use fiberglass reinforcement in the foundation, you can change the diameter of the rods to a smaller one, but the layout should be done only according to the drawing.

Scheme of reinforcement of a monolithic slab.

Initially, it is necessary to unwind rods of the required length from the coil and install them on stands parallel to each other. At specified intervals, place transverse bridges on the longitudinal strings. Tie the reinforcement at the intersections with tying wire or tighten it with tight plastic clamps (more about tying -). As a result, the bottom row of the frame will be ready for reinforcing the foundation with fiberglass reinforcement.

Prepare vertical posts of the required length. The top row of the frame is knitted similarly to the bottom row. After assembly, both rows are placed on top of each other and, starting from the edge, their vertical posts are connected, gradually raising the top row of reinforcement.

After assembling the structure, it must be moved and installed inside the formwork fence, as shown in the photo.

Before installing the reinforcing frame, sand is poured into the bottom of the trench and spilled with water or compacted. It is recommended to cover the compacted sand surface with waterproofing material or geotextile fabric. This will prevent moisture from entering the foundation and increase its reliability and service life.

In the process of installing a foundation made of fiberglass reinforcement, it must be remembered that the edges of the rods should not reach 5 cm from the formwork and the bottom of the trench. To ensure this condition, you can use special plastic fasteners such as “post” and “star” or dense moisture-resistant stone materials.

Belt reinforcement.

Pouring concrete mixture

Laying concrete inside the formwork is done in exactly the same way as when using metal reinforcement. However, extreme caution should be exercised, since the strength of fiberglass reinforcement may be insufficient under strong lateral impacts. Compacting concrete with a vibrator or tamper must be done in such a way as not to damage the installed frame.

Horizontal reinforcement

This method of using composite reinforcement in construction is used for the installation of slab foundations. Their main difference from the bases belt type consists in the absence of corners and adjacent areas. In fact, the entire structure is made in the form of two large grids, located one above the other. All assembly work is carried out at the installation site, since moving the assembled element of such big size quite problematic.

Therefore, the required number of longitudinal rods is initially laid. Transverse ones are placed on them and a mesh is knitted using wire or clamps. The second one is knitted directly on it. After this, the lower mesh must be raised onto stands above the bottom of the pit. Next, the upper mesh can be placed on vertical posts installed at the intersections of the reinforcement.

Finally

Fiberglass mesh for reinforcement on construction sites in our country is still considered a new material. Many builders still believe that the use of steel, the properties of which have long been studied, will provide a more reliable monolithic structure.

However, numerous tests and studies have shown that composite materials are superior to traditional metal in strength, durability and other characteristics. Plastic is more convenient to use and reduces installation time. It is also not susceptible to corrosion, stray currents or low temperatures.

Video on the topic

Fiberglass reinforcement for foundations appeared in the assortment of companies producing composite materials quite recently and immediately began to actively promote itself in the construction market, which is due to its fairly good characteristics and varied assortment.

In the range of companies producing composite materials fiberglass reinforcement for foundation appeared quite recently and immediately began to actively promote itself in the construction market, which is due to its fairly good characteristics and varied assortment.

Technical characteristics of fiberglass reinforcement

Standard construction reinforcement, which is produced today in accordance with GOST, has a cross-section from 4 to 32 mm. In low-rise construction, the most common fiberglass reinforcement is with a diameter of 6, 8, 10 mm, packaged in coils.

Depending on the type of continuous reinforcing filler, fiberglass reinforcement is divided into several types:

• ASK (glass composite)
• AUK (carbon composite)
• ACC (combined) and others.

Important properties of fiberglass reinforcement that must be taken into account when reinforcing the foundation are:

• maximum permissible operating temperature – 60°C;
• tensile strength (ratio of force and cross-sectional area):
  • ASK – from 800 MPa
  • AUK – from 1400 MPa;
• tensile strength on transverse section:
  • ASK – from 150 MPa
  • AUK – from 350 MPa;
• compressive strength – from 300 MPa.

You should also take into account the tensile modulus of elasticity, according to which AUK-type reinforcement is 2.5 times higher than ASK.

Advantages and disadvantages of fiberglass reinforcement

Comparing the properties of fiberglass with the characteristics of steel, it should be noted that fiberglass composite reinforcement for foundation has several significant advantages, such as:

• corrosion resistance;
• very low thermal conductivity and absence of cold bridges;
• dielectric non-conductivity and electromagnetic permeability (does not conduct electricity, does not interfere with radio waves);
• low weight (8-10 times lighter than metal);
• tensile strength (2-3 times higher);
• seamless (transportation in coils eliminates the need to cut into pieces to fit the size of the machine, as is the case with metal rods);
• ease of transportation (due to previous factors);

• ease of installation, which does not require a welding machine or other tools;
• absence of cracks in concrete due to equal values ​​of the coefficient of thermal expansion.

Along with its advantages, fiberglass reinforcement has a very significant drawback (except for the fact that its qualities have not yet been tested by time): a very low degree of fracture strength, which is significantly inferior to that of steel reinforcement.

Unlike metal, fiberglass has the properties of rubber and stretches when bent, so concrete has to work in tension, which it does not handle well enough. In this regard, manufacturers clearly indicate the areas of application of these building materials, beyond which it is not recommended.

Technology of foundation reinforcement with fiberglass rods

In low-rise construction reinforcement of the foundation with fiberglass reinforcement performed using rods with a cross-section of 8 mm, which correspond to steel rods with a diameter of 12 mm.

The technology of this type of reinforcement consists of several stages:

1- preparation of formwork:

2- protecting the surface of the formwork by covering it with glassine, which will ensure repeated use of the structure;

3- setting a level mark to which the concrete mixture will be poured. It is applied to the inside of the formwork, using a water level, to ensure even distribution of concrete;

4- laying bricks on the bottom of the foundation, which will allow the reinforcing mesh to be placed at an appropriate distance from the edges of the formwork (about 50 mm);

5- laying two rows of fiberglass reinforcement on bricks using solid rods;

6- laying horizontal jumpers (crossbars);

7- fastening all the rods together with nylon clamps (plastic ties);

8- installation and fastening of vertical rods, upper longitudinal and transverse, equal to the lower parts of the reinforcing mesh. The size of the cells is determined taking into account the fact that the recommended distance between the centers of the diameters is 150 mm.

9- pouring the foundation with concrete.

It takes 2-3 weeks to harden. During this period, it is covered with a film from the rain, and in extreme heat it is moistened with water.

Calculation of fiberglass reinforcement for different types of foundations

Correct calculation of fiberglass reinforcement for the foundation will allow you to buy the right amount of material, pre-determine the costs of its purchase, and avoid unnecessary expenses or additional problems caused by a lack of reinforcing bars.

To calculate reinforcement for slab foundation it is necessary to determine the length and number of rods based on the area of ​​the base and taking into account the pitch of the frame mesh. You should also know that the slab has two armored belts (upper and lower) and they are connected to each other by vertical rods over the entire area of ​​the slab in the corners of each cell.

The calculation for a strip foundation is performed in a similar way.

To reinforce a columnar foundation, the reinforcement in the columns is installed in reverse, that is, ribbed - vertically, smooth - horizontally. For the frame, 2-4 vertical rods with a length equal to the height of the pillar are usually used. For wide (more than 20 cm) pillars, more rods are taken, which are evenly distributed inside the pillar. In addition, each post requires at least 4 horizontal rods.

Use of fiberglass reinforcement

The clear advantages of fiberglass have provided a fairly wide range of use of fiberglass reinforcement in the foundation various structures:

• in civil, industrial and residential construction;
• for concrete buildings, in brick or block masonry using flexible connections;
• during construction in winter, which requires the addition of special anti-frost compounds and hardening activators to mixtures and solutions, which negatively affect the steel frame.

Also, composite fiberglass reinforcement is widely used in road construction and bank protection.

It is worth noting that today use of fiberglass reinforcement for the foundation remains highly controversial because the material has not stood the test of time. Many experts recommend using a combination of steel and fiberglass rods in order to make full use of the advantages of each material and minimize their disadvantages as much as possible.

“Pros” and “cons” of fiberglass reinforcement (video)

Until recently, reinforcement made of metal rods was considered not only the most reliable, but also the only acceptable option for creating a strong “skeleton” of the foundations of buildings for any purpose. The material in question did not appear yesterday (there are references to the experience of its use since the late 70s). But composite reinforcement did not gain popularity, so they forgot about it in our country for a while. But in foreign countries it was actively used. Therefore, we can talk about the successful use of composite rods for reinforcing concrete structures. And judging the strength and stability of such structures is not unfounded, but based on facts.

Some myths from unscrupulous manufacturers and sellers

Fiberglass reinforcement, although not a new material (as it turned out), is unfamiliar to most consumers. The fact that advertising positions it as an innovation is nothing to worry about. It’s worse when, taking advantage of the ignorance of potential customers, the manufacturer tries in every possible way to increase the selling price of the product, pointing out the supposedly unique properties of its composite reinforcement.

Composite reinforcement photo

While an ordinary private developer is collecting information about it bit by bit, getting acquainted with the properties and features of its application, and large construction companies are calculating the income and expenditure side of the budget when switching to a composite instead of metal, rumors are growing and multiplying. And they require a reasoned and honest answer.

One of the most common myths can be debunked right now.

• Externally this construction material are light rods with various shades of yellow (if they are made of fiberglass) or pronounced black (provided that basalt was used). However, an attempt to make the product more attractive in appearance, namely the addition of coloring pigments of various shades, made it possible to introduce colored fittings to the market. And a myth immediately appeared: these additives do not simply color the rods, but are special components that improve the characteristics of the material. Serious manufacturers give a clear answer: color does not affect the quality of composite reinforcement.

• In addition to improving the presentation, there is also a very noble impulse behind such experiments with color: to highlight rods of different diameters.

Reading the regulatory documentation for building materials will help you not to fall for the tricks of dishonest sellers.

Application of composite reinforcement

Composite reinforcement is gradually gaining space from its metal counterpart in the area of ​​laying the foundations of low-rise buildings. Glass, carbon, basalt or armide fibers are used as the basis for its production. They are bonded to each other by adding polymers.

Fiberglass reinforcement can also be produced in the form of smooth rods, but when it is supplemented with a spiral winding of glass thread, more reliable adhesion to the poured solution is ensured. So it’s better to give preference to the second option.

Experts cite a number of advantages of composite reinforcement:

• ease of transportation and use due to low weight. In addition, during installation they do not use welding work;
• resistance to various aggressive environments;
• corrosion resistance;
• tensile strength.

To create a foundation, composite reinforcement of a certain diameter is required. The section is calculated individually for each object. It depends on the number of floors, the complexity of the project and a number of other reasons. It is important that, while not being inferior in strength to metal rods of the same diameter, composite reinforcement will be lighter in weight.

Composite reinforcement for foundations

• When laying a foundation, composite rods are used in the same way as steel rods. A frame is assembled from them according to the recommendations for a certain type of base with the required pitch, and at the intersection points the reinforcement elements are fastened with ties or binding wire.
• Developers and manufacturers do not give recommendations prohibiting the use of composite reinforcement for the construction of any type of foundation. That is, if the developer wishes, any foundations for a low-rise building can be made using fiberglass reinforcement.
• But you can accurately determine in which foundations composite rods have proven themselves to be the best. We are talking about strip or column methods for buildings no more than three floors high. For those who want to build: a private house, cottage, bathhouse, garage, solid building for economic purposes.

• The service life of elements of non-metallic origin is quite long - 80 years according to minimum calculations. Their cost may be only slightly different from the price of conventional steel rods, but it is quite possible to save on transportation. The fittings, packed in a bay, can easily fit into the trunk of a passenger car.
• Construction conditions and technologies vary. Where reinforced concrete structures will be used in an environment that is aggressive to metal, it makes sense to use non-metallic reinforcement.
• Composite reinforcement, selected with equal strength to a reinforced concrete frame, will create a reliable foundation. And it will last much longer (due to resistance to the destructive effects of the environment and “complete indifference” to the corrosion process).

For massive concrete buildings, the following types of fiberglass reinforcement are used:

• External. Justified in cases where concrete structures are exposed to destructive effects in an unfavorable environment.
  • The characteristics of composite reinforcement, produced specifically for these purposes, make it possible to create a protective barrier around the structure. It is impenetrable to both air and water. This method is called continuous. Sometimes, when using it, they do the opposite. First, the frame is made, and then it is filled with concrete.
  • The discrete method means that composite meshes or strips of reinforcement strengthen the base from the outside.
• Internal. It is also divided into two ways.

• Discrete reinforcement assumes that composite meshes, individual rods, or even volumetric frames created from many elements will be placed inside the structure.
• Dispersed method somewhat simpler - crushed glass fibers are added to the total mass for pouring. The resulting material is called glass fiber reinforced concrete.
• A joint. The combined method got its name not only because of the simultaneous use of two types of reinforcement, but also because it allows a combination of fiberglass and metal rods. It is used when significant weight loads are expected on the foundation.

Diameter of composite reinforcement

If you have never encountered such a problem before, the following information may be useful.

• Due to its design features, metal reinforcement has several indicators that characterize the diameter:
  • external is measured along the ribs protruding along the profile;
  • the inner one belongs to the rod itself;
  • nominal, which is expressed as an integer, is the profile number.
• They do not match; the diameter measured on the outside exceeds the nominal value. You should be extremely careful not to buy fittings with a smaller diameter than required based on these dimensions.
• Determining the above dimensions for fiberglass reinforcement has nuances. Its outer diameter is determined in exactly the same way as for steel. There are some difficulties when trying to obtain internal size values.
• The fact is that composite reinforcement does not have a perfectly round rod shape. This is due to the fact that numerous lines producing this building material, due to certain features, cannot maintain such accuracy. So the fiberglass rods when cut have a shape tending towards an oval. And the larger the diameter of the rod, the more clearly the oval is visible. When measuring such a product for the first time, the consumer will receive one result. By rotating the rod 90° and repeating the procedure, he will see different numbers. The indicators should be summed and divided by 2. The result can be considered an average indicator of the internal diameter of the composite reinforcement.

• In order to carry out calculation work and when purchasing material, you need to know the nominal diameter. In the conditions available to a simple home craftsman, this indicator cannot be obtained. For those for whom solving such a problem is vital, there is one trick.
• The nominal diameter is essentially the average number between the outer and inner gauge sizes. Further, the sparser the ribs are located on the rod, the more the internal diameter approaches the nominal value.

That is, you can catch an unscrupulous seller trying to pass off the outer diameter numbers as its nominal size like this:

• you need to measure the outer diameter;
• take measurements of the internal diameter;
• compare the number given by the seller with both indicators.

If the outer diameter coincides with the nominal number according to the seller, you should buy the fittings elsewhere.

Weight of composite reinforcement

Methods for connecting composite reinforcement

Among the advantages of composite reinforcement listed above, one of the points indicated that its use does not involve welding. The rods are assembled into a frame by tying them together.

Plastic ties are used less frequently, but builders value tying wire more. This material is more traditional and has not yet been eradicated by new trends. It is carried out in the following ways:

• using an automatic pistol;
• using a crochet hook for construction (simple configuration);
• using a screw (motorized) construction crochet hook.

The popularity of the last two options is explained by the availability of the tool. It’s rare that anyone can afford to purchase an expensive pistol just to build one foundation. Some large companies, however, practice renting out expensive but very simplified equipment. And if such an opportunity arises, then it’s worth taking advantage of it.

Among the arguments for automating the knitting process are the following:

• It is quite obvious that mechanized labor is more effective and productive;
• Having such an “assistant” you can avoid overpaying hired workers. With its use, one person can handle the strapping on their own;
• the gun makes equally smooth and strong knots on the entire frame;
• the tool is functional at any temperature;
• A powerful battery allows you to work uninterrupted all day.

Particularly advanced models of this tool are equipped with a device that allows you to tie rods without bending close to them.

Foundation with composite reinforcement and construction in earthquake-prone areas

• Another proof of the magnificent strength characteristics Composite reinforcement can also be used in other areas of construction that require withstanding significant loads: walls and floors of buildings, road surfaces, coastal structures, bridges.
• But it’s rare to find mention that composite reinforcement can withstand impressive earthquakes. research institute building structures named after Kucherenko about five years ago they studied the behavior of this material under large dynamic loads. Reinforcement with a diameter of 8 mm was tested by an “earthquake” from 5 to 10 points. With its help, prototypes of panels were reinforced, which were subjected to appropriate loads and placed on vibration platforms. The material remained intact up to magnitude nine seismic activity!

Composite reinforcement video

Fiberglass reinforcement is a durable and easy-to-use material. Today it is a worthy replacement for metal rods, and its use for pouring foundations under low-rise construction, can be considered not just justified, but also an extremely desirable action on the part of the developer. This is why there are so many positive reviews about composite reinforcement among private developers.