The types of resins used are distinguished by the type of application and the resistance required; There are polyester resins, vinylester resins and epoxy resins.

Polyester resins are characterized by a good quality-price ratio, but they should not be applied to constantly wet concrete, due to the risk of alkaline hydrolysis that could, in the long term, compromise resistance, which is why they are intended for artisanal uses such as the installation of windows and doors, heating and plumbing, light carpentry and application in hollow bricks.

Vinylester resins are characterized by greater mechanical strength and resistance to alkaline hydrolysis, making them appropriate for the use of long-strength fixings in construction, including injection of reinforcing bars in heavy metal carpentry and road works.

Epoxy resins are characterized by greater mechanical resistance and better adhesion in holes made using diamond drills, but the hardening time is approximately ten times longer, which is why they are mainly used for splicing reinforcing rods, thanks to the greater fluidity that is suitable for injections in longer holes.

Application on perforated bricks

It is necessary to use a special injection cap that does not allow the resin to fall into the perforated masonry, facilitating the formation of a resin conglomerate that will anchor the brick holes made by the interlocking.

Application in compact masonry and concrete

If the resin in the mixer is hardened, another mixer will have to be used.

Applications in wet or water-filled holes

If the hole in the concrete in the masonry is wet or filled with water, it can delay hardening. It is estimated that the time required for hardening is 1.5 times longer than in dry holes. In any case, refer to the manufacturer's instructions.

Some resins are not suitable in water-filled holes. In other cases, safety factors that limit the load are recommended. In these applications the best resins are pure vinylester or epoxy.

Chemical anchor resins are generally classified as "irritant preparations" (Xi). That is why it is necessary to read the safety information on the label and, for professional use, receive and take into account the safety sheet. Subsequently, apply all necessary precautions. In general it is better to protect hands, skin and eyes from contact.

The calculation begins from the knowledge of the mechanical resistance of the substrate in which the anchor is made, usually perforated or solid brick, or concrete. As for perforated or filled bricks, the mechanical resistance is obtained through experimental tests. The different producers of chemical anchors generally declare this in the technical sheets.

The application of chemicals in concrete offers greater versatility than other systems, to give the possibility of varying the depth of the anchor and the ability to anchor close to the edges: chemical anchors do not exert expansion forces, therefore, they can be applied closer to the edge compared to expansion plugs.

To analyze the resistance of the anchor, the three main failure modes must be taken into account: breakage of the steel rod, breakage of the concrete cone and extraction due to breakage of the resin.

These modes vary differently depending on the depth of the anchor, the breaking strength of the rod is independent of depth, the pullout depends on the lateral surface of the hole and varies linearly with depth, and the breaking of the concrete cone varies with the square of the depth. In general, manufacturers recommend an insertion depth that takes into account the best possible result, also in relation to partial safety factors related to failure modes.

For more complex situations, shear resistance and bending moment must be considered.

Generally the shear resistance is that of the steel rod and does not depend on the type of chemical anchor.

A complex discussion of the calculation and more precise sizing of chemical anchoring is regulated in the guidelines of the European Technical Approval (ETAG) available on the website of the European Organization for Technical Approval www.eota.be.

For the use of chemical anchors as a system of reinforcing rods and reinforced concrete joints, it does not refer to the theory of anchoring (in which it is considered that the concrete is also subjected to tensile stress) but refers to the calculations of the reinforced concrete. In this case, by recommendation of the manufacturer and any ITE certification of the chemical anchor, it can be assimilated to the insertion of the corrugated bar with the resin into a similar bar embedded in the concrete before pouring the concrete. In this case, the rules for superimposing reinforcing bars are used.

However, reference should be made to the technical data of chemical anchor producers, which are usually simplified and may be useful for the project. it doesn't come out

The European Union has published technical standards for calcification and certification of suitability for the use of fastening systems, through EOTA, which issues ETAGs for fastening systems.

As a result, the ETA (DITE) can be obtained for a given fastening product, which defines the characteristics and aptitudes for the intended uses and the essential requirements for construction products established by the Construction Products Directive.

Structural anchors can be evaluated according to these standards at accredited institutions and obtain the certificate of conformity and CE marking.

Sites of chemical anchor manufacturers where you can find more information and calculation software:.

The types of resins used are distinguished by the type of application and the resistance required; There are polyester resins, vinylester resins and epoxy resins.

Polyester resins are characterized by a good quality-price ratio, but they should not be applied to constantly wet concrete, due to the risk of alkaline hydrolysis that could, in the long term, compromise resistance, which is why they are intended for artisanal uses such as the installation of windows and doors, heating and plumbing, light carpentry and application in hollow bricks.

Vinylester resins are characterized by greater mechanical strength and resistance to alkaline hydrolysis, making them appropriate for the use of long-strength fixings in construction, including injection of reinforcing bars in heavy metal carpentry and road works.

Epoxy resins are characterized by greater mechanical resistance and better adhesion in holes made using diamond drills, but the hardening time is approximately ten times longer, which is why they are mainly used for splicing reinforcing rods, thanks to the greater fluidity that is suitable for injections in longer holes.

Application on perforated bricks

It is necessary to use a special injection cap that does not allow the resin to fall into the perforated masonry, facilitating the formation of a resin conglomerate that will anchor the brick holes made by the interlocking.

Application in compact masonry and concrete

If the resin in the mixer is hardened, another mixer will have to be used.

Applications in wet or water-filled holes

If the hole in the concrete in the masonry is wet or filled with water, it can delay hardening. It is estimated that the time required for hardening is 1.5 times longer than in dry holes. In any case, refer to the manufacturer's instructions.

Some resins are not suitable in water-filled holes. In other cases, safety factors that limit the load are recommended. In these applications the best resins are pure vinylester or epoxy.

Chemical anchor resins are generally classified as "irritant preparations" (Xi). That is why it is necessary to read the safety information on the label and, for professional use, receive and take into account the safety sheet. Subsequently, apply all necessary precautions. In general it is better to protect hands, skin and eyes from contact.

The calculation begins from the knowledge of the mechanical resistance of the substrate in which the anchor is made, usually perforated or solid brick, or concrete. As for perforated or filled bricks, the mechanical resistance is obtained through experimental tests. The different producers of chemical anchors generally declare this in the technical sheets.

The application of chemicals in concrete offers greater versatility than other systems, to give the possibility of varying the depth of the anchor and the ability to anchor close to the edges: chemical anchors do not exert expansion forces, therefore, they can be applied closer to the edge compared to expansion plugs.

To analyze the resistance of the anchor, the three main failure modes must be taken into account: breakage of the steel rod, breakage of the concrete cone and extraction due to breakage of the resin.

These modes vary differently depending on the depth of the anchor, the breaking strength of the rod is independent of depth, the pullout depends on the lateral surface of the hole and varies linearly with depth, and the breaking of the concrete cone varies with the square of the depth. In general, manufacturers recommend an insertion depth that takes into account the best possible result, also in relation to partial safety factors related to failure modes.

For more complex situations, shear resistance and bending moment must be considered.

Generally the shear resistance is that of the steel rod and does not depend on the type of chemical anchor.

A complex discussion of the calculation and more precise sizing of chemical anchoring is regulated in the guidelines of the European Technical Approval (ETAG) available on the website of the European Organization for Technical Approval www.eota.be.

For the use of chemical anchors as a system of reinforcing rods and reinforced concrete joints, it does not refer to the theory of anchoring (in which it is considered that the concrete is also subjected to tensile stress) but refers to the calculations of the reinforced concrete. In this case, by recommendation of the manufacturer and any ITE certification of the chemical anchor, it can be assimilated to the insertion of the corrugated bar with the resin into a similar bar embedded in the concrete before pouring the concrete. In this case, the rules for superimposing reinforcing bars are used.

However, reference should be made to the technical data of chemical anchor producers, which are usually simplified and may be useful for the project. it doesn't come out

The European Union has published technical standards for calcification and certification of suitability for the use of fastening systems, through EOTA, which issues ETAGs for fastening systems.

As a result, the ETA (DITE) can be obtained for a given fastening product, which defines the characteristics and aptitudes for the intended uses and the essential requirements for construction products established by the Construction Products Directive.

Structural anchors can be evaluated according to these standards at accredited institutions and obtain the certificate of conformity and CE marking.

Sites of chemical anchor manufacturers where you can find more information and calculation software:.