Repairing

Grouting of machinery

RELATED MATERIALS

1- High-strength, non-shrinking pourable cast grout

2- Rapid-setting cement

3- Fast-setting patching mortar

1. NATURE OF THE PROBLEM – REQUIREMENTS

Machine mountings are constantly subjected to high static and dynamic stresses. Therefore, the material that is filling the space between the floor and the machine must fulfill the following requirements:

• Be of high strength so that it can absorb the static and dynamic loads resulting from the operation of the machine.
• Provide excellent fluidity so that it can fill the whole space between the floor and the machine.
• Expand slightly during the first hours and not shrink after hardening in order to avoid the formation of hairline cracks at the point of contact with the machine.

1. SOLUTION

High-strength, non-shrinking pourable cast grout provides the ideal solution for such applications, as it is a fluid, non-shrinking high-strength cement grout with special admixtures, providing:

• Very good fluidity without separation.
• High initial and final strengths.
• Efficient bonding to steel and concrete.
• Resistance to impacts and vibrations.
• Low water permeability.

III. APPLICATION
Substrate preparation

1. Substrate should be free of dust, oil or other material.
2. Substrate should be roughened in order to ensure proper bonding of the product on it.
3. Before applying High-strength, non-shrinking pourable cast grout, substrate surface must be thoroughly dampened, but without forming puddles.

Application of High-strength, non-shrinking pourable cast grout

1. High-strength, non-shrinking pourable cast grout forms, after hydration, a fluid and fine-grained mixture and part of it may run off through the joints of the various elements of the formwork. Therefore, formwork’s joints should be sealed with rapid setting cement or fast setting patching mortar.
2. A 25 kg bag of High-strength, non-shrinking pourable cast grout is added to 3 kg of water under continuous stirring using a low revolution mixer until a homogeneous fluid mass is formed. A quantity of water up to 0,5 kg is added to the mix under constant stirring in order to achieve the desired fluidity.
3. The mixture is then poured taking care to avoid air entrapment. In any case, it should be ensured that the cement grout has filled the whole space between the formwork and the existing construction.
4. Surfaces that are exposed to open air must be kept wet for at least 24 hours, covered with wet fabric or polyethylene sheets.
   Consumption of High-strength, non-shrinking pourable cast grout: 21,5 kg/m²/cm layer’s thickness or 2,1 kg for filling 1 lit of volume.
5. REMARKS

• High-strength, non-shrinking pourable cast grout is applied at a maximum thickness of 10 cm per layer.
• Temperature during application must be between +5^oC and +35^oC.
• Material that has started to set must not be “softened” again with water.
• The product keeps its fluidity for approx. 60 minutes at temperatures between +15⁰C and +25⁰C.
• At high temperatures, storage of the bags in a cool place is recommended, as well as mixing the material with cold water in order to have the appropriate fluidity for a sufficient length of time (approx. 60 minutes).
• At low temperatures and whenever fast strength gain is required, mixing of the material with lukewarm water and protection from cold by putting thermal insulating covers over the formwork are recommended.
• The product contains cement, which reacts as alkaline with water and is classified as irritant.
• Consult the directions for safe use and precautions written on the packaging.

Waterproofing of pools and painting with epoxy coating

RELATED MATERIALS

1- Two-component epoxy coating suitable for swimming pools

2- Two-component, colorless epoxy impregnation

3- Waterproofing admixture for mortars and non-reinforced concrete

4- Polymer latex for multiple improvements of mortars

5- Plasticizing/water reducing admixture for concrete

6- Two-component epoxy putty

7- Special solvent for epoxy coatings

1. NATURE OF THE PROBLEM – REQUIREMENTS

A usual and affordable way to prepare the final surface of a swimming pool is to paint it with a special paint, such as an epoxy coating. This is a technically efficient solution that is clearly more affordable than overlaying with ceramic tiles.

The choice of using epoxy coating affects significantly the selection of the means for waterproofing the pool, since it sets specific requirements for the waterproofing that will be carried out.

More specifically, the waterproofing layer must:

• Be long lasting, since its position between the pool’s structural elements and the layer of the epoxy coating makes future interventions difficult and  expensive.
• Bond well to the pool’s structural elements, in order to withstand negative pressure that may develop on it periodically.
• Have a smooth surface.

The coating to be used must have the following properties:

• Elasticity, in order not to crack from possible expansions and contractions.
• Resistance to water and chemicals that may be present in the pool water (e.g. chlorine).
• Resistance to weather effects (e.g. solar radiation, frost etc.).

1. SOLUTION

The primary requirement is that the pool’s frame must have been calculated properly so that it can withstand the water’s hydrostatic pressure successfully.

Waterproofing of the pool is achieved efficiently by applying a strong waterproof cement mortar to the pool’s walls and bottom, which acts as a sealing and smoothing layer at the same time. Thus, the smooth, stable and waterproof substrate needed for the application of the epoxy coating is created.

This cement mortar becomes waterproof with the addition of - waterproofing admixture, in a proportion of 1% of the cement weight.

Its bonding to the pool’s walls is ensured by the application of a spatterdash reinforced with polymer latex, while its bonding to the bottom is ensured by the application of a bonding layer reinforced with polymer latex, as well.

Moreover, it is recommended that during the concreting of the pool’s structural elements, concrete waterproofing admixture is added to the concrete, in the proportion of 0,2-0,5% of the cement weight.

The requirements of elasticity and resistance to chemicals that the coating must satisfy are met successfully by the application of epoxy coating. This is a 2-component epoxy system that displays increased elasticity and resistance to friction. Furthermore, it is especially resistant to a variety of chemicals, such as diluted acids, alkalis, petroleum products, some solvents, water, sea water, and to weather effects.

III.APPLICATION
Substrate preparation

1. The substrate should be cleaned thoroughly of grease residues, deshuttering agents, loose materials, dust etc.
2. Exceeding construction forks should be cut up to the surface of the wall.
3. A strong, waterproof undercoat layer of a cement mortar (cement : sand = 1 : 2,5) should be prepared, with the addition of waterproofing admixture, in a proportion of 1% of the cement’s weight.
   The bonding of the cement mortar to vertical surfaces is reinforced by the application of a spatterdash with the addition of polymer latex (cement : sand : polymer latex : water = 1 : 1 : 0,25 : 0,25 parts by volume).
   The cement mortar’s bonding to the bottom of the pool is reinforced by applying a bonding layer with the addition of polymer latex (cement : sand : polymer latex : water = 1 : 1 : 0,5 : 0,5 parts by volume).
   The undercoat layer should be applied with the aid of guiding beams at a thickness of 2-3 cm.
   Consumption of waterproofing admixture: approx. 4,2 kg/m³of cement mortar.
4. A strong, waterproof finishing layer of a cement mortar should be prepared, with the use of fine-graded sand (cement : sand = 1 : 2) to which waterproofing admixture is added, in a proportion of 1% of the cement’s weight.
   The cement mortar should be applied at a thickness of 5-10 mm and then rubbed with a sponge float.
   Consumption of waterproofing admixture: about 5 kg/m³of cement mortar.
5. At the intersection of the walls and bottom of the pool, and where walls meet, it is recommended that a groove is formed during the application of the cement mortar, in order to facilitate the subsequent application of the epoxy products.

Priming and painting with epoxy paint

1. At least 28 days after the application of the cement mortar, time which is required for it’s hardening, and as long as it is dry (moisture < 4%), the surface of the pool's bottom and walls should be primed with colorless epoxy
   Components A (resin) and B (hardener) are packed in two separate containers, having the correct predetermined mixing proportion by weight. The whole quantity of component B is added into component A. Mixing of the 2 components should take place for about 5 minutes, using a low revolution mixer (300 rpm). It is important to stir thoroughly the mixture near the sides and bottom of the container, to succeed uniform dispersion of the hardener.
   Consumption of colorless epoxy: about 150 g/m², depending on the substrate’s absorptivity.
   Alternatively, priming may be done with epoxy coating diluted 10% to 20% with SM-14 special thinner.
2. Any cracks or imperfections should be filled in with epoxy putty.
3. After the primer dries, and within 24 hours of its application, the pool should be painted with epoxy coating.
   Components A (resin) and B (hardener) are packed in two separate containers, having the correct predetermined mixing proportion by weight. The whole quantity of component B is added into component A. Mixing of the 2 components should take place for about 5 minutes, using a low revolution mixer (300 rpm). It is important to stir thoroughly the mixture near the sides and bottom of the container, to succeed uniform dispersion of the hardener.
   epoxy coating may be applied as it is or diluted up to 10% by weight with SM-14 special thinner with a brush, roller or airless gun in 2 layers. The second layer should be applied after the first one has dried, but within 24 hours of its application.
   Consumption of epoxy coating: 200-300 g/m²per layer.

1. REMARKS

• Particular attention must be paid to the proper placement of the “special parts” of the pool, such as lights, water inflow and outflow points etc., which are vulnerable points as far as waterproofing is concerned.
• Epoxy coating contains solvents. In cases of applications in closed rooms, measures should be taken for good ventilation.
• Working time of epoxy systems decreases when ambient temperature rises.
• Bonding between successive layers may be severely affected by the intervention moisture or dirt.
• Epoxy layers should be protected from moisture for 4-6 hours after application. Moisture may whiten the surface or/and make it sticky. It may also disturb hardening. Faded or sticky layers in parts of the surface should be removed by grinding or milling and laid again.
• In case that longer time than predicted interferes between the application of successive layers or in case that old floors are going to be laid again, the surface should be thoroughly cleaned and ground before application of the new layer.
• Before application, study the safety advice mentioned on the product’s labels.

Painting of metal surfaces with anti-corrosive epoxy primer

RELATED MATERIALS

1- Two-component anti-corrosive epoxy coating

1. NATURE OF THE PROBLEM – REQUIREMENTS

The protection of metal surfaces made of iron or steel, from oxidization or corrosion.

1. SOLUTION

anti-corrosive epoxy coating antirust epoxy primer is applied for active anti-corrosive and anti-rust protection of iron and steel surfaces that are to be coated with epoxy coat or epoxy systems.

It is extremely hard and resistant to friction. It is particularly resistant to diluted acids, alkalis, petroleum products, to some solvents, water, sea water etc.

It can even be used as a coating on its own if its reddish-brown or grey color is satisfactory. Typical examples of use are the protection of silos, steel bridges, iron roofs, pipes, fences etc.

III. APPLICATION
 Substrate preparation

1. The substrate must be dry, stable and free of anything which would hinder bonding, such as dust, loose particles, grease, rust or any kind of corrosion.
2. Depending on the nature of the substrate, it should be prepaired by brushing, rubbing down, sand blasting, etc. and then thoroughly cleaned from dust.

Application of anti-corrosive epoxy coating

1. Components A (resin) and B (hardener) are packed in two separate containers, having the correct predetermined mixing proportion by weight. The whole quantity of component B is added into component A. Mixing of the 2 components should take place for about 5 minutes, using a low revolution mixer (300 rpm). It is important to stir the mixture thoroughly near the sides and bottom of the container, to achieve uniform dispersion of the hardener.
   To prime the surface, 2 coats of anti-corrosive epoxy coating are applied with brush, roller or spray gun. The second coat is applied once the first one is dry, but within 24 hours.
   Consumption: 150-200 g/m²per coat.
2. Subsequently, in the next 24 hours and after the primer is completely dry, application of the chosen epoxy coat or epoxy system can take place. If alternatively, anti-corrosive epoxy coating is to be used as the final finish, 2 more coats of it should be additionally applied. The second coat follows after the first one is completely dry, but within 24 hours.
3. REMARKS

• anti-corrosive epoxy coating contains solvents. In cases of applications in closed rooms, measures should be taken for good ventilation.
• Working time of epoxy systems decreases when ambient temperature rises.
• Bonding between successive layers may be severely affected by the intervention moisture or dirt.
• Epoxy layers should be protected from moisture for 4-6 hours after application. Moisture may whiten the surface or/and make it sticky. It may also disturb hardening. Faded or sticky layers in parts of the surface should be removed by grinding or milling and laid again.
• In case that longer time than predicted interferes between the application of successive layers or in case that old floors are going to be laid again, the surface should be thoroughly cleaned and ground before application of the new layer.
• Before application, study the safety advice mentioned on the product’s labels.

Painting of walls with high durability epoxy coating

RELATED MATERIALS

1- Two-component epoxy coating

2- Two-component, colorless epoxy impregnation

3- Two-component anti-corrosive epoxy coating

4- Special solvent for epoxy coatings

1. NATURE OF THE PROBLEM – REQUIREMENTS

Walls in places such as factories, laboratories, hospitals, abattoirs, canneries, wineries, petrol stations, service stations, etc are exposed to chemical damage by the activities carried out in them.

Consequently, the finishing surfaces of such places need to be highly resistant to chemical loading and easy to clean.

1. SOLUTION

The use of epoxy coating, for walls whose surfaces must be highly resistant to chemical damage and easily washed, is the most appropriate solution.

The surface created by its application demonstrates particular resistance to diluted acids, alkalis, petroleum products, some solvents, water, sea water and weather effects.

epoxy coating acts as a protective and decorative paint on cement-based substrates, such as concrete, plaster, cement-mortar, cement boards etc. and also on metal surfaces.

It is suitable for factories, laboratories, hospitals, abattoirs, canneries, wineries, petrol stations, service stations etc.

III.APPLICATION
Substrate preparation

1. The surface to be treated must be dry (< 4% moisture) and stable, as well as being free from any materials that would hinder bonding, such as dust, loose particles, grease, etc. It must also be protected from attack by moisture from behind.
2. According to its nature, the substrate must be prepared by brushing, grinding, milling, sand blasting, water blasting etc.
3. Subsequently, the surface must be cleaned from dust using a high suction vacuum cleaner.
4. The surface should be primed as follows:
   Cement-based substrates should be primed with a single coat of colorless epoxy or with EPOXYCOAT, diluted 10% to 15% with the special solvent SM-14.
   colorless epoxy consumption: approx. 150 g/m², depending on the absorptivity of the substrate.
   Metal or steel surfaces should be primed with two coats of anticorossive epoxy coating. Second coat follows after the first one is completely dry, but within 24 hours.
   anticorossive epoxy coating consumption: 150-200 g/m²per coat.
5. After drying of mthe primer, but within 24 hours, application of EPOXYCOAT can take place.

Application of EPOXYCOAT

1. Components A (resin) and B (hardener) are packaged in containers in predetermined mixing proportions. The whole quantity of component B should be added to component A and the mixture must be stirred for about 5 minutes with a low-revolution (300rpm) mixer. It is important that the stirring reaches the wall and bottom of the container, in order to distribute the hardener evenly.
2. EPOXYCOAT should be applied as it is or diluted up to 5% with the special solvent SM-14. At least 2 coats should be applied by brush, roller or spray. The second coat is applied once the first one is dry, but within 24 hours of the first.
   EPOXYCOAT consumption: 200-300 g/m²per coat.

1. REMARKS

• EPOXYCOAT contains solvents. In cases of application in closed rooms, measures should be taken for good ventilation.
• The working time of epoxy products reduces as the ambient temperature rises.
• Bonding between the successive layers may be severely affected by any moisture or dirt introduced between them.
• The surfaces of the epoxy layers must be protected against moisture for 4-6 hours after their application. The effect of moisture may whiten surface and/or make it sticky. It may also disturb the hardening process. Discolored or sticky layers on parts of the surfaces must first be removed by grinding or milling and then subsequently recoated.
• If more than the recommended time has been left between successive layers or when recoating already used surfaces after a long period, the old surface must be thoroughly grinded and cleaned before the new coat is applied.
• Consult the instructions for safe use and precautions written on the packaging.

Painting of building facades with highly-elastic waterproofing paint

RELATED MATERIALS

1- High-quality, elastic, waterproofing paint

2- High-quality, acrylic, water-based primer

3- Polymer-modified cement mortar

4- Mortar for rendering and masonry

5- Fast-setting, white repairing mortar

6- Polymer-modified cement putty

7- Polymer-modified cement putty, extra fine-grained

8- Elastoplastic acrylic sealant

1. NATURE OF THE PROBLEM – REQUIREMENTS

The problem of moisture, due to rain, in external walls is a common one, especially if waterproof render was not used or where poor quality paint has been applied. The problem is even worse in walls that are north facing, have cracks or are near the sea.

These problems can be solved easily and effectively, even at a later stage, when the walls are painted.

The paint used must be waterproof, strong, elastic and highly resistant to adverse weather conditions.

1. SOLUTION

High-quality, elastic, waterproofing paint is an ideal solution for painting wall surfaces, making them waterproof and easy to wash. It is a high quality, highly elastic, water-paint, with elastomeric resins. It provides:

• Total waterproofing of walls against rain.
• High elasticity and ability to cover cracked surfaces.
• Vapor permeability, allowing the structure to breathe.
• Strong bonding to the substrate and excellent
  coverage
• Excellent washability.
• Aesthetically pleasing result.

High-quality, elastic, waterproofing paint is suitable for external or internal application, on new or old surfaces, on all building materials, such as render, exposed concrete, brick, gypsum board etc.

III.APPLICATION
Substrate preparation

1. The substrate must be dry and free of any grease, dust, loose materials etc.
2. Any existing imperfections in the render should be repaired with polymer modified cement mortar, with cement-lime mortar or with fast-setting cement-lime mortar.
3. Imperfections in exposed concrete, should be repaired with polymer modified cement putties.
4. Cracks or joints should be widened to approx. 3 mm before being filled with acrylic sealant.
5. The surface should be primed with, special primer-loose render stabilizer.
   primer consumption: 100-200 g/m², depending on the absorptivity of the substrate.
6. Once the primer has completely dried, application of High-quality, elastic, waterproofing paint can follow.

Application High-quality, elastic, waterproofing paint

High-quality, elastic, waterproofing paint is thoroughly stirred before use. It is applied at 2 coats, undiluted or diluted with up to 5% water, by brush, roller or spray. The second coat is applied after the first one has completely dried.
Coverage: 8-10 m²/lit per coat.

Where there are severe multiple cracks in the wall surface, the High-quality, elastic, waterproofing paint membrane can be reinforced overall with 100 cm wide polyester fabric. In this case, a coat of High-quality, elastic, waterproofing paint is applied, as wide as the reinforcing material, and while it is still wet the polyester fabric is positioned. The procedure is repeated over the remaining surface. Once all the reinforcement is in place, 2 more coats of High-quality, elastic, waterproofing paint are applied over the entire surface. Second coat is applied once the first one has dried.
Coverage: 1-1,5 m²/lit in total.

Repairing of damaged concrete elements by grouting with concrete or high strength mortar

RELATED MATERIALS

1- Concrete superplasticizer, type G

2- Concrete superplasticizer, type F

3- High-strength, non-shrinking pourable cast grout

4- Two-component epoxy injection resin for cracks > 3 mm wide -Bonding agent

5- Rapid-setting cement

6- Fast-setting patching mortar

1. NATURE OF THE PROBLEM – REQUIREMENTS

In repairs – reinforcements of this kind, the concrete for casting must have the appropriate fluidity and ability to penetrate, in order not to leave any spaces during concreting, since grouting is generally performed at 10-12 cm of thickness, making spreading of the concrete difficult. When it is necessary to grout at thin layers of 4-8 cm thickness, which makes casting of concrete very difficult, a liquid mortar of great fluidity and high strength is required.

Additionally, the concrete or mortar for casting must bond efficiently to the existing concrete so that the formation of a monolithic element consisted from the old and new concrete, is ensured.

1. SOLUTION

Normal grouting at 8-15 cm thickness
The filling material is concrete to which concrete superplasticiser is added to ensure the desired fluidity of the concrete poured, while increasing its strength, by virtue of the great compression achieved.

Grouting at thin layers of 4-8 cm thickness

High performance grout is used as the filling material. It has great fluidity and very high strength.

III.APPLICATION
Substrate preparation

1. Any broken concrete parts are removed and cavities are created in the old concrete in order to improve bonding of the concrete to be poured.
2. The existing reinforcement is exposed, wherever necessary.
3. The surface of the existing concrete is mechanically roughened (e.g. by sand blasting).
4. Subsequently the existing concrete is washed with plenty of water under pressure.
5. The form-work is prepared and the new reinforcement is placed to the engineer’s statics study and is joined to the old with pegs and dowels.
6. Wherever possible, the old concrete surface is coated with epoxy resin – bonding agent, to ensure a perfect bond between the old and new concrete.

Normal grouting at 8-15 cm thickness
Following the above preparation the concrete casting, is carried out with the addition of superplasticiser in the proportion of 0,6-0,8% by cement weight, or superplasticiser in the proportion of 1,2-1,7% by cement weight, until an approximate 20 cm slump of the concrete results. Vibration of concrete during the casting is essential in order to achieve better compression of the concrete.

Grouting at thin layers of 4-8 cm thickness

1. Where High performance grout will be cast into forms, it is recommended that the joints between form-works are sealed with rapid-setting cement or fast-setting patching mortar, because the material is so fluid and fine-grained that it may otherwise escape through them.
2. The content of a 25 kg bag of High performance grout is added to 3 kg of water and mixed thoroughly with a low revolution mixer, until a homogenous mass is formed. Then a small quantity of up to 0,5 kg of water may be added until the desired fluidity is achieved.
3. The mortar is cast, taking care to avoid trapping of air. It must be ensured that the mortar has filled the entire space between the form-work and the existing construction.
   Consumption of High performance grout: 21,5 kg/m²/cm thick coat or 2,1 kg to fill a volume of 1 litre.
4. Exposed to the atmosphere surfaces must be kept wet for at least 24 hours, by covering them with wet linoleum or polyethylene sheets.

1. REMARKS

• Temperature during application must be between +5⁰C to +35⁰C.
• The strength of the concrete to be cast must be greater than that of the old concrete by at least 10 N/mm².
• The particle size of the inert materials in the concrete to be poured must not exceed 20 mm.
• High performance grout can be applied at a maximum thickness of 10 cm per layer.
• Material that has started to set must not be softened again with water.
• The product keeps its fluidity for approx. 60 minutes at temperatures between +15⁰C to +25⁰C.
• At high temperatures, storage of the bags in a cool place is recommended, as well as mixing the material with cold water in order to achieve the appropriate fluidity for a sufficient length of time (about 60 minutes).
• At low temperatures and whenever fast development of strength is required, mixing of the material with lukewarm water and protection from cold by putting thermal insulating covers over the formwork are recommended.
• The product contains cement, which reacts as alkaline with water and is classified as irritant.
• Consult the directions for safe use and precautions written on the packaging.

Repairing of cracks in concrete elements with resin-injection

RELATED MATERIALS

1- Two-component epoxy putty

2- Two-component epoxy injection resin for cracks 0,1-1,0 mm wide

3- Two-component epoxy injection resin for cracks 0,5-3,0 mm wide

4- Two-component epoxy injection resin for cracks > 3 mm wide -Bonding agent

1. NATURE OF THE PROBLEM – REQUIREMENTS

Cracks in concrete elements (beams, slabs, columns, walls, etc) undermine the monolithic character and strength of the structural element.

1. SOLUTION

The materials used to restore a structural element to a complete monolithic piece, in order to ensure that it can function as originally designed, must have the following properties:

• High mechanical strength
• Strong bonding and great sealing ability
• The appropriate viscosity, in the case of injectable resins, in order to be able to penetrate into the smallest gaps in the crack.

1. a) Resin injection into 0,1-1 mm wide cracks

Suitable materials:

• injectable epoxy resin
• epoxy putty

1. b) Resin injection into 0,5-3 mm wide cracks

Suitable materials:

• injectable epoxy resin
• epoxy putty

1. c) Resin injection into cracks over 3 mm wide

Suitable materials:

• injectable epoxy mortar
• epoxy putty

III. APPLICATION

The complete resin injection procedure is as follows:

1. Any existing plaster in the area of the crack should be removed and the surface of the concrete must be cleaned thoroughly.
2. The crack is sealed with epoxy putty, using a spatula. At the same time the nozzles are positioned and fixed along the entire length of the crack, at approximately 20 cm intervals, with the same material.
3. Once the epoxy putty has hardened, the resin injection procedure is carried out, using either injectable epoxy resin or injectable epoxy mortar, depending on the width of the crack:
   a) The resin outlet tube (eg. a leveled tube) is placed in the first nozzle. If the crack is horizontal, the procedure starts from one end, if it is vertical, from the lowest nozzle.
   b) By manipulating the resin outlet tap on the pressure pot, the resin is forced into the nozzle until it starts to come out of the next nozzle, or until it is impossible to apply more pressure.
   c) The first nozzle is sealed with the special cap, then the resin is forced into the immediately adjacent nozzle until it starts to come out of the next one, and so on.
   d) The procedure mentioned above is carried out on all the nozzles. The next day the nozzle projections are removed, by being broken off, and any pre-existing plaster may be restored.

1. REMARKS

• Throughout the application, one person should hold steady the outlet tube in the nozzles, cap the nozzles and direct a second person on the manipulation of the resin outlet tap.
• The mixture of the epoxy materials must be carried out with great care, so that the whole of components A and B are used each time.
• It is recommended that resins are not poured directly into the pressure pot, but, once the two resin components have been mixed in component A’s container, then this container is placed in the pressure pot. This avoids soiling and possible hardening of any remaining resin in the pot, making it useless.
• Attention should be paid to the length of time required for application, in connection with the pot life of the material and the ambient temperature, so that the material does not harden during the resin injection procedure.
• It is essential to clean the pressure pot and other equipment once the application is complete. This should be done with solvent (rinsing of the pressure pot and outlet tube with under pressure).
• Protective gloves and goggles must be worn during the injection procedure.
• Before application, study the safety advice mentioned on the product’s labels.

Repairing of damaged concrete (surface damage, blisters, broken corners etc.)

RELATED MATERIALS

1- High-strength, fiber-reinforced repairing mortar

2- Polymer-modified cement mortar

3- Fast-setting patching mortar

4- Polymer-modified cement putty

5- Polymer-modified cement putty, extra fine-grained

1. NATURE OF THE PROBLEM – REQUIREMENTS

Damages at the surface of concrete may be caused by various reasons, such as bad concreting (insufficient vibration etc.) or blows etc.

This damages:

• Creat problems to the element’s appearance.
• Depending on the extent and level of damage, may even put the stability of the structuralelement at risk.
• Creat conditions for corrosion of the steel reinforcement.

1. SOLUTION

In order to choose the appropriate material for repairing damage, the following cases should be taken under consideration:

Damage to supporting structural elements
For the repairing of damaged concrete in supporting structural elements, high-performance patching mortar is used, providing the following:

• Excellent bonding to the substrate.
• Superior workability.
• Reduced water permeability.
• No shrinkage during setting.

Alternatively, if fast work is required, fast-setting patching mortar may be used instead.

Damage to non-supporting structural elements
For repairing of damages to non-supporting structural elements, besides the above mortars, polymer modified cement mortar may be used.

Small superficial damage to supporting and non-supporting structural elements
In case of smaller superficial damages that require the application of a thin layer of material for their repair, the use of FINE polymer-modified cement putty is recommended.

III. APPLICATION

Substrate preparation

1. All broken and loose particles of the damaged section of the concrete surface must be removed.
2. The uncovered undamaged concrete should be roughened and cleaned from dust etc.
3. Subsequently, the substrate must be well dampened, but without forming pondings.
4. The application of the appropriate patching mortar for each case follows.

Application of MEGACRET-40
The content of a 25 kg bag of High-strength, fiber-reinforced repairing mortar is added into 4,6 lit of water and mixed well until a uniform firm mass appropriate for repair work is formed. The material should be applied (pressed) with a trowel or by gunning, at the desired thickness, up to 4 cm per layer. When a second layer is required, the surface of the first layer should be roughened to achieve better adhesion. The final surface should be well protected from dehydration by covering it with wet cloths, polyethylene sheets or repeating dampening for 48 hours.
Consumption of High-strength, fiber-reinforced repairing mortar: approx. 17,5 kg/m²/cm of layer thickness.

Application of Fast-setting patching mortar
Fast-setting patching mortar is added to the water in the proportion of Fast-setting patching mortar : water = 3.6 : 1 parts by volume, and mixed well until a uniform firm mass appropriate for repair work is formed. Mixing time must not exceed 1 minute. Mixing of small quantities each time is recommended, due to the short working time of the material. (approx. 15 minutes at +20⁰C). Fast-setting patching mortar may be applied at a thickness of up to 3 cm per layer.
Consumption of Fast-setting patching mortar: approx. 17,5 kg/m²/cm of layer thickness.

Application of Polymer-modified cement mortar
The content of a 25 kg bag of Polymer-modified cement mortar is added to 4.6 kg of water under continuous stirring, until the desired workability is achieved. The material is applied by trowel as usual. Polymer-modified cement mortar T may be applied at a thickness of up to 2 cm per layer.
Consumption of Polymer-modified cement mortar: approx. 15 kg/m²/cm of layer thickness.

Application of Polymer-modified cement putty
Water is poured into a clean container, and Polymer-modified cement putty is gradually added under continuous stirring, in a ratio of Polymer-modified cement putty: water = 3 : 1 parts by volume, until a uniform pasty mass that can be applied with a smooth trowel is formed.
Consumption of Polymer-modified cement putty: approx. 1,3 kg/m²/mm of layer thickness.

1. REMARKS

• Temperature during application should be between +5^oC and +35^oC.
• Material that has started to set should not be re-softened with water.

At high temperatures, mixing Fast-setting patching mortar

•  with cold water is recommended, in order to avoid excessively fast setting.

At low temperatures, mixing Fast-setting patching mortar

•  with lukewarm water is recommended, in order to accelerate the setting process.
• During summer time, it is recommended that all mortars are dampened after their application, in order to be protected from dehydration due to high temperatures.
• The products contain cement, which reacts as alkaline with water and is classified as irritant.
• Before use, consult the safety advice and precautions written on the packaging.

Repairing of severe masonry cracks (cracks width > 1 cm) – Disorganised masonry

RELATED MATERIALS

1- Polymer-modified cement mortar

2- Fast-setting patching mortar

3- Mortar for rendering and masonry

4- Fast-setting, white repairing mortar

5- Polymer latex for multiple improvements of mortars

6- Fiberglass mesh for render reinforcing

1. NATURE OF THE PROBLEM – REQUIREMENTS

Severe cracking (cracks wider than 1 cm) and disruption of non-supporting masonry walls causes strength problems as well as being unsightly.

1. SOLUTION

The materials used to repair such cracks must have the following properties:

• Efficient bonding to bricks.
• Sufficient workability, to facilitate the filling of cracks.
• Low shrinkage during setting, so that they do not crack as they harden.

1. a) Repair of cracks

Suitable materials:

• polymer modified cement mortar, or
• fast setting patching mortar, where rapid work is required.

1. b) Repair of plaster

Suitable materials:

• cement-lime mortar, reinforced with polymer latex, or
• Fast setting cement-lime mortar, reinforced with polymer latex, where rapid work is required and the surface is not extended.

III. APPLICATION

The complete repair procedure is as follows:

1. a) Repair of cracks
2. The plaster is removed over the entire surface of the masonry.
3. The cracks are widened along their entire length by breaking the surrounding bricks with a sharp tool.
4. The cracks are thoroughly cleaned with compressed air or with a brush.
5. Subsequently, the substrate is thoroughly dampened.
6. polymer modified cement mortar or fast-setting patching mortar is introduced as deeply as possible into the widened crack, using a gouging trowel. These mortars are to be mixed with water only. After the material has hardened, repair of the plaster can follow.
7. b) Repair of plaster
8. The underlying surface should be carefully cleaned of loose particles, dust, etc. and dampened thoroughly with water.
9. A first coat of plaster is applied, using cement-lime mortar or fast setting cement-lime mortar, reinforced with polymer latex. polymer latex. is added to the mixing water in the ratio of polymer latex : water = 1 : 3.
10. While the first coat is still fresh, the glass mesh is laid over the entire surface and is lightly pressed onto the first coat.
11. Once the first coat has set, the final plaster coat of cement-lime mortar or fast setting cement-lime mortar is applied. The product is now mixed with water only. In case that a plaster of higher strength is desired, polymer latex is added to the mixing water in the ratio of polymer latex: water = 1 : 5.

1. REMARKS

• Temperature during application must be between +5⁰C to +35⁰C.
• Material that has started to set must not be softened again with water.
• During summer months it is recommended that the plaster dampened after being applied, to protect it from dehydration due to high temperatures.
• Consult the directions for safe use and precautions written on the packaging.