RT_050_01 Structural Concrete Repairx

TECHNICAL RECOMMENDATION Structural Concrete Repair

TECHNICAL DEPARTMENT

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DRIZORO S.A.U. C/Primavera, 50-52. 28850 Torrejn de Ardoz-Madrid (SPAIN) Tel./Phone: +34 916766676 Fax: +34 916776175

e-mail: [email protected] Web site: www.drizoro.com

n 6003176 / 6003176-MA



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INDEX 1. Introduction 2. Application field 3. Scope 4. Inspection and diagnosis

4.1 Visual inspection. Environment analysis 4.2 Surface tensile strength 4.3 Carbonation depth measurement 4.4 Chloride content 4.5 Sulphate content 4.6 Temperature y surface moisture

5. Previous jobs and products description 5.1 Substrate preparation 5.2 Reinforcement steel treatment 5.3 Structural bonding agents 5.4 Structural repairing mortars

5.4.1 Thixotrophic mortars. 5.4.2 Grout mortars for structural repair. 5.4.3 Selection table for structural repairing mortars.

5.5 Protective coatings 6. Application procedure

6.1 Mixing 6.2 Application of structural repairing mortars

6.2.1 Hand application of thixotrophic mortars. 6.2.2 Mechanical application of thixotrophic mortars. 6.2.3 Fluid mortars applied by pouring or injection.

6.3 Curing 6.4 Protection

7. Application conditions 8. Products information 9. Quality control

9.1 Product delivery control 9.2 Stock control 9.3 Substrate preparation control

9.3.1 Cleaning of the element to be repaired. 9.3.2 Moisture content before bonding agent application. 9.3.3 Substrate temperature. 9.3.4 Minimum tensile strength of the substrate. 9.3.5 Oxide elimination.

9.4 Application control of the bonding agents 9.5 Application control of the repairing mortars 9.6 Final Job control

9.6.1 Adherence control by pull out test. 9.6.2 Probe performance. 9.6.3 No hollow areas checking. 9.6.4 Thickness control

9.7 Control of emptied packaging. 10. Maintenance 11. Technical drawings



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1. INTRODUCTION

This document reports the different DRIZORO systems of structural repair for concrete repairing and restoration due to its deterioration caused by the effect of mechanical or/and chemical agents which carry the lost of structural integrity that affects the performance of functions for which resistance was designed.

2. APPLICATION FIELD

The procedure is applicable to concrete elements which have lost some of its original features due to structural, chemical or physical pathologies, included in normative UNE-EN 1504.

3. SCOPE

The scope of the concrete repairing job is to return the concrete element its structural capacity and original geometry by removing the concrete in poor condition and replacing it with a structural mortar with improved physical features and higher performance against chemical agents, finishing with a protective coating applied to match the durability of the repaired areas with undisturbed areas depending on the required needs.

4. INSPECTION AND DIAGNOSIS

To achieve a reliable diagnosis of the real condition of the concrete in order to be able to select the most suitable material to use in the repairing, it is recommended to perform a number of previous inspections and tests.

4.1. Visual inspection. Environment Analysis

Based on the local normative and regulations, the ambient in which the structural element is servicing, need to be classified.

4.2. Surface tensile strength

Tensile strength must be tested according to EN 1542 or equivalent.

4.3. Carbonation depth measurement

Carbonation depth in concrete shall be checked using the phenolphthalein method or test in such way that all areas showing a purple colour will be taken as a concrete with a pH higher than 12 and thus the steel rebars are protected, in the other hand a violet colour will be taken as a concrete with a pH lower than 12 and thus the carbonation process has began and the areas which has no colour variation will be taken as a concrete with a pH very low showing high level of carbonation and with no protection for the steel reinforcement.



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By using this method is possible to have an idea of the carbonation progress into the concrete and so it is possible to remove it around the steel reinforcement and replace applying structural mortars in order to recover the appropriate level of pasivation in the steel reinforcement avoiding the corrosion risk.

4.4. Chloride content

If suspected chloride ingress, a pathology which may cause degradation of concrete, some core testing at different levels and depths shall be carry out in order to establish a survey to perform a correct diagnosis.

When the amount of chloride detected are higher than the values given in the local normative or regulations, the chloride contaminated concrete must be removed with special care around of the steel reinforcement.

4.5. Sulphate content

As in the above situation, some core testing must be performed in the concrete under study in order to survey the amount of sulphates in the concrete.

4.6. Temperature and surface moisture control

Temperature and moisture values must be controlled both at concrete surface and surrounding environment with a moisture device and contact thermometer to ensure the application of materials is within of the recommended range of temperature and moisture.

For more accuracy is recommended to use a device for moisture measurement based on Calcium Carbide.

5. PREVIOUS JOBS AND PRODUCT DESCRIPTION

5.1. Substrate preparation

The preparation of the concrete surface is the main task of providing the support conditions for the subsequent application of repair materials and protective coating, so that the combination of the repair material along with support to behave accordance with the requirements of previously established resistance and adhesion.

For this reason, the preparation of the surface largely determines the success of the repair.

When deciding on the method used for the preparation of the support should take into account the material of choice for repair, the extent of the surface being treated, the degree of surface roughness necessary for the application of repair material and other factors affecting the time to take



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the decision as are the ventilation of the area of operation with systems that create dust or accessibility to use mechanical or manual means.

The surface preparation begins with the removal of the unsound and loose concrete, cleaning up the degraded and unsound concrete by removing the parts that have low resistance, are degraded or contaminated by chemicals such as chlorides or sulphates until reach an area structurally resistant.

Concrete surface must have cohesion higher than 1.0 MPa as measured by the method of direct pull out, and must be porous enough and with roughness to promote adhesion of the structural repair mortars. Concrete must be recess so that the thickness of mortar in the worst point is above the minimum thickness recommended for each type of repair mortar, avoiding wedge shapes for optimum transmission of forces.

The steel reinforcement affected by corrosion must be discovered completely for an effective cleaning, looking at the possible loss of section. If necessary a possible strengthening with more steel rebars or carbon fibber materials shall be considered.

The surface of the concrete and steel reinforcement should be cleaned by removing substances that may have a negative influence on the adhesion of the materials applied to concrete or promote corrosion of reinforcing steel. It should be removed fats, oils, efflorescence, loose particles, dust, laitance and traces of paint and rust from reinforcement with steel wire brush, sand blasting, needle gun, and so on. Depending on the steel reinforcement protection system selected.

5.2. Reinforcement steel treatment

DRIZORO materials are intended to provide lasting protection against future aggressive chemicals attacks to steel reinforcement, so the following products may be used:

Product Product type Appearance CE marking Steel

reinforcement preparation

Consumption

MAXREST PASSIVE Oxide converter

Water base one component liquid

EN 1504-7 P11(CA)11.1-2 St-2: 0,30 kg/m

2

MAXRITE PASSIVE

Oxide inhibitor slurry

Fluid coating Mortar

EN 1504-7 P11(CA) 11.1-2 St-3: 2,60 kg/m

2

MAXEPOX AC

Epoxy primer with oxide inhibitors

Two component Liquids --- Sa2 : 0,50 kg/m

2

Principles P11 (CA) = Principle 11. Control of Anodic Areas -----

Methods 11.1.= Control of anodic areas by painting reinforcement with coatings containing active pigments 11.2.= Control of anodic areas by painting reinforcement with barrier coatings containing active

pigments



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5.3. Structural bonding agents

Before the start of the repairing job is necessary to apply a bonding agent to enhance the adherence between existing concrete and the repairing material to optimize the transmission of forces

One of the great advantages of DRIZORO thixotrophic mortars is that the bonding agent is a slurry prepared with the same repairing mortar by adding 10% more water than is needed for semi-dry mortar consistency, since in his formulation are included additives which improve the adherence significantly. Prior to applying the bonding slurry, you should wet the concrete surface to saturation. The slurry should be applied by brush or broom spreading it over the surface in thin layer preventing the accumulation of excessive thickness of material on the surface. Should be allowed to tarnish the slurry prior to application of repair mortar, but should still be cool to the touch. If the slurry dries, you must reapply.

In the case of concrete with chlorides attack pathology, in which the contents of these are higher than the maximum allowed by the local regulations, it is necessary to apply an epoxy bonding agent to isolate the repair mortars and the steel reinforcement from the diffusion of the chlorides present in concrete. The epoxy bonding agent must be applied by brush or spray on all surface. The repair mortar should be applied during the open time, while the epoxy bonding agent has stickiness. In case the epoxy bonding agent dries, the epoxy bonding agent must again be applied to the existing one.

Product Product type Open time at 20 C Consumption

bonding slurry Fluid slurry made up from the repairing mortar h 2,00 kg/m

2

MAXEPOX BOND Epoxy bonding agent for dry surfaces 2 h 0,3-1,0 kg/m2 MAXEPOX BOND S Epoxy bonding agent for dry surfaces and

suitable for spraying methods 2 h 0,3-1,0 kg/m2

MAXEPOX BOND -W Epoxy bonding agent for wet surfaces 2 h 0,3-1,0 kg/m2

5.4. Structural repairing mortars

This section presents the different structural repair mortars with the scope to rehabilitate the concrete element, restoring all mechanical capabilities for structural servicing, geometry and the original state. DRIZORO products for this purpose are made with special cements, selected siliceous aggregates, additives and additions of polymers and synthetic fibbers. They are non-shrink mortar with excellent adhesion to the substrate and high mechanical strength. They have excellent compatibility with the concrete due to its cement-based composition. Its properties are similar in coefficient of thermal expansion in order to not create tensions due to volume changes and the modulus of elasticity is slightly lower for compatibility of deformations providing a monolithic behaviour, achieving structural integrity and a proper stress transfer between concrete and steel reinforcement. DRIZORO mortars have good resistance to environmental agents which causes most of the concrete pathologies; such as sulphates, freezing and thawing cycles, etc. They have good resistance against carbonation and reduce the chloride penetration, are compact and with very low permeability coefficients.

Mortars for structural repair may be divided in: - Thixotrophic mortars for structural repair. - Fluid mortars for structural repair.



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5.4.1. Thixotrophic mortars

Thixotrophic do not require concrete formworks for its application. Its application can be done manually with a trowel or palette and some of them allow commissioning work by wet spraying methods.

The most suitable repair mortar will be given by several criteria, mechanical performance, aggressiveness of the medium or type of exposure, layer thicknesses range, initial and final setting time, temperatures, extent of repair, performance, etc..

Depending on the needs of the project and commissioning work, it may be chosen quick, medium or normal setting mortars.

MAXREST is a mortar admixture with micro silica, thixotrophic, without shrinkage for structural repairs.

MAXRITE 500 y MAXRITE 700 are mortars modified with polymers and reinforced with synthetic fibbers incorporating corrosion inhibitors, giving structural mortars with higher mechanical performance, compatible modules of elasticity, excellent adhesion and greater resistance in aggressive environments, also allowing more thickness of application per layer and thereby facilitating the job.

The structural mortars MAXRITE S, MAXRITE HT and MAXRITE F are mortars specifically designed and formulated for applications of large areas or volumes by wet spraying methods.

Some minor repairs that need to be performed in short time , can be performed using quick-setting time mortar as MAXREST or MAXRITE 500, enabling to finish the repairing job rapidly after successive applications.

When ambient temperatures exceed 30 C, the time a vailable for the application of a mortar may be too short for quick-setting time mortars, or in some jobs with large repairing areas in which might be interesting to apply medium or normal setting time mortars by spraying methods as with the mortars MAXRITE 700, MAXRITE S, MAXRITE HT or MAXRITE F.

The finish surface of the repair mortar can be given either by notched trowel or hard hair brush. The texture should be slightly roughened to facilitate the adherence of the final protective coatings.

5.4.2. Grout mortars for structural repair

DRIZORO fluids mortars are non-shrink and slightly expansive grouts for repairing, filling and reinforcement of large volumes by pouring or injection into the formwork for rebuilding of concrete in pillars, beams, etc. Its use is also indicated for structural anchoring with large requests. The properties highlighted in these mortars are their high mechanical strength, excellent adhesion to concrete, steel reinforcements and steel plates, showing a mechanical behaviour very similar to concrete in their thermal expansion coefficient and elastic modulus.

These fluid mortars achieve high early strength, are resistant to repeated loads and impact, presenting a low water absorption by capillarity due to its compactness. Its high fluidity allows them to fill spaces in areas inaccessible, deep or narrow locations or when the large amount of steel



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reinforcement left little space between the rebars. Like DRIZORO thixotrophic mortars, there are also available, depending on the needs of the job, fast setting fluid mortars and normal fluid mortars.

Due to its mechanical performance, MAXGROUT and MAXRITE INJECTION are the more resistant mortars. MAXRITE INJECTION is a high performance mortar with corrosion inhibitors incorporated and modified with polymers to achieve improved adhesion to metallic surfaces.

DRIZORO range of fluid grouts is completed with MAXGROUT HR, a fluid mortar with high structural strength and fast setting time and with MAXGROUT INJECTION, a high fineness mortar with normal setting time for consolidation of walls and crack repair by injection.

5.4.3. Selection table for structural repairing mortars

Product

Polymers

Fibbers

Inhibitors

Thickness Application method

Setting time

Class UNE EN-1504-3

(mm) (MPa)

Thix

otr

oph

ic

MAXREST X 10 30 By hand Quick R4 MAXRITE 500 X X X 5 50 By hand Quick R4

MAXRITE 700 X X X 5 50 By hand Sprayed

Medium R4

MAXRITE HT X X X 5 100 By hand Projection

Normal R3

MAXRITE S X 5 50 By hand Sprayed

Normal R4

MAXRITE F X X 5 40 By hand Sprayed

Normal R4

Flu

ids

MAXGROUT* X 10 50 Pouring Injection

Normal R4

MAXGROUT*HR X 10 50 Pouring Injection

Quick R4

MAXRITE* INJECTION X X 10 50

Pouring Injection

Normal R4

MAXGROUT* INJECTION X 2 50

Pouring Injection

Normal n/n

* For thicker applications add 8 kg de of 3-5 mm aggregates per each paper bag of DRIZORO AGGREGATES 3050.



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Products and systems for the protection and repair of concrete structures. Structural and non-structural repair. EN 1504-3

Principles and Methods Type Class

CONCRESEAL -3 P3 (CR) 3.1 PCC R2 CONCRESEAL -5 P3 (CR) 3.1 PCC R2 MAXEPOX CEM P3 (CR) 3.1 PCC R2

MAXREST P3 (CR) 3.1 P4 (SS) 4.4 P7 (RP) 7.17.2 CC R4 MAXRITE -F P3 (CR) 3.1-3.3 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R4 MAXRITE -S P3 (CR) 3.1-3.3 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R4 MAXRITE -HT P3 (CR) 3.1-3.3 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R3 MAXRITE 500 P3 (CR) 3.1 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R4 MAXRITE 700 P3 (CR) 3.1-3.3 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R4

MAXGROUT P3 (CR) 3.1-3.2 P4 (SS) 4.4 P7 (RP) 7.17.2 CC R4 MAXGROUT -HR P3 (CR) 3.1-3.2 P4 (SS) 4.4 P7 (RP) 7.17.2 CC R4 MAXRITE INJECTION P3 (CR) 3.1-3.2 P4 (SS) 4.4 P7 (RP) 7.17.2 PCC R4

Principles P3 (CR) = Principle 3. Concrete Restoration P4 (SS) = Principle 4. Structural Strengthening P7 (RP) = Principle 7. Preserving or Restoring Passivity -----

Methods 3.1.= Concrete restoration by applying mortar by hand 3.2.= Concrete restoration by recasting with concrete 3.3.= Concrete restoration by spraying mortar or concrete 4.4.= Structural strengthening by adding mortar or concrete 7.1.= Preserving or restoring passivity by increasing cover to reinforcement with mortar or

concrete 7.2.= Preserving or restoring passivity by replacing contaminated concrete -----

Types and Classes CC = Hydraulic cement mortars PCC = Polymer modified hydraulic cement mortars R1-R2= Non-structural repair products R3-R4= Structural repair products

5.5. Protective coatings

High-build coating are materials with a dry thickness greater than 0,25 mm and less than 5 mm applied to concrete surface. This bigger thickness provides a better protection to concrete against water and pollutants. The base polymers of such products include, but are not limited to, acrylics, styrene-butadiene, polyvinyl acetates, etc. In addition, often contain special additives such as mildew-resistant chemicals. Since these products are water-resistant, they are highly resistant to freeze-thaw cycles; they eliminate water penetration that might freeze and cause scaling of concrete.



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Coatings will alter the appearance of the surface and will partially mask blemishes in the concrete surface due of the fact of these materials will have both high hiding power and some ability to fill in irregularities and level prepared surfaces. These products may be applied with brush, roller, or spray.

Resins used in waterproofing coatings allow enveloping a surface with a sufficient dry film thickness to produce a covering barrier that is watertight and breathable.

Advantages for coatings:

Water permeability. - Coatings have very low water absorption so they withstand freeze-thaw cycles.

Vapour permeability. - Resins used in elastomeric coatings are breathable. They allow moisture-vapour

transmission from substrate to escape through the coating without any blisters, bubbles or peeling-off. This is a favourable characteristic for construction details at undersides of cooling towers that are subjected to possible negative moisture drive.

Crack bridging. - Elastomeric acrylic coatings with application thickness from 0,25-0,75 mm have the ability

to elongate of 300% approximately, i.e. these products have the ability of expand and recovery to its original shape with no cracking or splitting. Therefore, coatings provide waterproofing and protection to existing or future cracks, fully avoiding the dangerous risk of reinforcement corrosion by pitting process on critical points.

Protection to reinforcement corrosion. - The low water permeability and the high vapour permeability for elastomeric coatings lead

a very good resistance of concrete reinforcement corrosion. - Elastomeric coatings are recognized as effective means of preventing substrate

deterioration due to industrial environment. They prevent deterioration from air and water pollutants and from dirt and other contaminants by not allowing the pollutants to be absorbed into a concrete substrate.

- Coatings prevent chloride ion penetration into a substrate and prevent damage from pitting corrosion.

- Create a physical barrier against industrial pollutant ingress, salts and other aggressive chemicals for concrete.

Carbon dioxide barrier - Excellent protection against reinforcement corrosion by carbonation process because it

does not allow the carbon dioxide ingress to concrete. i.e. diffusion of carbon dioxide gas will be inhibited so the amount of gas able to penetrate the concrete will be reduced. Laboratory tests have established that although acrylic coating allow water vapour diffusion, carbon dioxide gas is dramatically reduced when compared to a reference concrete without protection.

Durability - Provides higher and long-lasting solution and weathering resistance compared to sealers

(H & I).

Based product.



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- Water-based product, i.e., environmental friendly, non-flammable product suitable for both outdoor and indoor applications that require big quantities of material.

Appearance. Coatings are available in a wide range of textures and almost any colour. These products have

excellent UV stability, non-yellowing process and low dirt pickup.

DRIZORO protective systems classified as coatings

Appearance of dry product Base Chemistry Application Fields

MAXSEAL -/FLEX Rough coat -- Cement Indoor/Outdoor (UV) +/- hydrostatic pressure

MAXSHEEN -/ELASTIC Smooth coat Water Acrylic Indoor/Outdoor (UV) +/- (low) hydrostatic pressure

MAXURETHANE range Smooth coat Solvent Polyurethane Indoor/Outdoor (UV) + hydrostatic pressure

MAXEPOX FLEX Smooth coat -- Epoxy Indoor/Outdoor (UV) + hydrostatic pressure

Products and systems for the protection and repair of concrete structures. Surface protection systems for Concrete, EN 1504-2

Principles, Methods y Types Cement-based products

MAXSEAL+MAXCRYL P1(PI) 1.3 (C) P2 (MC) 2.2 (C) P8 (RI) 8.2 (C) MAXSEAL FLEX P1(PI) 1.3 (C) P2 (MC) 2.2 (C) P8 (RI) 8.2 (C) Acrylic-based products MAXSHEEN P1(PI) 1.3 (C) P2 (MC) 2.2 (C) P8 (RI) 8.2 (C) MAXSHEEN ELASTIC P1(PI) 1.3 (C) P2 (MC) 2.2 (C) P8 (RI) 8.2 (C) Epoxy-based products MAXEPOX FLEX P1(PI) 1.3 (C) P2 (MC) 2.2 (C) Polyurethane-based products MAXURETHANE P1(PI) 1.3 (C) P2 (MC) 2.2 (C) MAXURETHANE 2C P1(PI) 1.3 (C) P2 (MC) 2.2 (C) MAXURETHANE TOP P1(PI) 1.3 (C) P2 (MC) 2.2 (C)

Principles P1 (PI) = Principle 1. Protection against Ingress P2 (MC) = Principle 2. Moisture Control P8 (RI) = Principle 8. Increasing Resistivity by limiting moisture content -----

Methods y Types 1.3 = Protection against ingress by coating (C) 2.2 = Moisture control by coating (C) 8.2 = Increasing resistivity by coating (C)

For details on application of protective coatings consult RT 078 SURFACE PROTECTIVE SYSTEMS. PART II: COATINGS



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6. APPLICATION PROCEDURE

6.1. Mixing

Repair mortars must be mixed with the quantity of water indicated in the corresponding Product Technical Bulletin. Do not exceed the recommended amounts of water. Do not use the remains of previous mixings to make a new mix, neither add fillers, aggregates, and others cements in order to increase the application volume unless otherwise specified.

For mixing, manual means are recommended only for small amounts. For mixing a whole paper bag is preferable to use mechanical means such as low-speed mixer, 400 to 600 rpm, equipped with a mixer. The mixing time is about 3 minutes until obtain a homogeneous mortar in colour and appearance and free of lumps. In no case knead a structural repair mortar using violent mechanical agitators or high-speed mixer; neither kneads it for too long.

For quick-setting time mortars should only prepare the amount of material that may be placed before the initial setting time, which depends on temperature and humidity.

6.2. Application of structural repairing mortars

Following is explained the method of application for the different structural repairing mortars. - Thixotrophic mortars applied by hand. - Thixotrophic mortars applied by wet spraying methods. - Fluid mortars applied by pouring or injection.

6.2.1. Hand application of thixotrophic mortars

Apply the bonding agent for an optimum adherence, as stated in paragraph 5.3.

If the bonding agent is product slurry, wet the concrete surface to saturation and apply the slurry with hard hair brush on the surface to be repaired and on the steel reinforcement, filling all pores, voids and gaps. Wait until the surface loss the shine, and with the slurry still fresh, apply the thixotrophic mortar in layers with the maximum recommended thickness for each product. Scratch the surface of each layer with the spatula before apply the next layer in order to improve the adherence on each layer applied. Observe the waiting time between layers. If the layer warm up, slightly spray some clean and fresh water.

If the bonding agent is an epoxy bonding agent, apply the bonding agent and wait the recommended time for the product and apply the structural repairing mortar pressing on the surface of the epoxy bonding agent before its gets tack free.

Do not apply structural repairing mortars if the material slurry or the epoxy bonding agent has lost its properties. In such situation apply again the bonding agent, and apply the structural repairing mortar within the interval recommended.



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6.2.2. Mechanical application of thixotrophic mortars

When applying the structural repairing mortars by wet spraying methods, is not necessary to apply a bonding agent, but still is necessary to wet the surface to saturation. If were necessary to apply the bonding agent, follow the instructions given in paragraph 5.3 and 6.2.1

Spray the mortar on the surface according to the maximum thickness recommended per layer in such way that the sprayed mortar gets compact, with regular thickness and with the minimum rebound possible. If needed a smooth or trowelled finishing, it must be performed immediately after spraying the last layer of mortar.

6.2.3. Fluid mortars applied by pouring or injection.

Application of fluid structural repairing mortars shall be performed by pouring or injection methods. To do so, is necessary to build up formwork to retain the poured product.

Application by pouring is performed simply by gravity, pouring directly from the mixer in a continuous way and if possible from the same point in order to avoid cold joints formation and reduce the risk of air bubbles occluded. If necessary a vibrating tool may be used to fill the requested volume, some care must be take because too much vibration might cause segregation of the solid particles and add air bubbles into the material.

When grouting below anchoring plates, remember to practice holes to purge the air in the volume to be filled. When injecting with pumps, it should be done at low pressure and at low rate to allow the air pressure dissipation, otherwise uncontrolled pressures might cause the fracture of the element under reparation and like stated above, some holes must be drilled to purge the air volume inside the formwork or element.

6.3. Curing

Once the job is finished, observe the standards cautions for a good curing, such as spray clean and fresh water, cover with plastics or wet burlaps, etc...Also the curing process shall be improved using the curing agent MAXCURE.

Protect from rain showers, sunlight and freeze during the first 24 hours and avoid a fast drying due to high temperatures, wind, etc.

6.4. Protection

The repairing job shall be finished using a waterproofing and protecting cement based coating MAXSEAL MAXSEAL FLEX, or with an acrylic based anti carbonation coating MAXSHEEN or MAXSHEEN ELASTIC.



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7. APPLICATION CONDITIONS

Do not apply in rain or when rain, contact with water, condensation, dampness and dew is expected within the first 24 h after the application. Do not apply on substrates vitrified or enamelled, or treated with water repellent agents. Do not apply on bituminous materials, metals, wood, plasters or paints.

The optimum temperature range for application is from 10 C to 30 C. Do not apply with substrate and/or ambient temperature is at or below 5 C, or when temperatures are expected to fall below 5 C within 24 h after application. Do not ap ply to frozen or frost-covered surfaces.

For applications at hot temperatures, low relative humidity and/or windy conditions, i.e. summer time, surface must be wet thoroughly with plenty of water prior to application. Avoid applications in areas exposed directly to the sunlight with high temperatures.

Setting time data is measured at 20 C. Lower temperatures and/or higher R.H. values increase this value.

With low temperatures keep the product in a warm place. With hot temperatures keep the product in a cool place, wet the different layers and, mix small batches of material and apply immediately

Store in a cool, dry and covered place, protected from moisture, freezing and away from direct exposure to sunlight at temperatures above 5 C.



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8. PRODUCT INFORMATION

The repairing materials included in the Technical Recommendation are: - Steel reinforcement treatment: MAXREST PASSIVE, MAXRITE PASSIVE & MAXEPOX

AC - Bonding agents: MAXEPOX BOND, MAXEPOX BOND S & MAXEPOX BOND W. - Thixotrophic structural mortars: MAXREST, MAXRITE, MAXRITE 500, MAXRITE 700,

MAXRITE HT, MAXRITE F & MAXRITE S. - Fluid structural mortars: MAXGROUT, MAXGROUT HR, MAXRITE INJECTION &

MAXGROUT INJECTION. - Protective coatings: MAXSEAL, MAXSEAL FLEX, MAXSHEEN , MAXSHEEN ELASTIC,

MAXURETHANE, MAXEPOX FLEX, MAXQUICK

For further information, consult the Technical Bulletins and the Safety Data Sheet for each product.

9. QUALITY CONTROL

All repair jobs must be executed according to a detailed quality control planning for each of the proceedings performed during the repairing jobs. The number of control test will be established to evaluate the quality of the performed jobs. The type and number of test will be established according to UNE EN-1504-10 standards.

9.1 Product delivery control

All materials will be checked at its reception in the job site, verifying and recording the following parameters:

Total amount of materials. Name and classification of each material with a correct identification. Proper packaging, returning all damaged packages or containers. Expiration date of the products.

9.2 Stock control

All products will be stored in a cool, dry and covered place, protected from moisture, freezing and away from direct exposure to sunlight at temperatures above 5 C and below 30 C in its unpackaged containers and without direct contact with the ground.

After each workday must be checked the storage of each material.



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9.3 Substrate preparation control

9.3.1 Cleaning of the element to be repaired

Surface must be checked to verify that accomplish the necessary condition for the product application.

The control will be performed by visual inspection, verifying:

Cleaning and repairing of the substrate: Check that the substrate accomplishes with the specifications in section 5.1.

Surface must be clean, without dust and loose particles (bare hand checking) after surface preparation and before coating application.

Verify that substrate is absorbent and without rest of demolding agents, grease or oils, determined by water spraying before coating application.

Substrate temperature: Verify at the moment of application that substrate temperature is within the range established in the Technical Bulletin of each product.

9.3.2 Moisture content before bonding agents application

In the case of application of mortar slurry, you should check that the surface is saturated with water and there are no negative pressures of water through the surface.

If the bonding agent is epoxy base, the moisture on surface must not be higher than 4 %. Verify with moisture control device.

9.3.3 Substrate temperature

Check temperature at the moment of application to verify is within the optimum range for each product.

9.3.4 Minimum tensile strength of the substrate

Check minimum strength with pull out test to verify the substrate cohesion is higher than 1.0 MPa, according to paragraph 5.1. (Standard ISO 4624 or similar as described in the European Standard EN 1542)

9.3.5 Oxide elimination

Check the steel reinforcement using the models for steel preparation to verify the steel surface accomplish with the indicated in the technical bulletin of the selected product for the treatment of the steel rebars.



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9.4 Application control of the bonding agents

Check that application of the bonding agent is homogeneous and continuous, without exceeding the recommended thickness. Verify that at the moment of application the bonding agent still is fresh and tacky.

9.5 Application control of the repairing mortars

Verify during application the following:

Quality of the mixing water used according to local regulations Percentage of mixing water used Mixing methods used for blend or knead the mortar (as indicated in the Technical Bulletins of

each product), verifying the proper mixing time. Check the fresh mortar is homogeneous and free of lumps. Verify thickness and waiting time between layers according to specifications on Technical

Bulletins. Verify that at the moment of application the bonding agent still is fresh and tacky.

9.6 Final job control

9.6.1. Adherence control by Pull Out test

Pull out test as in Standard ISO 4624 or similar as described in the European Standard EN 1542. Acceptance: Minimum value 1,0 MPa. Whenever failure is in the concrete interface, other failure mechanism might be accepted if the minimum value is 1,0 MPa.

9.6.2. Probe performance

Test specimens must be taken during application according to UNE 12190 or similar.

9.6.3. No hollow areas checking

The beating on the concrete surface can be performed through light mallet or echo test equipment by impact with the aim of identifying areas detached from the concrete structure or loose individual aggregates on the surface of the concrete substrate.

9.6.4. Thickness measurement

Thickness measurement by method of profile measurement or wedge cut method according to standard ISO 2808. Acceptance: 80% of the requested value.



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9.7 Control of empty packages

Before used packaging disposal, the empty packages must be checked, verifying the hardening of the leftovers in the containers.

10. MAINTENANCE

Details of the method of execution of the repair and protection, quality control results and other information applicable to the subsequent maintenance of the structure must be registered and provide the right person.

Due to the nature of all mineral products used, the durability, efficiency and stability of the applied products is very high. Therefore, these products require no special maintenance.

Every five years or sooner if necessary, proceed to the visual inspection to verify new cracks or degradation on the protective coating or in the structural elements repaired. If an abnormality is found shall be repaired immediately to prevent its spread.



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11. TECHNICAL DRAWINGS

1.- Substrate preparation 2.- Steel reinforcement treatment 3.- Bonding agent 4.- Thixotrophic structural repairing mortar 5.- Coating for concrete surface protection

11.1 Repair of pillars and columns using thixotrophic mortars

1.- Substrate preparation 2.- Steel reinforcement treatment 3.- Bonding agent 4.- Setting of formworks 5.- Pour of the fluid structural grout 6.- Concrete coating for waterproofing and protection

11.2 Fluid structural grout for pillars and columns repairing



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1.- Substrate preparation 2.- Steel reinforcement treatment 3.- Pasivation of steel reinforcement 4.- Application of structural repairing mortar 5.- Concrete coating for waterproofing and protection

11.3 Structural mortars for beams repairing

1.- Substrate preparation 2.- Steel reinforcement treatment 3.- 1 Layer of structural mortar and scratching of surface 4.- 2 Layer of structural mortar and trowelling of surface 5.- Concrete coating for waterproofing and protection

11.4 Structural mortars applied by wet spreading methods for wall repairing

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RT_050_01 Structural Concrete Repairx