The repair compound Teknorep 300 EX(Текнореп 300 ЕХ)

Colour	Grey
Expiration date	12 months in a dry environment in a closed package.
Packaging	25 kg bag
Application temperature	+ 5 °C - + 35 °C
Mixing ratio	3.5-4.5 liters of water / 25 kg of powder
Viability	≥ 20 minutes
Commissioning	24 hours
Application thickness	10-40 mm (in one layer)
Flexural strength (EN 12808-3)	> 10.0 N/mm2
Adhesive strength with concrete (EN 1542)	> 2.0 N/mm2
Compressive strength (EN 12808-3)	> 50 N/mm2
Modulus of elasticity (EN 13412)	> 20 Gpa
Shrinkage (EN 12617-4)	> 2.0 N/mm2
Capillary water absorption (EN 13057)	< 0.5 kg/m2*h
Chlorine capacity	< 0,05%
Fire resistance	A1

Consumption table: 

Teknorep 300 EX	Density of the compound (kg/l)	Consumption of powder per 1 mm/1 m2 (kg)	Volume of water for mixing (l)
25 kg craft bag	2,06	1,8	3,5-4,5

• Before applying the material, the surface should be cleaned of any types of oil, rust, detergents, dirt and other substances that prevent setting.
• Before using Teknorep 300 EX, the surface should be moistened.
• To prepare the working solution, pour 3.5 - 4.5 liters of clean water into a clean container.  Pour the Teknorep 300 EX powder (25 kg) into a container with water and use a low-speed mixer to knead the composition for at least 5 minutes until a homogeneous mass is obtained. Leave the resulting compound for 3 minutes, then re-mix the compound for 2 minutes. Do not add water to the already prepared compound.
• The compound should be applied to the surface with a spatula. If necessary, apply a layer with a thickness of more than 40 mm, you should perform the work in several layers.
• When working on old concrete surfaces, you should first use the Tekno AD primer.
• When using Teknorep 300 EX in high wind conditions or other harsh environmental conditions, it is recommended to use Teknokur 100 as a curing material to prevent cracking of the surface.

Notes:

• For outdoor use,  it is necessary to protect the surface from moisture, sunlight and frost during the first 3 hours of solidification of the compound.
• When used at a low temperature, the lifetime of the compound increases, at an elevated temperature it decreases.
• When used in conditions of low temperature, it is necessary to use warm water, at high temperature – cold water.
• It is not recommended to use in contact with liquids whose pH value is lower than 5.5.
• Work should be carried out in compliance with safety and hygiene standards, using a mask and glasses.
• The tools and equipment used must be washed immediately after use.

1. What are the features of R4-class repair mortar for structural repairs?
R4-class repair mortars under EN1504 standard have high compressive strength (over 45 MPa), excellent adhesion to concrete and metal, and resistance to temperature variations. This makes them suitable for structural repairs. Teknorep 300 EX has strong adhesion to concrete and metal (2 MPa), compressive strength of 50 N/mm², and a modulus of elasticity of 20 GPa. It meets the R4 class requirements of EN1504 and can be used for structural repairs.

2. How can columns and slabs with deep damage be repaired?
For deep damage in concrete and precast reinforced concrete structures, R4-class repair mortars should be used. These fiber-reinforced mortars are designed to restore load-bearing structures, including columns, slabs, and beams with significant damage. For example, Teknorep 300 EX meets all structural repair standards and is ideal for such deep repairs. It can be applied in a layer from 10 mm to 40 mm thick.

3. What is the maximum layer thickness for structural repair mortar when fixing deep concrete damage?
R4-class mortars can vary in their specifications, so it’s important to follow the manufacturer’s instructions. Teknorep 300 EX is applied in layers from 10 mm to 40 mm. Once fully cured, a second layer or a thin-layer finishing mortar like Teknorep 200 can be used for final leveling.

4. Which repair mortar should be chosen for external use in harsh climatic conditions?
For concrete and reinforced concrete repairs exposed to severe weather — temperature fluctuations, heavy and constant loads, sulfate and chloride attack — repair mortars that meet the R4-class EN1504 standard are required. For quick deep repair, consider the fiber-reinforced mortar Teknorep 300 EX. This shrinkage-compensated cement-based mortar is ideal for external repairs of any type of reinforced concrete structure, ensuring high durability and strength of the restored surfaces.

5. At what temperature can damaged concrete be repaired outside, and which materials can be used at low temperatures?
Before starting repairs, it’s important to consider the freeze-thaw resistance and temperature tolerance of the mortar. Waterproof, frost-resistant mortars that meet R4-class standards are recommended. Teknorep 300 EX is a thixotropic mortar suitable for temperatures as low as +5°C.

6. Can structural repair mortars be applied on both vertical and horizontal surfaces?
For repairing horizontal and vertical concrete surfaces, plastic and thixotropic mortars that don’t sag or shrink should be chosen. Teknorep 300 EX meets these criteria, making it easy to restore both horizontal and vertical areas.

7. Is additional reinforcement needed before applying the repair mortar?
Typically, extra reinforcement (like steel mesh) is only required for large areas or heavily loaded zones. However, Teknorep 300 EX is already reinforced with polymer fibers and doesn’t need additional preparation.

8. How should concrete surfaces be prepared before applying an R4-class repair mortar?
The surface should be cleaned of dust, dirt, and weak concrete particles. For better adhesion, it’s advisable to treat it with a corrosion inhibitor and a bonding primer like Tekno AD.

9. What are the benefits of using fiber-reinforced mortars for repairing concrete and precast structures?
Polymer fibers in Teknorep mortars prevent microcracking and improve the strength and durability of the repaired structures.

10. Is R4-class repair mortar suitable for industrial areas or high-load zones?
Yes, R4-class mortars like Teknorep 300 EX can handle heavy loads and have excellent wear resistance, making them ideal for industrial applications.