RENOBUD R 103

Concrete substrate: The surface must be properly prepared before applying NEXLER RENOBUD R 103. The concrete substrate must be made of concrete of min. C20/25 grade, with a strength of at least 1,5 MPa measured by the pull-off method. The substrate must be clean and free of oil, grease, cement laitance and other substances that impair adhesion. Clean the substrate mechanically, remove dust and any loose layers. Concrete substrates that are significantly deteriorated, soiled or chemically or biologically corroded should be subjected to special treatments such as sandblasting, shot-blasting, milling, fungi removal. 
The substrate should be covered with a bonding layer of NEXLER RENOBUD R 102 mortar according to its application instructions. NEXLER RENOBUD R 103 should be applied over NEXLER RENOBUD R 102 using the ‘wet-on-wet’ technique.

Rebars: Prior to the application of NEXLER RENOBUD R 102 , the rebars should be cleaned of any rust film and other elements that can result in separation or accelerate corrosion. The exposed surfaces of the reinforcement elements should be thoroughly cleaned, for example by sandblasting, removing rust and any other dirt, up to a cleanliness grade of SA 2. In the case of bars with a fully or largely exposed surface, the concrete around them should be chiselled in such a way that after reprofiling the lagging made of NEXLER RENOBUD R 103 mortar has a minimum thickness of 1,5 cm.

Check the production date on the packaging before use. The product should not be incorporated beyond its shelf life. The product should not be objectionable (e.g. contain lumps, clumps, mechanical impurities) after opening. The mortar should be dry after opening the packaging, with no visible signs of moisture. Do not use a product that bears signs of freezing. After mixing with water, the mortar should be homogeneous and free of lumps and clumps resulting from under-mixing. Properly mixed, the product spreads easily over the surface and does not run off.

Before use, NEXLER RENOBUD R 103 should be poured into a vessel with a measured quantity of clean water and mixed with a slow speed mixer until a homogeneous consistency is obtained. The mortar can also be prepared in a concrete mixer. If partial use is assumed, the product should be prepared maintaining the weight ratio of the components. Use 1 kg of dry mix per 0,14 - 0,15 l of water. After the maturing time of 5 minutes, mix the material again. The mixed material, ready for processing, should be used within 1 hour. The thickened material cannot be stirred and processed again.

Check that the product is evenly applied and covers the entire surface. Check the progress of drying before further work is carried out. A well applied layer should be permanently bonded to the substrate and should not peel or crack. Depending on the design requirements, both the smoothness and roughness of the surface should be checked, adjusting for later stages of the finishing work.

Repair layer applied manually: NEXLER RENOBUD R 103 mortar should be applied evenly with a steel trowel directly onto the fresh bonding layer of NEXLER RENOBUD R 102 mortar using the ‘wet-on-wet’ technique. When applying, carefully press the mortar into the substrate, paying particular attention to areas that need filling. Depending on the requirements and intended use, the surface can be smoothed with a steel trowel or given a rough texture using a sponge trowel. Apply the mortar in a layer not thicker than 50 mm. 
If the depth of the defects to be repaired exceeds the maximum thickness of the mortar to be applied in one cycle, a second layer of NEXLER RENOBUD R 103 can be applied after 4 hours to a matt-damp substrate. Repeated application of the bonding layer of NEXLER RENOBUD R 102 mortar is then not required.

Repair layer applied mechanically: Substrate intended for mechanical application should be moistened with water until the surface is matt-damp. For porous and dry substrates, it is necessary to saturate them with water in advance, at least 24 hours before applying the NEXLER RENOBUD R 103 mortar. The mortar can be applied in a maximum layer thickness of 30 mm in one cycle. When applying, position the nozzle of the unit as close to 90 degrees to the surface as possible, maintaining a distance of 0,5 to 1,0 m between the nozzle and the substrate. 
The mortar layer should be uniform and compact. When applying to a surface with reinforcement, the application is done from a shorter distance and at different angles to thoroughly cover the rebars with mortar, avoiding the formation of 'caps' on their surface. If necessary, the spraying power can be increased. 
If the depth of the defects to be repaired exceeds the maximum thickness of the mortar to be applied in one cycle, a second layer of NEXLER RENOBUD R 103 can be applied after 4 hours to a matt-damp substrate. Repeated application of the bonding layer of NEXLER RENOBUD R 102 mortar is then not required.

After applying the NEXLER RENOBUD R 103 mortar, the fresh surface should be protected for 3 - 5 days against excessive drying, which can be achieved by using water mist or wet geotextile screens. At the same time, direct sunlight, draughts and significant fluctuations in temperature must be avoided and the mortar must be prevented from freezing. In the room where the work is carried out, the intensity of the heating should be reduced to maintain the right conditions for the mortar to dry.

Before use, please read the application details in the product's Technical Data Sheet.