The “supreme discipline” of concrete repair lies in the statically relevant reprofiling of concrete according to EN 1504-3. Intensive laboratory work and experience with KÖSTER Repair Mortar NC and KÖSTER Betomor Multi A resulted in the development of KÖSTER Repair Mortar R4.
All mandatory tests according to the standard were carried out by the IGH institute in Croatia (Department for Materials and Structures) and passed with excellent results. The crucial element for these products is the assurance of a good frost resistance while maintaining high strength. Even with high stresses through temperature change the mortar needs to maintain a strong bond to the substrate.
During the testing in Zagreb, to our surprise it became apparent that KÖSTER Repair Mortar R4 does not even require a bonding course since it contains a high cement paste proportion and is therefore easy to apply as well. Our expectations were exceeded – high bond strength throughout all testing conditions ensure a durable application. The combination of binding agents, (“fat mixture”), grading curve, and fine pore volume are well balanced.
The tests by the IGH include compressive strength, chloride ion content, adhesive bond strength, unrestrained shrinkage/expansion, carbonization resistance, thermal compatibility, freeze-thaw and dry cycling, and modulus of elasticity. These are documented in the declaration of performance (CE certification acc. to EN 1504-3: ZA. 1A).