Materials, Methods & Technologies, Volume 14, 2020

Rezumat: The reinforced concrete structures of most industrial sites suffer severe corrosion damage caused by various factors - mainly from the environment corrosion and specific production conditions. The need to design and perform the necessary repairs becomes urgently important. In recent years, the implementation of such repair works by using of properly reinforced thin overlays of concrete with special mix design has become increasingly relevant. Meanwhile these special composites have to be fully completely protected against any type of cracking especially from shrinkage ones. The use of special concrete with compensated drying shrinkage based on ordinary Portland cement and special shrinkage compensating admixtures is a much more attractive option - simply because the provision of special cements for each case is (to say the least) inconvenience of different types. This is exactly the approach used in the current research aimed at assessing the effectiveness of shrinkage compensating chemical admixture KEPTONITE applied in exactly the same concrete mix design made with the most commonly used different types of cement produced by Bulgarian factories. In this direction special testing program is fulfilled and original testing results are obtained and discussed. It is concluded that KEPTONITE demonstrates very good performance in direction to strongly minimize the final shrinkage of the concrete tested. The different dosage rate of KEPTONITE is optimal for Bulgarian cement used for testing.