Investigation of Expansive Additive on Properties of Repair Mortars

When building hydraulic structures in Lithuania, reinforced concrete (which is already 30-50 years old) was used for the construction of main structures. Presently, the technical maintenance and running repairs of CC2 and CC3 consequence class hydraulic structures are carried out periodically; however, the majority of the CC1 consequence class structures are derelict. In order to stop the further deterioration of reinforced concrete structures, the repair is necessary to be carried out. When repairing reinforced concrete constructions, it is very important that the old concrete and new repair materials should bond well and form monolithic construction. Evaluating repair mortars were determined the influence of concrete surface roughness and expansive additive to the bond and to the frost resistance of repair. The result show that mortars with expansive additive had created stronger adhesive relation with concrete. The bond strength of the samples increased approx. by 25%.