EFFECTS OF DE-ICING SALTS ON REINFORCED CONCRETE BRIDGE STRUCTURES

UNTERSUCHUNGEN ZUR EINWIRKUNG VON TAUSALZEN AUF BRUECKENBAUWERKE AUS STAHLBETON

DAMAGE TO BRIDGE STRUCTURES, WHETHER TO THE CONCRETE OR TO THE STEEL REINFORCEMENT, CAN ARISE DIRECTLY OR INDIRECTLY FROM THE EFFECTS OF DE-ICING SALTS (I.E. SODIUM CHLORIDE). HITHERTO, NO SYSTEMATIC RELATIONSHIP BETWEEN THE CHLORIDE CONTENT, THE CONCRETE PROPERTIES AND THE DEGREE OF CORROSION OF REINFORCEMENT HAD BEEN FOUND. IN ORDER TO DETERMINE THE CONDITION OF BRIDGE STRUCTURES AS WELL AS THE NECESSARY REPAIR MEASURES IT IS FIRST NECESSARY TO CLARIFY THE MECHANISM OF THE ATTACK OF DE-ICING SALT ON CONCRETE. THE OBJECT IS TO CARRY OUT LABORATORY TESTS ON CONCRETES WHICH HAVE BEEN SUBJECTED TO SOLUTIONS OF DE-ICING SALTS. THE QUESTION OF THE NATURE AND THE SPEED OF THE ENTRY OF THE SALTS INTO CONCRETE AND THE POSSIBLE STRUCTURAL CHANGES IN THE CONCRETE UNDER VARYING CLIMATIC STRESSES IS TO BE EXAMINED AS WELL AS THE DEGREE OF CORROSION OF THE CONCRETE. IN ORDER TO DETERMINE THE RELATION BETWEEN LABORATORY TESTS AND PRACTICE, MATERIAL TESTS ALREADY CARRIED OUT BY THE RESEARCHER INTO BRIDGE STRUCTURES ARE TO BE SYSTEMATICALLY EVALUATED AND ELABORATED BY PHASE ANALYSES.