Abstract: Through the study of recycled concrete by the chlorine salt erosion the micro-hardness of different interface changes, determine different recycled concrete strength grade and different interface transition zone, the chlorine salt erosion period the influence law of different interface microstructure of recycled concrete, reveals that the recycled concrete multiple interface degradation mechanism of the chlorine salt erosion. The study shows that: as the growth of the chlorine salt erosion age, with the strength of recycled concrete LG-XJ interface, LJ-XJ and LG-LJ interface of micro-hardness gradually reduce, transitional zone increased gradually. Erosion age of 30 d, C30 recycled concrete LJ-XJ interface transition zone range is almost have no change; Erosion age for 90 d, recycled concrete C60 LJ-XJ interface transition zone range change is not obvious. With the chlorine salt erosion resistance strength of recycled concrete interface strength relationships: LJ-XJ interface the chlorine salt erosion resistance >LG-LJ interface the chlorine salt erosion resistance>LG-XJ interface the chlorine salt erosion resistance performance. Different ages of the chlorine salt erosion of recycled concrete, with the improvement of strength grade, LG-XJ interface, LJ-XJ and LG-LJ interface of micro-hardness and transition zone and micro-hardness change of cement paste itself have different degree of reduction in amplitude.

Key words: recycled concrete;multiple interface;micro-hardness;chlorine salt erosion;age