DEVELOPMENT OF REPAIRING METHOD FOR CONCRETE STRUCTURES USING HIGH DUCTILITY SHOTCRETE TOGETHER WITH AFRP MESH

摘要

In this paper, in order to develop a rational repairing method for existing concrete structures, a new method using high ductility shotcrete mixed with vinylon short fiber together with Aramid FRP (AFRP) mesh was proposed, and its applicability was experimentally discussed. In this experiment, first of all, determining an optimum mix-proportion of high ductility shotcrete, punching shear test for investigating an anti-spalling performance of the proposed method was conducted. And also, freezing and thawing test and accelerated chloride permeability test were conducted to investigate an applicability of the method in cold and coastal area. The results obtained from this study were as follows: 1) flexural ductility of shotcrete can be upgraded due to a bridge effect of vinylon short fiber; 2) anti-spalling capacity of high ductility shotcrete can be more improved by arranging AFRP mesh and it is sufficiently satisfied a specification authorized by Japan Highway Public Corporation; and 3) high ductility shotcrete used in this study has high frost resistance and chloride penetration resistance. From these results, it is confirmed that the proposed repairing method will be one of the excellent methods and can be applied to rationally repair existing concrete structures constructed in cold and coastal area.