Behavior of masonry columns repaired using small diameter cords

The innovative technique here illustrated is the result of historical evolution of ancient systems of hooping and is conditioned by design criteria that take into account the structural life in the respect of existing elements. It consists in the application of small diameter cords able to provide overlapping hoops at every course over the entire height of the column. Three series of uniaxial compression tests, with a total of 22 specimens, were conducted on model brick masonry columns with these variables: cross-section geometry, amount and scheme of confining reinforcement. Laboratory outcomes have shown how the investigated confining systems are able to provide significant gains in terms of compressive strength. Test results have been finally used to assess the reliability of the existing design equations suggested by Italian National Research Council for design of FRP strengthening of masonry columns.