acts by contraction which is obtained by means of a jack system 5 a 5 d comprised within the means 5 the tensile force r 2 u2032 on the band 2 causes an elongation d 2 of the band 2 and a reactive force r 2 from the band 2 on the tensioning means 5 the band 2 is then mechanically attached to the construction work 1 in fig1 a and 1b this is done via another reinforcing band 3 the reactive force r 2 is transmitted to the work within an area which can support this stress here this area is an area 3 a which anchors the band 3 in fig2 a one can see that the force r 2 can be transmitted by a mesh of fibers 2 d originating from the weave of the band 2 or glued to it the mesh 2 d and the band 2 are joined by one or more layers of fanned out threads the mesh 2 d is connected by means of a head 5 c with an eye to a threaded rod 5 d inserted into a turnbuckle 5 a fig2 b shows an enlargement of the head 5 c which has an eye.