... Graphical Abstract Figure concrete cracking acoustic emission nonlinear ultrasonic test higher harmonic generation sideband peak count index SPC-I continuous and periodic condition assessment failure analysis materials testing structural engineering ultrasonics wave propagation modeling...

... embedded into a nonlinear medium. The nonlinear defect is mimicked by a Berea sandstone sphere (high nonlinearity). It is placed into a large concrete block (average nonlinearity) during casting. The proposed pump and probe propagating wave interaction method allows imaging of the presence of the highly...

...Anna Castellano; Aguinaldo Fraddosio; Mario Daniele Piccioni; Tribikram Kundu When stress in concrete exceeds certain threshold value, microcracks are nucleated, these microcracks can propagate and coalesce forming macrocracks, resulting in the gradual decay of the mechanical properties of concrete...