Non-destructive concrete stress evaluation

A testing system for concrete structures comprising:

• a load sensor positionable to measure a load on the concrete structure to distinguish between at least two different load values;
• a plurality of transmitters positionable on the structure and configured to independently transmit acoustic excitation waves into the structure;
• a plurality of receivers positioned positionable on the structure and configured to receive diffuse waves of the excitation waves from the plurality of transmitters;
• and
• an electronic computer executing a program stored in a non-transitory medium to:
• receive the diffuse waves from the plurality of receivers;
• calculate a decorrelation coefficient based on the diffuse waves and a wave speed of the diffuse waves for at least two different load values;
• calculate a sensitivity kernel based on the diffuse waves;
• and
• apply an inversion algorithm to estimate a distribution density based on the decorrelation coefficient and the sensitivity kernel and indicating a presence of defects within the concrete structure.