APPLICATION OF SONREB METHOD IN COMPRESSIVE STRENGTH EVALUATION OF ANCIENT BLUE BRICKS IN MING DYNASTY IN BEIJING

Taking the sintered clay brick of an ancient city wall of Ming Dynasty in Beijing as the research object, the mechanical properties of blue bricks in Beijing in Ming Dynasty were tested by rebound and ultrasonic methods, and the uniaxial compressive strength tests were also carried out. On this basis, linear and power functions were respectively used to fit the Rebound Number Ultrasonic Pulse Velocity with the strength test results. At the same time, one strength prediction model for the test block was established upon the ultrasonic-rebound synthesis method (SonReb) combined with linear fitting, nonlinear fitting and, Response Surface Methodology. And the accuracy of different models was compared and analyzed. The results show that: the comprehensive method is more reliable to predict the uniaxial compressive strength of bricks of the wall in Beijing city, and its prediction accuracy is more accurate than that of using a single detection method. The results of the study can provide the basis and reference for obtaining the strength index of ancient blue bricks quickly and non-destructively.