Application of the SiGMA analysis to the stress evaluation of the cracking structures

The paper presents the method for the elastic wave processing and propagation analysis applied to the reinforced concrete element under load. The quantitative method gives information about structural changes within the material and enables three-dimensional location of local damage. The Sigma analysis based on a waveform of longitudinal waves was chosen for the study. On this base the analysis can locate the place of the concrete deterioration and evaluate the stress which causing cracking. The acoustic emission test was conducted by the industrial apparatus and six piezoelectric sensors. The waveforms of acoustic emission signals were analysed using computer software. The experimental study confirmed the correctness of the analysis on the base of cracking appearing. The Sigma analysis identified tensile stress, shearing stress and both simultaneously. The method can be useful in the early detection of the micro-cracking of the reinforced concrete elements.