Influence of grouted sleeve and concrete strength of fabricated shear wall on acoustic emission detection method for sleeve compactness

It has been verified by relevant studies that the nondestructive detection method combining acoustic emission (AE) technology and signal generator can be used to detect sleeve grouting compactness of fabricated shear wall. However, sleeve material, grout type and concrete strength will affect the results of the above detection method. In this paper, the influence of these characteristics on the AE detection method for sleeve compactness was studied. The results show that the amplitude and energy of carbon steel sleeve are not much different from those of nodular cast iron sleeve. In contrast, the amplitude and energy of bellows sleeve are much smaller. Compared with the sleeve material, the volume and shape of the sleeve have a greater impact on the AE signal. The AE signal can be affected by the grout types. The amplitude and energy of the more compact UJOIN-108 grout are respectively 68.4 dB and 29.5 mV*ms. which are greater than those of BY(S)-YJ85 grout with 67.4 dB and 19.5 mV*ms. As the concrete compressive strength of the fabricated shear wall specimen increases from 48.5 MPa to 51.6 MPa, the amplitude and energy of AE signal increase accordingly. The amplitude and energy of AE signal of the specimens with high-strength grouting material and high-strength concrete are larger, and the AE signal is characterized by the same law. The frequency of AE signal is very effective in characterizing the change of sleeve material and concrete strength, but it does not perform well in characterizing the change of grout types.