The influence of existing cracks on acoustic emission (AE) wave propagation characteristics is not taken into account when using AE technology to locate cracks or detect damages in concrete structures

which often leads to large deviations in detection results. To explore the influence of crack parameters on the velocity and amplitude attenuation of AE wave in reinforced concrete (RC) slabs

four-point static loading test and AE test were carried out on three RC specimens with different protective layer thicknesses

and the influences of crack depth

crack width

and crack amount on the propagation properties of AE wave were analyzed. Tests and analysis results show that crack width and crack amount both had little effect on the velocity and amplitude attenuation of AE wave

while crack depth had significant effect. With the increase of the crack depth

the amplitude attenuation increased

and the velocity decreased. Then

a time-of-arrival location method based on variable velocity was proposed considering the effects of cracks

which was compared with traditional method in detecting crack locations. Results indicate that the proposed method had higher accuracy in detecting crack locations in RC structures.