2022 Volume 76 Issue 1 Pages 229-237
Piezoelectric phenomena in ferroelectrics are well known to correlate with elastic strain and power generation of cementitious material subjected to loading has also been reported as piezoelectric phenomena. However, cementitious materials, which are elasto-plastic materials, may become locally plastic at the microscopic even though they are elastic at the macroscopic during loading, or cracks may appear in the interfacial transition zone from the early stage of loading.
In this paper, to investigate the effect of microfracture on power generation, we conducted experiments on the correlation between strain and potential fluctuation, especially on the effects of the interfacial transition zone, which is the starting point of mortar and concrete fracture.
In Series1, the effect of the presence/ absence of interfacial transition zone on the piezoelectric potential was studied by comparing cement paste and mortar.
In Series2 and 3, potential measurements on concrete provided information about the effect of interfacial transition zone when compressive strain is at a minimum and when strain is increasing/ decreasing at a constant rate.
As a result, based on the obtained potential waveforms, we proposed a transient model consisting of a capacitor and a conductor, assuming that the potential fluctuation in cementitious materials is caused by the generation and recombination of electric charges at the shear interfaces.
