Dynamic properties of geofoam (EPS) from dry to fully saturated conditions

This study aims to evaluate the dynamic behavior of Expanded Polystyrene (EPS) geofoam in dry, wet, and fully saturated conditions by performing a series of resonant column (RC) tests on EPS samples with different mass densities ranging from 13.6 kg/m3 to 31.3 kg/m3. In addition, the adhesive effect due to the connecting agent on dynamic parameters of glued geofoam blocks was considered and the results were compared with those obtained from the RC test on the same intact samples. The evaluation was done by comparing the values of shear modulus and damping ratio obtained from the RC test in different conditions. The results show that the shear moduli of wet samples are between 2 % and 12 % lower than those of dry ones. Therefore, the shear modulus decreases with increasing water absorption content (WAC) and decreasing the sample density. Moreover, it was found that the damping ratio increases with increasing the WAC and this is more noticeable at high confining pressures. Integrating the EPS samples with adhesive reduces the equivalent shear modulus in compared to the intact ones. The amount of this reduction increases with the increase in EPS density. The results show that the moisture content influences the dynamic behavior of EPS in addition to the density and confining pressure. Finally, in structures where the performance of glued EPS blocks is considered stable under static loads, it is important to investigate and compare the proper dynamic behavior of total mono-block mass.