Confining stress influence on EPS water absorption capability

Expanded polystyrene (EPS) blocks are increasingly used in geotechnical applications, thus its stress–strain behavior has been the focus of several researches. However, water absorption mechanisms of expanded polystyrene blocks and the influence of water absorbed amount on their stress–strain behavior have received little attention. This paper presents a series of water absorption tests carried out to evaluate the water absorption capability of EPS specimens with nominal densities of 20.5 kg/m3 (EPS-20) and 29.9 kg/m3 (EPS-29), subject to various confining pressures. Additionally, the influence of water absorbed on the EPS stress–strain behavior is evaluated by means of uniaxial and triaxial compression tests conducted on immersed and non-immersed EPS twin specimens, subject to equal confining conditions. Test results show that EPS water absorption depends on applied stress magnitude. Furthermore, triaxial compression tests results indicate that EPS wetting does not affect significantly its stress–strain behavior.