Investigation of Key Properties of EPS Geofoams for Highway Embankments on Soft Ground

Abstract

Differential settlement of bridge abutments has taken place at most bridge abutments on untreated soft ground in Vietnam. The conventional technologies to improve soft ground have often been costly and time-consuming. EPS geofoam, a synthetic and lightweight material, can be used as a fill material to raise the elevation of highway embankments directly on untreat soft ground. However, EPS geofoam has little known as construction materials for transportation structures in Vietnam. This paper attempts to investigate key properties of geofoams made in Vietnam. Several laboratory tests such as compression, water absorption, inflammability, and dissolvent were conducted. The results show that (1) Geofoams made in Vietnam have densities of 12.1 to 34.8 kg/m³ for the EPS-12 to the EPS-34, respectively; (2) q_u increases in increasing in densities; (3) Elastic strain is less than 1.5%; (4) Initial modulus varying from 2-10 MPa with density; (5) Poisson ratio around 0.06-0.14; (6) Water absorption by volume from 0.4-3.2%; (7) Geofoam can be quickly burnt. These key properties will indicate suitable geofoam types that can be utilized as highway embankment fills placed on unimproved soft ground directly.