Evaluation of the Use of Cellular Lightweight Concrete as Embankment Material for Asphalt Concrete Road in Bangkok

Abstract

Road construction on soft clay foundations in Bangkok often faces long-term settlement problems due to the weight of the embankment fill than the shear strength of the foundation soil and the consolidation process of foundation soil in saturated conditions. At present, there are two techniques for improving the quality of foundation soil: transferring the weight of embankment fill to a stronger layer and accelerating the settlement with pre-loadings. This paper presents the use of lightweight concrete as an alternative material in embankment layers to reduce the weight of the material acting on soft clay foundations. Evaluation of the mechanical properties of cellular lightweight concrete consisted of compressive strength test, split tensile strength test, elastic modulus and Poisson's ratio test, and dynamic compressive strength test to select the appropriate density of cellular lightweight concrete and use it to evaluate the thickness for application in the embankment layer of asphalt concrete road structure through ANSYS model. From the study, it was found that the density of cellular lightweight concrete at 600 kg/m3 with a thickness of 0.4 m could reduce stress, strain and settlement on the foundation soil layer better than traditional structures, which resulted in the long-term stability of the road structure from permanent deformation.