Underwater Behaviors of Lightweight Air Foamed Soils Using Small-Scaled Simulator

Abstract

A series of triaxial and unconfined compression tests were performed to investigate behaviors of Lightweight air foamed soils (LWFS) that are composed of dredged soils, cement and air foam, and cured at underwater conditions. LWFS could be substitute of normal in situ soils used in backfill to earth structures and embankment materials for soft ground improvement because of certain effectiveness such as settlement reduction and reduced earth pressure decrease due to its lightness. The density of LWFS will be increased if LWFS be cured at underwater conditions because high water pressure makes air foam disappear or demolish during the curing compared with LWFS cured at normal air conditions. This paper is to find the mechanical behaviors of LWFS cured at seawater depth of 5 m and 10 m, which simulates underwater curing conditions by an underwater pressure simulator chamber system developed during this study. In addition, new normalized factor formula for LWFS mixtures, which take account of mixing design conditions with target compressive strength, was proposed to consider mixing design factor for LWFS.substitute of normal in situ soils used in backfill to earth structures and embankment materials for soft ground improvement because of certain effectiveness such as settlement reduction and reduced earth pressure decrease due to its lightness. The density of LWFS will be increased if LWFS be cured at underwater conditions because high water pressure makes air foam disappear or demolish during the curing compared with LWFS cured at normal air conditions. This paper is to find the mechanical behaviors of LWFS cured at seawater depth of 5 m and 10 m, which simulates underwater curing conditions by an underwater pressure simulator chamber system developed during this study. In addition, new normalized factor formula for LWFS mixtures, which take account of mixing design conditions with target compressive strength, was proposed to consider mixing design factor for LWFS.