Sustainable use of stabilized flood mud as subgrade soil for low volume traffic roads

Abstract

This research aims to identify the basic properties of ood mud and the efficiency of biomass silica (SH85) as a stabilizer to improve the strength of this mud. Unconfined Compressive Strength (UCS) testing was carried out on untreated soil and soil treated with 2%, 4%, and 9% SH85 contents within three and seven curing days. The microstructure of SH85 treated ood mud was investigated via Field-Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive X-ray (EDX) spectrometry. It was found that the strength of treated soil increased two to seven times that of the untreated soil where the highest strength was recorded at 949 kPa following seven-day soil treatment by 9% SH85 content. A polynomial trend was observed with an R2 value greater than 95% relationship between SH85 content and UCS in different curing periods. The seven-day UCS of SH85 treated ood mud met the strength requirement of 0.8 MPa for Malaysian subgrade material of low traffic volume roads and the compressibility was significantly reduced when SH85 content was greater than 4%. According to the FESEM and EDX results, cementitious products that promoted soil strength filled the voids of the treated soil.