Control of frost effects in susceptible soils using a novel sandwich geocomposite composed of geotextile-soil-nano silica aerogel-geotextile liners

The present work aims at introducing a new type of geotextile sandwich structure encapsulating soil and silica aerogel that prevents frost-susceptible-soil from penetration of cooling flows. Different Geotextile Soil-Aerogel Liners (GSAL) were prepared by different combinations of soil/aerogel placed between the two layers of geotextiles to be used as the thermal insulators on the surface of frost-susceptible-soil. Among various contents of silica aerogel mixed with soil, the most effective reduction of thermal conductivity of the mixture was obtained with incorporation of 1 and 2 wt% (wt.%) of silica aerogel. Further increase of the silica aerogel decelerated the reduction rate of the thermal conductivity of the mixture. It was found that GSALs were capable to reduce the rate of temperature drops in different frost-susceptible-soil depths by an average of 88%. Moreover, comparing the results of different samples revealed that increasing the GSAL thickness resulted in a considerable improvement of GSAL performance when compared with increasing the aerogel content. Therefore, the optimum condition of GSAL was achieved with low percentage of silica aerogel and high thickness of GSAL. A computer based simulation was also performed using ANSYS software. In the proposed simulation, natural soil having a GSAL layer on top was modeled. The simulation results were in good agreement with the experimental results.