California Bearing Ratio improvement and freeze–thaw performance of fine-grained soils treated with geofiber and synthetic fluid

This paper presents experimental results on the improvement of the California Bearing Ratio (CBR) performance of fine-grained soils by the addition of geofiber and synthetic fluid. CBR tests were conducted for freezing and thawing conditions in addition to non-freezing conditions. The improvement of soil was tested with the inclusion of: i) geofiber only, ii) synthetic fluid only, and iii) synthetic fluid and geofiber together. To represent unsaturated and saturated soil conditions for various field applications, both unsoaked and soaked samples were investigated. The results for unsoaked conditions indicated significant improvement in the CBR performance, particularly in samples treated with geofiber and synthetic together. For soaked conditions, the best performance was obtained from the samples treated with geofiber only. The CBR performance of samples subjected to a freeze–thaw cycle was also tested. Freezing and thawing tests on unsoaked samples showed that the addition of geofiber together with synthetic fluid was generally successful in providing resistance against freeze–thaw weakening, and that the addition of synthetic fluid alone was not very effective against the detrimental impact of freeze–thaw. The results from soaked samples subjected to a freeze–thaw cycle showed poor CBR performance for treatments involving synthetic fluid while samples improved with geofibers alone generally produced better performance.