Strength damage analysis on cement-and-fly ash treated organic soils subjected to freeze-thaw cycles.7z

Organic soil is usually required to be improved/treated before engineering construction, especially in cold regions. In this study, cement and fly ash are adopted as additives to stabilize the organic soil. A photogrammetric method is proposed to accurately reconstruct the surface of these cement-and-fly ash treated organic soils, and measure the volume before and after freeze thaw cycles (F-T-C). Meantime, unconfined compression (U-C) test was performed to evaluate the performance of these specimens after different numbers of F-T-C, and the influence of organic content on specimens behavior also was investigated. These results indicated that an increase in the cement content enhanced the resistance of the organic soils against volume change before and after F-T-C. The adoption of cement and fly ash at proper contents significantly improve the unconfined compression strength (UCS) of organic soils subjected to different number of F-T-C. The 15% organic matter content is an important boundary for reflecting the engineering properties of treated organic soil. A stress-strain curve prediction model was established with consideration of the number of F-T-C and volumetric change after the F-T-C.