Abstract:
A series of tests for eight wetting-drying cycles were carried out on Jingmen yellow-brown expansive soil under five different initial compactnesses (100%, 95%, 90%, 85%, 80%, respectively). And the volume change-cracking-water retention behaviors during wetting-drying cycles were investigated. The conclusions were drawn as follows: (1) After three to seven wetting-drying cycles, the volume change and water content of the expansive soil were reversible. (2) With the increase of the number of wetting-drying cycles, the shrinkage curves and swelling curves moved up, which showed that the volume increase was induced by the wetting-drying cycles. Stability time for swelling decreased with the increase of the number of wetting-drying cycles, and with the decrease of initial density. (3) The crack area of the sample after drying increased with the increase of the number of wetting-drying cycles. And the crack area became steady after five to six wetting-drying cycles. After enough wetting-drying cycles, the reference value of surface crack ratio of compacted expansive soil was 7%~10%. (4) The cracks healed during wetting, and the cracks healed completely in the first four wetting-drying cycles.