Experiment evidence on the temperature dependence of desiccation cracking behavior of clayey soils

When drying a clayey soil, shrinkage and then cracking on soil surface occur due to water loss by evaporation, this phenomenon seems to be temperature-dependent. In the present work, experimental tests were conducted on saturated slurry to investigate the desiccation cracking behavior at three temperatures (22, 60 and 105 °C). The initiation and propagation of desiccation cracks during drying was monitored using a digital camera. By applying computer image processing technique, the surface crack ratio (RSC) which is the ratio of the surface area of cracks to the total surface area of specimen, was defined to quantify crack networks at different water contents. The experimental results show that the initial critical water content (wIC), which corresponds to the initiation of desiccation crack, increases with temperature rise. After the initiation of a crack, the ratio RSC increases with decreasing water content and then keeps almost constant when the water content becomes lower than the critical water content (wFC). By comparing the cracking curve with shrinkage curve, it has been found that the cracking curve, to some extent, reflects the shrinkage properties of soil since the wFC is related to the shrinkage limit and slightly influenced by temperature.