Experimental study on water evaporation from compacted clay using environmental chamber

Water evaporation induces large volume change for clayey soils, often causing problems to geotechnical and geoenvironmental constructions. To better understand this process, an evaporation test on a compacted clay was conducted in a large-scale environmental chamber under controlled atmospheric conditions. Atmospheric parameters (wind speed, air temperature, and relative humidity) and the response of soil parameters (volumetric water content, temperature, soil suction as well as desiccation cracks) were monitored. The results show that the soil temperature is strongly related to the air conditions, evaporation process, and desiccation cracks. Unlike for sand, the evolution of volumetric water content is governed by both the high water retention capacity of clay and the effect of cracks. A three-stage evolution can be observed for not only the actual evaporation rate, but also the surface crack ratio. Thus, the surface crack ratio can be considered as one important parameter in the evaporation analysis taking into account the effect of desiccation cracks.