Salt weathering is a common deterioration phenomenon that affects outdoor cultural properties, and it is important to precisely predict the heat, moisture, and salt transfer in porous materials to suppress salt weathering. Osmosis and osmotic pressure were considered in the field of soil research, especially in clay research, but not in the field of outdoor cultural properties and building materials, which are the main target of salt weathering. Osmosis in clay is supposed to be caused by its surface charge. However, it has been suggested that sandstones and bricks that constitute cultural properties and buildings also have surface charge as clay. Thus, osmosis and osmotic pressure can occur in building materials, which may lead to materials degradation. In this study, we derive basic equations, based on nonequilibrium thermodynamics, for the simultaneous heat, dry air, water vapor, liquid water, cation, and anion transfer in building materials by considering osmosis. This equation was compared with existing model for heat and moisture transfer equations as well as models that considered the salt transfer. Based on the previous research for osmosis in clay, we summarized conditions under which osmosis occurs in building materials and presented an outlook for modeling the physical properties of materials related to osmosis.

The risk of frost damage to building materials is strongly dependent on the water content, particularly when the water content is high. Therefore, to understand the moisture behavior of materials with high water content is essential to predict the frost damage risks of buildings. While little liquid water transfer takes place over the capillary saturation under unfrozen conditions, the pressure drop of the unfrozen water contained in the frozen domain (cryosuction) may be a strong driving force for water transfer during the freezing processes. Therefore, in this study, we investigated water transfer in a building material over capillary saturation during freezing through a one-dimensional freezing experiment using the gamma-ray attenuation method and hygrothermal simulations. In the experiment, an aerated concrete specimen, with a water content greater than the capillary saturation, was subjected to a temperature gradient by cooling the specimen bottom to the freezing temperature. The results show that significant water transfer occurred even in the capillary-saturated material during freezing and thawing. Water moved to the cold side in the material and the most significant water accumulation was observed at a position where the temperature was close to 0 degrees C. The hygrothermal simulation, including the freezing processes, confirmed that cryosuction was a dominant driving force of water movement and accumulation in the material compared with other driving forces, such as gravity and temperature gradient. Moreover, mechanism of the water accumulation at a position where the temperature was close to 0 degrees C was discussed from the perspective of water chemical potential distribution and water conductivity of the material. The findings of this study will help develop a more reliable model for evaluating moisture damage risks by considering the hygrothermal behaviors of building envelopes.

In Tarim River Basin (TRB), the retreat of glacier and snow cover reduction due to climate warming threatens the regional economy of downstream basins that critically depends on meltwater. However, the quantitative evaluation of its impact on multiple sectors of the socioeconomic system is incomplete. Based on compiled regional input-output table of the year 2012, this study developed a method to analyze the relationships between economic activities and related meltwater withdrawal, as well as sectoral transfer. The results show that the direct meltwater withdrawal intensity (DMWI) of agriculture was much higher than other sectors, reaching 2348.02 m(3)/10,000 CNY. Except for A01 (agriculture) and A02 (mining and washing of coal), the embodied meltwater withdrawal (EMW) driven by the final demand of other sectors was greater than direct meltwater withdrawal, and all sectors required inflows of virtual water (72.45 x 10(8) m(3), accounting for 29% of total supply from cryospheric water resources) for their production processes in 2012. For sectors with high DMWI, improving water-use efficiency is an effective way to reduce water withdrawal. To some extent, the unbalanced supply of cryospheric water resources due to geographical segregation can be regulated by virtual water flows from water-saving to water-intensive sectors. Such decisions can affect the balance between socioeconomic development and environment conservation for long-term sustainability.