降温过程中孔隙的结晶变形

Deformation of a pore induced by crystallization during cooling process

盐风化过程中盐结晶在孔壁产生的结晶压力是导致多孔介质材料变形与破坏的主要原因。基于结晶动力学理论,考虑了晶体与孔壁的相互作用,建立了降温过程中孔隙晶体生长模型,对降温过程中不同含盐量、含水量和荷载条件下的孔隙盐胀变形行为进行了模拟和试验分析。结果表明,孔隙的结晶变形受盐结晶体积、起始孔隙直径和盐结晶形状(盐结晶长宽比)的影响,在相同降温条件下,水盐含量影响了降温过程中盐结晶体积,而荷载的增大迫使盐结晶产生更多的横向生长(长宽比增大)。本模型为揭示降温结晶过程中多孔介质盐胀变形机制和计算盐胀变形提供了新的途径。

The pressure exerted on pore walls by growing salt crystals in salt weathering is a major cause of deformation and damage in porous materials.Crystal growth model in a pore during cooling process was provided.The treatment considered the interaction between crystals and pore walls which is based on kinetics of crystallization.Simulations and tests are carried out to analyze the deformation behaviors of a pore induced by salt heave under conditions of different salt contents,water contents and loads during cooling process.The results show that the deformation behaviors are subjected to volume of salt crystals,initial pore diameter and length-width ratio of salt crystals,and the volume of salt crystals is influenced by water and salt contents,and the loads induced an enhancement of length-width ratio of salt crystals.This model provides a new method for revealing the mechanism and calculating the deformation of salt heave in porous materials during cooling process.