水泥基孔隙材料中水蒸气的等温吸附与脱附过程

发布时间：2018-04-15 15:43

本文选题：水蒸气等温吸附 + 吸附平衡　；参考：《硅酸盐学报》2015年05期

【摘要】：分别采用水胶比为0.3、0.4和0.5的净浆和砂浆,结合文献模型对水泥基材料中水蒸气的等温吸附(脱附)平衡和动力学过程进行了拟合和参数分析。结果表明:多层吸附的Guggenheim-Andersen-de Boer(GAB)模型能够更好地描述水泥基材料中水蒸气的吸附(脱附)平衡以及吸附-脱附滞回,吸附过程的第1层吸附能常数大于脱附过程的,但单层吸附量小于脱附过程的,吸附-脱附滞回在相对湿度为65%~70%时最大;二阶模型最能够描述水泥基材料中水蒸气的吸附(脱附)动力学过程,二阶模型中的初始吸附速率要明显低于初始脱附速率,两者均随相对湿度的增大而显著增加;速率常数在吸附过程中随相对湿度减小而增大,在脱附过程中则随相对湿度减小而减小。
[Abstract]:The isothermal adsorption (desorption) equilibrium and kinetic process of water vapor in cement based materials were simulated and analyzed by using clean mortar and mortar with water / binder ratio of 0.3 ~ 0. 4 and 0. 5 respectively.The results show that the multi-layer adsorption Guggenheim-Andersen-de model can better describe the adsorption (desorption) equilibrium of water vapor and the adsorption-desorption hysteresis in cement-based materials. The adsorption energy constant of the first layer of adsorption process is larger than that of desorption process.However, if the adsorption capacity of monolayer is smaller than that of desorption, the adsorption-desorption hysteresis is the largest at the relative humidity of 65 ~ 70, and the second order model can best describe the adsorption (desorption) kinetic process of water vapor in cement based materials.In the second order model, the initial adsorption rate is obviously lower than the initial desorption rate, and both of them increase significantly with the increase of relative humidity, and the rate constant increases with the decrease of relative humidity during the adsorption process.The desorption process decreases with the decrease of relative humidity.
【作者单位】：教育部土木工程安全与耐久重点实验室清华大学土木工程系;
【基金】：国家重点基础研究发展计划(2009CB623106) 自然科学基金项目(51378295)资助项目
【分类号】：TU528

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