硅烷浸渍水泥基材料水蒸气脱吸附性能与有机物含量的表征

Characterization for Water Vapor Sorption and Organic Content of Silane-impregnated Cement-Based Materials

硅烷浸渍处理是混凝土常用的耐久性防护措施。使用异丁基三乙氧基硅烷浸渍处理水泥基材料,通过裂解-气相色谱-质谱(PGC-MS)表征浸渍于水泥基材料表面硅烷的特征结构与含量,发现其裂解碎片主要成分为异丁基;使用水蒸气等温脱吸附研究硅烷浸渍水泥基材料与水分相互作用特性,发现硅烷浸渍水泥基材料在低湿度区间的等温脱吸附性质没有显著变化,但浸渍处理有效抑制了相对湿度30%以上孔隙中水蒸气的凝聚和“墨水瓶效应”,同时使60%以上相对湿度区间的脱吸附速率常数显著增大。硅烷浸渍水泥基材料经历实验室氙灯老化10周后硅烷含量并未明显降低,其水蒸气脱吸附特性也未明显改变。

Silane impregnation is commonly used as a durability protection measure for concrete.Cement-based materials impregnated with triethoxyisobutylsilane were analyzed by pyrolysis-gas chromatography-mass spectrometry(PGC-MS)to identify the characteristic structure and amount of impregnation.The main component of the pyrolysis fragments is isobutyl.The water vapor sorption isotherm(WVSI)was determined to investigate the interaction between moisture and the impregnated materials.There is no notable difference at a humidity of<30%,the pore condensation(adsorption)and“ink-bottle”effect(desorption)substantially decrease,and the adsorption/desorption rate increases due to the impregnation at a humidity of>60%.The Xenon lamp ageing(10 weeks)after laboratory accelerated ageing process does not change the silane content and the WVSI characteristics.