【摘要】 钢筋混凝土结构中的混凝土腐蚀和钢筋锈蚀都与混凝土的渗透性密切相关。提高水泥基材料的抗渗性有助于提高其使用寿命,减少使用期内的维修次数,降低全寿命周期内的成本,降低建筑垃圾排放量和能源消耗量。聚乙烯醇纤维增强的应变硬化水泥基复合材料(strain hardening cement-based composites(SHCC))具有超高韧性和应变强化等优异特性,但由于纤维的存在,增加了基材中的微孔隙,如果微孔隙造成材料的渗透性增高,则不利于SHCC在严酷环境下的应用。通过不同轴压荷载下SHCC的毛细吸水和氯离子渗透试验研究其抗渗性,探讨了内掺硅烷乳液防水剂对SHCC在不同轴压应变下的抗渗性能的影响。结果表明,毛细吸收试验是检测水泥基材料复合受力状态下耐久性能的便捷试验方法;内掺硅烷乳液的防水处理方式能够防止SHCC吸收过多的水分或水溶有害离子,可以使其高应变能力得到发挥。更多还原

【Abstract】 The behavior of concrete corrosion and reinforcement bar rusty in RC structures is affected by the permeability of concrete.Improving the anti-permeability of cement-based materials helps to prolong the service life of RC structures,reduce the repair frequency during the service life,cut down the costs in the whole life cycle,and lower the construction garbage and power source consumption.Polyvinyl alcohol fiber reinforced strain hardening cement-based composites(SHCC)possess some exceptional properties,such as high ductility strain hardening and multi-micro cracks.But the fibers may introduce millipore or tiny defect in the matrix,which may result in the increase of the penetrability and further,restrict the application of SHCC in the cruel environment.Experiments are carried out on capillary suction and chloride ion penetration to study the anti-penetration behavior of SHCC under different compressive loads.The effect of hydrophobic treatment is also discussed particularly.Results show that the capillary suction test provides a convenient and fast mean to characterize the durability of cement-based materials under combined mechanical and climatic loads.The high strain capacity of SHCC can be used more extensively if integral water repellent SHCC by saline emulsion is produced which is an efficient protection of SHCC against uptake of water and ions dissolved in water.更多还原