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中文摘要：
钢筋混凝土结构因为易于开裂而通常难于达到预期的设计使用寿命．原因之一就是水泥基材料在拉伸状态下的应变太小．通过添加聚乙烯醇纤维，水泥基复合材料的拉应变可以提高几百倍．多微缝开裂是准应变硬化水泥基复合材料（Strain Hardening Cement—based Composites（SHCC））的基本特征，然而，只有在外加拉应变下的裂缝不引起水、CO2、氯离子或硫酸根离子等对混凝土结构的侵蚀量显著地增加，这种大应变才对结构的安全性和耐久性有益，从而可以提高结构的使用寿命，降低全寿命周期成本．通过不同拉应变下SHCC的毛细吸水和氯离子渗透试验研究了SHCC的抗渗性能，并探讨了内掺硅烷乳液防水剂对SHCC在不同拉应变下的抗渗性能的影响．结果表明，毛细吸收试验是表征复合受力状态下的水泥基材料耐久性能的简便有效的试验方法；复合受力下极限拉应变不能作为耐久性设计的依据，必须根据渗透性确定能够保证使用寿命的临界拉应变极限状态；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离子。可以使其高应变能力得到更广泛的应用．
英文摘要：
The designed service life of reinforced concrete structures is not reached in practice usually due to its being prone to crack. The dominating reason for this well-known economical and ecological problem is the limited strain capacity of cement-based composites under tensile load. By adding PVA fibers to cement-based materials and since micro multi-crack formation, pseudo-strain-hardening cement-based composites（SHCC） have an extreme ductility as compared with other cement-based materials. However, the high strain capacity is beneficial with respect to durability only if the cracks formed under imposed strain do not lead to significantly increased ingress of aggressive compounds such as chlorides,sulfates even water only. In this contribution experimental results of measurement of capillary suction and penetration of water and chloride ions into SHCC under different imposed tensile strain will be presented and discussed. The influence of hydrophobic treatment has been studied in particular. Results show that capillary suction is a powerful method to characterize durability of the cement-based materials under combined mechanical and climatic load. The ultimate tensile strain under combined load should not be acted as the basis for durability design, whereas the critical tensile strain should be determined according to the anti-permeability of SHCC. 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.
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