中文摘要：

试验研究了四点弯曲荷载长期持续作用下混凝土中氯离子的输运规律,以及早龄期（浇筑7d以内）加载的影响。试验结果表明：持续四点弯曲拉应力作用会增大混凝土的渗透性,并且随着荷载水平的增加,相对氯离子扩散系数Di/D0随着荷载水平提高而呈非线性增大。纯弯段与弯剪段之间氯离子含量分布存在差异,这与弯剪段混凝土所受复杂应力状态有关。早龄期弯曲拉应力持续作用对后期混凝土耐久性能影响较小,这源于早龄期混凝土抗拉强度的较快发展和较强的水化自愈合作用。

英文摘要：

Experiment was carried out in this paper to study the chloride permeability regularities of concrete subjected to long-term sustained four-point bending loads, and the influence of early age load- ing. The test results show that the chloride concentration at a given depth increases with the effect of sus- tained flexural stress and with the increase of the stress level, the relative chloride permeability coefficient DI/Do is increased nonlinearly. The different distributions of chloride ions between the pure shear-bending bending and sections are largely related to the complex stress state in the shear-bending section. The early age bending tensite stress has little effect on the concrete durability at later age, which originates from the fast tensile strength development and the strong hydration self-healing effect at early age.