损伤混凝土毛细吸水性能试验研究和水分分布预测分析

发布时间：2019-06-17 15:22

【摘要】：混凝土内部微裂缝的产生或贯通,加快了水及侵蚀性介质侵入混凝土内部的速度,是引起混凝土性能劣化和结构耐久性不足的重要原因.开展了混凝土试件的轴心受拉、受压试验,采用持载、反复加载方式,对混凝土试块分别加载至极限荷载的70%、80%、90%后卸载.为了实现吸水过程的连续性,利用改进后的吸水装置开展损伤混凝土的累积吸水量测试试验.与未加载试件的吸水结果对比分析表明,荷载水平是影响混凝土毛细吸水速率的重要因素.对不同荷载水平的累积吸水曲线i-t1/2,采用线性拟合方法可得到混凝土的初始吸水率(S1)和后期吸水率(S2).根据吸水率试验结果,结合非饱和毛细吸水理论模型,引入Bolzmann变量,建立了损伤混凝土内相对含水量分布的预测分析方法,为开展混凝土内有害介质(如氯离子或者硫酸根离子等)的传输分析提供了工具.
[Abstract]:The generation or penetration of the micro-cracks in the concrete increases the velocity of water and aggressive media into the concrete, which is an important reason for the deterioration of the performance of the concrete and the insufficient durability of the structure. The axial tension and compression test of the concrete test piece are carried out, and the concrete test blocks are loaded to 70%,80% and 90% of the limit load, respectively, and unloaded after the load and the repeated loading method are adopted. In order to realize the continuity of the water absorption process, the improved water-absorbing device was used to test the cumulative water absorption capacity of the damaged concrete. The analysis of the water absorption results of the unloaded test piece shows that the load level is an important factor that influences the capillary water absorption rate of the concrete. The initial water absorption (S1) and the later water absorption (S2) of the concrete can be obtained by a linear fitting method for the cumulative water absorption curve i-t1/2 of different load levels. According to the water absorption test results, the Boltzmann variable is introduced in combination with the unsaturated capillary water absorption theory model, and the prediction and analysis method for the relative water content distribution in the damaged concrete is established, and the tool is provided for carrying out the transmission analysis of the harmful medium (such as chloride ions or sulfate ions, etc.) in the concrete.
【作者单位】：河海大学水文水资源与水利工程科学国家重点实验室;大连理工大学海岸和近海工程国家重点实验室;上海联创建筑设计有限公司青岛分公司;
【基金】：国家自然科学基金资助项目(51378090) 水文水资源与水利工程科学国家重点实验室开放研究基金资助项目(2013491711)
【分类号】：TU528

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