盐渍土地区聚丙烯纤维混凝土柱性能劣化机理与地震损伤模型研究

盐渍土侵蚀环境下混凝土结构腐蚀开裂、钢筋锈蚀等病害致使结构承载性能显著退化，强震下在役混凝土结构的安全隐患十分突出。针对上述问题，本项目将聚丙烯纤维、工业废料锂渣掺入混凝土，以改善混凝土结构的耐久性和力学性能，采用实验室加速腐蚀和盐渍土暴露站腐蚀相结合的方法，系统研究盐渍土地区聚丙烯纤维混凝土柱的抗震性能。通过现场原位研究新疆盐渍土地区混凝土结构性能劣化的主要因素，开展加速腐蚀试验，分析腐蚀损伤后钢筋、聚丙烯纤维混凝土及界面粘结滑移的退化力学性能，提出腐蚀损伤材料本构模型；根据荷载-环境耦合下聚丙烯纤维混凝土柱的拟静力试验，研究轴压比、龄期、纤维掺量对该类新型混凝土柱抗震性能的影响，分析聚丙烯纤维混凝土柱性能劣化机理，建立其地震损伤模型和抗震设计方法，结合盐渍土暴露站足尺纤维混凝土柱抗震试验结果，提出在役纤维混凝土柱抗震性能评估理论。研究成果对新疆盐渍土地区混凝土结构防灾减灾具有重要意义。

The load-bearing capacities of existing concrete structures deteriorate due to reinforcement corrosion and concrete cracking under saline soil aggressive environment attack. Thus, it is a great threat to the safety of exsiting structures located in the earthqauke prone area. Aiming at these problems, the durability and mechanical performance of concrete structures are expected to be improved by involving polypropylene fiber and industrial waste named lithium slag into concrete material, subsequently the seismic behavior of polypropylene fiber reinforced concrete columns will be addressed systemically by combining the laboratory accelerated corrosion test and saline soil exposure test. Firstly, the main factors that effect the performance deterioration of existing concrete structures located in saline soil area will be analyzed by detailed on-site survey of the structures in Xinjiang. Then, the deteriorated mechanical property of corroded steel bars and corrosion damaged polypropylene fiber concrete together with bond-slip interface model will be analyzed using accelerated corrosion test. Based on the pseudo-static test of polypropylene fiber reinforced concrete columns under the coupling of load and environment attack, the factors including axial compression ratio, age, and fibers content affecting the seismic behavior of polypropylene fiber concrete columns will be analyzed. Moreover, the performance degradation mechanism of polypropylene fiber concrete columns will be put forward. Afterward, seismic damage model and design method of polypropylene fiber reinforced concrete columns are established. Finally, the seismic performance assessment theory on existing fiber reinforced concrete columns will be presented based on the pseudo-static test results of full size polypropylene fiber reinforced concrete columns corroded by saline soil exposure. The study has a great significance on the disaster prevention and mitigation of concrete structures in Xinjiang saline soil area.