不锈钢筋混凝土受压构件破坏机理与计算理论研究

Stainless steel can essential solve the corrosion problem of rebar of concrete structures for harbor and hydraulic engineering under severe environment, and remarkably enhance the durability of concrete structures. Because both the basic mechanical properties and stress-strain relationship of stainless steel differ obviously from those of common steel, it is urgent to study the mechanical properties and calculation theory, and to draw up design specification of concrete structures with stainless steel. Taking the compressive concrete members as the object of study, experimental, numerical simulation techniques and theoretical analysis will be comprehensively employed in this research, and the compressive failure mechanism and calculation theory will be studied for the concrete compression members with stainless steel. On this basis, basic assumptions will be presented for the calculation of concrete compression members with stainless steel, and the calculation model of bearing capacity for normal section of concrete compression members with stainless steel, the stresses of stainless steel, crack resistance and the checking method for crack width of eccentric compression members with stainless steel will be set up. By analyzing the bond failure mechanism between concrete and stainless steel, the bond strength and calculation method of bond stress distribution will be established, and the proposal of construction design will be given eventually for the concrete compression members with stainless steel. Expected results could make up the deficiency in both design method and calculation theory of concrete compression members with stainless steel, and provide a scientific basis for the application of concrete compression members with stainless steel.

不锈钢筋可从根本上解决恶劣环境条件下水工、港工等混凝土结构的钢筋锈蚀问题，显著提高混凝土结构的耐久性。由于不锈钢筋的基本力学性能和应力-应变关系与普通钢筋存在明显差异，因此，迫切需要对不锈钢筋混凝土结构的受力性能和计算理论进行研究，并制定不锈钢筋混凝土结构设计规范。本项目拟以混凝土受压构件为研究对象，综合运用试验研究、数值模拟以及理论分析等技术手段，深入系统地研究不锈钢筋混凝土构件受压破坏机理和计算理论。提出不锈钢筋混凝土受压构件计算的基本假定，建立不锈钢筋混凝土受压构件正截面承载力计算模型以及不锈钢筋混凝土偏心受压构件的不锈钢筋应力、抗裂度、裂缝宽度验算方法；分析不锈钢筋与混凝土粘结破坏机理，建立不锈钢筋与混凝土的粘结强度和粘结力分布计算方法；给出不锈钢筋混凝土受压构件构造设计建议。预期成果将弥补不锈钢筋混凝土构件设计与计算理论的不足，为不锈钢筋混凝土结构的推广应用提供科学依据。

不锈钢筋可从根本上解决恶劣环境条件下混凝土结构的钢筋锈蚀问题，显著提高混凝土结构的耐久性。由于不锈钢筋的基本力学性能和应力-应变关系与普通钢筋存在明显差异，因此，迫切需要对不锈钢筋混凝土结构的受力性能和计算理论进行研究，并制定不锈钢筋混凝土结构设计规范。本项目以混凝土受压构件为研究对象，进行了33根不锈钢筋混凝土柱的静力试验，并综合运用数值模拟以及理论分析等技术手段，深入系统地开展了不锈钢筋混凝土受压构件破坏机理和计算理论研究。得到了不锈钢筋混凝土柱的受力破坏形态以及裂缝开展与扩展、荷载~侧向挠度曲线、荷载~钢筋应变曲线、荷载~混凝土应变曲线等变化规律，提出了不锈钢筋混凝土受压构件计算的基本假定；分析了偏心距、混凝土强度、纵向配筋率和体积配箍率等对不锈钢筋混凝土柱受力性能的影响，建立了不锈钢筋混凝土受压构件正截面承载力计算方法以及不锈钢筋混凝土偏心受压构件正常使用极限状态验算方法；分析了不锈钢筋与混凝土粘结破坏机理及其影响因素，建立了不锈钢筋与混凝土的粘结强度和粘结力分布计算方法；基于细观力学方法，建立了不锈钢筋混凝土细观数值模型，模拟了不锈钢筋混凝土柱偏心受压试验过程，分析了配筋率 、偏心距、长细比、截面尺寸等因素对构件破坏过程及承载力的影响，较好地反映试验现象及规律；根据已有试验数据，借助ABAQUS软件建立了不锈钢筋混凝土柱的有限元模型，分析了混凝土强度、偏心距、纵筋配筋率、长细比等参数对其力学性能的影响，所得结果的规律性与试验结果吻合较好；根据试验研究结果并参考我国相关混凝土结构设计规范，提出了不锈钢筋混凝土受压构件构造设计建议等。预期成果将弥补不锈钢筋混凝土构件设计与计算理论的不足，为不锈钢筋混凝土结构的推广应用提供科学依据。