氯盐环境下钢筋锈蚀损伤混凝土应力应变本构模型

采用加速腐蚀试验,对氯盐环境下钢筋锈蚀损伤混凝土棱柱体试件的破坏形态、应力-应变全曲线、峰值应力、峰值应变、极限应变及弹性模量进行了试验研究.结果 表明:钢筋锈蚀损伤混凝土试件的破坏多为微柱失稳破坏,大致平行于受力方向的锈胀裂缝是主要的破裂面;钢筋锈蚀损伤混凝土实测应力-应变全曲线与未锈蚀损伤混凝土相似,但是随着钢筋锈蚀率的增加,其应力-应变全曲线上升段的斜率逐渐减小,峰值应变增大;钢筋锈蚀率越大的试件,脆性越明显;钢筋锈蚀损伤混凝土试件的峰值应力均低于未锈蚀损伤试件,峰值应变、极限应变随钢筋锈蚀率增加而增大,弹性模量随钢筋锈蚀率增加而减小;建立了钢筋锈蚀损伤混凝土应力-应变本构模型,模型计算值与实测值吻合较好.

Stress Strain Constitutive Model of Concrete Damaged by Rebar Corrosion in Chloride Environment

Adopting accelerated corrosion method, the failure mode, stress strain curves, peak stress, peak strain, ultimate strain and elastic modulus of the prismatic concrete specimens damaged by rebar corrosion were studied experimentally. Results show that the failure of corrosion damaged concrete specimens is mainly caused by the instability failure of micro column. The corrosion induced cracks which are roughly parallel to the direction of force are the main fracture surface. The measured stress strain curves of concrete damaged by corrosion are similar to that of uncorroded concrete, however, the slope of stress strain curve decreases gradually and the peak strain increases with the increase of corrosion ratio, the higher the corrosion rate of specimen is, and the more obvious the brittleness is. The peak stress of concrete specimens damaged by corrosion is lower than that of the uncorroded specimens, the peak strain and ultimate strain increases with the increase of corrosion rate, the elastic modulus decreases with the increase of corrosion rate. A stress strain constitutive model of concrete damaged by rebar corrosion is established, the calculated value of the model agrees well with the measured value.