箍筋锈蚀混凝土棱柱体试件轴心受压试验研究

Experimental study on reinforced concrete prism specimens confined by corroded stirrups

通过电化学方法对方形箍筋约束混凝土棱柱体试件内箍筋进行了实验室加速腐蚀试验,得到了箍筋锈蚀程度不同的锈蚀试件,并进一步开展了箍筋锈蚀混凝土棱柱体试件的轴压试验,研究了箍筋锈蚀对混凝土棱柱体试件破坏形态的影响,分析了箍筋锈蚀造成的混凝土损伤。试验结果表明:箍筋在角部锈蚀严重,混凝土保护层锈胀裂缝在角部沿竖向发展,且随着锈蚀程度的增加,裂缝宽度加大;锈蚀产物在混凝土保护层与核心区混凝土界面上的堆积,降低了混凝土保护层对构件承载力的贡献;箍筋锈蚀程度对试件的裂缝发展速度、破坏形态均有影响,箍筋锈蚀越严重,裂缝发展越迅速,核心混凝土的破坏程度愈大,斜向破坏面愈明显,混凝土试件的破坏形式从延性破坏向脆性破坏转变。

The corroded reinforced concrete prism specimens confined by the square stirrups,which were subjected to accelerated corrosion,were obtained.The axial compressive test of the corroded reinforced concrete prism specimens and contrasted uncorroded reinforced concrete prism specimens was carried further.The effect of corrosion of stirrups on the deterioration form of reinforced concrete prism specimens and the concrete damage were analyzed.The results of axial compressive test show that,the corners of stirrups are corroded very seriously and the cracks of the protective layer are developed along the vertical direction at the corner of the reinforced concrete prism specimens,cracks widthes increase with the increase of corrosion degree.The ＂piling up＂ of corrosion products between the concrete cover and the core concrete zone reduces its contribution to the capacity of reinforced concrete prism specimens.The corrosion rate of stirrups has influenced directly on the development speed of cracks and the damage mode.The growth of cracks speeds up,the damage of the core concrete is more serious,the destroy incline section is more obvious and the deterioration form of the samples shift from ductile failure to the brittle failure,as the amount of stirrups corrosion grows.