腐蚀钢绞线与混凝土的长期粘结蠕变性能试验研究

为探讨腐蚀对钢绞线与混凝土长期粘结蠕变性能的影响，制作6根先张法预应力混凝土梁试件，其中5根试件通过掺盐并置于不同环境中进行为期47周不同强度的长期腐蚀，期间对所有6根试件进行定期粘结滑移监测，得到各试件在预应力作用下的粘结滑移时变曲线。结果表明：在未发生锈胀开裂的条件下，腐蚀引起粘结强度增大，从而抑制了粘结蠕变，使腐蚀试件的蠕变滑移小于无腐蚀试件；而且，腐蚀率越高、腐蚀产物体积膨胀率越大，长期粘结滑移也越小。分析表明：如果腐蚀引起锈胀开裂并导致粘结强度退化，则会引起长期粘结蠕变及锚固段裂缝宽度的增大，但不会引起预应力损失及锚固承载力的降低。

EXPERIMENTAL STUDY ON BEHAVIOR OF LONG-TERM BOND-CREEP BETWEEN CORRODED STEEL STRANDS AND CONCRETE

To study the influence of steel strands corrosion on the long-term behavior of bond-creep,6 pre-tensioned prestressed concrete beams were fabricated,of which,5 beams were mixed with salt and set in different places to be corroded in different intensity for 47 weeks,and the bond-slip of all the 6 beams was tested periodically through the whole period,and then the time varying curves of bond-slip under prestressing were obtained.The results show that under the condition of no corrosion crack,the bond strength increases with corrosion and the bond-creep is restrained,which contribute the creep slip of corrosion beams being less than that of the uncorrosion beam.Moreover,with the increase of corrosion rate and corrosion products expansion ratio,the long-term bond-slip decreases.The analysis shows that if there are corrosion cracks and the bond strength deteriorates,the long-term bond-creep and the load cracks width in anchoring segments should increase,but the prestressing loss and the anchoring bearing capacity should not decrease.