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预应力筋锈蚀后截面积减小,导致预加力损失。预压状态下的混凝土必然会发生弹性膨胀,其膨胀又受到预应力筋的约束,从而引起预应力筋和混凝土弹性变形的改变。考虑锈蚀过程中预应力筋截面积的减小,以及预应力筋和混凝土弹性变形的改变,对锈蚀预加力损失进行了计算。分析了预应力筋和混凝土弹性变形的改变对锈蚀预加力损失的影响,给出了剩余预加力的简化计算方法,并通过锈蚀PC构件抗弯试验对计算结果进行了验证。研究表明:预应力筋和混凝土弹性变形的改变对锈蚀预加力损失影响不大,采用预应力筋面积锈蚀率估算锈蚀预加力损失率的方法具有较高的精度。
Corrosion of prestressed tendons reduced cross-sectional area, resulting in loss of pre-force. The prestressed concrete is inevitably elastic expansion occurs, and its expansion by the prestressed tendons constraints, resulting in prestressed tendons and concrete elastic deformation changes. Considering the decrease of the cross-sectional area of the prestressing tendon during the corrosion process and the change of the elastic deformation of the prestressing tendon and the concrete, the loss of the pre-stressed corrosion force was calculated. The influence of the change of prestressing tendons and the elastic deformation of concrete on the loss of corrosion prestressing force is analyzed. A simplified calculation method for the residual prestressing force is given. The calculated results are verified by the bending test of the corroded PC member. The results show that the change of elastic deformation of prestressed tendons and concrete has little effect on the loss of corrosion prestressing force, and the method of estimating the loss rate of corrosion prestressing force by using the rate of corrosion of prestressing tendons has high accuracy.