大直径缓粘结预应力技术及应用的研究

Research on Prestressed Technology and Application of Large Diameter Reboot

缓粘结预应力技术是一种结合了无粘结、有粘结预应力两种技术优势的新型技术。赣州西站采用规格21.8mm的钢绞线断面面积是常用规格15.24mm的2.2倍。直径加大后预应力钢绞线表面形状、应力、摩擦系数、传递长度和受力性能等均可能发生变化。文中针对钢绞线直径变化对钢绞线摩擦系数的影响,对规格15.24mm、21.8mm钢绞线进行张拉试验研究。试验得出直径15.24mm与21.8mm钢绞线局部偏差系数κ分别为0.0040和0.0028,曲率摩擦系数μ分别为0.043和0.047。随着直径的加大,摩擦系数无影响。

Retard-bond prestress technology is a new technology which combines the advantages of unbonded and bonded prestress. The steel strand with specification of 21.8 mm is adopted in Ganzhou west station, and the cross-sectional area is 2.2 times of the common specification of 15.24 mm. After the diameter is increased, the surface shape, stress, friction coefficient, transmission length and stress performance of prestressed steel strand may change. Aiming at the influence of the change of steel strand diameter on the friction coefficient of steel strand, the tensile test of 15.24 mm and 21.8 mm steel strand is carried out in this paper. The local deviation coefficient of steel strand with diameter of 15.24 mm and 21.8 mm is obtained from the test κ They are 0.0040 and 0.0028, respectively μ 0.043 and 0.047, respectively. With the increase of diameter, the friction coefficient has no effect.