不同因素对缓粘结钢绞线摩擦系数的影响

Influence of different factors on friction coefficient of slow bonded steel strand

控制缓粘结预应力钢绞线的摩擦损失,对建立有效预应力,保证结构安全有着非常重要的影响,通过开展缓粘结预应力混凝土梁的摩擦损失试验,从定性或定量的角度分析了钢绞线直径、缓凝粘合剂、钢绞线弯曲角度以及施工过程中常采用的张拉措施对摩擦损失的影响。结果显示,钢绞线直径、弯曲角度和张拉措施对摩擦损失的影响较为明显,而张拉适用期内的锥入度则几乎没有影响。可根据此结论,布置合适规格、合理弯曲角度的钢绞线以及采取合适的张拉措施来降低摩擦损失,以建立满足要求的有效预应力,保证结构安全。

Controlling the friction loss of slowly bonded prestressed steel strand has a very important impact on building effective prestress and ensuring structural safety.Through the friction loss test of slowly bonded prestressed concrete beam,this paper analyzes the influence of steel strand diameter,retarding adhesive,steel strand bending angle and tensioning measures often used in the construction process on the friction loss from a qualitative or quantitative point of view.The results show that the diameter of the steel strand,bending angle,and tensioning measures have a significant impact on friction loss,while the cone penetration during the tensioning application period has almost no effect.Based on this conclusion,appropriate specifications and bending angles of steel strands can be arranged,and appropriate tensioning measures can be taken to reduce friction losses,so as to establish an effective prestress that meets the requirements and ensure the safety of the structure.