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预应力混凝土空心板梁是近几年来桥梁结构中常见的一种结构形式。以其抗弯、抗扭性能好,整体稳定性高,并有足够的混凝土截面来承受正负弯矩的作用等优点,近几年来适用于中、小跨径的桥梁结构中。经过近几年的施工实践发现,在空心板梁预制过程中,最多出现的质量问题就是空心板梁端部中间出现裂缝。如果裂缝得不到控制或处理不当,都将给空心板梁的强度和刚度带来一定的危害,甚至影响其使用寿命。因此,我们对空心板梁端部裂缝的成因进行分析,并且提出可行性处治方案。裂缝是混凝土结构普遍存在的现象,一类是由外部荷载作用引起的,称之为结构裂缝或受力裂缝,表示结构承载能力相对不足或者存在结构上缺陷问题。此类裂缝在结构设计时设计荷载考虑全面一些是可以防止的或者设计允许;另一类则是由于变形引起的,称之为非结构性裂缝,指变形得不到满足,在构件内部产生内应力,当内应力超过混凝土允许应力时,引起混凝土开裂,如混凝土表面的龟裂。在两类裂缝中,非结构性裂
Prestressed concrete hollow slab beam bridge structure in recent years is a common form of structure. Its bending, torsional performance, the overall stability is high, and have enough concrete cross-section to bear the role of positive and negative moment, etc., in recent years for medium and small span bridge structure. After several years of construction practice found that the most prevalent in the hollow beam precast process, the quality problem is the emergence of cracks in the middle of the hollow slab beam. If the cracks are not controlled or handled properly, it will bring some damage to the strength and rigidity of the hollow slab beam, and even affect its service life. Therefore, we analyze the cause of the crack in the end of the hollow slab beam and propose a feasible solution. Cracks are a common phenomenon in concrete structures. One is caused by external loads, which are called structural cracks or stress cracks, indicating that the structural load-carrying capacity is relatively insufficient or there are structural defects. Such cracks in the structural design of the design load to consider some of the overall can be prevented or designed to allow; the other is due to deformation caused, called non-structural cracks, refers to the deformation is not met, the internal components generated within Stress, when the internal stress exceeds the allowable stress of concrete, causing concrete cracking, such as concrete surface cracking. In two types of cracks, non-structural cracks