Abstract: The developing cracks lead to the stiffness change of Partially Prestressed Concrete(PPC)beams.The width of cracks are controlled by the method of layout suitable non pre bar so that the serviceability of structures are controlled.The mechanism of cracks occurring is discussed according to the deformation theory and the corresponding formulae are gained.The calculation results are compared with the testing results. The cracking load levels and the cracking spaces of the calculation is fit to that of testing.More testing research and theory work are needed to do at the aspects of calculating the crack width.

Key words: partially prestressed concrete, reinforced concrete, cracks, deformation, beam

摘要： 部分预应力砼 (PPC)梁裂缝开展直接导致结构的刚度发生变化 .在使用荷载作用下,通过配置非预应力筋来实现控制裂缝的开展宽度,从而达到控制结构的正常使用性能 .采用变形理论探讨了裂缝发生的机理,推导出相应的计算公式,与已有的试验结果进行对比,开裂荷载水平和裂缝间距的计算值与实测值吻合较好,并指出计算裂缝宽度需要做进一步的试验研究和理论探索工作

关键词: 部分预应力, 钢筋砼, 裂缝, 变形, 梁