Shear Strength of Continuous Lightly Reinforced Concrete Joist Systems

轻骨料混凝土构件在实际中得到了广泛的应用。尽管它们得到了广泛的应用，但关于这些构件的抗剪承载力的研究很少，特别是连续构件和托梁等带变截面腹板的构件。有限的研究表明，轻筋构件的抗剪承载力低于现行设计方法的预测值。因此，与钢筋混凝土结构的其他部件相比，这些结构部件的安全裕度似乎较低。目前的研究将确定连续、轻筋T型梁和托梁的抗剪强度。单腹板和三腹板构件都将进行测试。将考虑抗弯配筋率、抗剪配筋度和托梁之间的荷载分担的影响。将裂解剪与现有的经验公式和解析公式进行了比较。将估计混凝土、抗剪钢筋、销钉作用和骨料互锁对抗剪强度的贡献。将制定对当前设计表达式的修改。这项研究将填补目前认识上的一个重大空白，并允许制定合理的设计条款。这项研究将提高一类重要的钢筋混凝土结构构件的安全性。

Lightly reinforced concrete members are widely used in practice. In spite of their widespread use, there has been very little research regarding the shear capacity of these members, especially continuous members and members with tapered webs such as joists. Limited research indicates that the shear capacity of lightly reinforced members is below that predicted by current design procedures. Thus, these structural components appear to have a lower margin of safety than other components of reinforced concrete structures. The current research will determine the shear strength of continuous, lightly reinforced T.beams and joists. Both single web and triple web members will be tested. The effects of flexural reinforcement ratio, degree of shear reinforcement, and load sharing between joists will be considered. The cracking shears will be compared with existing empirical and analytical expressions. The contribution of concrete, shear reinforcement, dowel action and aggregate interlock to shear strength will be estimated. Modifications to current design expressions will be developed. The research will fill a major gap in current understanding and allow the formulation of rational design provisions. The research will result in improved safety for an important class for reinforced concrete structural components.