Beam stiffness degrades with its age in service and its service performanc e is weakened. According to the fundamental characteristics of the reinforced co ncre te, the influence of stiffness degradation caused by different kinds of damage i s obtained. Among them, the crack is the most direct and obvious factor. Further more, according to the analysis of bending rigidity formula presented in current stan dard, an influence parameter of crack development on the stiffness degradation, i.e., nonuniformity coefficient of tensile steel strain φ, is extracted. Av erage crack distance and crack depth are taken as crack statistic parameters. Based o n analysis and modeling with ANSYS, the modified bending rigidity formula relate d to crack is obtained.
Keywords:
Project Supported:
Supported by the Communication Scientific Research Project of Jiangsu Province(06Y21).