In the attached file, what is the tension in rebar come from? What is the plane of tension force? What is the shear plane? How program recognize amount of rebar in tension? Requirement and provided? Is the provided rebar in tension is how many rebar shown in the model? Why As, requirement/ As, provided ratio is different in tension development length and shear friction?
Hi Tracy,
Even though there's only shear force in your design, this will still cause a tension load in the shear plane. As shear forces extend across the shear plane, the bars are stretched which creates clamping forces across the shear plane. In ACI 318-19 Chapter 25, the development is in either in tension or compression, not shear. Section 3.2 is how much to develop the bar whereas 3.3 is how much to transfer the shear.
Please see the snip below for the design assumptions of the area, this can also be viewed in your design file. In 3.2 and 3.3, they are referring to different chapters in the code. 3.2 is As(requirement)/As(provided) whereas 3.3 is Avf.
Regards,
Ashley
