You can model an simple RC beam easily. There are many constitive model of concrete to select for your study aming.Such as concrete damaged plasticity (CDP) model, concrete smeared cracking (CSC) model. And the reinforcement can be adopted an ideal elasto-plastic material.
If you want to get the details, you can search the HTML documentation in the ABAQUS.
there is not any video about reinforced concrete structure modelling on you tube.. i am searching from 2 days.. if you have any video procedure about it.. can you please give the URL or something to me?