Historically, we only treat it as a hindrance, not a boon, for purposes of code stresses.

If increased stiffness exacerbates stresses and loads, you are incumbent to consider such effects within your analysis and route accordingly. Generally, increased stiffness is beneficial for piping, as long as poor piping practices are avoided.

I could envision that one could make a facsimile of cement coating by modeling the system as jacketed pipe, but there aren't any "cement" material options built in to CAESAR, which you'd need to research for yourself.