New guy with a dumb question

[runawaygun762]

Let me start by saying I'm a soldier, not a contractor, and I know next to nothing about construction, but I'm trying to learn.

Don't think me a kook or anything, but I plan to build a beefy underground shelter with room for stored goods. There are a few reasons, but the primary reason is that tornados and winter storms have been known to kick our butts where I live in southern Missouri, and living in the sticks doesn't make it any easier.

I have a set of plans for a reinforced concrete shelter that calls for 19.1 cubic yards of 4k psi concrete, which I understand is kinda the standard strength concrete. Is 5k psi going to provide better protection for the money, or is that too costly considering the shelter is going to be underground and not directly impacted by a tornado anyway?

I appreciate any assistance you folks can provide and look forward to snooping around here, learning more things outside my normal fields of expertise.

[rwanders]

I'm not an engineer but, I believe the standard mix would be fine-----thickness and reinforcement of walls and roof would be more critical factors to consider. The door design and it's attachment and latch mechanism may be another critical design element.