In fact it is not normal that the RAID volume needs to be reinitialized all the times that the system boots resetting all the partition(s) that have been previously created.
At this moment, keep in mind that Intel(R) Rapid Storage Technology 10.6 has not been validated for Windows* Server 2011, so this could be a driver compatibility issue.
Take under consideration that this is a software RAID solution, so everything runs through the driver on the operating system, and if it not validated to work properly, is not guaranteed to be stable.
In the other hand, a hardware RAID solution would be definitely an improvement in many levels, so if you have the change to use one, check for one compatible with the platform you are using. For information on our hardware RAID solutions and more information about them you can refer to: