Crab shells in raised beds

I will be happy to have feedback on this: today my Albertson's had fresh Dungeness Crabs for the giveaway price of $2.99 a pound- I haven't seen that in more than 8 years! So- I bought 8 big ones. I have 4 shelled, and took my old Vita-Mix and pulverized the shells in water. Made about 2 gallons, which I put in plastic coffee cans to freeze until I use. Please give me some help about how to incorporate this into my raised beds. In the past I have added small amounts to trenches in the off season and mix it in before planting time. I don't have the luxury of a real compost bin or pile, so I have to do it some other way. What will the shells add to my existing soil?