I want to cast my oven floor

[mikeye15]

Since my local fire bricks are very rough my next thought is to pour my own oven floor out of refractory concrete. I want a smooth spall free floor that wont shed material on my pizza. What are the pros and cons of doing this. Will the floor spall(peel) under heat. Does it finish like regular concrete. What is a recipe for refractory concrete. The rest of the oven will be firebrick. I only want to pour the floor. Thanks
Mike