Thank you for contacting AaE for help.

Here's what you might want to think about regarding the use of cement bricks or even concrete blocks to build a raised bed. An ingredient used in both materials is cement which contains lime (from limestone) which can raise the pH of soil if it leaches out into the soil. Ideal soil pH for crops is between 5.8 and 7.0. If the soil pH becomes too high (alkaline), plants lose the ability to take up needed nutrients.  Acid rain can cause leaching.   Acid rain isn't much of a problem here in the metro area so you're probably okay using cement bricks.  But if you're worried about the possibility of lime leaching in to your soils, you could consider lining the brick sides with some plastic.

Be sure to use new materials.  It's been pointed out that older bricks and cinder blocks were made with fly ash, the residue you get from burning coal, which is not recommended for use in vegetable gardens.

I hope this information helps.