Clay brick, red brick, always fried brick how to do?
Small white stones, such as Magnesium Oxide and limestone (calcium carbonate). Take "containing limestone" (calcium carbonate) stones, after firing, into lime (calcium oxide), put a long time, absorb the moisture in the air, will cause the lime (calcium oxide) reduction, volume expansion, resulting in fried brick.
Red brick fired, try using a bubble, if not burst, you can use.
Clay brick and red brick are of very important quality and must not contain sand or gravel.
