ABSTRACT
A l s o down t o the pH 3.5-4.0 the alumina g e l i n t h e aluminous cement paste i s not soluble and i t i s s t a t e d t h a t i t i s f o r t h i s reason t h a t i t i s stated t o be r e s i s t a n t t o t h i s l e v e l of a c i d i t y . I n t h i s aspect the absence of calcium hydroxide i n t h i s paste i s also of great importance. I t i s well known that h i s phase undergoes r a t h e r r a p i d t r a n s f o r m a t i o n s i n c o r r o s i v e s o l u t i o n s .
