2010年7月8日星期四

are there different types of portland cement ?

and 111A are cement us to make air-entrained concrete , They have the same properties as types 1234 , except that they have small quantities of air entrained material comvined with them


white portland cement is made from raw material conrtaining little or no iron or manganese m the substances that give conventional cement its gray colour .

没有评论:

发表评论