what does this mean second phase in two phases material ( first phase is binding cement ) ?
First consider the term 'phase' as in 'phase change', such as ice melting. It means a particular state of matter, solid or liquid in the melting of ice. However, in an inhomogenous solid material you can have two or more solid phases. For instance, Transite insulation board was made of portland cement and asbestos [not in use much nowadays]. So what you have is some two phase inhomogenous solid consisting of one phase as binder or cement, and the other phase could be a filler, a fiber, or whatever.
