Cementitious binder of phosphogypsum and other materials

This paper presents the properties of a binder developed to produce eco-friendly building products. The mixing ratio of the binder, comprising phosphogypsum, slag (ground granulated blast-furnace slag), lime and cement, was obtained based on orthogonal experiments. The test results showed that, under steam curing, calcium silicate hydrate gel and ettringite were formed in the hardened binder, leading to a higher strength. After steam curing at 90°C for 7 h and then air curing, the 28 d compressive strength of the binder reached 41·7 MPa. Using this binder and river sand, bricks with a 28 d compressive strength of 21·4 MPa were successfully manufactured.