The Cementitious Materials
Shen Weiguo, Zhou Mingkai, Wu Shaopeng( Key Laboratory of Silicate Materials Engineering of Ministry of Education, Wuhan University of Technology, Wuhan 430070 China )
The natural materials--clay and gingerstone were used in pre-pottery neolithic period;and lime--the earliest manmade cementitious materials were invented and used 9000 years ago.At 2500～3000B.C ,the gypsum-lime cementitious material was widely used;the lime-pozzolans was invented at early age A.D,this kind of material have very good durability.At the end of the 18th and the beginning of the 19th century,the modern Portland cement concrete was developed following the hydraulic lime's improvement. The Portland cement is famous for it fast hydraulicspeed. But the durability and environmental harmonization is very poor. The future concrete might have better durability and suitability to be made with low quality raw material,be easily recycled and be made with clean process.The geopolymer cement may be the most suitable cement for future.