ABSTRACT
Abstract Concrete is the most widely used construction materials: more than 2 tonnes of concrete were produced for every person on the planet. As the use of concrete will increase in the future due to the development do urbanization in developing countries, time has come to look at cement and concrete to environmental point of view; cement and concrete manufacturing is producing 8 percent of the annual amount of CO2 release in the atmosphere. The challenge is not to limit or forbid the use of concrete but rather to make more concrete having a lower impact on the environment. Different technological tools are already available but they have not yet received the attention they deserve. The three more promising avenues that can be implemented very rapidly are: • a more efficient use of portland cement involving the use of chemical admixtures and
supplementary cementitious materials; • the production of low energy-intensive cement and/or cement with a lower lime
content; • recycling concrete.
