**6. Conclusion**

The concrete industry is a major contributor to air pollution and the user of natural resources. As such it bears a special responsibility to make a contribution towards sustainable development that is commensurate with its size. It can do so by pursuing three goals: (1) Searching for cement production technologies that are less energy-intensive and cause less air pollution. Since such technologies will not be available in the foreseeable future, the more realistic approach is to reduce the need for Portland cement, primarily by increased use of supplementary cementitious materials, especially waste materials. (2) Replacing concrete ingredients with recycled materials, such as recycled concrete or waste glass. (3) Through careful concrete mix design and prudent choice of admixtures, improve the durability of structures such that they need to be replaced less frequently.

In addition to this, sustainable construction makes wise use of all the natural resources and a 50% reduction in energy use, improves occupant health, comfort, productivity, reduces pollution and landfill waste that is not easily quantified, a sustainable building may cost more upfront, but saves through lower operating costs over the life of the building, construction is designed as one system rather than a collection of stand-alone systems with the help of the integrated system approach. Saying all this, I recommend to researchers make material characterization on those potential cement replacing materials.
