The role of nano-particles in sustainable development of concrete industry

Most of the environmental investigators believe that the recent changes in climatic condition around the world arise from greenhouse gases. The detrimental effect of these gases on ozone layer leads to warmer climatic conditions and causes undesired climatic changes whose most obvious results are drought and famine. Carbon dioxide is one of the most important greenhouse gases forming almost 82% of these harmful substances. On the other hand, since approximately 5% of the annual mass of CO2 made by human activities is a direct product of the process of manufacturing clinker in cement factories, this process is one of the producing sources of CO2 on the earth. The nano-science and technology, which is called a scientific revolution, is serving us in different forms helping in our routine life. This issue can be seen clearly in the application of nano-technology in the development and construction of a high range of substances and materials. Alongside, nano-particles which are a result of nano-technology, combined with cementitious materials, have succeeded to affect the structure and develop the properties of cement based materials. Accordingly, by awareness of the data previously discussed, the objective of this research is reducing the amount of cement in high strength concrete by using nano-particles as a replacement of cement. Reduction of cement usage is a symbol of sustainable development and application of nano-particles is a mark of nano-technology helping us in the same direction to make a brighter future. In this study, the properties of concretes made by reduction of cement (including 10%, 20% and 30% of cement content) and combination of silica nano-particles (including 1%, 2% and 3% of cement content) are investigated. The conducted tests include measuring the fresh concrete density, compressive strength, splitting tensile strength and microstructure of Interfacial Transition Zone (ITZ).