Cement, Energy and Environment

48 Applicability & Durability Issues of Nanomaterials in Cement Mainak Ghosal PhD Research Scholar, Indian Institute of Engineering Science & Technology, Shibpur Arum Kumar Chakraborty Associate Professor, Dep’t of Civil Engineering, Indian Institute of Engineering Science & Technology, Shibpur Abstract Nanomaterials due to their smaller size exhibits many novel properties which may be absent in their conventional bulk material sizes. Cement is the most standard material among all of the materials used in cement concrete constructions and is the only binding medium. This Paper brings out the various beneficial aspects of nanomaterials when they are applied in ordinary cement mortar. Nanomaterials viz. NanoSilica (nS), Carbon Nanotubes (CNT) and Nano Titanium Dioxides (n-TiO 2 ) are non-virgin materials but when applied to a virgin cement medium like OPC not only enhances the mechanical properties but also increases the volume stability of cement-mortars to larger extent.Geo-polymers which are very low workability binders having no cement content, has their workability enhancement with nanomaterials. Introduction What a ‘Nano’ is? Is it ‘Tata-Nano’? Could anyone tell why it is called ‘Nano’? These are the pertinent questions which come into everyone’s mind when they hear about anything called ‘Nano’. ‘Nano’ as it aptly called, is so as it was the world’s smallest car invented till now. That was the marketing side of ‘Nano’ but this Paper discusses the scientific part of it as applied in cement constructions. ‘Nano’ is a Greek word which means ‘dwarf’ having dimensions in the order of 10 - 9 m.Nearly fifty years ago, Richard Feynman who is nicknamed as Albert Einstein-II of this century, is also known as the father of nanotechnology-the technology involving the manufacturing and manipulation of atoms. The construction industry was the only industry to identify nanotechnology as a promising emerging technology in the UK Delphi Survey in the early 1990s… (“Application of Nanotechnology in Construction”, Materials and Structures , 37 , 649 (2004), Springer).But now other industries like tyres, paints, medicines etc have paced ahead lagging construction industry behind. With the on-coming of the 4th industrial revolution as explored by Professor Klaus Schwab, Founder and Executive Chairman, World Economic Forum, also brings up the huge promise of the potentiality of nanotechnology and nanomaterials. Use of CNTs [4][5][20],have produced remarkable improvements in the mechanical properties of cement concrete on account of their crack bridging effects at the nano scale[7] and nucleation effects in the formation of different cement hydrates[6][17] and have replaced the state-of-the-art technologies using fibers which mainly includes steel bars[18], steel fibers[8][14][20],glass fibers[2][12],carbon fibers[24],polypropylene fibers[1][10],and various others[3].Literatures [9],[11],[13],[15],[16][21]&[22] are abound highlighting the importance of nano additions in cement concrete. Figure 1: Effect of nanotechnology & nanomaterials in construction sector