A TECHNICAL COMPARISON OF NANO-SILICA ADDITIONS IN BLENDED CEMENTS OVER ORDINARY CEMENT FOR BOTH SHORT & LONG TERMS

Abstract

The projected CO₂ emissions from the global cement industry through 2050 (assuming no change in current practices) are to increase (1.5^th times) from the present figures but as agreed by all nations (196 numbers) in Climate Conference in Paris (COP 21) on Dec.12, 2015 that it is mandatory for every nation to reduce CO₂ emission to the level 2005 by the year 2030.A tall order but Indian Government is confident. These CO₂ emissions have adverse effects as pollution-related syndrome like climate change on living beings and as environmental pollution-which needs to be mitigated at any cost. If corrective actions are not taken then, Times of India, Mumbai edition of 20^th September, 2013 rightly highlighted that “In 1.8 billion years Earth will become too hot as seas will evaporateâ€. The same paper in Mumbai edition of 21^st October, 2013 stated that “World average temperature will rise by at least 4°C by the year 2100 and at least by 8°C by 2200.†Cement industries is one of the largest sources of air pollutants i.e. it accounts for 51% air pollutants and 5% global CO₂ production. Also the farmers’ fields can be a bigger source of contamination than factory effluent if not checked properly as China reported in its first census on air pollution. Nanotechnology viz. nanomaterials has the potential to mitigate these effects. India has a major agribusiness sector which has achieved remarkable successes over the last three and a half decades and Rice husk ash, an agricultural waste material, is available in large quantities in the rice paddy growing countries of the world at little or no cost. Silica is the major inorganic constituent of the rice husk, and by carrying out an acid chemical treatment followed by the process of burning, it is possible to extract high-surface area amorphous silica (or Nano Silica (nS).