Cement, Energy and Environment

Concrete has become by far the most popular and widely used construction material in the world. In fact Concrete is not just another material, it is surpassed only by water as the most used material on earth. Concrete is perceived and identified as the provider of a nation's infrastructure and indirectly of its economic progress and stability, and indeed, of the quality of life of their people. Concrete is easily and readily prepared and fabricated in all sorts of conceivable shapes and structural systems in the realms of infrastructure, habitation, transportation, work and play. Its great simplicity lies in that its constituents are most readily available anywhere in the world. When a material becomes as integral to the structure as concrete, it is important to analyse its environmental impacts to conclude if the material is as sustainable as it is prevalent. If the material does not satisfy the credential of sustainability , it should be a matter of concern especially in present society when people and authority are more conscious environmentally . In 1987, the World Commission on Environment and Development defined sustainable development as Development that meets the needs of the present without compromising the ability of future generations to meet their own needs and later on at the 1992 Earth Summit in Rio de Janeiro as Economic activity that is in harmony with the earth's ecosystem. As a matter of fact concrete related activities consume gigantic quantum of non- renewable resources both in direct and indirect manner. It is heartening to hear that corrosion of steel in concrete shrinks the life span and serviceability of large number of structures. A huge sum of national wealth is spent for repairs and rehabilitation of concrete structures. Ever increasing problem of early aging & short life cycle of concrete structures has been adding to the huge volume of restoration, repair & rehabilitation works. Additionally, high volume of structural repair works consume huge quantum of non-renewable resources. Thus, to make concrete and built structures sustainable has to make it more durable or more emphasis has to be given to the durability right from the designing stage of structures. Important goals of a concrete structure are: 1. Safety 2. Economy 3. Durability & 4. Sustainability. Safety, Economy and Sustainability are functions of Durability. Hence, achievement of Durability is most critical and important in concrete construction. Durability : A durable concrete structure is one that performs satisfactorily in the working environment during its anticipated exposure conditions during service (IS 456-2000). Durability depends on two main factors: a) The concrete system & b) The service environment a) Concrete system is based on • Quality and quantity of materials used and • Processes involved in manufacture of concrete. b) Service environment affects concrete by way of SUSTAINABLE CONCRETE – AN INEVITABLE NEED FOR PRESENT & FUTURE R K Jha, GM [CTS], JK Cement Ltd 27