Reduction in ecology, environment, economy and energy in concrete industry using waste materials

Traditional concrete is a mixture of Portland cement, aggregates, water and admixtures. The principal binder in concrete is Portland cement, the production of which consumes high energy, costly, depletes natural resources and is a major contributor to green-house gases (GHG) emission that is implicated in global warming and climate change. Every ton of Portland cement production releases about 1 ton of CO2 into the atmosphere. If the world produces 3.5 billion tons of cement per year, it emits approximately the same amount of CO2 in the atmosphere every year, just from one industry. Moreover, concrete consumes more than 8 billion tons of aggregates every year, which also depletes the natural resources, thus causing additional problems to ecology and environment. On the other hand, millions of tons of agriculture, industrial and natural waste materials (fly ash, etc.,) are abundantly available in the world and are wasted every year. Most of them may contain one or more of hazardous and toxic chemicals from trace amount to several percentages. The majority of these unused wastes are dumped in landfills, quarries, rivers and oceans, exacerbating environmental concerns like air pollution, leaching into soil and water. Studies have shown that some of these waste materials have been and are being used successfully in all kinds of existing and future concrete structures by replacing cement, sometimes up to 70%. They reduce not only ecology, environmental pollution and energy but also produce stable, more durable and economical sustainable construction materials. This paper discussed the issues and solutions related to the reduction in ecology, environment, economy and energy in concrete industry using waste materials.