Sustainability of the present mode of production and consumption of building materials and currently adopted construction practices is questionable. Similar arguments arise for the case of aggregates (both coarse and fine aggregates) where natural stones and rocky outcrops as well as river beds are exploited indiscriminately. It has been estimated that 300 mm depth of fertile top soil of the entire county will be consumed for burnt clay brick production in about 60 years (assuming a compounded growth rate of 5%). Apart from meeting the energy demand, the material resources for the sustainable growth is another important aspect. Indian construction industry is growing at an alarming rate (>8% per annum). Energy consumption in the manufacturing and transportation of building materials is directly related to GHG emissions and the related environmental consequences. Energy resources include electricity, coal, oil and gas, biomass, etc. Basic raw material resources include soil, stones, sand, timber/tree products, minerals, chemicals, etc. The figures indicate that during 20 years, the CO 2 emissions from cement/clinker production have more than doubled, inspite of improvements in energy efficiency in the manufacturing process as well as the use of blended cements.Įnergy and raw materials are essential for the production of building materials and products. These numbers are based on the data from. Cement production and CO 2 emissions for global and Indian conditions are displayed in Table 3. Currently, GHG emissions from construction sector could be 30%. It has been estimated (in 1991) that 22% of green house gas (GHG) emissions is contributed by the construction sector in India. Total energy expenditure on these materials consumed in bulk quantities is 3155 × 10 6 GJ per annum. Quantity of materials produced and the energy consumption are based on the reports and papers and some estimates. Quantity of materials produced, their raw materials and energy expenditure are provided in the table. Materials produced and consumed in bulk quantities are listed in Table 2. Large variety of materials are manufactured and consumed in the building industry. Indian construction industry is one of the largest in terms of volume of raw materials/natural resources consumed and volume of construction materials/products manufactured. This paper focuses on certain issues pertaining to the energy, carbon emissions and sustainability of building construction with particular reference to Indian construction industry.Ģ ENERGY AND MATERIAL RESOURCES IN THE INDIAN CONSTRUCTION SECTOR Indiscriminate use of natural resources and energy-intensive process for the building materials will not lead to sustainable options. In the context of carbon emission reductions and the issues of global warming, there is a need to pay attention to use of modern building materials with reference to (i) energy intensity of materials, (ii) natural resources and raw materials consumed, (iii) recycling and safe disposal and (iv) impact on environment. These modern materials are energy intensive and are hauled over long distances before being used for construction. As we moved away from zero energy materials to more modern materials for the construction activities, it became imminent to spend more energy and natural resources. Thus, the journey through the developments in the building materials and technologies is traced in Table 1. Later on plastics and plastic products entered the construction industry. Portland cement and steel brought revolutionary changes in the construction practices since early part of twentieth century. Discovery of natural inorganic binders like pozzolanic materials resulted in lime-pozzolana (LP) cement and this paved the way for the invention of Portland cement in 1824. Metal products, lime and lime-based products represent the other manufactured energy-consuming materials used for the construction. Brick burning represents one of the earliest examples of using thermal energy to manufacture durable building materials. lead to the exploration for durable building materials ever since the man started construction activity. Some problems associated with the durability of the natural materials like soil, thatch/leaves, timber, etc. Hardly any energy is spent in manufacturing and use of these natural materials for construction. The art and science of building construction commenced with the use of natural materials like stones, soil, thatch/leaves, unprocessed timber, etc. Building materials and technologies, and building practices have evolved through ages.
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