Cement, Energy and Environment

Table-1 Selected coconut production statistics, 2005 14797 9500 3034 1500 972 950 Sri Lanka 890 Papua New Guinea 650 Malaysia 642 (Gunasekaran and Kumar, 200Ba). Almost, all over the world, various measures are taken to reduce the use of aggregates resorting to reuse and recycling the solid wastes, where it is technically, economically, or environmentally acceptable. As a result, in developing countries like India, the informal sector and secondary industries recycle 15- 20% of solid wastes in various building materials and components (Mathur, 2006). Presently in India, about 960 million tonnes of solids wastes are being generated annually as by-products from industrial, mining, municipal, agricultural and other processes. However, it is reported that about 600 million tonnes of wastes have been generated in India from agricultural sources alone (Asokan Pappu 2007). The major quantity of wasted generated from agricultural sources are sugarcane baggase, paddy and wheat straw and husk, vegetables wastes, food products, tea, oil production, jute fibre, groundnut shell, wooden mill waste, coconut husk, cotton stalk etc., Coconut is one of the most important tropical tree crops In the world. Coconut is grown in more than 93 countries In the world. The main coconut 27.3 30.4 17.5 1860 17.4 5.6 281 2.6 2.8 343 3.2 1.8 110 1.0 1.8 150 1.4 1.6 395 3.7 1.2 160 1.7 1.2 179 1.7 players in the global market for 2005 are shown in Table 1. Eight of the ten largest producers are in the Asia Pacific region. The three main producers, Indonesia, the Philippines and India account for 75 per cent of world production. India is the third largest coconut producing country, with an area of 1.9 million ha and annual production of 2.74 million tonnes copra equivalent (Warner et al., 2007). As per, Minnie Mathew, 2008, India is one of the leading coconut producing countries in the world. Coconut is cultivated over an area of 1.94 million hectares across the country, in that; approximately 90% of total production of coconut is concentrated in South India. Since, coconut shell has good durability characteristics, high toughness and abrasion resistant properties; it is suitable for long standing use. The shell is similar to hard woods in chemical composition; though lignin content is higher and cellulose content is lower. Because of its inherent characteristics of withstanding at high temperature, low burning and being floppy, it is widely used to manufacture insect/mosquito repellent coil, mouldings, abrasives, plywood, mica agarbathis, charcoal, activated carbon, shell powder and in plastic industries ( www.coconutboard.gov) . The new and alternative building construction materials developed using agro-industrial wastes have ample scope for introducing new building components. Coconut shell is one of the most promising agro wastes with its possible uses as coarse aggregate in concrete. This has good potential to use as an alternate material for crushed stones (Gunasekaran and Kumar, 2008b). However, the compatibility of CS particles with cement used as an inorganic binder during manufacture directly influences the physical and mechanical properties of concrete. Cement hydration is a complex reaction process requiring water, heat and an alkaline environment. Cement hydration, setting and hardening depend on wood extract concentration and not depend on wood species and preparation method (Jorge et al, 2004). Thus it is imperative to understand the compatibility of CS particles with cement for better utilization as a building material. This study is aimed at determining the technical feasibility of using CS particles and testing the compatibility with cement. Sourcing of coconut shell The coconut shells were collected from the local coconut oil mills (Figure 1). The fibers surround the coconut shells were removed and well seasoned. The seasoned coconut shells are crushed to required sizes in the range between 3 mm to 12 mm using the specially developed mini crusher installed at SRM University, Kattankulathur, Chennai, India (Figure 2). The sample of crushed coconut shell aggregate is shown in Figure 3. and Figure 4. 52