Cement, Energy and Environment

compressive strength of wood aggregate concrete depends on the strengths of the aggregate and the hardened cement paste, as well as the bonding of the aggregate/cement paste in the interfacial zone (Lee A we and Hong Z, 1986). The test result confirms and agrees with the other researchers. The maximum hydration temperature of neat cement and coconut shell fine cement composites is observed to be 73' C and 63'C respectively. The time to reach maximum temperature for neat cement is approximately 7 hrs and 10 minutes (430 minutes) (assuming that equal to final setting time)and that for the mix with CS fines is 9hrs and 50minutes (590 minutes). It is suggested that the maximum hydration temperature greater than 60'C, is considered suitable for aggregate/cement compatibility (Oiorunnisola, 2008). The maximum hydration temperatures values observed in this study are greater than 60'C and hence, it is compatible. From, Figure 7, the maximum slope of curve for neat cement and the maximum slope of curve for coconut shell fines-cement composites are 11.35'C/h and 7.55' C/h respectively. The inhibitory index (I) for coconut shell fines-cement composites is calculated as 2.59%. The calculated inhibitory index can be classified as low (less than 10%) and suggest that particles of coconut shell can be used to produce cement-bonded composites (Esmeralda et al 2004). Conclusions It was found that the CS fines-cement composite required more water for making standard consistent paste. The setting time of CS-fines-cement composite increases in the presence of coconut shell in finer form. The test on compressive strength reveals that cement quantity is to be enhanced to give the required compressive strength, If the CS fines are present with the neat cement mortar. The maximum hydration temperature for the mix containing CS fine was found to be 63'C and this value is greater than 60'C. Hence, it is compatible. The inhibitory index (I) for CS fines-cement composites is 2.59% and can be classified as low inhibitory. This test reveals that no pre treatment is required. The findings showed that particles of coconut shell can offer to use as an aggregate in concrete production. Courtesy: JCI Journal, April-June 2010. Pp27-30. India Country Profile CEMENT -STRONG BUILD-UP The demand for cement will grow at a CAGR(compound annual growth rate) of about 10-11% over the next five years, primarily driven by demand from infrastructure sectors. The proportion of demand for cement from the infrastructure segment is expected to increase from 17% between 2004-05 and 2008-09 to 33 per cent between 2009-10 and 2013-14. In addition an increase in independent housing projects in the semi-urban and rural areas will support demand for cement. Among all regions, the eastern region is expected to witness a maximum growth at a CAGR of 14%. Within infrastructure, we believe that road projects will be a key driver for cement consumption . But the pace of capacity addition is expected to slow down post-201 0-11. While growth in demand for cement is expected to be robust, we also expect significant capacity addition, going forward. We expect around 150 million tonnes of cement capacity to be added during 2009-14, out of which around 100 million tonnes will be added over the next two years, during 2009-11 . After 2010-11 , the pace of capacity addition is expected to slow. A majority of the capacity addition is expected in south India (around 42% of total). The operating rates are likely to bottom out in 2u1 0-11 . Due to significant capacity addition over the next two years, we expect cement operating rates to fall from 88 % in 2008-09 and bottom out at 78 % in 201 0-11 , before recovering to 82% in 2011 -12. Courtesy: The Financial Express New Delhi, 14.06.2010. CEMENT GIANTS EYE WEST ASIA TO PLUG OVERSUPPLY PROBLEM Oversupply and intense competition in the domestic market has prompted cement manufacturers to set sights abroad via acquisitions, especially in West Asia. However, the domestic cement demand is expected to rise by 8-10% this year. Industry experts suggest acquiring cement assets in West Asia currently may not augur well for Indian companies at a time when supply has overtaken demand in the Gulf region also. In India, competition in the sector is intensifying, with more foreign players eyeing the market and more capacities being added by small and mid 56 ~I