Cement, Energy and Environment July-Sep 2002

When demand-supply factors are in fu ll play, the situation is such that prices cannot but be under pressure. Established and unknown names set up cement capacities to capitalise on the expected rapid growth demand. The capacities duly came up. But what did not is demand. Jn the last five years, around 50 million tonnes of fresh capacit ies have been created. This has pushed the capacity with large players up to I29.43 million tonnes. With another 7-10 million tones in the hands of mini– cement plants, the aggregate capacity is way ahead of 2002-02 demand leve ls of 102.4 million tonnes, with a growth of 9.4 per cent. But for the late surge, the demand may have been stuck at around 95 million tonnes. The growth surge was useful in a year when around 13.5 million tonnes was added to the capacities. If a reasonable demand-supply balance has to be restored, the industry wi II need two-three years of 9- I0 per cent growth in demand. The capac ity story has dampened profitabil ity. It has made times diffi cu lt for smal ler players with capac iti es of I-2 million tonnes. Onl y the likes of Gujarat Ambuja, Grasim, L&T, ACC and Madras Cements have managed to weather the difficult times without too much trouble. But even th ese companies have not been able to s how sustained ea rnings g rowt h. ll owever, over the next three years, there is likely to be higher degree of di scipline vis-a-vis capacity creation. Investors in the equity market and lenders are likely to be wary or finan cing new projects by smaller players. Capac ity additions can happen onl y with L&T-Gras im , Madras Ceme nts, ACC-Guj ara t Ambuja and Zuari-ltalcementi. At best4-5 million tonnes may come up in the next couple of years. These players are likely to go about capac ity ex pansion in line with likely demand trends rather than in a rushed manner. This, coupled with the consolidati on, could lead to more stable trends in prices if the demand-supply gap is narrowed in the next two years or so. Then we may see major players show ing hea lthy profit levels and decent growth over time. Only then will be companies reap the benefits of consolidati.on . Courtesy: Indian Cement RevielV, Jul 02, P 23. Tel: 022-2076918; Fax: 022- 2072 tn2 HIGH PERFORMANCE CONCRETE Dr. N. Bhanumathidas, Advisor - R&D, RRDC. N. Kalidas, Director, JNSWAR£8 , Vishakhapatnam It is a well known fact that the ratio of concrete to steel is decided based on the conc rete grade st rength , subject to limitations whereve r app li cab le. Whil e the stru ctural practice was confined largely to M I5 to M30 concrete, in order to rationalise the concrete in mass ive construct ions HPC is developed with strength class of M 40 and above. For this purpose, three aspects were take·n as the advantage: • The increased grade strength of cement • The in c rease in cement content • Advent of chem ic a l admixtures to contro l water cement ratio Whi le the contribution due to chem ica l admixtures is notable during the prepa rat ion and placement orconcrete, the same gets nullifi ed on durability front on account of detrimental effects of high grade cements. There are two negative features associated with high grade cements viz., high heat of hydration and high surplus lime. These are surmounted with higher quantity of cement in HPC to achieve higher strengt h. Then the investigations revealed that: • Strength should not be the on ly criterion for high performance. Strength alone cannot ensure durability. • • What is requ ired is high sustainable performance but not high performance alone. To meet the above parameters the fo ll owing factors of ceme nt chemistry have been taken into consideration: • R.eduction in hea t of hydration and surplus li me in order to increase the envi ronment for durability. • For this purpose, the input of net cementitious mate rial is the c riterion but not the • • • cement. This means, the OPC need to be s ubs titu ted wi th com pl ementa ry cement materi als (CCM) such as fly ash, slag, si li ca fume, rice husk ash etc, in order to meet the net cemen t input fo r th e mix design of concrete. When supplementary cement mate ria ls are added, the reactive constituents of these materials react wi th surplus hydra ted lime of OPC to render additional (secondary) mineralogical hydrates an d commensurate strength. Secondary mineralogical hydrates he lp to densify the matrix, fi II up the pores and thus, contribute for durability enhancement. ( ·ourle.ly : 1\ la/erbuilder, Apr.-.\lay 02. P 85- f{r Fax:8529159 Email: dicomnet(t:j,l• .ml.com /Veb: ll'll'll'. masterbuilderindia.com INDIA ANI> THAILAND TO BE LINKED BY ROAD Orbit- World, 31 Jut o2 t\ landmark road project to m