CEE Oct-Dec 2002

a) b) c) d) e) and the debate of th e Committee for the last few years and the changed perceptions in the cement industry. The fl oor was then thrown open for di sc uss ion s, where the follow ing 0 bse rvat ions were made: The view that gradation or PPC would be needed for larger utilization of !ly ash f) comme rci a ll y the di fference bet\\een 33 grade and 43 grade ofOPC was of the order of only Rs 2 per bag at present. Some ceme nt manufacturers have 33 grade OPC as their main line of manufacture as 33 grade IS ve ry much required for construction of small houses. and thus help in resolving g) On behalf of th e cons ume rs. the v1ew expressed was that hardly anybody used 33 g rade OPC these days; also, there was hardly any difference between 33 grade and 43 grade of OPC when obtained from market. env iro nmental prob lem, was debatable as the total quantity of fly ash used in blended cements is only a small proportion ofthe total quantity of fly ash produced by the thermal power plants in the country. Lower grades in blended h) 3 3 grade should now be removed as it was substantia ll y substandard as per Internationa I Standards. cement s would util ize higher amount of !ly ash: howeve r. there co uld be other valid reasons for considering gradation or PPC. There have been, over the yea rs, several proposals for g rading PPC (and even PSC) from several cement manu ract urers numbe r of org.anizat ions. and a ot her The proposal for gradation of PPC had been pending since 1994. and after the intense debate fo r the last fe'vv yea rs , mo st of the major producers of cement such as Guj arat Ambuja Cement s Ltd. Grasim In dust ri es Ltd and The /\ssociatcd Cement Company Ltd '"'ere nO\\ in favour or the gr:tdation or PPC and PSC. Now PPC is being used widely replacing ore. 33 grade ore was not being accepted these days by majority or consumers due to vario us reasons; even i) Consumers require higher grades of PPC and PSC. j) In view o f the WTO 1\grecment, we should be bringing out standards in Iinc with the International St2.ndards. k) A view is he ld that the Indian 33 Grade OPC might be equivalent t.o 21.2 MPa when tested as per EN Standard. I) The /\II India Mini Cement Pl ant s Association has formed the said view that even mini cement plants could not produce 33 grade cement as their plants we re quite modern and suggested dele tion of JJ grade from OPC. m) 33 grade cement would continue to be manufactured by those havi ng marginal limestone. In the light o f the views expressed by the members, the Chai rman Dr. H.C. Visvesvaraya 38 said that in late fi flies or so. a survey of cements produced in the country was clone and one grade of OPC was agreed to and it ha s been serving all the purposes as at that stage 33 grade was very relevant; si nce then4J and 53 grades ofOPC have bee n introduced and n0w produc ti on of 33 grade was considerably reduced. In view of th is. the situation needed a review and any final conclusion arrived at should rcnect the change in the expec tations of th e users "vhilc balancing the same in terms of the tech nological feasibil ity, and the manufacturi ng considerati ons. lie stressed that the real cost of cement should be estima ted in te rms of performance, such as de Iivering maximum performance for a given weight or vol ume. In this context. the Chairman informed that it \\CIS India which introduced 33 Graefe (JJO kg/cm 2 compressive strength) firs t and wonde red if thi s what inspired adoption ofJ2.5 MPa as a benchmark for strength by the West. I le said that in I 456: 2000 what had been done for concrete was to remove M I5 for RCC, but provide for an enabling provision to still use M I 5 Grade concrete in certain s ituations. He said, these are the ways the Committee should provide the leadersh ip and show the way from time to time and also fore see the development <1 nd prov ide enabling. g uid e li nes to effect th e changes whenever needed. The Chairman further pointed out that. considering the changed scenario, whe re industry has most mode rn p lants. tec hniques, knowledge and trained manpower. and excellent capacity lo make best quality cement. 131 S as a National tandards 13ody or the country has the responsibility to positively react to the changed s ituation. to the advantage of all concerned, speciall y the users. who should get the best, as a fruit of ind ustr ial ...