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Karandikar M.V.,ACC Ltd | Khadilkar S.A.,ACC Ltd and Head
Indian Concrete Journal | Year: 2014

The paper attempts to review the different types of the available natural biopolymers and the effects of these additions on the fresh and hardened properties of modern day Portland cement mortar and concrete. The paper further discusses the experimental data generated at the author's laboratory as a part of exploratory work carried out, on use of natural polymers and its impact on the properties of cements, mortars and concretes in terms of increased early strengths, air entraining effect, better adhesiveness, anti microbiological agent, improvement in plasticity and workability of the mortars and concrete, comparing the results of the natural biopolymeric additions with the commercially available additives/ admixtures used to induce similar properties in mortar and concrete. The paper concludes that the observed effects of use of these biopolymeric additions on the properties of Portland cement mortar and concrete would inspire more researchers to work in these areas and evolve natural admixtures, which would further add sustainability to the modern day concrete constructions.

Dhuri S.S.,ACC Ltd
Indian Concrete Journal | Year: 2012

Manufactured sand is a purpose-made crushed fine aggregate produced from a suitable source material. Its production requires specially designed crushing equipment, screening and possibly washing. Like any other component of concrete, manufactured sand must conform to the specification that is suited to the performance required of the concrete. Blending is effective in reducing the level of microfines in the fine aggregate used in the concrete mix compared with the microfines in the manufactured sand. Despite the improvements made in the manufacturing process, complete use of manufactured sand has the risk of concrete segregation in high workability mixes. This problem can be taken care of by using mineral admixtures such as fly ash and designing mixes appropriately. It has now been made possible to produce high strength pumpable concrete mixes replacing natural sand completely.

Najar P.A.M.,Jawaharlal Nehru Aluminum Research Development and Design Center | Gondane S.R.,Jawaharlal Nehru Aluminum Research Development and Design Center | Jeurkar J.U.,ACC Ltd | Nimje M.T.,Jawaharlal Nehru Aluminum Research Development and Design Center
Separation Science and Technology (Philadelphia) | Year: 2013

Silica gel H impregnated with microcrystalline cellulose gel in alkaline medium was used as a stationary phase for the thin layer chromatography of heavy metal cations. A mixture of 10% aqueous potassium thiocyanate and triton X-100 in 1:1 v/v has been identified as the best combination of mobile phase for achieving selective separation of cobalt from nickel. The efficacy of the chromatographic system has been investigated by monitoring reproducibility of RF values and spot compactness with respect to the change in sample concentration and matrix effect. The improved selectivity of impregnated silica gel H was expounded by SEM and FTIR studies. The typical surface modification as well as the chemical changes in impregnated silica gel H was attributed. Chromatograms of the cations were quantitatively evaluated by scanning densitometry in comparison with ICP elemental analysis. The proposed method is applied for the determination of cobalt and nickel cations in spiked samples of geological and industrial origin. © 2013 Copyright Taylor and Francis Group, LLC.

With the growing population and the changes in the life style of the society, the demand of the cement product is increasing rapidly. The present global demand is > 2.5 Bio TPA. Based on a study carried out by IEA, the cement demand is expected to reach > 5 Bio TPA by 2050. Cement manufacture is a highly resource intensive activity and it consumes large quantum of mined resources as raw materials and fuels. These natural resources are slowly getting scarce posing a challenge for the cement industry. Further, existing technology of cement manufacture releases large amount of CO2 which has been identified as the most important reason for global warming. Hence, the challenge before cement industry is to produce required quantum of cement with reduced quantities of resources and with reduced CO2 emissions. This aspect is mandating cement industry to explore and implement innovative technologies and approaches in the manufacture of cement. Several new dimensions are getting evolved already and several options are under active exploration by the scientist globally. These include carbon capture and sequestration, clinker substitution, using raw material sources other than limestone, use of alternative fuels and raw materials, fuel switching and improving energy efficiency etc. This paper captures some of the developments related to the technological advances that are being explored and implemented so as to be able to produce cement in an ecologically sustainable manner, conserve our natural resources, reduce the GHG emissions and also use them effectively as a input resource to mitigate the climate change impact, and help improve the condition of our environment to the desired levels.

Shandilya A.,ACC Ltd
26th International Mineral Processing Congress, IMPC 2012: Innovative Processing for Sustainable Growth - Conference Proceedings | Year: 2012

ACC ECOSAND is finely powdered crystalline silica, which can replace natural sand usage in concrete and plasters. ACC ECOSAND ensures a comparatively denser concrete than those made only with natural sand and / or quarry fines / Manufactured Sand (Artificial Sand). Moreover, there is a significant gain in compressive strength (10-15 %) & durability in concretes (Reduced chloride conductivity leads to increased durability). ECOSAND is a by-product of froth flotation of limestone. At ACC Madukkarai cement works, Coimbatore, Tamilnadu, full-fledged mineral beneficiation process is adopted to enhance the usage of flotation reject in concrete and plasters. Optimum level for usage of ECO-SAND is 50%. With 50% usage of natural sand+50% ECO-SAND in concrete mix, 1 day, 3 day, 7 day & 28 day compressive strength is increased by 30.1 %, 22.6 %, 15.1 % & 11.0 % respectively and with moderate chloride permeability as compare to 100% Natural Sand.

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