- Vicon
VICON CementVICON or high-performancecement can be made to order: from super-strong cements with rugged durability to low cost cements with up to 70% mineral additives. To use a high volume of mineraladditives (sand ,limestone , naturalpozzolans or various industrialby-products ) has an important economic andecological impact. As a result,VICON cement is stronger, cheaper and green.High-Performance Concrete
Following the latest advances in
concrete science, a high-performance concrete has been developed and successfully applied worldwide. This highly efficient product competes in new market niches not only with conventional concrete, but also withsteel , naturalstone ,ceramic , and constructionpolymers . To ensure a high level of performance a variety of chemicaladmixtures and mineraladditives must be used in exact doses; and precise control is the key to the high performance. The latest technology used inhigh-performance concrete plants is becoming highly sophisticated, like a chemical or pharmaceutical process. In order to manufacture high-performance concrete most concretebatching plants need additional equipment for precise control, dispatching,dosing andbatch processing.High-Performance Cement
VICON technique using a special
admixture during thecement grinding process helps significantly improve properties of ordinary cement. This approach resulted in the development of a new high-tech product: high-performance cement orVICON . VICON is versatile and is expected to be a widely used material in future construction. The main idea of VICON is the addition of a new reactivesilica -based complexadmixture during thegrinding of the portlandcement . Thus, in the case of VICON cement, theclinker is ground in aball mill together with mineraladditives ,gypsum and the newly inventedadmixture . The resulting cement is then available for the production of the high-performance concrete using conventional equipment.[http://www.uwm.edu/~sobolev/Vicon/Vicon_files/image002.gifVICON uses a special admixture during the cement grinding]
Effect of Complex Admixture "The use of the specially formulated
admixture provides the following effects:• pulverization of cement
clinker and mineraladditives ;• formation of optimal size distribution of cement particles;
• creation of highly active
amorphous structures;• physical and chemical modification of the
minerals ."Importantly, in the production of VICON the amount of
clinker can be drastically reduced. Even at high volumes of mineraladditives the special qualities of theadmixture produceblended VICON cement that is far superior to ordinary cement. Up to 70% of the cement can be replaced by cheaper localadditives :sand ,limestone , naturalpozzolanic orvolcanic materials,fly ash , granulatedblast furnace slag , brokenceramic andglass items. All these can be used as low cost indigenous mineral additives. In blended VICON cement, the use of granulated blast-furnaceslag in addition tohigh strength also provides excellent resistance tochemical attack and high temperatures. Because of lowpermeability and more resistantchemical structure , the blended VICON cement should easily exceedstandard requirements for a sulfate- resistant cement.Key Ingredients
To be most effective, the pre-made complex
admixture requires a reactivesilica -based component. Different types of availableclinker can be used in the proposed process, but the best results were achieved with high C3S and mineralized clinkers. As a result, optimized samples of high-performancecement achieved a 28-daycompressive strength of up to 95 MPa (13,775 psi). The 1-day compressive strength of VICON cement was found to be as high as 44 MPa (6,380 psi), by contrast, normal cement requires one month to reach this value. Similarly, compressive strength ofVICON at 2, 3, 7 and 90 days was far higher than normal cement.New Standard for a New Cement
Various
standard procedures are in place to test and control the quality of cements. VICON cement has a radically improved set of characteristics and so requires updated testing procedures. Research results indicated that theASTM C109 or C387test procedures are the most appropriate. The development of a newstandard would lead to a breakthrough in the application of thesehigh-performance cements . From precisely upgraded production centers VICON can be delivered to any construction site,ready mixed orprecast concrete factory in standard shipments, ensuring remarkably high quality of the final products.Global Warming & Eco-Considerations
It is generally agreed that the production of cement clinker is expensive and
ecologically damaging.Carbon dioxide , a principlegas contributing to the “greenhouse effect ”, is a hazard generated by the conventionalportland cement process (approximately 1 ton ofcarbon dioxide for every 1 ton of cement). BlendedVICON cement incorporates a wide range of mineraladmixtures or industrialby-products , which partly replace the cementclinker . Indeed, VICON uses about 50% less clinker than inferior cements, and so it creates lessecological damage. In this way VICON contributes to the reduction of carbon dioxide at source; it economically useswaste materials that otherwise would transported tolandfill sites.Cement Plant Expansion
The manufacture of
clinker consumes the bulk of capital investment and yields a slow return. Therefore expanding an existing plant requires a proportionally high rate of investment. In the case ofblended VICON cement new investments only required to upgrade thegrinding complex. This can help to increase the production capacity by 30-50% due to the saving on clinker. The installation ofmilling and control equipment requires extra investment. The complex admixture brings an additional operational cost. At the same time there is an immediate reduction in the cost of cement because lessclinker is used. The increased capacity can double revenues.Applications and Advantages
VICON cement can be used to reliable standards of high performance and high strength for manufacturing concrete in almost all conditions, therefore extending its applications.
Concrete made with VICON can be applied inhigh-rise buildings ,pre-cast reinforced concrete structures, airportrunways ,bridges ,marine andoffshore structures,tunnels , parkingdecks , inshotcrete and repairing of structures, underwater concrete, and specialfloors and many others.Furthermore, it could become the product of choice and specification in
earthquake zones. The containment ofnuclear andhazardous waste is another promising area."The properties of VICON cement are quite remarkable, and there are considerable savings over existing construction procedures. The most important economical benefits of VICON concrete are:"
• reduced cross-sections of
structures and consequent savings;• reduced construction cost due to less weight of structures and quick erection;
• increased
life-time of structures and reduced cost ofrepairs .The application of high performance cement approach is not limited to materials with high
strength and extremedurability , but it also can be utilized for the engineering ofcomposite materials with special properties, such as lowthermal expansion , electricalconductivity , light-reflection and many others.The VICON cement based concretes are characterized by:
• high workability and ability to fill complicated forms;
• low bleeding and good pumping;
• excellent
adhesion to any surfaces;• high
density andhardness ;• early
strength up to 44 MPa (6380 psi) in 24 hours;• ultimate
compressive strength up to 145 MPa (21,025 psi);• high
abrasion resistance;• high thermal and
fire resistance ; • superimpermeability togas ,vapor ,water and dangerouschemicals ;• excellent resistance to
corrosion andefflorescence ;• very high
freeze/thaw resistance (600 cycles and more);• high resistance to
chemical attack fromchlorides ,nitrates ,acids andsulfates .In summary, VICON cement is a
cement with superior technicalperformance ; it can be even cheaper than normal cement and has distinctecological advantages. Neatly, VICON cement combinestechnological advance at a lower cost andecological compatibility.References [1] Sobolev K., Mechano-Chemical Modification of Cement with High Volumes of Blast Furnace Slag. CEMENT AND CONCRETE COMPOSITES, Vol. 27, No. 7-8, 2005, pp. 848-853. http://www.uwm.edu/~sobolev/ks-mca-cement.pdf
[2] Sobolev K. and Ferrada-Gutiérrez M., How Nanotechnology Can Change the Concrete World: Part 2. AMERICAN CERAMIC SOCIETY BULLETIN, No. 11, 2005, pp. 16-19. http://www.uwm.edu/~sobolev/SobolevP2.pdf
[3] Sobolev K., The Effect of Complex Admixtures on Cement Properties and Development of a Test Procedure for the Evaluation of High-Strength Cements. ADVANCES IN CEMENT RESEARCH, Vol. AC15, No. 2, UK, 2003, pp. 65-75. http://www.uwm.edu/~sobolev/ACR-SOBOLEV-2419.pdf
[4] Sobolev K. and Podmore C., Vicon - Una Gran Idea. CONSTRUCCIÓN Y TECNOLOGÍA, 11, 2004, pp. 52-55. http://www.uwm.edu/~sobolev/ViconGCL.pdf
[5] Sobolev K. y Hermosillo R., Desarrollo De Materiales Basados En Cementos De Alto Desempeño Utilizando El Método De Activación Mecano-Química Y Su Comportamiento Con Nano-Aditivos Y Superfluidificantes http://www.uwm.edu/~sobolev/ReporteVICON.pdf
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