Study on strength and corrosion performance for steel embedded in metakaolin blended concrete/mortar

摘要

It is an undeniable fact that concrete is the most widely used man-made construction material in the world today, and will remain so for decades to come. The popularity of concrete is largely due to the abundance of raw material, low manufacturing and maintenance cost, excellence in compression, and corrosion aspects, durability to weathering and fire hazards, versatility in forming various shapes and its unlimited structural applications in combination with steel reinforcement. However, the cement industry is also highly energy intensive, and the emission of carbon dioxide during cement manufacturing has created enormous environmental concerns. There has also been an increase in the number of incidents where concrete structures experienced severe deterioration in extreme environments. All these factors have contributed pressures from various quarters to reduce cement consumption, and to intensify research in exploring the possibilities of enhancing strength, durability and corrosion reduction through the use of pozzolans as supplementary cementing materials. The utilization of calcined clay in the form of metakaolin as a pozzolan for concrete has received considerable interest in recent years. The use of metakaolin as a mineral admixture for concrete is a well documented practice. Metakaolin is a quality enhancing pozzolan for concrete. It is manufactured from kaolin which is abundance in India and other parts of the country. In the present investigation mechanical property and corrosion behavior of carbon steel using metakaolin (5-20%) as partial replacement in ordinary Portland cement (OPC). Compressive strength, resistivity, ultra pulse velocity, open circuit potential, studies on water absorption, weight loss were studied. It was found that up to 15% replacement of metakaolin in OPC improves the mechanical properties of concrete. Corrosion of carbon steel improved by the addition of metakaolin up to 15%.