This grade was introduced in the country by BIS in the year 1987 and commercial production started from 1991. Advent of this grade in the country owes it to the improved technology adopted by modern cement plants. OPC 53 Grade cement is required to conform to BIS specification IS:12269-1987 with a designed strength for 28 days being a minimum of 53 MPa or 530 kg/sqcm.
53 Grade OPC provides high strength and durability to structures because of its optimum particle size distribution and superior crystallized structure. Being a high strength cement, it provides numerous advantages wherever concrete for special high strength application is required, such as in the construction of skyscrapers, bridges, flyovers, chimneys, runways, concrete roads and other heavy load bearing structures. Not only is this grade of cement stronger than other grades / types, it is also more durable. Further, by substituting lower grade cement with OPC 53, overall savings can be obtained through reduced quantity of cement that would be required to be used. A savings of 8-10% can be achieved with the use of 53 Grade OPC in place of any other grade.
53 Grade cement attains higher early strength as compared to any other grade of cement but because of early gain, does not increase much after 28 days. In addition, due to faster hydration process, the cement releases heat of hydration at a much faster rate initially and therefore, the chances of micro cracking of concrete is much greater. Thus, during initial setting period of concrete, the higher heat of hydration can lead to damage arising out of micro cracks with in the concrete structure, which may not be visible on the surface. The situation can be worsened when construction supervisors / masons tend to increase the quantity of cement in concrete with a wrong notion that such increases are better for both strength and durability of concrete. Grade 53 should therefore be used only where such application is warranted for making the concrete of higher strength, where good supervision and quality assurance measures are in place and where proper precautions are taken to relieve the higher heat of hydration through a proper curing process.
The physical and chemical characteristics of OPC 53 Grade Deccan Cement very comfortably surpasses the stringent standards specified by BIS, including compressive strength which is remarkably higher than the prescribed standards.