A study on the Mix Design parameters of High Strength Concrete using Iso-Strength lines

摘要

Concrete production exists around the globe and is one of the leading construction material, essentially man made stone that has become a most versatile and universally recognised tool to build with. Concrete is a widely used structural material which essentially consists of a binder and a mineral filler. It has the unique distinction of being the only construction material which is manufactured actually on the site, whereas other materials are merely shaped and fabricated and eventually assembled at site. Ever since the time of Romans, there has been a continuous effort by the research workers in the field of cement and concrete technology to produce better quality cement resulting in concretes of overall improved quality. The introduction of reinforced concrete as an alternative to steel construction, in the beginning of 20th century, necessitated the developement and use of low and medium strength concretes. In keeping with the demands of the nuclear age, high density concrete has been successfully used for the radiation shielding of highly active nuclear reactors. Considerable progress has been achieved in the design and use of structural light weight concretes, which have the dual advantage of reduced density coupled with increased thermal insulation. With the present state of knowledge in the field of concrete mix design, it is possible to select and design concrete capable of resisting heat, sea water, frost and chemical attack arising out of industrial effluents. High strength and high performance concrete are being widely used throughout the globe and in the production of these concretes it is necessary to reduce the water/binder ratio with the subsequent increase in the binder content. High strength concrete refers to good abrasion, impact and cavitation resistance. The deterioration and premature failure of concrete structures such as marine structures, concrete bridge deck etc. has lead to the developement of high performance concrete. The high performance concrete is defined as the high-tech concrete whose properties have been altered to satisfy specific engineering properties such as high workability, very high strength, high toughness and high durability to severe exposure condition. Nowadays silica fume is almost invariably used in the production of High Performance Concretes. In future, high range water reducing admixtures (Superplasticizers) will open up new possibilities for the use of such material as partial replacement of cement to produce and develop high strength concrete, as some of them are much finer than cement. The existing literature is rich in information on silica fume concrete and after performing a detail review of the research papers published over the last two decades, the objective of the present study was framed.