INVESTIGATION ON HIGH PERFORMANCE CONCRETE USING MICRO CALCITE

V.Dass Mohan ¹, Dr.T.Sekar ^2
1 V.Dass Mohan, Assistant Professor, Vickram College of Engineering, Enathi, Sivagangai, India.
² Dr.T.Sekar, Professor, University College of Engineering, Ramanathapuram, India

     This paper is aimed at to evaluate the mechanical properties and durable properties of High Performance Concrete (HPC) with Micro Calcite (MC) as a mineral admixture. In this project, the cement is replaced by MC powder with five different replacement levels, namely, 5%, 10%, 15%, 20% and 25% in HPC of M60 grade. Concrete using the aforesaid replacement levels are prepared and the following tests were conducted in order to find the optimum replacement level of MC. With respect to fresh concrete, the following tests were conducted and the test results are exhibited in tables. Slump cone test and Compaction factor test were conducted. With regard to other samples after 7, 14 and 28 days curing, cube compression, Split tension and flexural strength were found. For all the tests 99 cubes, 54 cylinders and 54 prisms were cast, cured and tested as per Indian standard code provisions. Over and above the conventional test, the following specialized tests were conducted for durability such as permeability test, Sulphate attack test and Chloride attack test. In order to recommend HPC with MC powder for water retaining structures, water tanks etc., permeability test was conducted and the results found suggest it is less permeable than conventional concrete. When this concrete is exposed to chemical fumes, sulphate and chloride attack in sewers, and sewage treatment plant and chemical factories specific test on sulphate and chloride attack were conducted and found to perform better than conventional concrete. Finally the results exhibit that HPC with 15% replacement of cement by Micro calcite gives the maximum strength and very low permeability. It also show a lesser sulphate and chloride attack by showing minimum loss of weight and minimum loss of strength. Thus it is clear that conventional concrete materials in combination with MC mineral admixture can be utilized for making HPC and such concrete can be effectively used in structures which are exposed to severe chemical attacks.