Investigation of Mechanical and Durability Properties of Concrete Influenced by Hybrid Nano Silica and Micro Zeolite

Abstract

Today, concrete is the most widely used construction material in the world, cement is major component of concrete. Consuming energy in cement industry is very high and CO2 emissions generated during the production of Portland cement has serious environmental threatens. Therefore utilize of pozzolanic material as a supplementary cementitious material has a direct relationship with sustainable development. In this investigation, 2% Nano Silica and 5, 8 and 10% Micro Zeolite (by weight percent) replaced Portland cement constitutes and standard cylindrical specimens were prepared from the mixture. Two types of concrete mixture with water to cementitious material ratio (W/(C + P)) of 0.45 and 0.4 were prepared and they were tested after aging for 7, 28 and 90 days. The effect of these additives on mechanical properties (compressive and tensile strength) and durability were investigated by Electrical Resistivity (ER) and Rapid Chloride Penetration Test (RCPT) at the ages 28 and 90 days. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) revealed that nano particles could improve quality of concrete. As a result of the tests, increase of mechanical characteristics is not considerable but make significant decrease in penetration of chloride ion and increase electrical resistivity that are appropriate option for controlling of corrosion in reinforced concrete structures.