Experimental Investigation on Carbonation of Concrete Using SEM –EDX(Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) & Environmental Scanning Electron Microscope(ESEM) Analysis

Abstract

The alkalinity of the concrete protects the reinforcing bars againstcorrosion, but the carbonation phenomenon accelerates the loss of their motionless coating, favouring corrosion start. Concrete that has been carbonated has a lower pH values which can lead to reinforcement corrosion. Reinforcement corrosion is the most common cause of reinforced concrete degradation Variables such as dimensional carbon dioxide in gress, duration of carbon dioxide ingress, grade of concrete, and CO2 volumetric concentration are all considered in this research. The specimens wereplaced in a chamber with a carbon dioxide gas supply after 28 days of water curing .The specimens were exposed to carbon dioxide for 145 hours and 290 hours, respectively, in a carbon dioxide chamber. The specimens were then cut at 1cm, 2cm, and 3cm intervals from the concrete surface. The powder from crushed concrete specimens was pulverised and sieved through a 90m sieve, with the powder collected as sample powder. In the present study an experimental investigation was conducted on concrete for determining the flexural strength and SEM-EDX & ESEM analysis. The specimens were tested after 28 days of curing as per determined time. The compressive strength, tensile strength and flexural strength of concrete is determined for the 7days, 14 days and 28days curing.