Experimental Study on the Effects of Crack Width and Crack Depth on the Carbonation of Concrete in Electric Power Utility Tunnels

An underground electric power utility tunnel is an important piece of infrastructure. Securing the durability of such structures is essential to ensuring their long lifecycles. However, the concrete of an electric power utility tunnel is likely to be carbonized, owing to long-term exposure to high carbon dioxide. Moreover, the carbonation of concrete may be intensified by damage, such as cracks. In this study, the characteristics of carbonation in electric power utility concrete were examined based on crack width and depth. The results of the experiment showed that the crack width was an important variable in the carbonation of concrete in an electric power utility tunnel. Carbonization proceeded at the tip of the crack, even if the crack was deep and the width was small.