Title |
Study on the Effect of Rainfall on the Moisture Behaviour in Hardened Concrete |
Authors |
Ryu Dong-Woo ; Ko Jeong-Won |
Keywords |
Temperature ; Relative Humidity ; Rainfall ; Relative Moisture Content ; Moisture Transfer ; Crack ; Concrete |
Abstract |
Deterioration of concrete structure is caused by mass transfer with moisture. In order to predict the service life of concrete structures quantitatively, it is necessary to clarify the mechanism of deterioration of concrete and reinforcement at exposure state from the viewpoint of moisture movement affected by environmental condition. Especially rainfall may cause water penetration heavily and deeply in a liquid state and leads to more significant changes of water content in concrete than a process in a vapor state. In this paper the effects of a cover roof and a crack in concrete on the moisture movement were investigated experimentally using specimens embedding humidity sensors and electrodes. Experimental results showed that water penetrated more deeply in uncracked concrete with higher water-to-cement ratio but water content did not change in the deeper part than 5cm. In case of cracked concrete the wider crack caused faster and deeper water penetration, and the water content in the deep part increased before the saturation of surface part in the concrete with lower water-to-cement ratio. The change of relative humidity in the concrete due to temperature change showed different trends depending on the humidity in the pore. |