Internal Temperature and Humidity Response of Concrete Under Atmospheric Environment in Qingdao Area

In the harsh coastal environment, the micro-environment of concrete directly affects carbonation of concrete, chloride penetration into concrete and corrosion of rebar in concrete. The temperature and humidity of the micro-environment inside concrete are affected by the temperature and humidity of the natural environment, and are different from that of the natural environment. In order to study the relationship between them, the effect of temperature and humidity at sheltered and exposed atmospheric environments in Qingdao area, and the response of temperature and humidity at different depths in concrete were monitored on the spot for one year. Results indicated that the temperature and humidity of the atmosphere showed obvious harmonic periodic fluctuation in the period of 24 hours, and the temperature peak was opposite to the relative humidity peak. The variation amplitude of daily temperature and humidity in exposed environment was greater than that in sheltered environment. The maximum temperature difference between the two environments was up to 9 ℃, and the maximum difference of relative humidity was up to 20%. The response of temperature at different depths inside concrete was consistent and the numerical difference was small. In a short period of time, the response value of relative humidity inside the concrete fluctuated slightly, and it increased gradually with the increase of depth. Based on theoretical analyses, the action spectrum of temperature and humidity at atmospheric environment and the response spectrum of internal temperature and humidity of concrete were established. The field measurement results verified that the model could represent the effect of environmental temperature and humidity and the change regulations of temperature and humidity inside concrete well, and it provided a basis for the accurate evaluation and prediction of the durability of concrete structures. Copyright ©2020 Advanced Engineering Sciences. All rights reserved.