Temperature dependence of concrete drying and a method for estimating the effect of temperature on the relative humidity in concrete pores

In northern climates, the drying temperature of concrete floors under construction can range from 5 °C to 60 °C, covering average outdoor temperatures and potential increases to enhance drying. Given that the internal relative humidity (RH) of concrete is temperature-dependent, its effect on RH should be considered to eliminate the risk of moisture damage. The hygrothermic coefficient κ, which characterizes the effect of temperature, is determined and used to define temperature-dependent sorption (TDS) with the introduction of a novel method. Modeling methods for moisture transfer in early-age concrete are examined and models developed to take temperature effects into account within the studied temperature range. Model results are then compared with those of drying experiments performed at various temperatures. The conventional model, which lacks TDS, fails to describe the effect of temperature on RH; however, it can account for the impact on drying. Conversely, the TDS model can depict the temperature effect on RH, which was found to be substantial, especially at larger temperature deviations. The developed models improved the prediction of drying at low temperatures. In addition, κ results are applicable to the temperature correction of measurements. A novel method is presented that takes into consideration the direction of the correction and thus provides additional certainty from a moisture safety perspective.