Testing and modelling of hygro-thermal expansion properties of concrete

A moisture-dependent thermomechanical constitutive model for concrete subjected to transient high temperatures

“…This phenomenon cannot take place in completely dry concrete, because of the absence of free water in the capillary pores, nor in saturated concrete, because of the absence of capillary menisci in the gel pores. Such an explanation of the phenomenon is consistent with experimental results showing that, for ambient temperatures, the coefficient of thermal expansion of hardened cement pastes presents a maximum for a concrete relative humidity in the range 70 -85% [13][14][15].…”

“…The hygral state of the material at the time of the temperature change not only affects the drying shrinkage of the cement paste on heating, but also influences its neat thermal expansion, i.e. the expansion occurring without overall loss of moisture [13][14][15]. This is commonly explained by considering the neat thermal expansion of the cement paste as made up of two contributions: a true kinetic and a swelling pressure expansion [12].…”

Evaluation of the Moisture Dependence of Concrete Coefficient of Thermal Expansion and Its Impacts on Thermal Deformations and Stresses of Concrete Pavements

“…This pattern agrees with the results of previous laboratory studies. Laboratory studies also show that, as concrete dries, its CTE increases until reaching a maximum and that, beyond that maximum, its CTE decreases with further drying (7)(8)(9).…”

“…Other laboratory studies have been published since then, most of them in line with Meyers's statement. Lim et al (8) concluded that concrete CTE reached a maximum at 85% internal RH, where it was 60% higher than the value measured at internal relative humidities close to 100%. Jeong et al (9) also concluded that concrete CTE reaches a maximum at 85% internal RH, although they did not specify the exact CTE gain.…”

“…Transportation Research Record 2674 (8) Most of the experimental data comes from the instrumentation of the six thin concrete overlays of asphalt sections, however, most of the conclusions presented in this paper are directly applicable to standard concrete pavements, including conventional jointed plain and continuously reinforced concrete pavements.…”