Studies on the wet expansion deformation of hydraulic concrete with fly ash under non-standard temperatures

Concrete manifests wet expansion deformation when the moisture content of concrete increases via the seeping of water into the pores of the concrete. Moreover, concrete manifests different wet expansion deformations if the hydraulic concrete is submerged in water under different temperature histories. In the present work, wet expansion tests are conducted using hydraulic concrete (in which a strain gauge is embedded) cured under different temperatures. First, the statistical model of the measured strain is established before the concrete is submerged in water, and then the coefficient of thermal expansion and the autogenous volume deformation of the concrete are obtained. The wet expansion deformation of the concrete is then separated according to the measured strain after the concrete has been submerged in water. The analysis results show that the stability values of wet expansion deformation of the 3 groups of concrete specimens under different temperature histories are 35.57 μe, 42.35 με and 31.07 με. If the relationship between the wet expansion deformation of concrete and the moisture content of concrete is assumed to be linear, then the aforementioned stability values are equivalent to increases in the concrete moisture content of 1.052%, 1.253% and 0.919%, respectively. In addition, the wet expansion deformations of concrete specimens are positively correlated with the average temperature during the test process.