Relationship between autogenous deformation and internal relative humidity of high-strength expansive concrete

The relationship between autogenous deformation and internal relative humidity (IRH) of high-strength concrete and high-strength expansive concrete were investigated. The experimental results indicate that, there exists a good linear relationship between autogenous shrinkage and IRH of high-strength concrete but a nonlinear relationship between autogenous deformation and IRH of high-strength expansive concrete with expansive agent. The new autogenous deformation curve can be obtained by transforming the autogenous deformation data of high-strength expansive concrete, and there exists linear relationship between the autogenous deformation and IRH. The concept of “critical internal relative humidity” was proposed, which is defined as the value of IRH when autogenous deformation is zero, to effectively reflect the autogenous deformation characteristic of expansive concrete.