Abstract:Shrinkage distribution on the early-age in different height of high performance concrete plate component and the developing process of early-age shrinkage, temperature and humidity with age are investigated. The results showed that relative humidity is decreased and presenting two stage features with age in different height of high performance concrete plate component. At the same time, the early-age shrinkage is out-sync along different height of high performance concrete plate component, what generates surface tensile stress of plate component. When the tensile stress is larger than the tensile strength of concrete, it products surface shallow cracks in plate component. This is the same as surface cracking situations found in actual engineering. Meanwhile, by comparing the early-age shrinkage of concrete plate components and the early-age free shrinkage of the same concrete, prediction model of early-age shrinkage of plate components introducing degree of relative constraint is established, and the accuracy of the prediction model is verified. This model can predict the early-age shrinkage deformation in different height of high performance concrete plate component. This result has practical significance to control the early-age shrinkage crack of concrete bridge plate.