Autogenous deformation of dam concrete still brings influence to crack resistance performance.With test results from full-graded and wet-screened samples,autogenous deformation model of Jinping I arch dam was presented. Dam concrete’s initial deformation is not related with temperature stress and final deformation is from concrete’s drying shrinkage.It showed that autogenous deformation maximum of Jinping I arch dam is to -29.8×10-6,autogenous deformation values from full-graded tests of 120 d age is below those from wet-screened samples.But,in 150 d age,deformation values of full-graded tests are above those from wet-screened samples. Expansion admixture is introduced into concrete on construction period and could prevent shrinkage deformation.
