Abstract:Four groups of concrete specimens of different dimension were splitted in the test. The displacements of the concrete specimen surface were analyzed through DSCM(digital speckle correlation method). Furthermore, damage parameters, damage area based on the MCOD(micro crack opening displacement) and damage variable DE based on the weighting damping elastic modulus, were determined. At the same time, Cl- permeation of concrete specimens before and after the splitting test were all studied by NEL method, and the influences of micro crack damage on the Cl- permeability were discussed. The test results show that there are more affection for micro crack damage on the concrete permeation in the low water binder ratio of concrete than the high ones;there is a increasing relationship between damage variable DE based on the damping elastic modulus and change rate of Cl- diffusion coefficients; strength of cement paste, different aggregate gradation, varied porosity, uncertain damage area and so on have significant impacts on Cl- permeability of concrete.