Abstract: Firstly,an accelerated corrosion test was conducted with 6 groups of concrete cylinder specimens to simu- late the sulfuric acid corrosion environment with interrupted corrosion layer.Secondly,the corrosion depths of cor- roded specimens were measured by using a three-dimension (3D) laser scanner and a vernier caliper,respectively.Then,an objective function was proposed with the help of least square cylinder,and the 3D point coordinates ob- tained with 3D laser scanner were treated with Matlab to calculate the corrosion depth of each point on cylinder sur- face.Finally,the corrosion depth was statistically analyzed.The results indicate that the corrosion depth can be ex- pressed as a Gaussian random process with normal distribution; and that both mean value and standard deviation of the depth approximately increase with corrosion time in a linear way.Moreover,it is found that the mean corrosion depth measured with vernier caliper is slightly less than that obtained with 3D laser scanner,while the correspond- ing standard deviation measured with vernier caliper is obviously less than that obtained with 3D laser scanner.As the amount of data obtained with 3D laser scanner is tens of thousands of times as such as that obtained with vernier caliper,it is more reliable to calculate corrosion depth with Gaussian random process model.

Key words: concrete, sulfuric acid-caused corrosion, corrosion depth, stochastic model