Sulfuric acid corrosion on concrete structures is more prevalent and its damage evaluation becomes gradually imperative. This study attempts to characterize the sulfuric acid corroded surfaces of concrete in terms of three-dimensional fractal dimension. Accelerated sulfuric acid corrosion tests were conducted using concrete cylinders with six different corrosion durations, and the 3D coordinates of points on the surface of cylinders were captured using 3D laser scanning technique. The fractal dimensions were calculated using the cubic covering method, and the corrosion depth and mass loss of concrete were obtained correspondingly. The results indicated that fractal dimension can be considered as an indicator to evaluate the corrosion deterioration. The surface fractal dimension was positively correlated with the corrosion duration by a power function, where the value increased dramatically in the early stage, and gradually slowed down to maintain constant. Therefore, empirical functions to evaluate the corrosion depth and mass loss of concrete after sulfuric acid attacks were proposed. The parameters to establish the equivalent accelerated relation between experimental and natural conditions were also recommended under different degradation degrees.

中文翻译：

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受硫酸侵蚀的混凝土表面的三维分形表征

硫酸对混凝土结构的腐蚀更为普遍，其损伤评估逐渐变得势在必行。本研究试图根据三维分形维数来表征混凝土的硫酸腐蚀表面。使用具有六种不同腐蚀持续时间的混凝土圆柱体进行硫酸加速腐蚀试验，并使用 3D 激光扫描技术捕获圆柱体表面点的 3D 坐标。采用三次覆盖法计算分形维数，得到混凝土的腐蚀深度和质量损失。结果表明，分形维数可以作为评价腐蚀恶化的指标。表面分形维数与腐蚀持续时间呈幂函数正相关，其值在早期急剧增加，并逐渐放缓以保持恒定。因此，提出了评估硫酸侵蚀后混凝土腐蚀深度和质量损失的经验函数。还推荐了在不同降解程度下建立实验和自然条件之间等效加速关系的参数。