The paper discusses the structural behaviour of concrete struts deteriorated by internal swelling reactions due to delayed ettringite formation (DEF). To assess this behaviour, nonlinear finite elements analyses were performed using concrete damaged plasticity (CDP) model of ABAQUS, which was calibrated and validated. The effects of the internal swelling reactions were simulated numerically using a strategy of decreasing mechanical properties of concrete. MATLAB scripts were developed to automate the process of determining the CDP model parameters, especially those related to the damage in tension and compression with few input data. Decreases in the first crack and failure loads of 78% and 56% were observed which means that DEF expansions are an important issue in the load capacity of concrete structures. Besides, it was also observed a significant increase in cracks openings width, even for low expansion level, with values of 3.65 mm, and for high level of expansion with values of 4.51 mm. This is a relevant aspect for the durability of concrete structures that is severely affected by DEF expansions.

本文讨论了由于钙矾石形成延迟（DEF）而导致的内部膨胀反应使混凝土支杆结构恶化的现象。为了评估这种行为，使用了经过校准和验证的ABAQUS混凝土破坏塑性（CDP）模型进行了非线性有限元分析。使用降低混凝土力学性能的策略对内部溶胀反应的影响进行了数值模拟。开发了MATLAB脚本以自动化确定CDP模型参数的过程，尤其是那些与拉伸和压缩损伤有关的，很少输入数据的过程。观察到的第一次裂纹和破坏载荷分别降低了78％和56％，这意味着DEF膨胀是混凝土结构的承载能力中的重要问题。除了，还观察到裂纹开口宽度显着增加，即使对于低膨胀水平，其值为3.65 mm，对于高膨胀水平，其值为4.51 mm。这是受DEF膨胀严重影响的混凝土结构耐久性的一个重要方面。