硫酸盐腐蚀下钢纤维混凝土力–化耦合损伤细观模拟

Mesoscopic Simulation of Force-Chemical Coupling Damage of Steel Fiber Reinforced Concrete under Sulfate Corrosion

摘要: 利用有限元软件开展钢纤维混凝土在硫酸盐腐蚀下的细观模拟。首先，在Abaqus中基于Monte Carlo方法构建钢纤维和粗骨料随机分布的二维钢纤维混凝土模型，并进行硫酸根离子扩散模拟，确定不同龄期的硫酸根离子浓度场。然后，通过虚拟温度场法进行化学损伤模拟，得到不同龄期的化学进程。最后，对化学损伤后的试件施加位移荷载得到力–化耦合后的应力–应变曲线。模拟结果表明，随着腐蚀龄期的增加，由腐蚀产物导致的化学损伤不断增加，具体表现为导致的拉伸应变不断增大；但由于混凝土中钢纤维的存在，能量被有效地吸收和分散，明显阻止了贯穿裂缝的产生，从而提高了混凝土的耐久性和可靠性。

Abstract: The meso-simulation of steel fiber reinforced concrete under sulfate corrosion was carried out by using finite element software. Firstly, a two-dimensional steel fiber reinforced concrete model with random distribution of steel fiber and coarse aggregate was constructed based on Monte Carlo method in Abaqus, and the sulfate ion diffusion simulation was carried out to determine the sulfate ion concentration field at different ages. Then, the chemical damage simulation was carried out by the virtual temperature field method to obtain the chemical process of different ages. Finally, the displacement load is applied to the specimen after chemical damage to obtain the stress-strain curve after force-chemical coupling. The simulation results show that with the increase of erosion age, the chemical damage caused by corrosion products increases continuously, which is manifested in the increase of tensile strain. However, due to the existence of steel fiber in concrete, the energy is effectively absorbed and dispersed, which obviously prevents the occurrence of penetrating cracks, thus improving the durability and reliability of concrete.