仿钢纤维对混凝土耐腐蚀性的影响

Impact of steel fiber mimicry on the corrosion resistance of concrete

C60混凝土常作为立井井壁建设的关键性材料,易受复杂多变的外荷载与部分地层中含有的硫酸盐侵蚀耦合作用,致使井壁的混凝土材料发生损伤、开裂,产生安全隐患。以C60混凝土为研究对象开展单轴压缩试验,测试不同干湿循环次数下不同仿钢纤维掺量的混凝土试件岩石力学行为,标定PFC^(2D)细观力学参数。通过建立混凝土峰值强度预测模型,进一步研究仿钢纤维掺量对混凝土使用寿命的影响,发现使用Clump命令模拟粗骨料,线性平行粘结模型模拟的单轴压缩试验,其峰值应力与轴向应变率符合室内试验力学规律,具有可靠的参考价值;仿钢纤维掺量为1.0%时,试件峰值应力应变波动最小,抗压强度耐蚀系数下降最平缓。GM(1,1)峰值强度预测模型结果表明,1.0%仿钢纤维掺量混凝土寿命明显优于其他组别,与数值模拟结果相符。研究结果可为评价防腐蚀混凝土涉及的岩石工程质量提供理论参考。

C60 concrete is a crucial material commonly used in wellbore wall construction,which is susceptible to the complex and varying external loads and the coupled effect of sulfate erosion in certain geological formations.These factors can lead to damage and cracking of the concrete material in wellbore walls,posing safety risks.Our study focuses on C60 concrete and conducts uniaxial compression tests with varying steel fiber dosages under different dry-wet cycle conditions to investigate the rock mechanics behavior of concrete specimens.The study also calibrates microscopic mechanical parameters using the PFC2D software and further explores the impact of steel fiber dosages on the service life of concrete by establishing a peak strength prediction model.The results indicate the following:simulating coarse aggregates using the Clump command and modeling uniaxial compression tests with the linear parallel bond model align with the mechanical behavior observed in laboratory experiments,providing reliable reference values;with increased corrosion,concrete specimens with a 1.0% steel fiber dosage exhibit the smallest fluctuations in peak stress-strain and the most gradual decrease in compressive strength corrosion resistance coefficient;results from the GM(1,1)peak strength prediction model show that the service life of concrete with a 1.0% steel fiber dosage is significantly better than other groups,consistent with numerical simulation results.The findings of the research can serve as a theoretical reference for evaluating the quality of rock engineering related to corrosion-resistant concrete.