卤水环境下离子侵蚀对HPC强度的影响研究

Influence of Ion Erosion on HPC Strength in Brine Environment

本文针对青海省西宁市兴建轨道交通工程中混凝土耐久性的研究,配制了不同配合比的HPC,记录并分析了其在2年腐蚀期内的抗压与抗折强度随腐蚀龄期的变化规律。结果表明:在卤水腐蚀环境下混凝土的抗折与抗压强度在0.5-1.0a、1.0-1.5a、1.5-2.0a这3个时间段内的变化与离子侵蚀密切相关,抗折强度在龄期内表现为增强,抗压强度表现为降低;标号为Ca50z的HPC试件为最佳配合比,表现了良好的抗腐蚀性;矿物掺合料的掺加能有效的提高混凝土的抗腐蚀性能;硫酸根离子侵蚀导致混凝土的损伤是其抗压强度下降的原因之一,且氯离子能够减缓硫酸盐侵蚀破坏的速度。

Aiming at the research of concrete durability in the construction of rail transit engineering in Xining, Qinghai Province, HPC with different mixture ratio was made, and the changes of compression and flexural strength with corrosion age during the 2 year corrosion period were recorded and analyzed.The results show that ： the change of flexural and compressive strength of concrete is closely related to ion erosion in the period of 0.5-1.0a、 1 .0 -1 .5 a、 1.5-2 ,0a at the bittern corrosion environment. The flexural strength was enhanced and the compressive strength was reduced, in the age. The HPC specimens of Ca50z marked as the best mixture ratio show good corrosion resistance. The addition of mineral admixture can effectively improve the corrosion resistance of concrete. The damage of concrete caused by sulfate ion erosion is one of the reasons for its decrease of compressive strength, and chloride can slow down the rate of sulfate attack.