盐酸侵蚀下不同强度等级混凝土力学性能退化行为研究

Mechanical Properties Degradation Behavior of Different Strength Grade Concrete under Hydrochloric Acid Erosion

混凝土材料是当今运用最广泛的土木工程材料之一,其在极端环境下的耐久性性能变化是研究重点。以不同浓度的盐酸溶液腐蚀对常用的三种强度等级混凝土(C25, C45, C55)的力学性能进行研究,对比了腐蚀后的损伤形貌。将所有的混凝土小梁试件(100 mm×100 mm×600 mm)标准养护250 d后浸泡于4种不同浓度的盐酸溶液。测试腐蚀后的试件重量损失、动弹性模量损失、抗弯强度损失和抗压强度损失。结果表明:混凝土力学性能的退化程度随着盐酸溶液浓度的增大而增大,高强混凝土(C55)和普通强度混凝土(C25)的抗压强度衰减具有相似规律;盐酸腐蚀后混凝土抗弯强度明显降低,高强混凝土(C55)比起普通混凝土(C25)抗弯强度降低更多;根据试验结果,可为今后高性能混凝土设计提供依据。

The influence of different concentration of hydrochloric acid solution on the mechanical properties of three kinds of strength grade concrete(C25,C45,C55)commonly used in engineering is studied,and the damage morphology after corrosion is compared. All the small concrete beam specimens(100 mm×100 mm×600 mm)standard maintenance of 250 d immersed in four different concentrations in hydrochloric acid solution,soak 24 h after taking out the test after corrosion of concrete beam specimen weight loss,loss of dynamic elastic modulus and flexural strength loss and the loss of compressive strength. The results show that the degree of degradation of the mechanical properties of concrete increases with the increase of concentration of hydrochloric acid,the compressive strength of high strength concrete(C55)and ordinary concrete(C25)with similar attenuation law;concrete flexural strength decreased obviously after hydrochloric acid corrosion,high strength concrete(C55)has high defect sensitivity compared with ordinary concrete(C25)the flexural strength decreased more;weight loss and elastic modulus a greater loss.