盐渍土地区高性能混凝土耐久性研究

Durability Study of High Performance Concrete in Salt Region

以内掺掺合料、中砂、细石、普通硅酸盐水泥以及抗硫水泥制成的细石高性能混凝土作为研究对象,在3种不同硫酸根浓度的浸泡液中进行100次干湿循环,用动弹性模量、抗折强度和抗压强度的变化研究硫酸盐侵蚀对混凝土耐久性的影响。结果表明,随着浸泡液中硫酸根浓度的逐步增加,混凝土受硫酸盐侵蚀程度逐步增加,试件的动弹性模量呈现逐步降低的趋势;在干湿交替环境下,混凝土试件的抗折强度指标比抗压强度指标更敏感,试件的抗折强度比抗压强度更能反应试件的受损程度。在干湿交替的水侵蚀和硫酸盐侵蚀环境中,掺加复合掺和料的高性能混凝土对硫酸盐侵蚀有较好的抵抗性能。

This paper describes a study carried out to examine the performance of various high performance minute stone concretes, which are made up of compound admixtures, riddled sand, minute stone, portland cement concrete and sulfur-resistant cement concrete. They experienced 100 dry-wet cycles in 3 kinds of solutions with different sulfate radical density. With the changes of the dynamic elastic modulus, the flexural strength and the compressive strength, the influence of sulfate attack on concrete durability was studied. Results show that the sulfate attack degree of concrete increases gradually with the stepping up of sulfate radical density in the solution. The dynamic elastic modulus of the test piece tends to reduce. Under dry-wet alternant environmant, the flexural strength index of concrete test piece is more sensitive than its compressive strength index. The flexural strength of the test piece can better reflect the damage degree of the test piece than its compressive strength. Under dry-wet alternant environment of water corrosion and sulfate attack, high performance concrete with compound admixtures shows better resistant performance to sulfate attack.