Method for inhibiting alkali activity of concrete aggregates

Abstract

The invention provides a method for inhibiting alkali activity of concrete aggregates. The method comprises doping chemical additives and / or mineral admixtures into concrete, wherein the chemical additives are a high-efficiency water reducer and an air entraining agent, and the mineral admixtures are coal ash and silica fume, and the water-cement ratio is controlled. The doping amount range of single doping and the mixing proportion of mixed doping are determined through experiments, so that the relation between doping amounts of various materials and the expansion rate of base aggregates is determined. In the method, four materials comprising the fly ash, the silica fume, the high-efficiency water reducer and the air entraining agent are determined to serve as a part of concrete components, and a reasonable matching ratio of the materials is determined through single-factor tests and a five-factor quadratic orthogonal rotation combined test method, so that an effective reference measure is provided for prevention of reactions of alkali aggregates in the engineering, inhibition of alkali-silica reactions (ASR) is effective for a long time, and engineering damage caused by the reactions of the alkali aggregates is reduced.

Description

technical field [0001] The invention relates to a method for proportioning concrete, in particular to a method for inhibiting alkali activity by concrete aggregate. Background technique [0002] In recent years, concrete, as one of the most widely used building materials in various engineering structures, has gradually become an indispensable part of human social life. And with the increasing maturity and development of concrete technology, it is not only used in civil engineering structures such as houses, highways, and bridges, but also in hydraulic engineering, ocean engineering, and some special engineering structures. Initially, the design of concrete structures focused on meeting the requirements of strength, and strength was used as the standard for the life of concrete structures. However, with the expansion of the scope of application and the complexity of environmental factors, in order to better play the role of concrete structures in various environments, variou...

AI Technical Summary

Problems solved by technology

[0008] 3. At present, an admixture or mineral admixture is basically added alone to inhibit the alkali-aggregate reaction, and it is generally believed that the higher the admixture, the better the inhibitory effect. Due to the high replacement rate of aggregates, other properties are affected Adverse effects are less considered

[0009] 4. At present, admixtures and mineral admixtures are usually used at the same time in actual engineering. For high-performance concrete, high-performance chemical admixtures and mineral admixtures have become essential components, and most of the research on alkali-aggregate reaction inhibition measures The approximate range of the amount of the admixture is obtained through the experiment with one or several active admixtures, and the comprehensive effect between the admixtures or between the admixture and the admixture is less considered, and due to the test The aggregates used are taken from different places, and there are great differences in activity. The inhibitory dosage obtained from the test can only be used as a reference when applied to other projects. The long-term effectiveness of the mixture to inhibit ASR cannot be determined.