09 Jan,2019 UTC+8 Views:
China began to use slag powder in the mid-1990s. After nearly 20 years of promotion and application, slag powder use has become popular. Today's high-speed railways and large-scale cross-river bridges are almost always mixed with slag (slag product applications) powder when formulating high-performance concrete.
The slag powder suitable for high performance concrete has national standards. As a mineral admixture, slag powder has higher activity than general mineral admixture except silicon powder. In the range of large dosage, there is still good strength performance, which is an important feature of slag powder.
Then, when using cement powder in cement plants and concrete mixing stations, what experience can be used to ensure the performance of cement and concrete? What problems should be paid attention ?we must pay attention to the following questions:
(1) The specific surface area, activity index and fluidity ratio of slag powder are important technical indicators in the application of slag powder, not the finer the mineral powder, the better.
Generally, the finer the slag is ground, the greater the fluidity ratio and the higher the activity. After being mixed into concrete, the earlier hydration heat is generated. However, when the grinding is too fine, a property similar to silica fume is produced, and although the activity is high, the fluidity ratio is lowered. Therefore, slag powder with a large activity index and a large fluidity ratio should be used as much as possible.
(2) Adding slag powder is beneficial to improve the anti-penetration performance and chemical corrosion resistance. The slag powder also has a small electric flux, and has good strength properties. Therefore, it is suitable for marine environment, saline soil environment and other projects. A large amount of anti-corrosion is added.
(3) When the ratio of slag powder is large, the viscosity of concrete is large, which will affect the concrete construction performance. Therefore, combined with fly ash, it can exert its own characteristics and can fully exert its superposition effect. To maximize the performance of concrete.