Dispersion method of nano magnesium oxide, nano magnesium oxide expanding agent and application of nano magnesium oxide expanding agent in preparation of expanding cement base material

Abstract

The invention discloses a dispersion method of nano magnesium oxide, which comprises the following steps of uniformly mixing nano magnesium oxide, a polycarboxylate superplasticizer and water to obtain a mixed solution, dispersing the nano magnesium oxide in the mixed solution by magnetic stirring, and dispersing by ultrasonic wave to obtain the nano magnesium oxide expanding agent. The invention also provides a nano magnesium oxide expanding agent prepared by the dispersion method of nano magnesium oxide and application of the expanding agent in preparation of expanding cement. The application comprises the following steps of adding the nano magnesium oxide expanding agent into a cement base material, and stirring and mixing to obtain the expanding cement base material. The prepared nano magnesium oxide expanding agent can effectively improve the expanding effect of cement, improve the dry shrinkage cracking phenomenon of the cement, and improve the crack resistance and mechanical properties of the cement.

Description

technical field [0001] The invention relates to the application of nano-magnesia, in particular to a dispersion method of nano-magnesia, a nano-magnesia expansion agent and its application in preparing expansive cement substrates. Background technique [0002] Traditional cement has the disadvantages of high heat of hydration, large dry shrinkage, and poor crack resistance. Therefore, traditional cement-based materials often have problems of easy fracture and micro-crack spalling, resulting in poor durability, safety and functionality of concrete structures, and a short life cycle. In order to improve the drying shrinkage and cracking of concrete structures, adding expansion agent is an effective way to improve the crack resistance of cement-based materials, but it is easy to cause the deterioration of the mechanical properties of cement-based materials. [0003] Magnesium oxide in cement clinker has low activity due to high calcination temperature, and the external additio...

AI Technical Summary

Problems solved by technology

[0008] The nano-magnesia expansion agent prepared by this method has not been dispersed, which will easily cause particle agglomeration, and the expansion performance of magnesium oxide cannot be effectively exerted, which will easily lead to the slow expansion of cement-based materials in the early stage and the reduction of mechanical properties in the later stage.

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