A kind of retarded setting magnesium potassium phosphate cement and preparation method thereof

Abstract

The invention provides a retarded setting magnesium potassium phosphate cement and a preparation method thereof. The retarded setting magnesium potassium phosphate cement, in parts by weight, comprises: 40-60 parts of magnesium oxide microcapsules; 10-20 parts of potassium dihydrogen phosphate; 1-5 parts of magnesium chloride; 4-9 parts of hollow microbeads; 0.2-0.5 parts of potassium chloride; wherein, the capsule wall of the magnesium oxide microcapsules is calcium carbonate, and its thickness is 30-80 μm. The slow-setting magnesium potassium phosphate cement provided by the invention encapsulates the magnesium oxide in the calcium carbonate capsule wall in the form of microcapsules, and can realize the effect of gradually slow-releasing magnesium oxide during the use process, which solves the problem of traditional magnesium potassium phosphate. The problem of short setting time of cement. In addition, compared with other existing processes, the preparation method of the retarded magnesium potassium phosphate cement provided by the present invention is simple, does not need to add an additional retarder or control the activity of magnesium oxide, is easy to operate, and does not reduce the reduction of magnesium potassium phosphate cement. It has many advantages such as controllable setting time, small reaction heat release, and green environmental protection.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a retarded setting magnesium potassium phosphate cement and a preparation method thereof. Background technique [0002] Due to various unfavorable environmental conditions, such as salt solution erosion, dry-wet cycle, freeze-thaw cycle and other environmental factors, concrete will be damaged to varying degrees during use. These damages can affect the appearance, cause financial loss, and even create serious safety hazards. Reinforcing damaged structures with repair materials is a cost-effective solution. If the damaged concrete is repaired and strengthened with traditional ordinary portland cement (OPC), it will take a long time to block buildings and traffic, which seriously affects people's life and travel. Taking into account factors such as personnel entering the site, construction preparation and site clearance and evacuation, the repair materials a...

AI Technical Summary

Problems solved by technology

Among them, the use of retarder can prolong the setting time of MKPC and control the heat of hydration, but the amount of retarder is not easy to control. When the amount is small, the retarding effect is limited, and when the amount is large, the strength of MKPC Especially the early strength will be greatly reduced, and the elastic modulus will also be reduced; reducing the dead burning activity and fineness of MgO can prolong the coagulation time of MKPC appropriately, but MgO with low activity requires a higher calcination temperature and is difficult to control. Too thick MgO will affect the fluidity and early strength of MKPC slurry, and the retarding effect is not obvious when the ambient temperature is high; increasing the amount of phosphate can properly delay the setting time of MKPC, but too high a amount of phosphate will increase the MKPC cost and reduce its strength and water resistance

[0005] To sum up, the existing schemes for improving the setting time and hydration heat release of MKPC all have some deficiencies, which limit their application to a certain extent.

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