Retarded potassium magnesium phosphate cement and preparation method thereof

Abstract

The invention provides retarded potassium magnesium phosphate cement and a preparation method thereof, and the retarded potassium magnesium phosphate cement comprises the following components in parts by weight: 40-60 parts of magnesium oxide microcapsules; 10 to 20 parts of monopotassium phosphate; 1-5 parts of magnesium chloride; 4-9 parts of hollow microspheres; 0.2 to 0.5 part of potassium chloride; wherein the capsule wall of the magnesium oxide microcapsule is made of calcium carbonate, and the thickness of the magnesium oxide microcapsule is 30-80 microns. According to the retarded potassium magnesium phosphate cement provided by the invention, the magnesium oxide is wrapped in the calcium carbonate capsule wall in the form of microcapsules, so that the effect of gradually slowly releasing the magnesium oxide can be realized in the use process, and the problem of short coagulation time of the traditional potassium magnesium phosphate cement is solved. Besides, compared with other existing processes, the preparation method of the retarded potassium magnesium phosphate cement provided by the invention is simple, does not need to additionally add a retarder or control the activity of magnesium oxide, is simple and convenient to operate, does not reduce the early strength of the potassium magnesium phosphate cement, and has the advantages of controllable setting time, small reaction heat release, greenness, environmental protection and the like.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a slow-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 may affect the appearance, cause economic losses, and even create serious safety hazards. Reinforcement of damaged structures with repair materials is a cost-effective solution. If the traditional Ordinary Portland Cement (OPC) is used to repair and strengthen the damaged concrete, it will take a long time to block buildings and traffic, seriously affecting people's life and travel. Taking into account factors such as personnel entering the site, construction preparations, site clearance and evacuation, the repair material is ...

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.

Images