Method for controlling setting time and early hydration speed of magnesium potassium phosphate cement

Abstract

The invention relates to a method for controlling the setting time and early hydration speed of magnesium potassium phosphate cement, and belongs to an early strength quick hardening cement cementing material. A composite retarder can effectively adjust the setting time of magnesium potassium phosphate cement slurry, and the setting time of the magnesium potassium phosphate cement slurry can be effectively controlled in the range of 10 minutes to 6 hours by adjusting the content of chloride and disodium hydrogen phosphate dodecahydrate in the composite retarder, so that the problems of a limited retarding effect, low operability and the like are solved; the composite retarder can change the hydration heat release characteristic of the magnesium potassium phosphate cement, the magnesium potassium phosphate cement slurry doped with the conventional retarder borax has a hydration heat release peak at the initial reaction stage and has a high heat release speed and large heat release amount, and the magnesium potassium phosphate cement doped with the composite retarder has two hydration heat release peaks and has small hydration heat release amount at the initial hydration stage; and the doped composite retarder improves the microstructure and later strength of a hardened magnesium potassium phosphate cement body, so that enough construction operable time can be ensured while the magnesium potassium phosphate cement slurry has early strength and is quickly hardened.

Description

technical field

[0001] The invention relates to an early-strength and fast-hardening cement cementitious material, in particular to a method for controlling the setting time and early hydration speed of potassium magnesium phosphate cement. Background technique

[0002] After searching the general situation of cement technology at home and abroad: some developed countries in the west have used magnesium phosphate cement for the rapid repair of concrete pavements and industrial plants, curing harmful and radioactive wastes, and combining industrial wastes to produce building materials since the 1990s. The use of magnesium phosphate cement to repair pavement has been investigated, and its durability has been effectively proved. In my country: some scholars and enterprise R&D personnel have conducted various researches on the mechanical properties of magnesium phosphate cement and its various properties as a repair material in the laboratory. So far, it has not developed to the...

Examples

Embodiment 1

[0036] The traditional retarder borax, which accounts for 10% of the cement mass, is mixed into the potassium magnesium phosphate cement. First, the borax and potassium dihydrogen phosphate are added to the water. Procedure, first take the slow speed stirring for 1-2 minutes, then adjust to the fast rotating gear and stir for 1-2 minutes to obtain the potassium magnesium phosphate cement reaction solution, continue to adjust to the slow speed stirring gear, slowly put in dead-burned magnesium oxide, and wait for it to be put in After completion, adjust to rapid stirring for 1 to 2 minutes to obtain potassium magnesium phosphate cement slurry (A).

[0037]The same proportion of potassium magnesium phosphate cement is mixed with a composite retarder that accounts for 10% of the cement mass, and the composite retarder is added to the water. , stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, then adjust to ...

Embodiment 2

[0042] Add compound retarder into potassium magnesium phosphate cement, adjust the content of chloride in compound retarder, add compound retarder with different chloride content into water, use SJ-160 double shaft speed at room temperature The manual control program of the cement slurry mixer is to stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, and then adjust to the fast rotation gear and stir for 1 to 2 minutes to obtain a potassium magnesium phosphate cement reaction solution. Continue to adjust to the slow speed stirring gear, slowly put in the dead-burned magnesium oxide, and after the addition is completed, adjust to the fast stirring speed for 3 to 5 minutes to obtain potassium magnesium phosphate cement slurry.

[0043] The setting time of the slurry was tested with a Vicat instrument at an ambient temperature of 20° C., and the compressive strength of the hardened body was tested with a cylin...

Embodiment 3

[0047] Mix the composite retarder into potassium magnesium phosphate cement, adjust the content of disodium hydrogen phosphate dodecahydrate in the composite retarder, add the composite retarder with different content of disodium hydrogen phosphate dodecahydrate into water, Use the manual control program of the SJ-160 double-shaft speed cement slurry mixer at room temperature, stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, and then adjust to the fast rotation gear and stir for 1 to 2 minutes to obtain the potassium magnesium phosphate cement reaction solution, continue to adjust to the slow speed stirring gear, slowly put in dead-burned magnesium oxide, and after the addition is completed, adjust to rapid stirring for 3 to 5 minutes to obtain potassium magnesium phosphate cement slurry.

[0048] The setting time of the slurry was tested with a Vicat instrument at an ambient temperature of 20° C., and t...

technical field

[0001] The invention relates to an early-strength and fast-hardening cement cementitious material, in particular to a method for controlling the setting time and early hydration speed of potassium magnesium phosphate cement. Background technique

[0002] After searching the general situation of cement technology at home and abroad: some developed countries in the west have used magnesium phosphate cement for the rapid repair of concrete pavements and industrial plants, curing harmful and radioactive wastes, and combining industrial wastes to produce building materials since the 1990s. The use of magnesium phosphate cement to repair pavement has been investigated, and its durability has been effectively proved. In my country: some scholars and enterprise R&D personnel have conducted various researches on the mechanical properties of magnesium phosphate cement and its various properties as a repair material in the laboratory. So far, it has not developed to the...

Examples

Embodiment 1

[0036] The traditional retarder borax, which accounts for 10% of the cement mass, is mixed into the potassium magnesium phosphate cement. First, the borax and potassium dihydrogen phosphate are added to the water. Procedure, first take the slow speed stirring for 1-2 minutes, then adjust to the fast rotating gear and stir for 1-2 minutes to obtain the potassium magnesium phosphate cement reaction solution, continue to adjust to the slow speed stirring gear, slowly put in dead-burned magnesium oxide, and wait for it to be put in After completion, adjust to rapid stirring for 1 to 2 minutes to obtain potassium magnesium phosphate cement slurry (A).

[0037]The same proportion of potassium magnesium phosphate cement is mixed with a composite retarder that accounts for 10% of the cement mass, and the composite retarder is added to the water. , stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, then adjust to ...

Embodiment 2

[0042] Add compound retarder into potassium magnesium phosphate cement, adjust the content of chloride in compound retarder, add compound retarder with different chloride content into water, use SJ-160 double shaft speed at room temperature The manual control program of the cement slurry mixer is to stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, and then adjust to the fast rotation gear and stir for 1 to 2 minutes to obtain a potassium magnesium phosphate cement reaction solution. Continue to adjust to the slow speed stirring gear, slowly put in the dead-burned magnesium oxide, and after the addition is completed, adjust to the fast stirring speed for 3 to 5 minutes to obtain potassium magnesium phosphate cement slurry.

[0043] The setting time of the slurry was tested with a Vicat instrument at an ambient temperature of 20° C., and the compressive strength of the hardened body was tested with a cylin...

Embodiment 3

[0047] Mix the composite retarder into potassium magnesium phosphate cement, adjust the content of disodium hydrogen phosphate dodecahydrate in the composite retarder, add the composite retarder with different content of disodium hydrogen phosphate dodecahydrate into water, Use the manual control program of the SJ-160 double-shaft speed cement slurry mixer at room temperature, stir at a slow speed for 1 minute, add potassium dihydrogen phosphate, continue to stir at a slow speed for 1 to 2 minutes, and then adjust to the fast rotation gear and stir for 1 to 2 minutes to obtain the potassium magnesium phosphate cement reaction solution, continue to adjust to the slow speed stirring gear, slowly put in dead-burned magnesium oxide, and after the addition is completed, adjust to rapid stirring for 3 to 5 minutes to obtain potassium magnesium phosphate cement slurry.

[0048] The setting time of the slurry was tested with a Vicat instrument at an ambient temperature of 20° C., and t...

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