A kind of preparation method of modified limestone powder for mass concrete

Abstract

The invention discloses a preparation method of modified limestone powder for large-volume concrete, which comprises the following steps: heating and stirring limestone powder and silane coupling agent in ethanol solution for 1-2h; cooling down to 60-70°C, adding polyoxygen Vinyl ether and ammonium persulfate, stirred for 1-2h and cooled; adding high-molecular polymer and stirring at high speed for 1-2h; drying and removing ethanol to obtain modified limestone powder. The limestone powder prepared by the present invention has a phase change material grafted on its surface, which can melt into a liquid state within the range of 40-60°C and absorb the heat of concrete hydration, delay the temperature rise rate, and when the temperature of the concrete is lower than 40°C, it can be cooled Solidify and release heat, reduce the temperature difference between the inside and outside of the concrete structure, and reduce surface cracking.

Description

technical field

[0001] The invention belongs to the technical field of concrete materials, and in particular relates to a preparation method of modified limestone powder for large-volume concrete. Background technique

[0002] The heat of cement hydration in concrete can easily lead to cracks in mass concrete. For some large-scale engineering projects that require mass concrete, concrete cracks can easily adversely affect the safety and stability of concrete structures. It has never stopped at home and abroad. Research on crack control of mass concrete. Phase change materials have heat storage properties and have been widely used in wall insulation materials. Introducing phase change materials into concrete to control the temperature of concrete to avoid damage to concrete due to temperature changes has become a new research topic.

[0003] In recent years, limestone powder has been widely used in concrete to reduce the pressure of social environmental protection, but the ...

Examples

Embodiment 1

[0030] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH570 and stir at 80°C for 1h; cool down to 65°C, add 242g of prenol polyoxyethylene ether, add 1g of ammonium persulfate, stir for 1.5h, and cool down to room temperature ; Add 0.5 g of PEG-PCL copolymer with a molecular weight of 20,000, stir at high speed for 1 hour, and dry to obtain modified limestone powder.

Embodiment 2

[0032] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH550 and stir at 80°C for 1.5h; cool down to 65°C, add 242g of prenol polyoxyethylene ether, add 1g of ammonium persulfate and stir for 1.5h, drop to Room temperature; add 2.5 g of PEG-PBLA copolymer with a molecular weight of 20,000, stir at high speed for 1 hour, and dry to obtain modified limestone powder.

Embodiment 3

[0034] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH570 and stir at 80°C for 2h; cool down to 65°C, add 242g of hydroxybutyl vinyl ether, add 1g of ammonium persulfate and stir for 1.5h, then cool down to room temperature; add 2.5 g of PEG-PCL copolymer with a molecular weight of 20,000 was stirred at high speed for 1 hour, and dried to obtain modified limestone powder.

technical field

[0001] The invention belongs to the technical field of concrete materials, and in particular relates to a preparation method of modified limestone powder for large-volume concrete. Background technique

[0002] The heat of cement hydration in concrete can easily lead to cracks in mass concrete. For some large-scale engineering projects that require mass concrete, concrete cracks can easily adversely affect the safety and stability of concrete structures. It has never stopped at home and abroad. Research on crack control of mass concrete. Phase change materials have heat storage properties and have been widely used in wall insulation materials. Introducing phase change materials into concrete to control the temperature of concrete to avoid damage to concrete due to temperature changes has become a new research topic.

[0003] In recent years, limestone powder has been widely used in concrete to reduce the pressure of social environmental protection, but the ...

Examples

Embodiment 1

[0030] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH570 and stir at 80°C for 1h; cool down to 65°C, add 242g of prenol polyoxyethylene ether, add 1g of ammonium persulfate, stir for 1.5h, and cool down to room temperature ; Add 0.5 g of PEG-PCL copolymer with a molecular weight of 20,000, stir at high speed for 1 hour, and dry to obtain modified limestone powder.

Embodiment 2

[0032] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH550 and stir at 80°C for 1.5h; cool down to 65°C, add 242g of prenol polyoxyethylene ether, add 1g of ammonium persulfate and stir for 1.5h, drop to Room temperature; add 2.5 g of PEG-PBLA copolymer with a molecular weight of 20,000, stir at high speed for 1 hour, and dry to obtain modified limestone powder.

Embodiment 3

[0034] Dissolve 50g of limestone powder in 200ml of absolute ethanol, add 50g of KH570 and stir at 80°C for 2h; cool down to 65°C, add 242g of hydroxybutyl vinyl ether, add 1g of ammonium persulfate and stir for 1.5h, then cool down to room temperature; add 2.5 g of PEG-PCL copolymer with a molecular weight of 20,000 was stirred at high speed for 1 hour, and dried to obtain modified limestone powder.

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