A kind of regenerated self-setting cementitious material and preparation method thereof

Abstract

The invention provides a regenerated self-hardening cementitious material and a preparation method thereof. According to the mass percentage, the cementitious material is composed of 90-60% of gypsum slag cement and 10-40% of recycled concrete powder. The preparation method is as follows: crushing waste concrete in construction waste to obtain recycled concrete fine aggregate, grinding and sieving for 2-4 times, and the apertures of the 2-4 times of sieving are successively reduced, and the grinding time is successively Increase; the sieved material is then calcined at 750°C for 2-4 hours to obtain recycled concrete powder; gypsum, clinker, and slag powder are mixed and ground for 1 hour to obtain gypsum slag cement; mixed recycled concrete powder and gypsum slag cement are prepared Recycled self-setting cementitious material. The invention utilizes a large number of industrial waste residues and construction wastes, the production energy consumption is much lower than that of common Portland cement, and the production process is energy-saving and environment-friendly, and has good economic and environmental benefits.

Description

Technical field

[0001] The invention belongs to the field of building materials, and specifically relates to a regenerated self-hardening cementitious material and a preparation method thereof. Background technique

[0002] At present, my country is in the process of large-scale urbanization, and a large number of old buildings need to be demolished in the process of urban construction, resulting in a sharp increase in the amount of waste concrete in recent years. In recent years, the total annual discharge of construction waste in my country has been between 15.5 to 2.4 billion tons, and most of the construction waste is waste concrete. If these waste concrete is not used, it will occupy a lot of valuable land resources and seriously pollute the environment, which has become a social and environmental protection issue that cannot be ignored. On the other hand, general-purpose Portland cement is increasingly restricted due to high energy consumption and high emissions due to env...

Examples

Embodiment 1

[0022] First, add anhydrous gypsum, slaked lime and limestone powder at a ratio of 1:1:1 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 14 parts of gypsum, 3 parts of clinker, and 83 parts of slag powder. Gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0023] Among them, natural anhydrite is used as gypsum; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is above S95.

[0024] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 2 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0025] 10wt% recycled concrete micropowder and 90wt% gypsum slag cement ...

Embodiment 2

[0031] First, add anhydrous gypsum, slaked lime and limestone powder in a ratio of 1:2:3 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 11 parts of gypsum, 6 parts of clinker, 83 parts of slag powder, gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0032] Among them, gypsum is anhydrite obtained by calcining desulfurized gypsum at 750°C for 2-4 hours; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is S95.

[0033] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 4 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0034] 20wt% recycled concrete mi...

Embodiment 3

[0039] First, add anhydrous gypsum, slaked lime and limestone powder in a ratio of 1:3:2 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 12 parts of gypsum, 5 parts of clinker, 80 parts of slag powder, gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0040] Among them, gypsum is anhydrite obtained by calcining desulfurized gypsum at 750°C for 2-4 hours; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is above S95.

[0041] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 3 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0042] 30wt% recycled concr...

Technical field

[0001] The invention belongs to the field of building materials, and specifically relates to a regenerated self-hardening cementitious material and a preparation method thereof. Background technique

[0002] At present, my country is in the process of large-scale urbanization, and a large number of old buildings need to be demolished in the process of urban construction, resulting in a sharp increase in the amount of waste concrete in recent years. In recent years, the total annual discharge of construction waste in my country has been between 15.5 to 2.4 billion tons, and most of the construction waste is waste concrete. If these waste concrete is not used, it will occupy a lot of valuable land resources and seriously pollute the environment, which has become a social and environmental protection issue that cannot be ignored. On the other hand, general-purpose Portland cement is increasingly restricted due to high energy consumption and high emissions due to env...

Examples

Embodiment 1

[0022] First, add anhydrous gypsum, slaked lime and limestone powder at a ratio of 1:1:1 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 14 parts of gypsum, 3 parts of clinker, and 83 parts of slag powder. Gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0023] Among them, natural anhydrite is used as gypsum; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is above S95.

[0024] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 2 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0025] 10wt% recycled concrete micropowder and 90wt% gypsum slag cement ...

Embodiment 2

[0031] First, add anhydrous gypsum, slaked lime and limestone powder in a ratio of 1:2:3 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 11 parts of gypsum, 6 parts of clinker, 83 parts of slag powder, gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0032] Among them, gypsum is anhydrite obtained by calcining desulfurized gypsum at 750°C for 2-4 hours; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is S95.

[0033] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 4 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0034] 20wt% recycled concrete mi...

Embodiment 3

[0039] First, add anhydrous gypsum, slaked lime and limestone powder in a ratio of 1:3:2 as clinker, ball mill for 50 minutes, and its specific surface area is greater than 350m 2 / kg; parts by mass: 12 parts of gypsum, 5 parts of clinker, 80 parts of slag powder, gypsum, clinker, and slag are ground together for 1 hour to prepare gypsum slag cement.

[0040] Among them, gypsum is anhydrite obtained by calcining desulfurized gypsum at 750°C for 2-4 hours; the specific surface area of ​​slag powder is greater than 400m 2 / kg, and the grade is above S95.

[0041] Crush the waste concrete in the construction waste to less than 5mm, grind it for 5 minutes and then pass it through a 0.3mm sieve, grind the sieve residue for 10 minutes and then pass 0.15mm, then grind the sieve residue for 60 minutes and pass it through a 0.075mm sieve; After calcination at 750°C for 3 hours, recycled concrete powder is obtained with a specific surface area of ​​360-450m 2 / kg.

[0042] 30wt% recycled concr...

Images