CN-117865538-B - Preparation method of building garbage self-reinforced recycled aggregate and prepared recycled aggregate

Abstract

The invention discloses a preparation method of a self-reinforced recycled aggregate of construction waste, which comprises the following steps of (1) crushing construction waste containing red bricks and hardened cement paste, separating red brick materials and blocks containing the hardened cement paste, (2) mixing and grinding the red brick materials and a solution containing carboxyl ether to obtain modified slurry containing nanoscale red brick micropellets, (3) immersing the separated blocks containing the hardened cement paste in the modified slurry, taking out the blocks containing the hardened cement paste after the impregnation is completed, and drying to obtain the self-reinforced recycled aggregate of the construction waste, wherein the solvent is water in the solution containing the carboxyl ether, the concentration of the carboxyl ether is 0.1-0.8mol/L, the particle size range of the nanoscale red brick micropellets is 50-200nm, and in the immersing process, the mixture is heated and stirred at a heating temperature of 40-80 ℃. The method can prepare the self-reinforced recycled aggregate of the construction waste with high strength and low water absorption.

Inventors

• CHEN JING
• CHEN SHAOYOU
• JIANG JUN
• WANG XIAOMING
• YANG CHAO
• GUAN XIAOJUN
• LU ZHONGYUAN
• LI JUN

Assignees

• 宁波建工工程集团有限公司
• 西南科技大学

Dates

Publication Date

20260508

Application Date

20240103

Claims (5)

1. 1. The preparation method of the self-reinforced recycled aggregate for the construction waste is characterized by comprising the following steps of: (1) Crushing construction waste containing red bricks and hardened cement paste, and separating red brick materials and blocks containing the hardened cement paste; (2) Mixing and grinding the red brick material and the solution containing the carboxyl ether to obtain modified slurry containing nanoscale red brick micropellets; (3) Immersing the separated blocks containing the hardened cement paste in the modified slurry, taking out the blocks containing the hardened cement paste after the immersing is completed, and drying to obtain the self-reinforced recycled aggregate of the construction waste; In the step (2), the solution containing the carboxyl ether is water, and the concentration of the carboxyl ether is 0.1-0.8mol/L; In the step (3), when the block containing the hardened cement paste is immersed in the modified slurry, the mixed material is heated and stirred, and the heating temperature is 40-80 ℃; in the step (3), the block containing the hardened cement paste is immersed in the modified slurry for 0.5-6 hours.
2. 2. The method for preparing the self-reinforced recycled aggregate of construction waste according to claim 1, wherein in the step (2), the particle size of the nanoscale red brick micro-particles is 50-200nm.
3. 3. The method for preparing the self-reinforced recycled aggregate of construction waste according to claim 1, wherein in the step (3), the drying temperature is 50-80 ℃ and the drying time is 2-6 hours.
4. 4. The construction waste self-reinforced recycled aggregate is characterized by being prepared by the preparation method of the construction waste self-reinforced recycled aggregate according to any one of claims 1-3.
5. 5. The recycled aggregate of claim 4, wherein the self-reinforcing recycled aggregate of construction waste has a particle size ranging from 3 to 25mm.

Description

Preparation method of building garbage self-reinforced recycled aggregate and prepared recycled aggregate Technical Field The invention relates to the technical field of building materials, in particular to a preparation method of a self-reinforced recycled aggregate of building waste and the prepared recycled aggregate. Background In the construction waste of suburban areas, red bricks and a large amount of low-grade mortar and low-grade concrete are generally contained, which generally refers to mortar and concrete with a strength grade of M5-M10. Wherein, the low-grade mortar and the low-grade concrete have large porosity, large pore diameter and extremely high water absorption, and the strength is seriously influenced when the low-grade mortar and the low-grade concrete are used as recycled concrete aggregate. The red brick mainly contains oxides such as silicon dioxide (SiO 2), aluminum oxide (Al 2O3), iron oxide (Fe 2O3), magnesium oxide (MgO) and the like, the specific color and the texture of the red brick can be influenced by the proportion of the oxides and the existence of other materials, and the aggregate prepared from the demolished materials such as the red brick has the problems of high porosity, high water absorption, particularly high crushing index and the like, and is limited in application in concrete. In the prior art, the cement blocks and the red bricks in the construction waste concrete are not suitable for directly preparing the recycled aggregate, the treatment of the recycled aggregate still stays in simple stacking, landfill and the like, and the recycling recovery and reutilization rate is low. Disclosure of Invention The invention aims to solve the technical problem of providing a preparation method of the self-reinforced recycled aggregate for building waste, which can prepare the recycled aggregate with high strength and low water absorption. The technical scheme of the invention is that the preparation method of the self-reinforced recycled aggregate of the construction waste comprises the following steps: (1) Crushing construction waste containing red bricks and hardened cement paste, and separating red brick materials and blocks containing the hardened cement paste; (2) Mixing and grinding the red brick material and the solution containing the carboxyl ether to prepare modified slurry containing nano red brick micropellets; (3) And immersing the separated blocks containing the hardened cement paste in the modified slurry, taking out the blocks containing the hardened cement paste after the immersing is completed, and drying to obtain the self-reinforced recycled aggregate of the construction waste. After the steps are adopted, the preparation method of the self-reinforced recycled aggregate for the construction waste has the following advantages: The construction waste is separated to obtain red brick materials and hardened cement paste materials, the red brick materials and the solution containing carboxyl ether are mixed and ground to prepare modified slurry containing nano-scale red brick microparticles, and the carboxyl ether in the solution can enable the nano-scale red brick microparticles to be better suspended in the solution in the process of grinding the modified slurry. In the process of soaking the blocks of the hardened cement paste in the modified slurry, the surface tension of the blocks of the hardened cement paste can be reduced due to the presence of the ether groups in the modified slurry, so that a large amount of nano-scale red brick micro-particles and carboxyl ether enter pores or cracks of the blocks of the hardened cement paste. And in the process that the moisture of the self-reinforced recycled aggregate of the construction waste is gradually lost, the Mg ions crystallize in the pores or the cracks to form a mutually-interwoven magnesium hydroxide lamellar crystal structure, namely Mg (OH) 2 lamellar crystal structure, so that the effect of filling, supporting the pores or the cracks and refining the pore structure is achieved, the strength of the self-reinforced recycled aggregate of the construction waste is enhanced, the water absorption rate of the recycled aggregate can be remarkably reduced, and the self-reinforced recycled aggregate of the construction waste with high strength and low water absorption rate can be prepared. When the self-reinforced recycled aggregate of the construction waste is applied to concrete, on one hand, cement dissolves out a large amount of calcium ions when meeting water, and the inner surface of the pore or crack of the recycled aggregate is provided with a large amount of carboxyl anions, namely COO -, so that the solid phase of the nano-scale red brick particles which permeate into the pore or crack is negatively charged, the ferric iron ions, namely Fe 3 < + >, and the calcium ions, namely Ca 2 < + >, can be deposited on the solid phase surface of the nano-scale red brick particles due to the electrical prop