Method for preparing high-quality recycled fine aggregates by utilizing waste concrete

A technology for waste concrete and recycled fine aggregate, applied in the field of building materials, can solve the problems of high crushing index value, poor firmness, and weakened internal coarse aggregate performance, and achieves reduction of water demand ratio, improvement of durability, and improvement of firmness. sexual effect

Inactive Publication Date: 2011-04-13
QINGDAO TECHNOLOGICAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Cement stone has a high water absorption rate, and exists in the recycled fine aggregate in the form of mortar blocks and cement stone blocks, resulting in high water demand ratio of recycled fine aggregate mortar, poor firmness, and high crushing index value, which seriously affects all Properties of Formulated Recycled Concrete and Recycled Mortar
In addition, there are some buildings whose service life is too long, which weakens the performance of the internal coarse aggregate, and the demolished waste concrete is no longer suitable for the production of recycled coarse aggregate; the building itself cannot continue to be used due to the quality of the coarse aggregate. , unable to use demolition concrete to prepare recycled coarse aggregate, etc., hindering the recycling of waste concrete

Method used

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  • Method for preparing high-quality recycled fine aggregates by utilizing waste concrete
  • Method for preparing high-quality recycled fine aggregates by utilizing waste concrete
  • Method for preparing high-quality recycled fine aggregates by utilizing waste concrete

Examples

Experimental program
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Effect test

Embodiment 1

[0020] The raw materials used are 6-year-old discarded concrete with a strength grade of C30 collected from a demolition site, and the raw stones are granite particles with a maximum particle size of 31.5mm.

[0021] according to figure 1 The preparation process shown in the present invention is produced according to the method of using waste concrete to prepare high-quality recycled fine aggregate, including the following specific steps:

[0022] (1) Collect waste concrete, use a hammer crusher to process concrete blocks into particles with a particle size below 10mm as aggregate particles, and use manual selection and magnetic separation to remove wood, plastic, and metal in waste concrete before and after crushing Materials and other sundries, in this example, according to the crushing capacity of the crushing equipment used, the specific upper limit is set to 10mm, and the material particles whose particle size exceeds the specific upper limit after crushing are screened o...

Embodiment 2

[0032] The raw materials used are 12-year-old discarded concrete with a strength grade of C30 collected from a demolition site, and the raw stones are granite particles with a maximum particle size of 26.5mm.

[0033] according to figure 1 The preparation process shown in the present invention is produced according to the method of using waste concrete to prepare high-quality recycled fine aggregate, including the following specific steps:

[0034] (1) Collect waste concrete, use a hammer crusher to process concrete blocks into particles with a particle size below 8mm as aggregate particles, and use wind separation method combined with magnetic separation method to remove wood, plastic, steel materials and other impurities in waste concrete In this example, the specific upper limit is set to 8mm, and the material particles whose particle size exceeds the specific upper limit after crushing are screened out and then crushed again until the specific upper limit is met;

[0035]...

Embodiment 3

[0043] The raw materials used are 16-year-old discarded concrete with a strength grade of C20 collected from a demolition site, and the raw stones are granite particles with a maximum particle size of 31.5mm. according to figure 1 The preparation process shown in the present invention is produced according to the method of using waste concrete to prepare high-quality recycled fine aggregate, including the following specific steps:

[0044] (1) Collect waste concrete, manually remove wood, plastic and other sundries in waste concrete, use jaw crusher to process concrete blocks into particles with a particle size below 5mm as aggregate particles, and use magnetic separation to remove steel bars and other impurities , in this example, the specific upper limit is set to 5mm. The crushing process adopts a multi-stage crushing method. The materials processed by the crushing equipment are screened, and the obtained material particles with a particle size of no more than 5mm are used...

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Abstract

The invention belongs to the field of building materials and relates to a method for preparing recycled fine aggregates with waste concrete as a raw material. The method comprises the following steps: collecting waste concrete and utilizing crushing equipment to crush the concrete to aggregate particles with maximum size being not beyond 5-10mm through single-stage crushing or multi-stage crushing; utilizing strengthening equipment to remove the mortar and cement paste adhering to the surfaces of the aggregate particles, eliminate the protruding edges of the aggregate particles and ensure the appearances of the aggregate particles to be smooth to realize strengthening treatment of the aggregate particles and removing dust in the strengthening treatment process; and screening the strengthened aggregate particles and removing dust in the screening process, thus obtaining the particles with size being not beyond 5mm, namely the finished products. The method has strong applicability and high waste utilization rate, provides a feasible new way for recycling various waste concrete and has great significance in environment protection and resource protection and even sustainable social development.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a method for preparing recycled fine aggregate by using waste concrete as a raw material. Background technique [0002] At present, the annual consumption of concrete in the world exceeds 4 billion cubic meters. If the life of concrete buildings is considered to be about 50 years, then the concrete buildings built in large quantities in the 1960s will be gradually demolished in the near future. In addition to urban reconstruction and other projects, the amount of waste concrete demolished every year is very huge, and it is increasing year by year. According to incomplete statistics, my country's existing total construction area is more than 40 billion square meters, and by 2020, the construction area will increase by about 30 billion square meters. Based on this, it is estimated that at least 2 billion tons of construction waste containing a large amount of waste con...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B18/16
CPCY02W30/91
Inventor 李秋义秦原
Owner QINGDAO TECHNOLOGICAL UNIVERSITY
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