A kind of modification method of recycled concrete aggregate and its concrete composition and application

A technology of concrete composition and recycled concrete, applied in the field of recycled concrete, can solve problems affecting the mechanical strength of concrete, concrete broken and collapsed, and limit the application of recycled concrete aggregates, so as to achieve the effect of resource utilization and improvement of performance indicators

Active Publication Date: 2022-07-26
QINGDAO AGRI UNIV +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] According to statistics, the current annual concrete consumption in the world exceeds 6 billion cubic meters. my country's construction industry is facing two problems: On the one hand, in order to meet the huge demand for sand and gravel aggregates, a large number of quarrying has caused serious damage to the ecological environment. Destruction; on the other hand, my country's construction field wins a large number of reconstruction and demolition projects every year and produces a large amount of waste concrete, and most of these waste concrete are landfilled or piled up as construction waste, which not only takes up a lot of land, and easy to cause environmental pollution
[0004] However, the residual hardened cement mortar on the surface of the recycled coarse aggregate has high porosity and high water absorption rate. During the hydration process of concrete, the moisture in the cement in contact with the recycled concrete aggregate will be absorbed into the recycled concrete aggregate, resulting in cement The actual amount of bound water is reduced and complete hydration cannot be achieved, which not only affects the mechanical strength of the final concrete, but also leads to poor interfacial bonding between the hardened cement slurry and aggregate, poor performance in the interfacial transition zone, and easy separation when the force is applied, even causing concrete Broken and collapsed
In addition, the crushing, shaping and strengthening process causes a large number of microcracks in the internal structure of recycled concrete aggregates, and the performance of recycled concrete aggregates is much worse than that of natural aggregates, which limits the application of recycled concrete aggregates

Method used

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  • A kind of modification method of recycled concrete aggregate and its concrete composition and application
  • A kind of modification method of recycled concrete aggregate and its concrete composition and application
  • A kind of modification method of recycled concrete aggregate and its concrete composition and application

Examples

Experimental program
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Effect test

Embodiment 1

[0043] A method for modifying recycled concrete aggregates, comprising the steps of:

[0044] (1) Immerse the regenerated concrete aggregate in a calcium chloride solution with a mass concentration of 35%, and make the calcium chloride solution completely submerge the regenerated concrete aggregate, so as to be fully impregnated, filter and separate after dipping for 6 hours, and wait for The recycled concrete aggregate can not drop the liquid, and the modified aggregate can be obtained once for use.

[0045] (2) in the high-pressure reaction tank, add the ammoniacal liquor 450ml that the mass concentration is 25%, and in this high-pressure reaction tank, the ammoniacal liquor is provided above the support screen plate, the described primary modified aggregate of 550g is placed on the support screen plate, then Close the sealing cover of the reaction tank, heat the water bath of the high-pressure reaction tank to 55 ° C, and keep the temperature for 3 hours, so as to use the a...

Embodiment 2

[0048] A method for modifying recycled concrete aggregates, comprising the steps of:

[0049] (1) Immerse the recycled concrete aggregate in a calcium chloride solution with a mass concentration of 32%, and make the calcium chloride solution completely submerge the recycled concrete aggregate, so as to be fully immersed, and filter and separate after immersion for 7.5 hours. The recycled concrete aggregate can not drop the liquid, and the modified aggregate can be obtained once for use.

[0050] (2) in the high-pressure reaction tank, add the ammoniacal liquor 450ml that the mass concentration is 25%, and in this high-pressure reaction tank, the ammoniacal liquor is provided above the support screen plate, the described primary modified aggregate of 550g is placed on the support screen plate, then Close the sealing cover of the reaction tank, heat the water bath of the high-pressure reaction tank to 45 ° C, and keep the temperature for 4 hours, so that the primary modified agg...

Embodiment 3

[0053] A method for modifying recycled concrete aggregates, comprising the steps of:

[0054] (1) Immerse the recycled concrete aggregate in a calcium chloride solution with a mass concentration of 30%, and make the calcium chloride solution completely submerge the recycled concrete aggregate, so as to be fully immersed, filter and separate after 8 hours of immersion, and wait for The recycled concrete aggregate can not drop the liquid, and the modified aggregate can be obtained once for use.

[0055] (2) adding the ammoniacal liquor 450ml that the mass concentration is 20% in the high-pressure reaction tank, and in the high-pressure reaction tank, above the ammoniacal liquor, a support screen is arranged, the described primary modified aggregate of 550g is placed on the support screen, and then Close the sealing cover of the reaction tank, heat the water bath of the high-pressure reaction tank to 60 ° C, and keep the temperature for 3 hours, so that the primary modified aggre...

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PUM

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Abstract

The present invention relates to a method for modifying recycled concrete aggregate, and its concrete composition and application. The modification method includes the steps: (1) immersing the recycled concrete aggregate in a calcium chloride solution, and after soaking, the recycled concrete aggregate is taken out to obtain a primary modified aggregate for use. (2) steam curing the primary modified aggregate with alkaline water vapor obtained by heating with ammonia water in a sealed environment to obtain secondary modified aggregate for use. (3) mixing nano-silicon dioxide and cathode electrolyzed water to make a suspension, then mixing the secondary modified aggregate with the suspension and mixing well, until the nano-silica and the secondary modified aggregate The calcium hydroxide in the reaction is completed, and the modified recycled concrete aggregate is obtained. The invention adopts high-pressure alkali steaming, nano-silica-alkaline electrolysis water and other technical means to jointly modify the recycled concrete aggregate, which significantly improves the performance index of the recycled concrete aggregate and promotes the application of waste concrete.

Description

technical field [0001] The invention relates to the technical field of recycled concrete, in particular to a method for modifying recycled concrete aggregates, and a concrete composition and application thereof. Background technique [0002] The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not necessarily be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. [0003] According to statistics, the current annual consumption of concrete in the world exceeds 6 billion cubic meters. my country's construction industry is facing two problems: on the one hand, in order to meet the huge demand for sand and gravel aggregates, a large number of mountain quarrying has caused serious damage to the ecological environment. On the other hand, my country's construction field wins a large number o...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B20/12C04B28/02C04B111/20
CPCC04B20/12C04B28/02C04B2201/50C04B2111/20C04B18/16C04B20/107C04B20/1066C04B20/1074C04B14/06C04B14/048C04B2103/302
Inventor 王亮王美楠李秋义刘桂宾于琦陈旭许冬李浩然
Owner QINGDAO AGRI UNIV
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