Method for controlling shrinkage of recycled aggregate concrete

A technology of recycled concrete and recycled fine aggregate, which is applied in the field of low-shrinkage recycled concrete materials and recycled aggregate concrete materials. It can solve the problems of large shrinkage of recycled concrete and achieve good workability and excellent performance.

Inactive Publication Date: 2019-01-25
国检测试控股集团北京有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to improve the workability problems encountered in the process of preparing recycled concrete and solve the problem of large shrinkage of recycled concrete after hardening, the present invention provides a method for controlling the shrinkage of recycled concrete, that is, to use expansion agents to compensate shrinkage and aggregate Dual control technology for pre-wetting treatment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032]A low-shrinkage recycled concrete material prepared by controlling the shrinkage of recycled concrete, comprising the following components by weight ratio: cement: fly ash: slag powder: natural sand: natural stone: recycled fine aggregate : Regenerated coarse aggregate: water: water reducing agent: expansion agent The weight ratio is 9.84: 3.79: 3.79: 27.90: 25.64: 3.09: 17.12: 6.91: 0.42: 1.52;

[0033] Wherein: said cement is 42.5 grade ordinary Portland cement.

[0034] The fly ash is the powder collected in the flue gas of the pulverized coal furnace of the power plant, which is a high-quality F class I grade fly ash with a strength activity index greater than 70% and a specific surface area of ​​424m 2 / kg;

[0035] The slag powder is S95 granulated blast furnace slag powder with a specific surface area of ​​520m 2 / kg;

[0036] The natural sand is river sand, with a particle size of 0.01-3.75mm, a fineness modulus of 2.7, and a mud content of 2.0%;

[0037] The...

Embodiment 2

[0048] A low-shrinkage recycled concrete material prepared by a method of controlling the shrinkage of recycled concrete using dual control technology, including components in the following weight ratios: cement: fly ash: slag powder: natural sand: natural stone: The weight ratio of recycled fine aggregate: recycled coarse aggregate: water: water reducer: expansion agent is 8.53: 3.28: 3.28: 29.53: 30.48: 3.28: 13.08: 6.89: 0.33: 1.31;

[0049] Wherein: said cement is 42.5 grade ordinary Portland cement.

[0050] The fly ash is the powder collected in the flue gas of the pulverized coal furnace of the power plant, which is a high-quality F class I grade fly ash with a strength activity index greater than 70% and a specific surface area of ​​485m 2 / kg;

[0051] The slag powder is S95 granulated blast furnace slag powder with a specific surface area of ​​590m 2 / kg;

[0052] The natural sand is river sand, with a particle size of 0.05-4.25mm, a fineness modulus of 2.8, and a...

Embodiment 3

[0064] A low-shrinkage recycled concrete material prepared by a method of controlling the shrinkage of recycled concrete, comprising the following components by weight ratio obtained after mixing: cement: fly ash: slag powder: natural sand: natural stone: The weight ratio of recycled fine aggregate: recycled coarse aggregate: water: water reducer: expansion agent is 9.18: 3.53: 3.53: 29.07: 29.97: 3.24: 12.83: 6.88: 0.39: 1.39;

[0065] Wherein: said cement is 42.5 grade ordinary Portland cement.

[0066] The fly ash is the powder collected in the flue gas of the pulverized coal furnace of the power plant, which is a high-quality F class I grade fly ash with a strength activity index greater than 70% and a specific surface area of ​​525m 2 / kg;

[0067] The slag powder is S95 granulated blast furnace slag powder with a specific surface area of ​​610m 2 / kg;

[0068] The natural sand is river sand, with a particle size of 0.1-3.25mm, a fineness modulus of 2.5, and a mud cont...

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Abstract

The invention discloses a method for controlling shrinkage of recycled aggregate concrete. The low-shrinkage recycled concrete is prepared by adopting aggregate pre-wetting treatment and an expandingagent compensation and shrinkage dual control technology and is prepared from 20-40 parts of natural sand, 25-45 parts of natural stone, 2-15 parts of recycled fine aggregate, 10-30 parts of recycledcoarse aggregate, 5-15 parts of cement, 0.5-10 parts of pulverized fuel ash, 0.5-10 parts of slag powder, 0.1-3 parts of expanding agent, 3-8 parts of water and 0.1-1.5 parts of water reducer. The shrinkage of recycled aggregate concrete is controlled by adopting the dual control technology, the slump degree of newly stirred recycled concrete reaches 220-240 m, the slump degree H60 within 1 hour reaches 210-230 nm, the shrinkage of the recycled concrete is controlled to 4.0-10-4 or below under the situation that 50% of the recycled aggregate is replaced, and the compressive strength reaches C50 or above.

Description

technical field [0001] The invention relates to a recycled aggregate concrete material, provides a method for controlling the shrinkage of recycled aggregate concrete, and a low-shrinkage recycled concrete material prepared by the method, belonging to the field of building materials. Background technique [0002] Concrete material refers to the general designation of engineering composite materials that use cementitious materials to cement aggregates into a whole. Cement is used as cementitious material, sand and stone are used as aggregates, compound admixtures and mineral admixtures are mixed with water in a certain proportion. With stirring derived. There are many types of concrete, and there are many classification methods, such as ordinary concrete, high-performance concrete, high-strength concrete, recycled concrete, lightweight aggregate concrete, foam concrete, etc. [0003] Recycled concrete refers to the new concrete made by crushing, cleaning and grading solid co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/04C04B20/10C04B22/14
CPCC04B20/1088C04B28/04C04B40/0039C04B2201/50C04B18/16C04B14/068C04B14/02C04B18/08C04B18/142C04B22/002C04B24/24C04B22/064C04B22/142
Inventor 张利俊项斌峰秦宪明王灵秀张磊何小强韩小华邱洪华蔡素燕
Owner 国检测试控股集团北京有限公司
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