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Freeze-thaw resistant recycled concrete and preparation method thereof

A cyclic regeneration and freeze-thaw resistance technology, applied in the field of building materials, can solve the problems of poor freeze-thaw resistance of recycled concrete, restrict development and application, and large expansion pressure, so as to improve freeze-thaw resistance and promote hydration. , the effect of internal densification

Active Publication Date: 2021-09-24
崇德建材集团有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, compared with artificial sand aggregate, recycled aggregate has residual slurry attached to its surface, which has the characteristics of high water absorption and low apparent density, and has a higher water content. Therefore, the recycled aggregate prepared from recycled The free water inside the concrete is easy to crystallize and expand under the low temperature environment, resulting in a large expansion pressure inside the recycled concrete specimen, resulting in cracks. After the specimen is subjected to repeated freeze-thaw cycles, the surface of the recycled concrete will appear cracking, peeling, falling off, etc. , the freeze-thaw resistance of recycled concrete is not good, which seriously restricts its development and application in the construction industry

Method used

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  • Freeze-thaw resistant recycled concrete and preparation method thereof
  • Freeze-thaw resistant recycled concrete and preparation method thereof
  • Freeze-thaw resistant recycled concrete and preparation method thereof

Examples

Experimental program
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Effect test

preparation example 1

[0039] A silicone resin modified regenerated coarse aggregate and a silicone resin modified regenerated fine aggregate are prepared according to the following steps:

[0040] Put the waste cement blocks into the crusher and crush them to aggregates with a maximum particle size of no more than 31.5mm, and put the aggregates into the 5X series gravel shaping machine to produce machine-made sand equipment. The speed is 100m / s, and the reshaped recycled aggregate particles are rolled and screened once, and then screened twice, and the recycled aggregates with a particle size of 3-25mm are screened out, and the recycled aggregates are put into water and soaked for 48 hours. Take out the recycled aggregate and dry it in the sun;

[0041] Weigh 1kg of silane coupling agent KH-550 and 99kg of water, stir and blend, configure a silicone resin emulsion with a concentration of 1wt%, add 100kg of silicone resin emulsion to 200kg of recycled aggregate, and stir at a speed of 600rpm After ...

preparation example 2-3

[0043] A silicone resin-modified regenerated coarse aggregate and a silicone resin-modified regenerated fine aggregate differ from Preparation Example 1 in that the concentration of the silicone resin emulsion is different, and the specific concentrations are shown in Table 2 below.

[0044] Table 2. Concentrations of Silicone Resin Emulsions

[0045] Preparation example Silane coupling agent KH-550 / kg water / kg Silicone resin emulsion concentration / wt% Preparation Example 1 1 99 1 Preparation example 2 4 96 4 Preparation example 3 2 98 2

Embodiment 1

[0047]Embodiments 1-7 all provide a freeze-thaw cycle-resistant recycled concrete, which will be described below by taking Embodiment 1 as an example.

[0048] A kind of anti-freeze-thaw cycle recycled concrete provided in embodiment 1, its preparation steps are:

[0049] Take by weighing 24kg Portland cement, 73kg by the organosilicon resin modified regeneration fine aggregate that preparation example 3 makes, 90kg by the organosilicon resin modification regeneration coarse aggregate that preparation example 3 makes, 13.2kg water, 3kg poly Carboxylate superplasticizer LA-8Q, 0.12kg fatty alcohol polyoxyethylene ether AEO-7 and 0.5kg rubber powder RA-789A (mesh 20-60 mesh);

[0050] Put Portland cement, organosilicon resin modified regenerated fine aggregate, organosilicon resin modified regenerated coarse aggregate, polycarboxylate superplasticizer and rubber powder into the mixer, and stir and blend at a speed of 600rpm for 5min. After the stirring is completed, water and f...

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Abstract

The invention discloses freeze-thaw resistant recycled concrete and a preparation method thereof. The concrete is prepared from the following raw materials: Portland cement, fine aggregate, coarse aggregate, water, a water reducing agent, an air entraining agent and rubber powder; the fine aggregate comprises organic silicon resin modified recycled fine aggregate, and the coarse aggregate comprises organic silicon resin modified recycled coarse aggregate. The rubber powder and the air entraining agent provide an expansion space for free water expansion in the recycled concrete, the expansion stress in the recycled concrete is reduced, meanwhile, the surface of the recycled aggregate is coated with the organic silicon resin, the water absorption of the recycled aggregate is reduced, and the freeze-thaw resistance of the recycled concrete is improved; and the modified recycled aggregate is tightly connected with a cement gel system, so the interior of the recycled concrete is compact, and the compressive strength of the recycled concrete is enhanced.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a freeze-thaw-resistant recycled concrete and a preparation method thereof. Background technique [0002] The development of the construction industry is often accompanied by the generation of a large amount of construction waste. Construction waste mainly refers to a large number of waste cement blocks produced during the demolition of abandoned buildings. Since the cement blocks contain a large amount of calcium oxide and other components, long-term contact with the soil will change the acidity and alkalinity of the soil, thereby changing the soil properties. , so the waste cement blocks cannot be buried on the spot, and it is difficult to process them. [0003] At present, the construction industry is gradually trying to recycle waste cement blocks: the waste cement blocks are broken into recycled aggregates of different particle sizes, and the recycled aggregates ...

Claims

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Application Information

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IPC IPC(8): C04B28/04C04B20/10C04B18/22C04B16/04C04B18/16C04B24/32C04B28/26
CPCC04B28/04C04B20/1051C04B18/22C04B16/04C04B18/16C04B24/32C04B28/26C04B2201/50C04B2103/302Y02W30/91
Inventor 章碧业戴剑海
Owner 崇德建材集团有限公司
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