Nano reinforcing method for recycled aggregate concrete

A technology for recycling aggregate and concrete, applied in sustainable waste treatment, solid waste management, climate sustainability, etc., can solve the problem of increased equipment investment and production costs, increased vacuum equipment, difficult to regenerate aggregate reinforcement, etc. problems, to achieve the effect of increasing compressive strength, increasing strength, and improving interfacial bond strength

Inactive Publication Date: 2011-06-15
ZHEJIANG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there are many methods to improve the interface transition zone, such as using decompression mixing process or vibration mixing intensified agitation process to improve the recycled aggregate-cement interface, but the decompression mixing process needs to increase vacuum equipment, and the vibration mixing process needs to be The original equipment is modified or replaced, and its equipment investment and production costs increase significantly
The recycled aggregate concrete is prepared by the secondary mixing process of cement-wrapped sand and gravel. A layer of cemen

Method used

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  • Nano reinforcing method for recycled aggregate concrete
  • Nano reinforcing method for recycled aggregate concrete
  • Nano reinforcing method for recycled aggregate concrete

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1~3

[0016] Natural coarse aggregate is natural coarse aggregate with continuous particle size between 4.75mm and 19mm in particle size. The natural fine aggregate is a mixed sand made by mixing artificial sand and ultra-fine sand in a ratio of 80:20. The cement uses PO42.5 ordinary Portland cement from Qianchao Cement Plant. Regenerated aggregate is to roughly crush the discarded concrete with an original strength grade of about C30-C50 in the laboratory, then crush it with a jaw crusher, and sieve it into continuous-grained recycled coarse bone with a particle size between 4.75mm and 19mm. material and recycled fine aggregate <4.75mm, the superplasticizer used is SP404 superplasticizer. The silica sol used is NS-30 silica sol produced by Zhejiang Shangyu Yuda Chemical Co., Ltd. When using it, the silica sol is directly added to water in a certain proportion to prepare silica sol with a mass concentration of 10-20%; the admixture used is slag powder It is Shagang S95 grade blast...

Embodiment 4~6

[0020] Natural coarse aggregate is natural coarse aggregate with continuous particle size between 4.75mm and 19mm in particle size. The natural fine aggregate is medium sand with a fineness modulus of 2.53, and the grading is qualified. The cement uses PO42.5 ordinary Portland cement from Qianchao Cement Plant. Regenerated aggregate is to roughly crush the discarded concrete with an original strength grade of about C30-C50 in the laboratory, then crush it with a jaw crusher, and sieve it into continuous-grained recycled coarse bone with a particle size between 4.75mm and 19mm. The high-efficiency water reducer used is SP404 type high-efficiency water reducer, and the silica sol used is NS-30 type silica sol produced by Zhejiang Shangyu Yuda Chemical Co., Ltd.; the silica powder used was purchased from Elkem (International) Shanghai Co., Ltd. The white carbon black was purchased from Zhejiang Genglou Chemical Co., Ltd. The nano-SiO2 powder used was produced by Zhejiang Shangyu...

Embodiment 7~9

[0025] Natural coarse aggregate is natural coarse aggregate with continuous particle size between 4.75mm and 19mm in particle size. The natural fine aggregate is a mixture of artificial sand and ultra-fine sand in a ratio of 80:20. The cement uses PO42.5 ordinary Portland cement from Qianchao Cement Plant. Regenerated aggregate is coarsely crushed waste sintered ordinary bricks with a strength grade of MU10-MU20, then crushed by a jaw crusher, and sieved into continuous-grained recycled coarse aggregate with a particle size of 4.75mm-19mm and < 4.75mm recycled fine aggregate. Superplasticizer SP404 superplasticizer. The silica sol used is NS-30 type silica sol produced by Zhejiang Shangyu Yuda Chemical Co., Ltd.; the admixture slag powder used is Shagang S95 grade blast furnace slag powder, and the fly ash used is Grade II from Hangzhou Boneng Thermal Power Co., Ltd. fly ash.

[0026]The concrete mix ratio of each embodiment is shown in Table 3. When mixing concrete, firs...

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Abstract

The invention discloses a nano reinforcing method for recycled aggregate concrete, which belongs to the technical fields of recycling comprehensive utilization of waste and production of building materials, and is mainly characterized by comprising the steps of: mixing and stirring a recycled aggregate and a nano particle dispersion for 5-10s; after the surface of the recycled aggregate is in a moist state, further mixing the recycled aggregate with all admixtures for 5-10s; and mixing and stirring with cement, water and a high-efficiency water reducing agent for 20-45s to obtain a nano-reinforced recycled aggregate concrete mixture. The nano reinforcing method has a principle that by changing a stirring process and introducing the nano dispersion, nano particles can be adsorbed into the opening pores and microcracks of the recycled aggregate, an admixture enriched layer is further formed on the surface of the recycled aggregate, the nano particles permeating into the interiors of the opening pores of the recycled aggregate and the admixture enriched layer formed on the surface of the recycled aggregate are used for jointly absorbing calcium hydroxide enriched on the surface and the pores of the recycled aggregate in the strength development process of the recycled aggregate concrete, a gelling material with higher strength is generated through hydration, liquid-phase or solid-phase reactions so as to reinforce the recycled aggregate per se and an interface between the recycled aggregate and set cement, and thus, the strength of the recycled aggregate concrete is enhanced. After the nano reinforcement, the recycled aggregate concrete has the 28-day compression strength improved by around 15-20%.

Description

technical field [0001] The invention relates to a nano-reinforcement method for recycled aggregate concrete, which belongs to the technical field of comprehensive utilization of construction waste and production of building materials. Background technique [0002] With the acceleration of urbanization, construction wastes are also piled up in large quantities, accounting for 30-40% of the total amount of urban wastes. A large amount of concrete, sintered bricks, autoclaved bricks, ceramics and other block materials contained in them are crushed and reused as aggregates, which can not only save natural aggregate resources, alleviate the contradiction between supply and demand of aggregates, but also protect the quality of aggregate production Ecological environment, solving the problems of construction waste stacking, land occupation and environmental pollution is of great significance to saving energy and resources and protecting the ecological environment. [0003] Usually...

Claims

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Application Information

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IPC IPC(8): C04B28/00C04B18/16
CPCC04B28/02Y02W30/91C04B18/06C04B18/08C04B18/148C04B18/167C04B20/008C04B40/0032C04B2103/302
Inventor 钱匡亮詹树林钱晓倩张津践孟涛赖俊英方明晖余世策王章夫周堂贵沈翀杨青
Owner ZHEJIANG UNIV
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