In-situ reinforcement method of recycled aggregate

A recycled aggregate and in-situ strengthening technology, applied in sustainable waste treatment, solid waste management, climate sustainability, etc., can solve equipment investment and production cost increase, non-in-situ strengthening of recycled aggregate, cement slurry Problems such as small water-cement ratio to achieve the effect of improving bond strength, avoiding production costs, and improving compressive strength

Inactive Publication Date: 2015-12-09
ZHEJIANG UNIV OF TECH
View PDF5 Cites 29 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the vacuum stirring process needs to increase the vacuum equipment, resulting in a substantial increase in equipment investment and production costs
RYU, Tam et al., Nobuaki et al. used cement-wrapped sandstone mixing process to prepare recycled aggregate concrete, forming a layer of cement paste with low water-cement ratio on the surface of recycled aggregate, which can effectively improve the recycled aggregate-cement stone interface and improve the quality of recycled bone. However, the water-cement ratio of the cement paste wrapped on the surface is small, and the cement paste is difficult to absorb into the capillary pores on the surface of the recycled aggregate that communicate with the outside world, and has no in-situ strengthening effect on the recycled aggregate.
Kong Deyu et al. used the admixture-wrapped aggregate process to further improve the recycled aggregate-cement stone interface. This process first added part of water to make the recycled aggregate absorb water, and then added admixtures for stirring to make the surface of the recycled aggregate coated. The admixture particles absorb the hydration product calcium hydroxide enriched at the interface, thereby further improving the recycled aggregate-cement stone interface, but in this process, the admixture cannot be absorbed into the capillary pores on the surface of the recycled aggregate that communicate with the outside world Particles, so there is no in-situ strengthening effect on recycled aggregates

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • In-situ reinforcement method of recycled aggregate
  • In-situ reinforcement method of recycled aggregate
  • In-situ reinforcement method of recycled aggregate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1～8

[0026] Examples 1-8: In-situ strengthening and interface strengthening simulation of recycled aggregates

[0027] (1) Prepare old concrete with a slump of 30-50mm and a design strength grade of C30. After 60 days of natural curing, use a coring machine to drill a cylindrical core sample with a diameter of 100mm and a height of 150mm from the old concrete, and use it as a simulation recycled aggregate.

[0028] (2) Disperse the admixture in water to prepare an admixture dispersion. During preparation, add a water reducer in advance, and the mass ratio of the admixture, water and water reducer is 1:1:0.01. The types of admixtures are detailed in Table 1. The water reducer is a polycarboxylate high performance water reducer.

[0029] (3) After drying the simulated recycled aggregate, soak it in the admixture dispersion for 1min, then place it in the middle of the 150mm×150mm×150mm test mold, pour new concrete around it, and the concrete mix ratio used is the same as that of the...

Embodiment 9～16

[0039] Examples 9-16: Simulation test of in-situ strengthening of recycled aggregates and the effect of in-situ strengthening on the strength of recycled aggregate concrete

[0040] (1) Prepare old concrete with a slump of 30-50mm and a design strength grade of C30. After 60 days of natural curing, use a coring machine to drill a cylindrical core sample with a diameter of 50mm and a height of 100mm from the old concrete, and use it as a simulation recycled aggregate. At the same time, the rest of the old concrete is crushed, screened, and dried to obtain recycled coarse aggregate with a nominal particle size of 5-20mm and recycled fine aggregate with a nominal particle size of less than 5mm.

[0041] (2) The designed new concrete mix ratio is (mass ratio): (cement + admixture): water: fine aggregate: coarse aggregate = 1:0.50:1.71:2.58, and the fine aggregate used is natural medium sand and A mixture of one or two kinds of regenerated fine aggregates in step (1), the coarse a...

Embodiment 17～18

[0064] Examples 17-18: In-situ strengthening of different recycled aggregates

[0065] (1) Cylinder core samples with a diameter of 50mm and a height of 53mm were drilled in the sintered ordinary brick and the autoclaved lime-sand brick, respectively, and used as simulated recycled aggregate. Sintered ordinary bricks and autoclaved lime-sand bricks are crushed, screened and dried to prepare recycled coarse aggregate with a nominal particle size of 5-20mm and recycled fine aggregate with a nominal particle size of <5mm.

[0066] (2) New concrete mix ratio (cement+admixture) designed: water: fine aggregate: coarse aggregate = 1:0.50:1.71:2.58, and the admixture used is 20% fly ash (20% refers to powder The ratio of coal ash to the total mass of all admixtures and cement) and 20% slag micropowder (20% refers to the ratio of slag micropowder to the total mass of all admixtures and cement) are compounded, and the mass of all admixtures ( That is, the mass ratio of fly ash and slag...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
shear strengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses an in-situ reinforcement method of a recycled aggregate; the method comprises that concrete containing the recycled aggregate is stirred and mixed and subjected to in-situ reinforcement, wherein the concrete comprises raw materials of an admixture, cement, a coarse aggregate, a fine aggregate and water. The method is characterized by comprising the steps: firstly, stirring all the admixture and half of the mass of water for 10-20 s, then adding all the coarse aggregate and all the fine aggregate, stirring for 10-20 s, next adding all the cement, stirring for 20-40 s, finally adding the remaining half of the water, continuing to stir for 30-60 s, and thus obtaining the in-situ reinforced recycled aggregate concrete mixture. The recycled aggregate concrete prepared by the process can achieve in-situ reinforcement of the recycled aggregate, and the compressive strength of the recycled aggregate concrete can be effectively improved.

Description

(1) Technical field: [0001] The invention relates to an in-situ strengthening technology of recycled aggregate, which belongs to the technical field of building material production. (2) Background technology [0002] With the rapid development of the construction industry and infrastructure construction, various construction wastes have increased unprecedentedly, accounting for 30-40% of the total urban waste. Construction waste contains a large amount of block materials such as concrete, sintered bricks, autoclaved bricks, and ceramics. It is a great waste of resources to use them as simple landfill materials. Reusing them as aggregates after treatment will not only save natural bone It protects the ecological environment of the aggregate production area, and can solve the problems of construction waste stacking, land occupation and environmental pollution. [0003] At present, there are many researches on the recycling of blocky construction waste at home and abroad, whic...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/00C04B18/16
CPCY02W30/91
Inventor 万励孔德玉徐林强
Owner ZHEJIANG UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap