A kind of preparation method of chitosan-immobilized microorganism urease in situ strengthening regeneration aggregate

A technology of recycled aggregate and in-situ strengthening, applied in the field of concrete, can solve the problems of weak surface bonding of recycled aggregate, affecting the performance of recycled aggregate, and insufficient compactness of the sedimentary layer, so as to improve mineralization efficiency, performance improvement, and water absorption. The effect of reducing the rate and crushing indicators

Active Publication Date: 2022-07-08
YANGZHOU UNIV
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current technology of microorganism-induced mineralization and strengthening of recycled aggregates still has problems such as uneven distribution of mineralized sediment product calcium carbonate on the surface of recycled aggregates, insufficient density of some sedimentary layers, and weak bonding with the surface of recycled aggregates, which affect microbial mineralization. The properties of recycled aggregates are chemically treated, which limits the application of this technology

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] 1. Preparation:

[0023] 1. Preparation of recycled aggregate:

[0024] The waste concrete is preliminarily crushed by a press, and then crushed by a jaw crusher, and the recycled aggregates with a particle size of 10-20 mm are screened out.

[0025] 2. Preparation of chitosan solution:

[0026] It is prepared by dissolving acetic acid and chitosan powder in water, and the acetic acid and chitosan in the formed chitosan solution respectively account for 1 wt% of the chitosan solution.

[0027] 3. Preparation of microbial liquid:

[0028] Preparation of microbial culture medium: Weigh 20 g of yeast extract, weigh 950 mL of deionized water, adjust the pH value to 8 with 1 mol / L sodium hydroxide after thorough mixing, and set the volume to 1 L to prepare a yeast extract medium at 121°C Sterilize for 15 min, cool to room temperature, and then weigh 20 g of sterilized urea and add it to the yeast extract medium to mix to obtain a microbial culture medium.

[0029] Pasteu...

Embodiment 2

[0042] 1. Preparation:

[0043] 1. Preparation of recycled aggregate:

[0044] The waste concrete is preliminarily crushed with a press, and then crushed with a jaw crusher, and the recycled aggregates with a particle size of 5-10 mm are screened out.

[0045] 2. Preparation of chitosan solution:

[0046] It is prepared by dissolving acetic acid and chitosan powder in water, and in the chitosan solution formed, acetic acid and chitosan respectively account for 0.5wt% of the chitosan solution.

[0047] 3. Preparation of microbial liquid:

[0048] Preparation of microbial culture medium: Weigh 20 g of yeast extract, weigh 950 mL of deionized water, adjust the pH value to 8 with 1 mol / L sodium hydroxide after thorough mixing, and set the volume to 1 L to prepare a yeast extract medium at 121°C Sterilize for 15 minutes, cool to room temperature, and then weigh 20 g of sterilized urea and add it to the yeast extract medium and mix to obtain a microbial culture medium.

[0049] ...

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 diameteraaaaaaaaaa
particle diameteraaaaaaaaaa
water absorptionaaaaaaaaaa
Login to view more

Abstract

A method for preparing chitosan-immobilized microbial urease in-situ reinforced regenerated aggregate belongs to the technical field of concrete. Regenerated aggregate covered with chitosan film; inoculated with Pasteurella spp. in microbial culture medium to obtain microbial bacterial liquid; the surface covered with chitosan film of regenerated aggregate was soaked in microbial bacterial liquid , to obtain the regenerated aggregate with surface adsorption of microbial urease; soak the regenerated aggregate with surface adsorption of microbial urease in a mixed solution of urea, calcium chloride and water with a pH of 9 to 10 and then dry it to obtain enhanced regenerated bone material. The performance of the chitosan-immobilized microbial urease in-situ enhanced regenerated aggregate prepared by the invention is significantly improved, and the water absorption rate and the crushing index are significantly reduced compared with those before treatment.

Description

technical field [0001] The invention belongs to the technical field of concrete, and particularly relates to the preparation technology of recycled aggregate. Background technique [0002] With the development of urbanization, the discharge of construction waste has increased year by year, which has become another major difficulty in protecting the environment. Construction waste is like the "sore" associated with urban construction, which not only occupies land, but also has a serious and bad impact on the surrounding environment, and some even bring about siege. At the same time, with the increasing demand for sand and gravel aggregates in the construction industry, the natural sand and gravel aggregate resources are becoming increasingly tight, and the environmental damage caused by the random mining of sand and gravel aggregates is becoming more and more prominent. Therefore, the reuse of construction waste into recycled aggregate for concrete production is of great sig...

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 Patents(China)
IPC IPC(8): C04B20/02C04B18/16
CPCC04B20/023C04B20/02C04B18/167Y02W30/91
Inventor 罗勉丁子奇刘野李旭
Owner YANGZHOU UNIV
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