Modified coarse aggregate, fiber nano recycled concrete prepared from modified coarse aggregate and preparation method of fiber nano recycled concrete

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a modified coarse aggregate with improved performance, excellent-performance fiber nano recycled concrete prepared from the modified coarse aggregate and a preparation method of the fiber nano recycled concrete. The preparation method includes the following steps that waste concrete test blocks and waste sintered bricks are crushed and screened to obtain a recycled coarse aggregate, and the recycled coarse aggregate is dried after being soaked with a nano silica sol to obtain a modified concrete coarse aggregate and a modified brick coarse aggregate; water, cement, fine aggregate, the modified concrete coarse aggregate, the modified brick coarse aggregate and polyvinyl alcohol fiber are preparedin proportion; the modified brick coarse aggregate, the modified concrete coarse aggregate, the cement and the fine aggregate are put into a stirrer and pre-stirred, the polyvinyl alcohol fiber is evenly dispersed and added, and dry mixing is carried out; water and a water reducer are sequentially added into the stirrer and stirred until the mixture is evenly mixed. Construction waste is effectively utilized to prepare the recycled concrete with certain performance indexes.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a modified coarse aggregate with excellent performance, fiber nano-regenerated concrete prepared by using the modified coarse aggregate and a preparation method thereof. Background technique [0002] With the continuous expansion of cities in our country, a large number of existing buildings are facing demolition, and the resulting construction waste is huge. It is estimated that my country's construction waste will reach 6.38×10 in 2020. 9 t. The recycling of abandoned construction waste is not only the need of the times, but also has great significance for protecting the environment, saving resources, and developing ecological buildings. At present, waste concrete and waste fired bricks often coexist in urban construction waste, of which waste bricks account for about 30%-50%. [0003] In engineering practice, except for a small amount of landfill in lo...

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Problems solved by technology

[0005] In the prior art, there have been many research results related to the preparation of concrete from recycled aggregates, but the following issues are still less involved: (1) The research on recycled concrete in the prior art mostly focuses on the application of a single type of recycled aggregate research on the mixture of different types of recycled aggregates, that is, mixed recycled aggregates

(2) In engineering practice, the source of recycled aggregate often appears in the form of a proportionate waste brick and waste concrete mixture, and it is difficult to separate it

(3) At present, it is generally believed that the performance of recycled concrete has certain disadvantages compared with ordinary concrete. The research on the modification and enhancement of recycled concrete mostly focuses on the reinforcement of aggregates, such as simple treatment of particle shaping and outer coating of cement slurry, as well as through the addition of various The addition of fiber materials to improve the performance of concrete is less common for the use of nanomaterials

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