Preparation method of green ultra-high-performance concrete

Abstract

The invention relates to a preparation method of green ultra-high-performance concrete, and solves the problems of complex process, high cost and low waste residue utilization rate of the existing ultra-high-performance concrete. According to the technical scheme, the preparation method comprises the following steps: 1) uniformly mixing fly ash and water by stirring, then feeding the mixture intoa vertical ball mill, carrying out wet grinding until the particle size is 400-800nm to obtain fly ash slurry; 2) feeding blast furnace slag, water and a dispersing agent into a planetary ball mill, and carrying out grinding until the particle size is 2.2-2.8 microns to obtain slag slurry; (3) firstly crushing tailings, then feeding the crushed tailings into a dry grinding machine, and carrying out grinding until the average particle size is 0.5-5mm to obtain a tailing fine aggregate; and (4) uniformly mixing the fly ash slurry obtained in the step (1), the slag slurry obtained in the step (2), the tailing fine aggregate obtained in the step (3), cement and silica fume by stirring, sequentially adding a polycarboxylate superplasticizer and steel fibers while continuously stirring, and carrying out stirring and molding to obtain the green ultra-high-performance concrete. The method is simple in process, low in energy consumption and low in production cost, is environmentally friendly and is high in waste residue utilization rate.

Description

technical field [0001] The invention relates to the field of concrete, in particular to a method for preparing green ultra-high performance concrete. Background technique [0002] The raw materials for preparing ultra-high performance concrete are usually ordinary Portland cement, silica fume, natural sand, quartz powder, steel fiber and water reducing agent, etc., and the production cost is several times that of ordinary concrete. In most projects, traditional concrete can meet the performance requirements, while ultra-high performance concrete is expensive and difficult to replace traditional concrete, which limits its promotion. Using wet grinding of active mineral admixtures and crushing of tailings to replace part of the cementitious material can not only reduce a lot of cost, but also improve the mechanical properties, make up for the shortage of natural sand and stone, and reduce the need for the construction industry. The mining of natural sand and gravel protects t...

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Problems solved by technology

[0003] CN109584973A discloses a design and preparation method of construction waste powder-based ecological ultra-high performance concrete, using construction waste powder to replace part of the cementitious material, reducing the The amount of cement is low, and it is ecological and environmentally friendly, but the mechanical properties are insufficient

[0004] CN109293311A discloses a kind of ultra-high performance concrete slurry, ultra-high performance concrete and preparation method thereof, and material component comprises: cement, microsilica fume, nano silicon dioxide, quartz powder, silica sand, steel fiber, water reducer and water , the experimental formula is calculated by the closest packing, and a kind of ultra-high performance concrete with excellent mechanical properties is prepared, but there are many types of materials, the cost is high, and it is not widely used.

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