Preparation method of green ultra-high performance concrete

Abstract

The invention relates to a preparation method of green ultra-high-performance concrete, which solves the problems of complex process, high cost and low utilization rate of waste slag in the existing ultra-high-performance concrete. The technical solution comprises the following steps: 1) mixing and stirring the fly ash and water evenly and then sending them into a vertical ball mill for wet grinding until the particle size is 400-800nm ​​to obtain a fly ash slurry; 2) mixing blast furnace slag, water , The dispersant is sent to a planetary ball mill for grinding to 2.2-2.8 μm to obtain a slag slurry; 3) The tailings are crushed first, and then sent to a dry mill to be ground to an average particle size of 0.5-5mm to obtain tailings fine bone 4) the tailings fine aggregate, cement and silica fume obtained by step 1) are uniformly mixed and stirred with the fly ash slurry obtained in step 1), the slag slurry obtained in step 2), cement and silica fume, and polycarboxylate is added successively under continuous stirring. Acid superplasticizer and steel fiber are mixed and molded to obtain green ultra-high performance concrete. The method of the invention has the advantages of simple process, low energy consumption, low production cost, environmental friendliness and high 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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