High-performance concrete slurry-shaped admixture mixed by CaCO3 having multi-scale particle sizes

Abstract

The invention discloses a high-performance concrete slurry-shaped admixture mixed by CaCO3 having multi-scale particle sizes. The admixture solves the problems that current high-performance concrete has high costs and a large number of unhydrated cement particles exist, and the working performance is improved. The dry slurry-shaped admixture comprises the following components in percentages by weight: 1%-5% of nano micro limestone, 5%-20% of limestone powder, 50%-80% of ultrafine mineral slag, 5%-40% of a composite activator, and 0.1%-0.3% of a water reducing agent, wherein the total percentage is 100%; and water is added into each component, wet grinding is performed, uniform mixing is performed, and therefore the slurry-shaped admixture is obtained, wherein each component is controlled to meet the following grading requirements after wet grinding is performed: the nano micro limestone is composed of slurry with two particle size ranges including a median particle diameter of 2-1 [mu]m and a median particle diameter of less than 0.3 [mu]m; the ultrafine mineral slag has a median particle diameter of 4-8 [mu]m; and the composite activator and the limestone powder separately have amedian particle diameter of 9-13 [mu]m. The admixture disclosed by the invention has simple components and low production costs, and fully utilizes mineral slag; and slurry produced by the admixture has the advantages of high fluidity, good dispersibility, no shrinkage, micro expansion and early strength.

Description

technical field [0001] The invention relates to a concrete admixture, in particular to a multi-scale particle size CaCO 3 High performance concrete paste admixture. Background technique [0002] Ultra-high performance concrete (UHPC) is a new type of cement-based engineering material with ultra-high mechanical properties and good durability. The application prospect of UHPC is very broad. It can not only be applied to some new special engineering components, but also can be used as a repair material to maintain and strengthen basic engineering. Although the application potential of UHPC is very great, its application in practical engineering has not been widely used due to various factors, among which the ultra-high production cost of UHPC is one of the main reasons. The traditional UHPC mix ratio contains a large amount of cement, silica fume, water reducing agent and steel fiber and other components, and the cement content is usually 1100-1300kg / m 3 , the content of sil...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned cementitious materials may have a phenomenon of low compressive strength in the later stage due to high limestone content, or there may be shrinkage after construction and solidification due to material batching problems, resulting in insufficient structural strength of the concrete after solidification, so the batching room for improvement

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