High-activity composite mixed material for improving erosion resistance of cement concrete

Abstract

The invention belongs to the field of building materials, and particularly relates to a high-activity composite mixed material for improving erosion resistance of cement concrete. The high-activity composite mixed material is prepared from the following raw materials in parts by weight: 50-80 parts of calcined clay, 19-49.9 parts of limestone and 0.1-1 part of a water reducing agent, wherein the mass percentage of CaO in the limestone is less than 48%. The invention provides the composite mixed material prepared from the calcined clay, the low-grade limestone and the water reducing agent, andthe composite mixed material has relatively high activity. When the composite mixed material is used in a large amount, strength of cement and concrete is not reduced, and meanwhile, sulfate corrosionresistance and chloride ion permeation resistance of the cement and the concrete can be obviously improved.

Description

technical field [0001] The invention belongs to the field of building materials, in particular to a high-activity composite mixed material for improving the erosion resistance of cement concrete. Background technique [0002] Existing techniques and drawbacks: [0003] Mixed materials refer to activated silica, alumina and other effective minerals as the main components, which can replace clinker in cement production, or replace cement in the process of concrete mixing, have pozzolanic activity or potential hydraulicity, and can improve cement and concrete Performance powder material. In addition to reducing the cost, using a large amount of mixed materials in cement and concrete can also improve the workability and durability of cement and concrete to a certain extent, and has been increasingly valued by manufacturers. [0004] At present, the main mixed materials used in China's cement and concrete industry are traditional industrial waste such as finely ground slag and ...

AI Technical Summary

Problems solved by technology

[0004] At present, the main mixed materials used in China's cement and concrete industry are traditional industrial waste such as finely ground slag and fly ash. A large number of studies have shown that both slag and fly ash can enhance the compactness of cement and concrete, and improve the resistance of cement stone hardening. The ability of the outside world to erode ion penetration, however, the improvement of this compactness needs to be based on a higher dosage, and it will inevitably bring other adverse effects: 1) The slag contains a high aluminum phase, and the hydration After that, more AFm (monosulfide calcium aluminate hydrate) is generated, and it is easier to generate secondary ettringite (AFt, trisulfide calcium aluminate hydrate) in a sulfate erosion environment, and ettringite crystal expansion occurs , so that its resistance to sulfate erosion is reduced; 2) the use of large amounts of fly ash will easily increase the number of interconnected pores in cement stones, making it easier for corrosion ions to migrate and diffuse in cement stones, resulting in a decrease in the resistance of cement and concrete to chloride ion penetration ; 3) After more than ten years of rapid development of China's cement industry and the intensive development of commercial concrete, a large amount of high-quality mixed materials have been basically exhausted, and the remaining industrial waste such as slag and fly ash or activity is not high, so it is difficult to ensure the strength , or the price is high, the transportation distance is long, and it is difficult to be widely used

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