Low cost active powder concrete and preparation thereof

Abstract

The invention discloses active powder concrete which is prepared by Portland cement, steel slag powder, fly ash, silicon ash, effective water reducing agent, river sand, mixing water and steel fiber with the mass ratios of 0.52 to 0.58 : 0.16 to 0.18 : 0.10 to 0.16 : 0.13 to 0.16 : 0.012 to 0.018 : 0.9 to 1.1 : 0.14 to 0.18 : 0.156 to 0.234. The preparation method thereof is as follows: each component is sequentially added into a stirring machine for being uniformly stirred and shaped; then after the components are maintained, the temperature is raised to 80 to 90 DEG C at the temperature rising speed of 15 to 20 DEG C/h and then constant temperature maintaining is carried out for 72 to 96h; then, the components are cooled to room temperature at the cooling speed of not more than 20 DEG C/h to obtain the active powder concrete product. The invention employs the industrial wastes like steel slag powder and fly ash to replace quartz powder, partial cement and silicon ash, and employs thin river sand to replace quartz sand to prepare the active powder concrete of 200 grade under the maintaining conditions of normal pressure below 100 DEG C, thus not only being capable of remarkably reducing the material cost and the shaping maintaining cost, but also playing important roles on saving resources and energies, protecting the environment and promoting sustainable development as a large amount of industrial waste slag is used.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a low-cost active powder concrete containing a large amount of industrial waste and a preparation method thereof. Background technique [0002] Reactive Powder Concrete (RPC) is a new type of ultra-high performance cement-based composite material that was first developed by the French Bouygues company in the 1990s. It is based on the principle of maximum dense accumulation, optimizes particle gradation, and uses high-activity, high-fineness pozzolan materials and removes coarse aggregates to achieve the smallest defects such as micro-cracks and pores, so as to obtain ultra-high strength and excellent durability. During the setting and hardening process, maintenance molding processes such as pre-compression and heating are adopted to further improve its mechanical properties; micro-steel fibers are added to improve the ductility and tensile strength of RPC. Due to t...

AI Technical Summary

Problems solved by technology

However, a large amount of quartz powder is still used in its active powder, and the fine aggregate is quartz sand, so the raw material cost is still high

In addition, studies have shown that the finely ground quartz powder in active powder concrete can only observe obvious signs of reaction when it is cured under high temperature autoclave above 200°C and under a certain pressure, while under normal pressure heat curing (100°C and below) Under certain conditions, the reactivity of quartz powder is low, which makes there is an obvious interfacial transition zone between it and the cement stone matrix.

On the other hand, although silica fume and finely ground slag powder are currently recognized as the best active materials, due to their limited quantity, they can no longer meet the needs of cement concrete projects.

For other active materials, such as volcanic ash, diatomaceous earth, zeolite powder, pumice powder and rice husk ash, etc., there are also problems of insufficient resource distribution and total amount

However, industrial waste slag with a relatively wide distribution and a large amount, such as steel slag, has a large fluctuation in its composition and lacks more in-depth theoretical research and theoretical innovation. The high-efficiency utilization technology is not yet mature, and the actual utilization rate is low.

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