Additive capable of improving durability of steam-cured concrete, and concrete coarse aggregate treated thereby

Abstract

The invention relates to an additive capable of improving the durability of steam-cured concrete, and concrete coarse aggregate treated by the additive; the additive comprises 20-80wt% of calcium hydroxide crystallization inhibitor and 20-80wt% of ettringite crystallization inhibitor. The concrete coarse aggregate is treated by the following steps of: taking the additive, wherein the mass of the additive is 0.25-3.35% of that of the concrete coarse aggregate, and preparing a solution with the concentration of 1-10wt%; then, adjusting the pH value to be 7.0-7.5; soaking the concrete coarse aggregate into the solution, or evenly spraying the solution onto the concrete coarse aggregate; and after 24hours, taking out the concrete coarse aggregate and drying until no obvious water stain is visible on the surface of the coarse aggregate. The invention effectively improves the durability of a steam-cured concrete component.

Description

technical field [0001] The invention relates to an additive for improving the durability of steam-cured concrete, which belongs to the technical field of building materials. Background technique [0002] In recent years, with the rapid development of my country's society and economy, inter-regional passenger and cargo exchanges have become increasingly frequent, and people's demand for rail transit has grown rapidly. In January 2004, the State Council passed the "Medium and Long-term Railway Network Plan", and it is planned that by 2020, the operating mileage of national railways will reach 100,000 kilometers, including 12,000 kilometers of dedicated passenger lines. Due to the impact of the financial crisis, under the encouragement of the state's policy of increasing investment, in October 2008, with the approval of the State Council, the "Medium and Long-term Railway Network Planning" was adjusted. According to the new plan, by 2020, my country's railway operating mileage...

AI Technical Summary

Problems solved by technology

First of all, the demoulding time of non-steamed concrete is generally about 12 hours, and that of steamed concrete is about 8 hours. In comparison, the turnover rate of the formwork is still insufficient; in addition, the early strength development of concrete is too fast to cause insufficient strength development in the later stage; finally, early Accelerated hydration is accompanied by the generation of a large amount of heat of hydration, which has a large negative effect on the volume stability of concrete materials

In summary, the current technical approaches to solve the insufficient durability of steam-cured concrete precast components have certain limitations.

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