High-performance marine Portland cement composite additive and marine Portland cement

Abstract

The invention relates to a high-performance marine Portland cement composite additive and marine Portland cement. The composite additive is prepared from raw materials comprising the following components in percentage by weight: 20-30% of metakaolin, 40-50% of fly ash, 5-10% of sodium silicate, 10-20% of gypsum and 10-20% of magnesium oxide, wherein the granularity of the fly ash is 32 microns ormore; and the particle size of the metakaolin is 8 microns below. The composite additive is capable of effectively improving anti-erosion ability of the marine Portland cement, reducing water demandsand reducing construction cost.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a high-performance marine Portland cement composite additive and marine Portland cement. Background technique [0002] my country is a country with a large ocean, and the development potential of ocean engineering is huge. In order to meet the demand for cement in various marine engineering constructions, the state has specially formulated the "Marine Portland Cement" standard (GB / T 31289-2014), which was officially implemented on October 1, 2015. [0003] 1. A large amount of mineral powder, fly ash and other mixed materials are added to the cement. These mixed materials need to be in an alkaline environment to exert their maximum effect. The content of clinker in marine portland cement is small, and the hydrogen produced by hydration Calcium oxide is low, and it is difficult to meet the later hydration requirements of mixed materials such as mineral powder and fly...

AI Technical Summary

Problems solved by technology

[0003] 1. A large amount of mineral powder, fly ash and other mixed materials are added to the cement. These mixed materials need to be in an alkaline environment to exert their maximum effect. The content of clinker in marine portland cement is small, and the hydrogen produced by hydration Less calcium oxide, it is difficult to meet the late hydration requirements of mixed materials such as mineral powder and fly ash

In response to this problem, some methods adopt the method of compounding multiple active activators in order to meet the hydration requirements of the mixture, but the cost of compounding multiple active activators is high, the use is complicated, and it will also lead to cement admixtures (such as reducing Water agent) has poor adaptability, reduces the working performance of cement, and even cannot be applied in concrete

[0004] 2. The amount of total mixed material in cement is more than 50%, resulting in low early strength of cement

[0005] 3. The content of high-quality S95 grade mineral powder in cement is generally above 40%, resulting in high water demand for cement

To solve this problem, the existing technology usually needs to add additional water reducing agent, which undoubtedly increases the construction cost

[0006] 4. In order to further improve the durability of marine structures, the corrosion resistance of marine Portland cement needs to be improved

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