Preparation methods of chemical micro-corroded coral aggregate and geopolymer-based ultrahigh-strength coral concrete

Abstract

The invention discloses preparation methods of chemical micro-corroded coral aggregate and geopolymer-based ultrahigh-strength coral concrete, and relates to the technical field of concrete. The preparation method of the aggregate specifically comprises the steps that coral coarse aggregate is placed and soaked in a phosphoric acid solution, taken out and directly dried to obtain chemical micro-corroded coral coarse aggregate; and after ball milling and sieving, compounding is performed by adopting a directional grading compounding method to obtain chemical micro-corroded coral sand. The coral coarse aggregate is subjected to micro-corrosion by using phosphoric acid, so that phosphate grows on the surface of the coral aggregate and in communicated pores in situ, and the porosity of the coral coarse aggregate is reduced. The chemical micro-corroded coral coarse aggregate is subjected to ball milling and screening to obtain chemical micro-corroded coral fine aggregate, and then the coral aggregate is compounded in a directional grading compounding mode to obtain coral sand with low void ratio and high close packing density. The concrete is prepared by taking the substance as aggregate and an alkali-activated active powder material as a cementing material, so that the effects of delaying the setting time of the geopolymer-based coral aggregate concrete, optimizing a concrete interface transition region and improving the mechanical property of the concrete can be achieved.

Description

technical field [0001] The invention relates to the technical field of concrete, in particular to a method for preparing chemically micro-corroded coral aggregate and geopolymer-based ultra-high-strength coral concrete. Background technique [0002] In recent years, the development of islands in my country has gradually increased, and the engineering construction as the basis for development has also encountered certain challenges. The reserves of building aggregate gravel and river sand in inland areas are decreasing day by day, and the cost of inland shipping sand and gravel for ocean construction is high, which is not conducive to project cost control. At the same time, there is a huge stock of coral reefs and reef sand around the islands, which are potential building materials. However, the particularity of the growth environment of undisturbed coral reefs leads to their own porous structure, different shapes, low strength and a large amount of sediment. From the persp...

AI Technical Summary

Problems solved by technology

[0004] At present, people often use strong acids such as HCl and H 2 SO 4 Technical methods such as immersion treatment of aggregates are used to solve and remove a large amount of salt and sediment on the surface of coral reef coarse aggregates and in the pores, but such treatment methods will introduce corrosive ions such as sulfate and chloride ions, which will be detrimental to the durability of concrete. influences

For example, the Chinese invention patent application number CN201610079268.8 announced "a method of using coral reefs to prepare coarse aggregates and concrete", which uses dilute hydrochloric acid to soak coral aggregates. The main problem faced by this method is that Cl - The presence of may increase the risk of steel corrosion in structural concrete

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