Method for preparing coarse aggregates from coral reefs and concrete

Abstract

The invention discloses a method for preparing coarse aggregates from coral reefs and concrete.The method for preparing the coarse aggregates comprises the following steps that 1, the cleaned coral reefs are soaked for 2-10 h with hydrochloric acid of 0.1-1 mol/L, and then the soaked coral reefs are cleaned with water to remove hydrochloric acid remaining on the surfaces of the coral reefs; 2, the coral reefs soaked with hydrochloric acid are sieved, and residues on a sieve are obtained; 3, the residues on the sieve are soaked for 10 h or above with a water glass solution with the mass fraction ranging from 5% to 30%, the soaked residues are taken out and dried, and the coarse aggregates are obtained.The method solves the technical problem of taking the coral reefs as the coarse aggregates of concrete; the coarse aggregates are successfully applied to the concrete or even sea water and sea sand concrete, the coral reefs, sea water and sea sand are directly used for preparing the concrete, the processes such as sea water desalination and sea sand desalination are omitted, the problem that long distance transportation of river sand, fresh water and gravel is high in cost is solved, and enormous social and economic benefits are achieved.

Description

technical field [0001] The invention relates to a method for preparing coarse aggregate by using coral reefs and concrete thereof, in particular to a technology for making concrete materials and products by using seawater, sea sand and coral reefs. Background technique [0002] In the report of the 18th National Congress of the Communist Party of China, the strategy of "improving the development of marine resources, resolutely safeguarding the country's maritime rights and interests, and building a maritime power" was put forward. The development of the ocean is a major demand for economic construction, social development, national security, and promotion of energy structure adjustment and scientific and technological development. [0003] my country's ocean area is 3 million square kilometers, and the total number of islands is more than 5,000. For coastal and offshore areas, there is an increasing shortage of river sand and gravel for construction. Searching for sand sourc...

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Problems solved by technology

The farthest offshore distance of islands in the South my country Sea is more than 1500km, and the longest offshore distance of islands in the East China Sea is about 530km. If fresh water, river sand, stone and other materials are transported from land, it will take a lot of labor and cost;

[0004] Due to the high mud content of untreated sea sand and complex chemical substances in sea water, the direct use of sea water, sea sand and coral reefs to produce concrete has problems of unstable work performance and poor frost resistance, and the main component of sea water is chlorine. Salts such as chemical compounds and sulfates may cause early setting of seawater and sea sand concrete, which may affect concrete construction in light cases, and may even cause engineering accidents in severe cases

[0005] The most important thing is that the surface of coarse aggregates such as untreated coral reefs contains sediment, which cannot be firmly bonded with other components in the concrete. Directly using coral reefs as coarse aggregates will lead to poor bonding performance of the concrete interface , Poor concrete workability and other issues

[0006] Another point that cannot be ignored is that the coral reef is honeycombed and porous, and the concrete slurry will enter the pores of the coral reef, resulting in a decrease in the amount of slurry, a large water demand, and insufficient concrete strength, which will eventually lead to unusable concrete.

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