Recycled concrete and its preparation method

Abstract

The invention discloses a recycled concrete and a preparation method thereof, which belong to the technical field of concrete. The key point of the technical solution is a recycled concrete, which comprises the following components in parts by weight: 340-360 parts of cement, 90-100 parts of slag powder 60-80 parts of fly ash, 1000-1150 parts of modified recycled coarse aggregate, 620-640 parts of fine aggregate, 5-7 parts of admixture and 160-170 parts of water; the modified recycled coarse aggregate It is made by crushing and screening waste concrete, physical strength and chemical modification. The modified regenerated coarse aggregate obtained after the waste concrete of the present invention is modified has excellent mechanical strength, low porosity and small water absorption, and is composed of modified regenerated coarse aggregate, cementitious material, fine bone The recycled concrete made of raw materials and admixtures has excellent mechanical strength and impermeability.

Description

technical field [0001] The invention relates to the technical field of concrete, more specifically, it relates to a recycled concrete and a preparation method thereof. Background technique [0002] Concrete is the building material with the largest consumption in the field of civil engineering. In recent years, with the development of urban construction, a large amount of waste concrete is produced every year in my country due to the reconstruction and expansion of buildings and the maintenance and demolition of old buildings; these Most of the waste concrete is piled up near the roads and rivers in the suburbs of the city, which not only occupies land resources, but also affects the ecological environment. In this regard, people began to develop and utilize recycled concrete. [0003] Recycled concrete refers to new concrete made by crushing, cleaning and grading discarded concrete blocks, mixing them with grading in a certain proportion, replacing part or all of natural agg...

AI Technical Summary

Problems solved by technology

[0004] Compared with natural coarse aggregate, recycled coarse aggregate has high porosity and high water absorption; with the increase of water absorption of recycled coarse aggregate, the water consumption of concrete mixture is also increasing. When mixing concrete , the slump will decrease, which will affect the mechanical properties of recycled concrete; and the concrete will be broken and deformed again during the crushing process, resulting in increased surface cracks, which also leads to the use of recycled concrete made of coarse aggregate. The impermeability performance is significantly lower than that of ordinary concrete, which limits the application range of recycled concrete. Therefore, it is necessary to develop a recycled concrete with good impermeability and mechanical properties.

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