Lightweight high-strength concrete doped with recycled aggregate, machine-made sand and stone powder

Abstract

The invention provides a lightweight high-strength concrete doped with recycled aggregate, machine-made sand and stone powder. The lightweight high-strength concrete comprises the following raw materials: 350-450 parts of cement, 200-500 parts of recycled aggregate, 500-700 parts of machine-made sand, 100-400 parts of stone powder, 5-15 parts of a water reducing agent, 100-300 parts of a reinforcing agent and 100-200 parts of water; wherein the particle size of the machine-made sand is smaller than 2.5 mm, the stone powder content is 16%-17%, the apparent density is 2-3 g / cm<3>, the porosity is 28%-29%, and the fineness modulus is 2-2.5; the particle size of the recycled aggregate is less than 25mm, the apparent density is 2400-2500kg / m<3>, the bulk density is 1500-1600kg / m<3>, the porosity is 50-52%, and the water absorption rate is 4-4.5%. The invention also provides a preparation method and application of the lightweight high-strength concrete. By selecting and scientifically proportioning proper machine-made sand, recycled aggregate and stone powder, the concrete can have two incompatible properties of low density and high strength at the same time, the density is as low as 1829-2058 kg / m<3>, and the compressive strength can reach 78.9-85.6 MPa.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to a lightweight high-strength concrete mixed with recycled aggregate, machine-made sand and stone powder. Background technique [0002] With the rapid development of my country's economy and the acceleration of urbanization, billions of tons of natural aggregates are collected for pouring concrete every year, and the demolition of old buildings produces a large amount of construction waste, which brings a series of resources. Exhaustion, environmental pollution, energy consumption and other issues. In order to alleviate this contradiction, aggregates made from waste concrete in construction waste after crushing and screening are called recycled aggregates. Recycled concrete produced from recycled aggregates through a series of treatments can not only improve the disaster prevention ability of the structure, but also make full use of waste aggregates; it can not only pr...

AI Technical Summary

Problems solved by technology

[0003] In recent years, my country's central and western regions such as Yunnan, Guizhou, Guangxi, Chongqing and other regions have built high-speed railways and expressways. Sand is expensive and not conducive to ecological construction. It is imperative to use machine-made sand instead of natural sand to prepare concrete

[0004] However, the quality and quality of machine-made sand in various regions are currently uneven. The gradation and particle shape of the prepared machine-made sand are poor, and the content of stone powder is high. The workability and mechanical properties of the prepared concrete are poor in repeatability, which affects its popularization and use.

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