Machine-made sand concrete and preparation method thereof

Abstract

The invention discloses machine-made sand concrete and a preparation method thereof. The concrete is prepared from 120 to 200 parts of cement, 70 to 110 parts of coal ash, 750 to 1200 parts of gravels, 400 to 750 parts of machine-made sand, 150 to 220 parts of tap water and 5 to 8 parts of additives, wherein the machine-made sand comprises 150 to 200 parts of coarse sand and 200 to 550 parts of fine sand. The flowability (expansibility) is 550 + / -100 mm, the concrete is soft, easy to construct and pump, low in water-binder ratio and high in strength, and the adopted artificial machine-made gravel is environmentally friendly and capable of saving energy.

Description

technical field [0001] The invention relates to a machine-made sand concrete and a preparation method thereof. Background technique [0002] At present, machine-made gravel and machine-made sand are mostly used to prepare concrete. Machine-made crushed stone and machine-made sand have poor gradation, rough surface, many edges and corners, and poor grain shape, so the mixed machine-made sand concrete has high water demand, easy segregation, and poor pumpability. Especially in the preparation of low-grade machine-made sand concrete, the amount of cementitious materials is small, the concrete is discrete, poor in cohesion, poor in water retention, poor in fluidity, and pumpability and construction performance cannot be guaranteed. At the same time, during the downward pumping process, the sand and gravel without slurry in the vertical pump pipe fall to the bottom of the pump pipe first, directly causing the concrete to block the pipe; once the pumping is stopped halfway, the c...

AI Technical Summary

Problems solved by technology

Machine-made crushed stone and machine-made sand have poor gradation, rough surface, many edges and corners, and poor grain shape, so the mixed machine-made sand concrete has high water demand, easy segregation, and poor pumpability

Especially in the preparation of low-grade machine-made sand concrete, the amount of cementitious material is small, the concrete is discrete, poor in cohesion, poor in water retention, poor in fluidity, and pumpability and construction performance cannot be guaranteed

At the same time, during the downward pumping process, the sand and gravel without slurry in the vertical pump pipe fall to the bottom of the pump pipe first, directly causing the concrete to block the pipe; once the pumping is stopped halfway, the concrete in the pump pipe Under the action, the slurry flows away, leaving sand and gravel, which is also easy to cause plugging; some people solve this problem by increasing the amount of cement to improve the workability of concrete. Although this method can effectively avoid concrete plugging, it improves the concrete. cost

Therefore, it is necessary to develop a kind of machine-made sand concrete with simple preparation process, low cost, excellent workability and pumpability, which can effectively solve the downward pumpability and workability of low-grade concrete made of machine-made sand. problems, to avoid concrete pipe plugging, causing unnecessary losses

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