Self-compacting micro-expansion concrete and preparation method thereof

Abstract

The invention discloses self-compacting micro-expansion concrete. The concrete comprises a first group of raw materials including water and ester, and a second group of raw materials including cement, mixed sand, crushed stones, an expanding agent, an admixture, water reducer and dipropyl amine. The admixture comprises active mineral admixture. A preparation method of the self-compacting micro-expansion concrete includes the steps that firstly, ester is dispersed in water to be evenly dispersed, the expanding agent and the water reducer are added into a mixture of the ester and water at a certain flow speed, and the mixture is still standing for 12 h or longer; secondly, the mixed sand and the crushed stones are mixed evenly and smashed into particles, then evenly mixed with cement, the admixture and dipropyl amine and still standing for 3 h or longer; thirdly, the mixture obtained in the second step is added into the mixture obtained in the first step at the flow speed of 20-50 kg / h, and stirring is conducted in the addition process at the speed of 10-20 rpm so as to prepare the self-compacting micro-expansion concrete. Flowability of the concrete can be improved, and the construction requirements for delayed coagulation and plasticity maintenance are met.

Description

technical field [0001] The invention relates to a self-compacting micro-expansion concrete and a preparation method thereof. Background technique [0002] At present, concrete pouring generally adopts bucket self-draining or pump truck pumping, but both require vibration. Due to limited conditions on site, manual vibrating rods are generally used for vibrating. Manual vibrating has strict requirements on the thickness of a pouring, the insertion depth and angle of the vibrating rod, the vibrating speed, the vibrating time, the vibrating sequence, and the vibrating point. On-site workers are unskilled or not standardized enough to easily cause leakage and over-vibration. [0003] Once leakage or over-vibration occurs, it will affect the quality of concrete pouring, and in severe cases, it will cause diseases that are not easy to repair. For example: vibration leakage will cause too many air bubbles on the concrete surface, pockmarked surface, honeycomb, exposed ribs, dog h...

AI Technical Summary

Problems solved by technology

However, when pouring special-shaped components, special thin-walled structures, high-slender structures, shallow buried excavation projects, tunnels and underground structures, and concrete-filled steel pipe structures, vibration is quite difficult or even has no room for vibration operations.

[0005] Especially when pouring concrete-filled steel pipe arch bridges, using traditional concrete pouring can easily cause blockage of steel pipes and inaccurate pouring, which will affect the overall stress of steel pipes and concrete