Self-stress and self-compacting fiber concrete and preparation method thereof

Abstract

The invention discloses a self-stress and self-compacting fiber concrete and a preparation method thereof. The preparation method comprises the following steps: (1) adding awater reducer or the water reducer and the thickening agent into water at the same time and stirring evenly; (2) feeding coarse aggregate and fine aggregate according to a ratio into a stirring barrel and evenly stirring; (3) adding fibers according to a certain ratio into an evenly mixed coarse aggregate-fine aggregate mixture and stirring so that the fibers can be evenly dispersed; (4) feeding cement or cement and a mineral additive into the stirring barrel according to a certain ratio and evenly stirring; and (5) feeding water doped with an additive obtained in the step (1) into the mixture obtained in the step (4), stirring evenly and discharging, thus obtaining the self-stress and self-compacting fiber concrete. According to the self-stress and self-compacting fiber concrete and the preparation method thereof, expansion of microcracks and generation of macro-cracks inside core concrete can be effectively inhibited, tensile strength, flexure strength, toughness, shock resistance and fatigue resistance of the core concrete can be improved, brittleness of the core concrete can be obviously reduced, and ductility of components can be enhanced.

Description

Technical field [0001] The invention relates to the technical field of building structural materials, in particular to a concrete filling material for steel tube concrete structures and a preparation method thereof. Background technique [0002] The concrete-filled steel tube structure is a composite structure with superior performance. Its good performance comes from the interaction between steel tube and concrete during the stress process, that is, restraint and support. Therefore, there are the following requirements for core concrete: [0003] (1) Concrete is easy to pouring, easy to ensure pouring quality and good interface performance; [0004] (2) The core concrete has small shrinkage, ensuring that steel pipes and concrete have good restraint and support effects in the short and long term; [0005] (3) It has high strength and good deformation ability, and meets the requirements of modern structure heavy load, large use space and good seismic performance. [0006] The existing...

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Problems solved by technology

[0008] 1. Common-strength concrete is cheap and widely used. However, with the increase of building structure height and load, if ordinary-strength concrete is used, the component size will be larger, which will waste the structural space and lower economic benefits;

[0009] 2. High-strength concrete has a high bearing capacity, which saves the space used by the building structure, but with the increase of strength, the brittleness of the material increases, which is not conducive to the seismic performance of the CFST structure;

However, the effect of fibers is affected by the degree of fiber dispersion. In concrete with general working performance, the degree of fiber dispersion is difficult to guarantee. At this time, it will not only increase the difficulty of pouring, but also cause the decline of concrete performance due to unevenly dispersed fibers.

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