Light low-shrinkage super-high performance concrete and preparation method thereof

Abstract

The invention discloses light low-shrinkage super-high performance concrete which is prepared from cement, coal ash beads, silica fume, pottery sand, a brass coated steel fiber, shrinkage and viscosity reduction type water reduction agent, a water-retention shrinkage-reduction inner curing agent and water as main raw materials. According to the concrete, the pottery sand is adopted as aggregate, the self weight of the concrete is reduced, and a high-strength and dense 'arch housing' interface area is formed on the surface of the pottery sand by using a pre-mixing process, so that the interfacestrength is improved, and the mechanical properties and the anti-penetrability performance of the concrete are improved; due to the adoption of the shrinkage and viscosity reduction type water reduction agent and the coal ash beads, the working performance and the density of the concrete are improved; due to the adoption of the pre-wetted pottery sand and the developed water-retention shrinkage-reduction inner curing agent, reduction of wetness inside the concrete is retarded, the self-shrinkage and the drying shrinkage of the concrete are reduced, and the volume stability of the concrete isimproved. While the self weight of the concrete is reduced, the light low-shrinkage super-high performance concrete disclosed by the invention is good in working performance, mechanical property, anti-penetrability and durability, and has significant practical application values.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a lightweight low-shrinkage ultra-high performance concrete and a preparation method thereof. Background technique [0002] Nowadays, concrete bridge deck bridges are gradually developing towards long-span, high-heavy load, light weight, and high durability, which puts forward new requirements for the performance of concrete materials. Major, easy to damage and other shortcomings, can no longer meet the actual needs of the project. Compared with ordinary concrete, ultra-high performance concrete has the following advantages: the removal of coarse aggregate improves the homogeneity of aggregate; the gradation of fine aggregate is optimized to increase the compactness of aggregate; the addition of The micro-aggregate filling effect and the ultra-fine active mineral admixture of the volcanic ash fire system reduce the porosity and optimize the internal pore structure; ...

AI Technical Summary

Problems solved by technology

[0003] However, the following problems still exist in ultra-high-performance concrete at present: due to its low water-cement ratio and high amount of ultra-fine particles in the preparation process, ultra-high-performance concrete has the disadvantages of high viscosity and large slump loss, which is not conducive to its pouring Construction; the amount of cement used in ultra-high performance concrete is relatively high, and there are a large number of unhydrated cement particles inside. These unhydrated cement particles may continue to hydrate during the use of the concrete structure, thereby affecting the dimensional stability of the concrete structure; if It is prepared with lightweight aggregates. Due to the limitation of the strength of lightweight aggregates, ultra-high performance concrete has a strength limit, and has low flexural strength and high brittleness. These shortcomings limit its wide application in the field of civil engineering.

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