Micro-expansion fiber reinforced concrete and preparation method thereof

Abstract

The invention discloses micro-expansion fiber reinforced concrete for a steel-concrete combined beam bridge panel wet joint and a preparation method of the micro-expansion fiber reinforced concrete, and relates to the preparation field of the micro-expansion fiber reinforced concrete. The micro-expansion fiber reinforced concrete comprises gel materials (cement, coal ash, slag powder and an expanding agent), aggregate, reinforcing materials, imitated steel fibers, a water reducer and water, wherein the 28 compressive strength of the micro-expansion fiber reinforced concrete is not lower than 69.0MPa, the 28d breaking strength of the micro-expansion fiber reinforced concrete is not lower than 7.0 MPa, the 28d splitting tensile strength of the micro-expansion fiber reinforced concrete is not lower than 5.0 MPa, the 28d elasticity modulus of the micro-expansion fiber reinforced concrete is not lower than 36.0 GPa, the cracking resistance level of the micro-expansion fiber reinforced concrete reaches L-IV level, the 28d bending toughness index I20 of the micro-expansion fiber reinforced concrete is not lower than 8, the 56d chlorine ion diffusion coefficient of the micro-expansion fiber reinforced concrete is lower than 4.0*10<-12>m<2> / s, the 21d shrinkage percentage of the micro-expansion fiber reinforced concrete is lower than 200*10<-6>. By using the preparation method, the shrinkage cracking of the micro-expansion fiber reinforced concrete can be effectively avoided, so that the reinforced concrete is relatively compact. The micro-expansion fiber reinforced concrete disclosed by the invention is relatively high in strength, relatively low in shrinkage percentage, good in bending toughness and durability, relatively low in cost and conveniently to widely use.

Description

technical field [0001] The invention relates to the field of preparation of micro-expansion fiber toughened concrete for wet joints, in particular to micro-expansion fiber toughened concrete for wet joints of steel-concrete composite girder decks and a preparation method thereof. Background technique [0002] In modern bridge construction, steel-concrete composite beams have a small building height, large spanning capacity, and good navigability; big advantage. [0003] The use environment of steel-concrete composite beams can be divided into the general natural environment and the marine environment. Compared with the general natural environment, the steel-concrete composite beams in the marine environment are not only subjected to repeated traffic loads, but also subject to tides, typhoons, etc. , temperature difference changes, dry-wet cycle, salt spray erosion and other effects, the working environment of steel-concrete composite beams is extremely harsh. The wet joint...

AI Technical Summary

Problems solved by technology

However, engineering practice has proved that the addition of mineral admixtures will increase the self-shrinkage of concrete, which is prone to cracks, thereby reducing the durability of concrete structures; at the same time, adding steel fibers, polymer fibers and toughening materials to concrete Although it can improve the toughness and fatigue performance of concrete, the shrinkage rate of concrete is relatively large

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