High-ductility concrete and preparation method thereof

Abstract

The invention relates to high-ductility concrete. The high-ductility concrete comprises the following raw materials: a cementing material, an admixture, a fine aggregate, polyhedral oligomeric silsesquioxane modified polyvinyl alcohol fibers, an auxiliary agent and water, wherein the admixture comprises the reinforcing agent fly ash, silica fume and polytetrafluoroethylene micropowder. The ductility-increasing component of the high-ductility concrete is the polyhedral oligomeric silsesquioxane modified polyvinyl alcohol fibers; on one hand, a grafted modifier destroys partial intramolecular and intermolecular hydrogen bonds of the fibers in the aspect of structure, so the flexibility of the fibers is further enhanced, and a rigid cage-shaped structure is also beneficial to improving the breaking strength and compressive strength of the fibers; and on the other hand, the surface polarity of the grafted fibers is reduced, the adaptability of the grafted fibers to a concrete system is enhanced, the workability of mortar can be improved, hydration reaction is facilitated, and coagulation is promoted. The invention also finds that modified polyethylene fibers and the polytetrafluoroethylene micropowder have the effect of synergistically improving the shrinkage strain resistance of the concrete.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to a high-ductility concrete and a preparation method thereof. Background technique [0002] High ductility concrete is a new type of material that uses cementitious materials, aggregates, and admixtures as masterbatches, and synthetic fibers with high elastic modulus (PVA) as auxiliary materials. This material mixes fibers into the cement matrix to improve the physical and mechanical properties of concrete, such as tensile performance, crack resistance, self-healing ability, and durability. [0003] Since high-elongation concrete has no coarse aggregate, it is easy to be cast into any shape, and can be used for repairing and strengthening components and structural parts of various shapes, such as bridges, roads, buildings, etc. For example, Chinese patent CN201910267138.0 discloses a crack self-healing SMA-ECC cement-based composite material and its preparation method...

AI Technical Summary

Problems solved by technology

The high-extensibility concrete disclosed above is the most common technology to use fibers to improve the ductility and healing ability of concrete, but as we all know, in order to restore the use as soon as possible or improve the firmness, repair and reinforcement projects generally require concrete to set quickly, and to resist bending, elongation, The compressive strength should be high, and the use of less fiber will improve the ductility of the concrete less. Although the ductility of the concrete will be increased if the amount is too large, it will affect the contact between cement and water, delay the hydration and condensation of cement, and cause slow coagulation and poor hydration. Uniform, incomplete, and the strength did not reach the ideal value

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