A kind of high ductility concrete and its preparation method

Abstract

The invention relates to a high ductility concrete, which comprises the following raw materials: cementitious materials, admixtures, fine aggregates, cage polysilsesquioxane modified polyvinyl alcohol fibers, additives, and water. Admixtures include reinforcing agent fly ash, silica fume and polytetrafluoroethylene micropowder. The extension component of the high ductility concrete of the present invention is cage-type polysilsesquioxane modified polyvinyl alcohol fiber. On the one hand, structurally, the modifier on the graft destroys the hydrogen bonds in the fiber part and between molecules Destruction, the flexibility of the fiber is further enhanced, and the rigid cage structure is also conducive to improving the flexural strength and compressive strength of the fiber. On the other hand, the surface polarity of the grafted fiber is reduced, and the adaptability to the concrete system is enhanced, which can improve The workability of mortar is conducive to the hydration reaction and promotes coagulation. The invention also finds that the modified polyethylene fiber 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 particularly relates to a high ductility concrete and a preparation method. Background technique [0002] High-extensibility concrete is a new type of material that uses cementitious materials, aggregates and admixtures as master batches, and high elastic modulus synthetic fibers (PVA) as auxiliary materials. This material incorporates fibers into the cement matrix to improve the physical and mechanical properties of concrete such as tensile properties, crack resistance, self-healing, and durability. [0003] Since high-elongation concrete has no coarse aggregate, it is easy to be poured into any shape, and can be used for the repair and reinforcement of various shapes of components and structural parts, such as bridges, roads, buildings, etc. For example, Chinese patent CN201910267138.0 discloses a self-healing SMA-ECC cement-based composite material and a preparation method thereof, inclu...

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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