Engineered cementitious composite (ECC) repairing material and preparation method thereof

Abstract

The invention discloses an engineered cementitious composite (ECC) repairing material comprising the following components: cement, coal ash, quartz sand, water, a water reducer, an early strength additive and polyvinyl alcohol fiber. All the components are stirred and mixed according to a certain sequence to obtain the ECC repairing material disclosed by the invention. Due to the addition of a great deal of cheap coal ash in raw materials, on one hand, the strength of a substrate material can be weakened and the high ductility of the material is ensured, and on the other hand, the price of the coal ash is far lower than that of an artificial defect material; the ECC repairing material has higher compressive strength and bending strength than a common ECC material; and meanwhile, a proper amount of early strength additive is added, the strength of the material used for seven days can be up to 80% of the final strength, and compared with the traditional engineered fiber reinforced cementitious composite material, the ECC repairing material has the advantages that the maintenance time is shortened, the material can be desterilized as soon as possible, and the material meets the general engineering requirement on the aspect of time. Therefore, the ECC repairing material has a favorable engineering application value.

Description

technical field [0001] The invention relates to a rapid repair material for cement concrete structures, in particular to a high-ductility cement-based composite repair material. Background technique [0002] High-ductility fiber-reinforced cementitious composite (ECC) is a new type of civil engineering material with pseudo-strain hardening and multi-slit cracking characteristics optimized based on micromechanics principles. Among them, the volume content of polyvinyl alcohol fiber (PVA) is usually about 2%, and its tensile strain is 2% to 5%, which is hundreds of times that of ordinary concrete. The compressive strength can be as high as 70 to 80 MPa when the mix ratio is appropriate. . The high tensile strain capacity of a highly ductile material is based on its ability to form "steady state cracking" during tension. "Steady state cracking" means that when the tensile strain exceeds 1%, the crack width in the material will be stable at about 60 μm. With the increase of th...

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Problems solved by technology

[0004] Technical problem to be solved: Aiming at the deficiencies of the prior art, the present invention provides a high-ductility cement-based composite repair material and its preparation method, which has fast strength development and high cost performance, and is suitable for engineering use, and comprehensively solves the traditional problems in the prior art. The high-ductility cement-based composite materials have long curing time, and the high-early-strength cement-based composite materials have high cost technical problems.

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