Method for pre-mixing high-ductility cement-based composite material

A composite material, high ductility technology, applied in the direction of climate change adaptation, etc., can solve problems such as uneven dispersion, achieve the effect of ensuring dispersion, solving agglomeration, and ensuring project quality

CN102603234AInactive Publication Date: 2012-07-25SOUTHEAST UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-07-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a method for pre-mixing a high-ductility cement-based composite material. The method technically includes steps: firstly, adding cement, fly ash, quartz sand and powdery high-efficiency water reducer into a large-sized mixing station / plant / machine at first, and leading the various components to be uniformly mixed; secondly, conveying ECC (engineering cementitious composites) dry mixture which is uniformly pre-mixed by a concrete mixing vehicle to a construction field, loading the ECC dry mixture into a small-sized mixing machine in the field and finally adding a proper quantity of water to uniformly mix the mixture; thirdly, adding a certain quantity of water into the mixing vehicle in the construction field, and then leading a mixing barrel of the mixing vehicle tomix the mixture at the rotation speed of 18r / min; and fourthly, stopping mixing when the expansion radius of fiber cement slurry reaches 20mm at least under jumping table fluidity experimental conditions, and carrying out construction. By the aid of the method, fibers are finally uniformly dispersed in the cement slurry, the problem of fiber balling is avoided, and accordingly high performances of the high-ductility cement-based composite material are guaranteed.
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Description

technical field

[0001] In particular, the present invention relates to techniques for improving the uniformity of dispersion of fibers in high ductility cementitious composites. The invention belongs to the technical field of construction of high-ductility fiber reinforced cement-based composite materials. Background technique

[0002] ECC (Engineered Cementitious Composites) material is a high-ductility fiber-reinforced cement-based composite material. It is a new type of civil engineering material with pseudo-strain hardening characteristics and multi-slit cracking characteristics optimized based on micromechanics principles. Among them, the volume content of polyvinyl alcohol fiber (PVA) is usually about 2%, the tensile strain of ECC is 2% to 5%, which is several hundred times that of ordinary concrete, and the compressive strength can be as high as 70~ 80 MPa. The high tensile strain capacity of ECC material is based on its ability to form "steady state cracking" durin...

Examples

specific example

[0025] Step 1: In the large mixing station / building / machine, first add cement, fly ash, quartz sand and powdered superplasticizer, and mix it at low speed for 10-15 minutes, then add fiber and in high speed. Stir for 10 to 15 minutes to make the components mix evenly to make a high ductility fiber-reinforced cement-based composite material ECC dry material mixture;

[0026] Step 2: Use a concrete mixer truck to transport the pre-mixed and uniform ECC dry material mixture to the construction site, or transport the packaged ready-mix ECC dry material mixture to the construction site by truck, and load it into the small mixer on site. Finally add an appropriate amount of water and stir evenly,

[0027] Step 3: Add water to the mixing truck at the construction site, and then mix the mixing bucket of the truck with a rotation speed of 18 r / min; or pour the ECC cement material that is basically evenly mixed after adding water into the construction site In the mixer, a second intensive s...