Forced vacuum mixer for preparing 3D printing ultra-high performance concrete

Abstract

The invention relates to the technical field of 3D printing concrete. A forced vacuum mixer for preparing 3D printing ultra-high performance concrete comprises a mixing cylinder, a mixing assembly, avacuumizing assembly, a feeding assembly, a discharging assembly and a control system, wherein a discharging port is formed in the bottom of the mixing cylinder; the mixing assembly is arranged in themixing cylinder, and a sealing unit is arranged between the mixing assembly and the mixing cylinder; the vacuumizing assembly is connected with the mixing cylinder; and the feeding assembly is connected with the mixing cylinder through a conveying pipeline. The forced vacuum mixer is reasonable in structural design, vacuum sealing mixing of the whole mixing assembly can be realized, the intelligent control system can accurately regulate and control actions of all the assemblies and units, so that bubbles in mixed materials are reduced, the homogeneity, compactness, strength and durability ofthe concrete are improved, and the forced vacuum mixer is particularly applicable to mixing of fiber-doped ultra-high performance concrete and 3D printing ultra-high performance concrete mixtures.

Description

technical field [0001] The invention relates to the technical field of 3D printing concrete, in particular to a forced vacuum mixer for preparing 3D printing ultra-high performance concrete. Background technique [0002] The disadvantages of traditional concrete, such as high consumption of resources and energy and high pollution to the environment, restrict its future development. The third industrial revolution marked by additive manufacturing such as 3D printing has brought concrete technology to a higher level. A new 3D printing concrete technology based on 3D modeling, electromechanical control, information processing and material science, etc., with the help of computers to carry out 3D modeling of buildings and components, and then mix the prepared concrete with intelligently controlled 3D printing equipment The composite is printed layer by layer to the predetermined position according to the set procedure, and finally the concrete building or component product is ob...

AI Technical Summary

Problems solved by technology

However, as an emerging technology, 3D printing concrete is not yet mature in terms of materials and preparation equipment.

3D printing has high requirements on the performance of concrete, which is difficult for traditional concrete to meet. Existing theories can no longer guide the design and construction of 3D printed concrete.

However, the structural feature of the forced concrete vacuum mixer of this application is that the motor is placed outside the mixing drum, and the rotating shaft connected with the motor must pass through the mixing drum, and the connection between the rotating shaft and the mixing drum is difficult to ensure the airtightness and vacuum of the mixing drum Spend

At the same time, the feeding and mixing procedure of this application will also affect the performance of concrete, and it is not suitable for the mixing of UHPC mixture

In view of the problems existing in this application, another Chinese patent (CN201721108634.4) tries to solve them. This application proposes a conical reverse discharge concrete vacuum mixer, which is characterized in that the motor drives the mixing drum to rotate during the mixing process, but Due to the rotation of the mixing drum during the stirring process, it is also necessary to complete vacuuming before stirring. Since the vacuum cannot be continuously pumped, it will still cause the loss of vacuum degree during the process of adding water and stirring, so that the effect of eliminating air bubbles in the mixture is still limited. In particular, the relatively low rotational speed of the mixing drum and the lack of the puncture effect of the forced blades on the air bubbles determine that this kind of mixer is not suitable for mixing UHPC mixtures with higher viscosity, especially those mixed with fibers.

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