CN-121989337-A - Basalt fiber cement-based composite gradient functional material forming device and method

CN121989337ACN 121989337 ACN121989337 ACN 121989337ACN-121989337-A

Abstract

The invention discloses a basalt fiber cement-based composite gradient functional material forming device and a basalt fiber cement-based composite gradient functional material forming method, and belongs to the technical field of additive manufacturing of building materials. The device comprises a main material extruding bin, at least two sub-material stirring bins, a driving device, a radar level gauge and a control system. Each functional slurry is respectively injected into a sub-slurry stirring bin for temporary storage after being stirred, and a radar level gauge is arranged at the top of each sub-slurry stirring bin for monitoring the uniformity and rheological property of the slurry in real time. The control system independently opens the bin blocking devices according to the preset gradient model sequence, so that different functional slurries sequentially flow into the main material extrusion bin, are extruded and printed layer by layer after secondary homogenization and rechecking, and empty the main material bin after each layer of printing is finished, so that the multifunctional gradient composite component such as bearing, sound absorption, heat preservation, decoration and the like is formed. The volume doping amount of the fiber is distributed in a stepwise manner, so that continuous transition of performance is realized, and interface stress is relieved. The invention is suitable for constructing key infrastructure in severe environments such as open sea island reefs.

Inventors

WANG YIBO
LI GUANGXIANG
LIN LIN
YANG KUN
YAO YUAN
ZHANG YUSI
LI JUN
Yi Chengtong

Assignees

辽宁工业大学

Dates

Publication Date: 20260508
Application Date: 20260403

Claims (10)

1. The basalt fiber cement-based composite gradient functional material forming device is characterized by comprising: The main material extruding bin is internally provided with a main material stirring screw, and the bottom of the main material extruding bin is communicated with a printing nozzle; At least two sub-material stirring bins fixedly arranged above the main material extrusion bin, wherein each sub-material stirring bin is provided with an independent feed inlet, an independent discharge outlet and a sub-material stirring screw, and the discharge outlet is communicated with the main material extrusion bin through a blocking device with controllable flow; the first driving device is used for driving the sub-material stirring screw to rotate; the second driving device is used for driving the main material stirring screw to rotate; The first material level monitoring module is arranged at the top of each sub-material stirring bin and is used for monitoring the material level height and stirring state of the slurry in the bin in real time, wherein the stirring state comprises the uniformity and rheological property of the slurry; The second material level monitoring module is arranged on a channel between a discharge hole of the main material extrusion bin and the printing nozzle and is used for checking the final state of the slurry which is about to enter the printing nozzle; The control system is electrically connected with the blocking device, the first driving device, the second driving device, the first material level monitoring module and the second material level monitoring module respectively, and is configured to execute a preset printing task, control the stirring process of each sub-material stirring bin according to the feedback signal of the first material level monitoring module, start each blocking device according to a preset gradient structure model in sequence or proportion, and determine whether extrusion printing is allowed or not according to the rechecking result of the second material level monitoring module.
2. The molding device of claim 1, wherein the number of the sub-material stirring chambers is four, the four sub-material stirring chambers are welded and fixed in or around the main material extrusion chamber, and the sub-material stirring screw and the main material stirring screw are of a replaceable structure.
3. The molding apparatus of claim 1, wherein the first level monitor module and the second level monitor module are radar level gauges that determine the uniformity and rheological state of the slurry by emitting high frequency electromagnetic waves onto the surface of the slurry and analyzing the signal stability and fluctuation amplitude of the reflected echoes.
4. A method for forming basalt fiber cement-based composite gradient functional material based on the forming device of any one of claims 1 to 3, characterized by comprising the following steps: S1, preparing materials and storing materials, respectively mixing and stirring various basalt fiber cement-based slurries with different functions through a stirrer, respectively injecting each functional slurry into a corresponding sub-material stirring bin through a screw pump, wherein a blocking device below each sub-material stirring bin is in a closed state, and temporarily storing the slurries in the sub-material stirring bin; S2, independently stirring and online monitoring, wherein a control system starts a first driving device to drive sub-material stirring screws in each sub-material stirring bin to independently stir the slurry; meanwhile, each first material level monitoring module collects radar echo signals of the surface of the slurry in the bin in real time, and judges whether the slurry meets the preset printable process requirement or not by analyzing the stability and fluctuation amplitude of the echo signals; s3, printing a first functional layer, starting a first driving device of a sub-material stirring bin storing slurry of the first functional layer and a sub-material stirring screw rod according to a preset gradient structure model by a control system, opening a blocking device below the bin to enable the slurry to flow into a main material extruding bin, driving the main material stirring screw rod by a second driving device to carry out secondary homogenization treatment on the flowing slurry, carrying out final state rechecking on the treated slurry through a second material level monitoring module, extruding the slurry through a printing nozzle after the treated slurry is qualified in detection, printing the first functional layer by a printing nozzle according to a preset printing path until the treated slurry is printed to a preset thickness, and closing the blocking device of the bin and stopping the sub-material stirring screw rod after printing is finished; S4, emptying the main material bin, and emptying the residual first functional layer slurry in the main material extrusion bin; And S5, printing the subsequent functional layers, repeating the steps S3 to S4, and sequentially starting a sub-material stirring bin storing second and third functional layer slurry, and printing each functional layer by layer in sequence until all the functional layers are printed, so as to form the composite component with the multi-layer gradient function.
5. The molding method according to claim 4, further comprising a gradient transition step, wherein when a composition gradient transition layer is required to be formed, the control system simultaneously opens the blocking devices of two adjacent sub-material stirring bins, and dynamically adjusts the opening degrees of the blocking devices respectively, so that the slurries with two different functions are extruded after being instantaneously mixed in the main material extrusion bin, and a composition gradient transition region with the thickness of 2-5 mm is formed.
6. The molding method of claim 4, wherein the printable process requirement is determined by the first level monitoring module by analyzing the echo signal, determining that the uniformity and rheology of the slurry meet a predetermined threshold when the amplitude of fluctuation of the echo signal is continuously below the predetermined threshold, and if the slurry is monitored to be not met, automatically prolonging the stirring time, adjusting the stirring rotation speed, or suspending the discharge and giving an audible and visual alarm by the control system.
7. The molding method according to claim 4, wherein the process parameters in the printing process are that the printing environment temperature is 5-35 ℃, the relative humidity is less than or equal to 80%, the temperature of the extrusion paste of the printing nozzle is less than or equal to 30 ℃, the interval time between layers is controlled to be not more than 15 minutes before the initial setting of the cement-based material, the component after the printing molding is immediately covered and maintained, the maintenance time is not less than 14 days, and the maintenance temperature is 20+/-2 ℃.
8. The molding method according to claim 4, wherein the basalt fiber cement-based composite gradient functional material of the molding method has a concrete matrix prepared by a method comprising the steps of: (1) Adding fine sand, sulphoaluminate cement, silica fume and fly ash into a stirrer according to the mass ratio, and dry-stirring for 30-120 seconds; (2) Adding water and a high-efficiency polycarboxylate superplasticizer, and wet-mixing for 60-180 seconds to form cement mortar; (3) Adding basalt fibers in batches, firstly stirring at a low speed of 20-30 r/min for 30-60 seconds, and then stirring at a high speed of 40-60 r/min for 120-240 seconds to obtain a concrete matrix; and slag powder, ceramsite, diatomite and perlite are respectively added into the concrete matrix and uniformly stirred, so that four concrete slurries with different functions are obtained.
9. The molding method of claim 8, wherein the specific surface area of the sulphoaluminate cement is 350-450 m 2 /kg, the entering temperature is less than or equal to 50 ℃, the using temperature of fine sand is less than or equal to 28 ℃, the length of basalt fiber is 6-12 mm, the basalt fiber is subjected to surface modification treatment, the total amount of cementing materials is not less than 400kg/m 3 , the sulphoaluminate cement is not less than 300kg/m 3 , the silica fume doping amount is 5-10%, the fly ash doping amount is 10-20%, and the water-cement ratio is not more than 0.35.
10. The method according to claim 8, wherein the volume mixing amount of basalt fiber in the four kinds of concrete slurries with different functions is distributed in a gradient manner, the volume mixing amount of slurry fiber for the surface layer of the member is 0.5% -1.0%, the volume mixing amount of slurry fiber for the transition layer is 1.0% -1.5%, and the volume mixing amount of slurry fiber for the core layer or the bearing layer is 1.5% -2.5%.

Description

Basalt fiber cement-based composite gradient functional material forming device and method Technical Field The invention relates to the technical field of additive manufacturing of building materials, in particular to a basalt fiber cement-based composite gradient functional material forming device and a basalt fiber cement-based composite gradient functional material forming method. Background The gradient functional material (FunctionallyGradedMaterials, FGM) eliminates the obvious internal interface existing in the traditional composite material through the continuous change of the components and the microstructure in space, thereby effectively relieving the thermal stress and avoiding the abrupt change of the performance. The FGM concept is introduced into the cement-based material, so that the inherent defects of low tensile strength (usually only 1/10 of compressive strength), high brittleness and single function (such as bearing capacity and incapability of simultaneously meeting the requirements of heat preservation, sound insulation, decoration and the like) can be obviously improved theoretically. However, the research on cement-based composite gradient functional materials is still in the beginning, and mature special forming equipment is lacking. The traditional preparation method relies on manual stirring and layered pouring by other mediums, the process is lag, the efficiency is low, and the interlayer gradient distribution and the bonding quality are difficult to accurately control. In recent years, the development of 3D concrete printing technology has provided the possibility for layered extrusion of cement-based materials, but the existing 3D printing apparatus has the following drawbacks: (1) Only adapting to single material, can not automatically switch and accurately supply the sizing agent with various different functions in one printing process; (2) The online real-time monitoring of the stirring degree and the rheological state of the slurry is lacking, and the extrusion of each layer of material under the optimal technological state cannot be ensured; (3) The interfaces between different material layers are suddenly changed, and the transition design of gradual component change is lacking, so that the interlayer bonding strength is insufficient and the cracking is easy to occur. Therefore, developing a special forming device and process capable of realizing precise multi-material supply, online state monitoring and gradient transition control is a technical problem to be solved in the field. Disclosure of Invention The invention aims to provide a basalt fiber cement-based composite gradient functional material forming device and a basalt fiber cement-based composite gradient functional material forming method, which solve the problems that the traditional cement-based gradient functional material preparation process is behind, automatic switching of multiple materials cannot be realized, and on-line state monitoring and gradient transition control are lacked. In a first aspect, the present invention provides a basalt fiber cement-based composite gradient functional material molding device, including: The main material extruding bin is internally provided with a main material stirring screw, and the bottom of the main material extruding bin is communicated with a printing nozzle; At least two sub-material stirring bins fixedly arranged above the main material extrusion bin, wherein each sub-material stirring bin is provided with an independent feed inlet, an independent discharge outlet and a sub-material stirring screw, and the discharge outlet is communicated with the main material extrusion bin through a blocking device with controllable flow; the first driving device is used for driving the sub-material stirring screw to rotate; the second driving device is used for driving the main material stirring screw to rotate; The first material level monitoring module is arranged at the top of each sub-material stirring bin and is used for monitoring the material level height and stirring state of the slurry in the bin in real time, wherein the stirring state comprises the uniformity and rheological property of the slurry; The second material level monitoring module is arranged on a channel between a discharge hole of the main material extrusion bin and the printing nozzle and is used for checking the final state of the slurry which is about to enter the printing nozzle; The control system is electrically connected with the blocking device, the first driving device, the second driving device, the first material level monitoring module and the second material level monitoring module respectively, and is configured to execute a preset printing task, control the stirring process of each sub-material stirring bin according to the feedback signal of the first material level monitoring module, start each blocking device according to a preset gradient structure model in sequence or proportion, a