A UHPC premixing process and production line

Abstract

The present invention discloses a UHPC premixing process, which performs UHPC dry premixing in advance, and sets a number of movable wet mixers in the later on-site construction according to the construction progress requirements, thereby increasing the output of UHPC finished materials and construction efficiency, ensuring metering accuracy, and improving quality. Also disclosed is a UHPC premixing production line for realizing the UHPC premixing process.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a UHPC premixing process and a production line thereof. Background Art

[0002] Ultra-high performance concrete is referred to as UHPC, also known as active powder concrete. UHPC is an ultra-high strength cement-based material with high strength, high toughness and low porosity. Its basic formulation principle is to minimize the pores and micro cracks inside the material by increasing the fineness and activity of the organizational components and not using coarse aggregates, so as to obtain ultra-high strength and high durability. Ultra-high performance concrete has ultra-high durability and ultra-high mechanical properties (compression, tension and high toughness). Due to its light weight and reliable performance, it has broad application prospects in construction engineering and national defense engineering.

[0003] At present, the domestic and foreign UHPC mixture mixing equipment is mainly in the form of an integrated machine similar to ordinary cement concrete mixing. Since UHPC involves multiple raw materials such as cementitious and steel fibers, ordinary cement concrete mixing cylinders cannot achieve its batching and weighing well, and require a large number of manual labor and auxiliary machinery to put materials, causing serious environmental pollution and a low degree of mechanical automation production. In addition, steel fibers are added to the raw material batching of UHPC, which is easy to clump and difficult to break up; at the same time, since UHPC has a high content of cementitious materials such as cement compared to ordinary cement concrete, but a low water content and a low water-binder ratio, in order to achieve a uniform mixing effect, the mixing time required is about 10 minutes or more, and the mixing efficiency and output are low, affecting the quality and progress of on-site construction. At the same time, the accuracy of the measurement of each raw material, that is, the degree of coincidence with the designed mix ratio, is not high, which restricts and affects the final quality of UHPC. Summary of the invention

[0004] The purpose of the present invention is to provide a UHPC premixing process, which performs UHPC dry premixing in advance, and sets up a number of movable wet mixers in the later on-site construction according to the construction progress requirements, thereby increasing the output of UHPC finished materials and construction efficiency, ensuring metering accuracy, and improving quality.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A UHPC premixing process, comprising the following steps: Step S1: transporting cement to a cement tank, transporting fine quartz sand to a first quartz sand tank, transporting coarse quartz sand to a second quartz sand tank, transporting silica ash to a silica ash tank, and transporting fly ash to a fly ash tank; Step S2: firstly transporting the cement in the cement tank, the fine quartz sand in the first quartz sand tank, and the coarse quartz sand in the second quartz sand tank to a first cumulative scale for measurement in sequence by means of a spiral conveyor, and then transporting them to a first transition bin; and then transporting the cement in the cement tank, the fine quartz sand in the first quartz sand tank, and the coarse quartz sand in the second quartz sand tank to a first cumulative scale for measurement by means of a spiral conveyor. The silica ash in the silica ash tank and the fly ash in the fly ash tank are sequentially transported to the second cumulative scale for measurement; the steel fiber is transported to the weight loss scale for measurement, and then transported to the second transition bin; step S3: the cement, fine quartz sand and coarse quartz sand in the first transition bin are transported to the mixing tank, the silica ash and fly ash in the second cumulative scale are transported to the mixing tank, and the steel fiber in the second transition bin is transported to the mixing tank, and uniformly premixed through the mixing tank; at the same time, in steps S1 to S3, the silica ash tank and the fly ash tank are located above the second cumulative scale, and the second cumulative scale is located above the mixing tank.

[0006] The present invention is further configured as follows: in step S2, the steel fibers in the weight loss scale are broken up, and the clumped steel fibers are screened out when being transported to the second transition bin.

[0007] The present invention is further configured as follows: in step S3, the dust generated during the unloading process of the first transition bin and the second accumulating scale is recovered by means of pulse dust removal, and the recovered dust is put into the mixing tank.

[0008] In summary, the present invention has the following beneficial effects:

[0009] 1. Carry out UHPC dry premixing in advance, and set up several mobile wet mixers in the later on-site construction according to the construction progress, so as to increase the output of UHPC finished materials and construction efficiency, ensure measurement accuracy, and improve quality;

[0010] 2. By analyzing the characteristics of UHPC raw materials, different transportation and storage methods are adopted for each raw material to ensure the basic physical properties of each raw material, effectively solve the mechanized storage and distribution of each raw material of UHPC, and reduce the intensity of manual work; for example, cement, fine quartz sand, and coarse quartz sand are transported by spiral conveyor, and are weighed by the first cumulative scale to ensure the measurement accuracy of each raw material; silica ash and fly ash have fine particles and small bulk density. In order to reduce quality loss and ensure measurement accuracy, their storage and weighing work are arranged above the mixing tank, and they are directly put into the mixing tank after measurement; steel fiber has the property of easy agglomeration. By breaking up the steel fiber, the dispersion degree has been improved, which is convenient for uniform mixing in the mixing tank;

[0011] 3. Cement, coarse quartz sand, fine quartz sand, silica fume and fly ash are stored in a closed manner and do not come into contact with the outside, so as to maximize the original characteristics of the raw materials and thus ensure product quality;

[0012] 4. The design theory of UHPC is the maximum packing density theory. The particles of different particle sizes of its constituent materials form the most compact stacking in the best proportion, that is, the gaps between the accumulation of millimeter-level particles (aggregates) are filled with micron-level particles (cement, fly ash, mineral powder), and the gaps between the accumulation of micron-level particles are filled with submicron-level particles (silica fume). The volatilization and loss of micron-level and submicron-level particle materials during the production process can easily form small "holes" in the mixture, greatly reducing the strength of concrete. In order to solve the problem of volatilization and loss of fine particles during the feeding and mixing process, the dust generated during the feeding process of the first transition bin and the second cumulative scale is recovered by pulse dust removal, and the recovered dust is put into the mixing tank to ensure that the core components of the core material are not lost.

[0013] The purpose of the present invention is to provide a UHPC premix production line, which can carry out UHPC dry premixing in advance, and set up a number of movable wet mixers in the later on-site construction according to the construction progress requirements, so as to improve the output of UHPC finished materials and construction efficiency, ensure the metering accuracy, and improve the quality.

[0014] The above technical objectives of the present invention are achieved through the following technical solutions: 1. It includes the following parts: a cement, fine quartz sand, and coarse quartz sand conveying and weighing system, including a cement tank, a high-pressure air pump for pumping cement into the cement tank, a fine quartz sand tank, a coarse quartz sand tank, a first lifting and conveying device for conveying coarse quartz sand and fine quartz sand into the fine quartz sand tank and the coarse quartz sand tank, a first cumulative scale, a plurality of first screw conveyors, a plurality of first pneumatic butterfly valves, a first transition bin, and a feeding device for conveying raw materials in the first cumulative scale to the first filtering bin; the plurality of first screw conveyors respectively and successively convey the raw materials in the cement tank, the fine quartz sand tank, and the coarse quartz sand tank to the first transition bin, and the plurality of first pneumatic butterfly valves are respectively arranged in the plurality of first between the screw conveyor and the first cumulative scale; a silica ash and fly ash conveying and weighing system, including a silica ash tank, a fly ash tank, a second lifting and conveying device for conveying silica ash and fly ash to the silica ash tank and the fly ash tank, a second cumulative scale, and two second screw conveyors, the silica ash tank and the fly ash tank are located above the second cumulative scale, and the two second screw conveyors respectively convey the raw materials in the silica ash tank and the fly ash tank to the second cumulative scale; a steel fiber conveying and weighing system, including a weight loss scale, a belt conveyor for conveying steel fibers to the weight loss scale, and a second transition bin for receiving the steel fibers output from the weight loss scale; a mixing and premixing system, including a mixing cylinder for receiving and mixing raw materials from the first transition bin, the second cumulative scale, and the second transition bin.

[0015] The present invention is further configured as follows: two of the coarse quartz sand tank and the fine quartz sand tank are provided, the first lifting and conveying device includes a first elevator for conveying fine quartz sand or coarse quartz sand, a pneumatic four-way valve for receiving materials from the first elevator, a third screw conveyor connected to one of the discharge ends of the pneumatic four-way valve, and a first pneumatic dividing valve connected to the discharge end of the third screw conveyor, the other two discharge ends of the pneumatic four-way valve are respectively connected to two coarse quartz sand tanks, and the two discharge ends of the first pneumatic dividing valve are respectively connected to two fine quartz sand tanks.

[0016] The present invention is further configured as follows: the loading device includes a fourth screw conveyor connected to the discharge end of the first cumulative scale, and a second elevator connected to the discharge end of the fourth screw conveyor and conveying the raw materials to the first transition bin.

[0017] The present invention is further configured as follows: the second lifting and conveying device includes a third elevator for conveying silica ash or fly ash, and a second pneumatic dividing valve connected to the discharge end of the third elevator, and the two discharge ends of the second pneumatic dividing valve are respectively connected to the silica ash tank and the fly ash tank.

[0018] The present invention is further configured as follows: the middle portion of the belt conveyor extends upwardly and obliquely toward a direction close to the weight loss scale, and the inclination angle of the oblique upward extending portion of the belt conveyor is 65-75 degrees. The weight loss scale includes a base, a vibration plate, a plurality of buffer rubber blocks arranged between the base and the vibration plate, a vibrator arranged on the outside of the vibration plate, a weighing sensor arranged at the connection between the buffer rubber block and the base and used to detect the gravity from the buffer rubber block, a discharge channel which is connected to the discharge end of the vibration plate at one end and extends downward at the other end, a screen arranged at one end of the discharge channel away from the vibration plate, and a return channel connected between the discharge channel and the vibration plate and used to recover the clumped steel fibers left after passing through the screen during the vibration process.

[0019] The present invention is further configured as follows: a first pre-delivery bin is provided at the feeding end of the first elevator, a first manual butterfly valve is provided between the first pre-delivery bin and the feeding end of the first elevator, a second pre-delivery bin is provided at the feeding end of the third elevator, a second manual butterfly valve is provided between the second pre-delivery bin and the feeding end of the third elevator, and also includes a first pulse dust collector, a first dust removal main pipe connected to the first pulse dust collector, a first dust removal branch pipe connected between the first dust removal main pipe and the first pre-delivery bin, a second dust removal branch pipe connected between the first dust removal main pipe and the discharge end of the first elevator, a third dust removal branch pipe connected between the first dust removal main pipe and the second pre-delivery bin, a first dust removal branch pipe connected between the first dust removal main pipe and the third elevator A fourth dust removal branch pipe between the discharge end of the elevator, and a fifth dust removal branch pipe connected between the first dust removal main pipe and the second transition bin, and a third manual butterfly valve is respectively provided at one end of the first dust removal branch pipe, the second dust removal branch pipe, the third dust removal branch pipe, the fourth dust removal branch pipe, and the fifth dust removal branch pipe away from the first dust removal main pipe; two cement tanks are provided, including a second pulse dust collector, a second dust removal main pipe connected to the second pulse dust collector, a sixth dust removal branch pipe connected between the second dust removal main pipe and the top of one of the cement tanks, and a seventh dust removal branch pipe connected between the second dust removal main pipe and the top of another cement tank, and a fourth manual butterfly valve is respectively provided at one end of the sixth dust removal branch pipe and the seventh dust removal branch pipe away from the second dust removal main pipe.

[0020] The present invention is further configured as follows: the first transition bin and the second cumulative scale are located above the mixing cylinder, and also include a third pulse dust collector, a third dust collection main pipe connected to the third pulse dust collector, an eighth dust collection branch pipe connected between the third dust collection main pipe and the first transition bin, and a ninth dust collection branch pipe connected between the third dust collection main pipe and the second cumulative scale. The eighth dust collection branch pipe and the ninth dust collection branch pipe are respectively provided with a fifth manual butterfly valve at one end away from the third dust collection main pipe, and the discharge end of the third pulse dust collector is connected to the top of the mixing cylinder.

[0021] In summary, the present invention has the following beneficial effects:

[0022] 1. The factory-centralized, continuous and intelligent production of UHPC premixes has been realized to a high degree. Currently, most of the UHPC premix (dry mix) fields adopt an open-air intermittent production method of "metering-lifting-production-metering-lifting-production", and have failed to realize the closed and continuous production method of "raw materials lifting into tanks + automatic batching and metering + temporary storage + continuous production". This production line realizes the above-mentioned production method through the effective combination of targeted material analysis and mechanical principles, with better production capacity; at the same time, it realizes the advance premixing of UHPC dry mix, and in the later on-site construction, several mobile wet mixers are set up according to the construction progress requirements, thereby increasing the output of UHPC finished materials and construction efficiency, ensuring metering accuracy, and improving quality;

[0023] 2. By analyzing the characteristics of UHPC raw materials, different transportation and storage methods are adopted for each raw material to ensure the basic physical properties of each raw material, effectively solve the mechanized storage and distribution of each raw material of UHPC, and reduce the intensity of manual work; for example, cement, fine quartz sand, and coarse quartz sand are transported by spiral conveying, and are weighed by the first cumulative scale to ensure the measurement accuracy of each raw material; silica ash and fly ash have fine particles and small bulk density. In order to reduce quality loss and ensure measurement accuracy, their storage and weighing work are arranged above the mixing tank, and they are directly put into the mixing tank after measurement; steel fiber has the characteristics of large feeding amount and easy agglomeration. It is transported by belt conveyor to increase the feeding amount. The steel fiber is broken up by the vibration of the weight loss scale to improve the dispersion degree, which is convenient for uniform mixing in the mixing tank, and the large-angle belt conveyor (the inclination angle is 65-75 degrees) avoids the problem of high labor intensity caused by directly transporting steel fiber to a height for feeding, and is convenient for replenishing and measuring steel fiber;

[0024] 3. Cement, coarse quartz sand, fine quartz sand, silica fume and fly ash are stored and managed in a closed manner without any external contact, so as to maximize the original characteristics of the raw materials and thus ensure product quality;

[0025] 4. The design theory of UHPC is the maximum packing density theory. The particles of different particle sizes of its constituent materials form the most compact stacking in the best proportion, that is, the gaps between the stacking of millimeter-level particles (aggregates) are filled with micron-level particles (cement, fly ash, mineral powder), and the gaps between the stacking of micron-level particles are filled with submicron-level particles (silica fume). The volatilization and loss of micron-level and submicron-level particle materials during the production process can easily form tiny "holes" in the mixture, greatly reducing the strength of concrete. In order to solve the problem of volatilization and loss of fine particles during the feeding and mixing process, the dust generated during the feeding process of the first transition bin and the second cumulative scale is recovered by pulse dust removal (the third pulse dust collector), and the recovered dust is put into the mixing tank to ensure that the core composition of the core material is not lost;

[0026] 5. The whole process of feeding production is closed and pulse dust removal is carried out. The whole production site is closed with a canopy and adopts workshop-style management, which is far higher than the emission standards and meets the requirements of "green" environmentally friendly sites. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 1 is a working principle diagram of Embodiment 2 (in the figure, the position of the belt conveyor is moved up so that the belt conveyor does not overlap with other components);

[0028] Figure 2 It is a working principle diagram of the cement, fine quartz sand and coarse quartz sand conveying and weighing system of Example 2;

[0029] Figure 3It is a working principle diagram of the silica ash and fly ash conveying and weighing system in Example 2;

[0030] Figure 4 is a working principle diagram of the steel fiber conveying and weighing system in Example 2;

[0031] Figure 5 Schematic diagram of the structure of the weight loss scale in Example 2 (the positions of the belt conveyor and the weight loss scale in the figure are actual positions);

[0032] Figure 6 is a top view of the weight loss scale in Example 2;

[0033] Figure 7 It is a partial working principle diagram in Example 2 (used to embody the third pulse dust collector).

[0034] Figure numerals: 1, cement tank; 2, high-pressure air pump; 3, fine quartz sand tank; 4, coarse quartz sand tank; 51, first elevator; 52, pneumatic four-way valve; 53, third screw conveyor; 54, first pneumatic material distribution valve; 6, first cumulative scale; 7, first screw conveyor; 8, first pneumatic butterfly valve; 9, first transition bin; 101, fourth screw conveyor; 102, second elevator; 11, silica ash tank; 12, fly ash tank; 131, third elevator; 132, second pneumatic material distribution valve; 14, second cumulative scale; 15, second screw conveyor; 16, weight loss scale; 161, base; 162, vibration plate; 163, buffer rubber block; 164, vibrator; 165, weighing sensor; 166, discharge channel; 167, screen; 168, return channel; 17. Belt conveyor; 18. Second transition bin; 19. Mixing tank; 20. First pre-delivery bin; 21. First manual butterfly valve; 22. Second pre-delivery bin; 23. Second manual butterfly valve; 24. First pulse dust collector; 241. First dust removal main pipe; 242. First dust removal branch pipe; 243. Second dust removal branch pipe; 244. Third dust removal branch pipe; 245. Fourth dust removal branch pipe; 246. Fifth dust removal branch pipe; 247. Third manual butterfly valve; 25. Second pulse dust collector; 251. Second dust removal main pipe; 252. Sixth dust removal branch pipe; 253. Seventh dust removal branch pipe; 254. Fourth manual butterfly valve; 26. Third pulse dust collector; 261. Third dust removal main pipe; 262. Eighth dust removal branch pipe; 263. Ninth dust removal branch pipe; 264. Fifth manual butterfly valve. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0036] Embodiment 1: A UHPC premixing process comprises the following steps: Step S1: transporting cement to a cement tank, transporting fine quartz sand to a first quartz sand tank, transporting coarse quartz sand to a second quartz sand tank, transporting silica ash to a silica ash tank, and transporting fly ash to a fly ash tank; Step S2: firstly transporting the cement in the cement tank, the fine quartz sand in the first quartz sand tank, and the coarse quartz sand in the second quartz sand tank to a first cumulative scale for measurement in sequence by means of a spiral transport, Then transport it to the first transition bin; by means of spiral transport, transport the silica ash in the silica ash tank and the fly ash in the fly ash tank to the second cumulative scale for measurement; transport the steel fiber to the weight loss scale for measurement, and then transport it to the second transition bin; step S3: transport the cement, fine quartz sand and coarse quartz sand in the first transition bin to the mixing tank, transport the silica ash and fly ash in the second cumulative scale to the mixing tank, transport the steel fiber in the second transition bin to the mixing tank, and pre-mix them evenly through the mixing tank.

[0037] In step S2, the steel fibers in the weight loss scale are broken up, and the clumped steel fibers are screened out when being transported to the second transition bin. In step S3, the dust generated during the unloading process of the first transition bin and the second cumulative scale is recovered by pulse dust removal, and the recovered dust is put into the mixing tank. At the same time, in steps S1 to S3, the silica ash tank and the fly ash tank are located above the second cumulative scale, and the second cumulative scale is located above the mixing tank.

[0038] Implementation effect: (1) UHPC dry premixing is carried out in advance, and several mobile wet mixers are set up in the later on-site construction according to the construction progress, so as to improve the output of UHPC finished materials and construction efficiency, ensure the measurement accuracy, and improve the quality. (2) By analyzing the characteristics of UHPC raw materials, different transportation and storage methods are adopted for each raw material to ensure the basic physical properties of each raw material, effectively solve the mechanized storage and distribution of UHPC raw materials, and reduce the intensity of manual work; for example, cement, fine quartz sand, and coarse quartz sand are transported by spiral conveyor, and the first cumulative weighing scale is used to ensure the measurement accuracy of each raw material; silica ash and fly ash have fine particles and small bulk density. In order to reduce quality loss and ensure measurement accuracy, their storage and weighing work are arranged above the mixing tank, and they are directly put into the mixing tank after measurement; steel fiber has the property of easy agglomeration. By breaking up the steel fiber, the dispersion degree has been improved, which is convenient for uniform mixing in the mixing tank. (3) Cement, coarse quartz sand, fine quartz sand, silica fume, and fly ash are stored in a closed manner and do not come into contact with the outside world, which maximizes the original characteristics of the raw materials and thus ensures product quality. (4) The design theory of UHPC is the maximum packing density theory. The particles of different particle sizes of its constituent materials form the most compact packing in the best proportion, that is, the gaps between the accumulation of millimeter-level particles (aggregates) are filled with micron-level particles (cement, fly ash, mineral powder), and the gaps between the accumulation of micron-level particles are filled with submicron-level particles (silica fume). The volatilization and loss of micron-level and submicron-level particle materials during the production process can easily form small "holes" in the mixture, greatly reducing the strength of concrete. In order to solve the problem of volatilization and loss of fine particles during the feeding and mixing process, the dust generated during the feeding process of the first transition bin and the second cumulative scale is recovered by pulse dust removal, and the recovered dust is put into the mixing tank to ensure that the core components of the core material are not lost.

[0039] Example 2: A UHPC premix production line of a UHPC premix process, such as Figures 1 to 4 As shown, it includes the following four parts: cement, fine quartz sand, coarse quartz sand conveying and weighing system; silica ash, fly ash conveying and weighing system; steel fiber conveying and weighing system; mixing and premixing system.

[0040] like Figure 1 and Figure 2As shown, the cement, fine quartz sand, and coarse quartz sand conveying and weighing system includes a cement tank 1, a high-pressure air pump 2 for pumping cement into the cement tank 1, a fine quartz sand tank 3, a coarse quartz sand tank 4, a first lifting and conveying device for conveying coarse quartz sand and fine quartz sand into the fine quartz sand tank 3 and the coarse quartz sand tank 4, a first cumulative scale 6, a plurality of first screw conveyors 7, a plurality of first pneumatic butterfly valves 8, a first transition bin 9, and a feeding device for conveying raw materials in the first cumulative scale 6 to the first filtering bin. The plurality of first screw conveyors 7 respectively and sequentially convey the raw materials in the cement tank 1, the fine quartz sand tank 3, and the coarse quartz sand tank 4 to the first transition bin 9, and the plurality of first pneumatic butterfly valves 8 are respectively arranged between the plurality of first screw conveyors 7 and the first cumulative scale 6.

[0041] like Figure 2 As shown, two cement tanks 1, coarse quartz sand tanks 4, and fine quartz sand tanks 3 are provided, and the first lifting and conveying device includes a first elevator 51 for conveying fine quartz sand or coarse quartz sand, a pneumatic four-way valve 52 for receiving materials from the first elevator 51, a third screw conveyor 53 connected to one of the discharge ends of the pneumatic four-way valve 52, and a first pneumatic dividing valve 54 connected to the discharge end of the third screw conveyor 53. The other two discharge ends of the pneumatic four-way valve 52 are respectively connected to the two coarse quartz sand tanks 4, and the two discharge ends of the first pneumatic dividing valve 54 are respectively connected to the two fine quartz sand tanks 3. The loading device includes a fourth screw conveyor 101 connected to the discharge end of the first cumulative scale 6, and a second elevator 102 connected to the discharge end of the fourth screw conveyor 101 and conveying the raw materials to the first transition bin 9.

[0042] like Figure 1 and Figure 3 As shown, the silica ash and fly ash conveying and weighing system includes a silica ash tank 11, a fly ash tank 12, a second lifting and conveying device for conveying silica ash and fly ash to the silica ash tank 11 and the fly ash tank 12, a second cumulative scale 14, and two second screw conveyors 15. The silica ash tank 11 and the fly ash tank 12 are located above the second cumulative scale 14. The two second screw conveyors 15 respectively convey the raw materials in the silica ash tank 11 and the fly ash tank 12 to the second cumulative scale 14. A pneumatic butterfly valve (not marked in the figure) is arranged between the second screw conveyor 15 and the second cumulative scale 14. The second lifting and conveying device includes a third hoist 131 for conveying silica ash or fly ash, and a second pneumatic dividing valve 132 connected to the discharge end of the third hoist 131. The two discharge ends of the second pneumatic dividing valve 132 are respectively connected to the silica ash tank 11 and the fly ash tank 12.

[0043] like Figure 1 , Figures 4 to 6As shown, the steel fiber conveying and weighing system includes a loss-in-weight scale 16 , a belt conveyor 17 for conveying the steel fibers into the loss-in-weight scale 16 , and a second transition bin 18 for receiving the steel fibers output from the loss-in-weight scale 16 . The middle part of the belt conveyor 17 extends upwardly and obliquely toward the direction close to the weight loss scale 16. The inclination angle of the oblique upward extending part of the belt conveyor 17 is 65-75 degrees (72 degrees in the figure). The weight loss scale 16 includes a base 161, a vibration plate 162, a plurality of buffer rubber blocks 163 connected between the base 161 and the vibration plate 162, a vibrator 164 arranged on the outside of the vibration plate 162, a weighing sensor 165 arranged at the connection between the buffer rubber block 163 and the base 161 and used to detect the gravity from the buffer rubber block 163, a discharge channel 166 which is connected to the discharge end of the vibration plate 162 at one end and extends downward at the other end, a screen 167 arranged at one end of the discharge channel 166 away from the vibration plate 162, and a return channel 168 connected between the discharge channel 166 and the vibration plate 162 and recovering the clumped steel fibers left by the screen 167 during the vibration process.

[0044] As shown in 1 , the mixing and premixing system is a mixing tank 19 for receiving raw materials from the first transition bin 9 , the second cumulative scale 14 , and the second transition bin 18 and mixing them.

[0045] like Figure 1 , Figure 2 and Figure 3As shown, a first pre-delivery bin 20 is provided at the feed end of the first elevator 51, a first manual butterfly valve 21 is provided between the first pre-delivery bin 20 and the feed end of the first elevator 51, a second pre-delivery bin 22 is provided at the feed end of the third elevator 131, and a second manual butterfly valve 23 is provided between the second pre-delivery bin 22 and the feed end of the third elevator 131. It also includes a first pulse dust collector 24, a first dust collecting main pipe 241 connected to the first pulse dust collector 24, a first dust collecting branch pipe 242 connected between the first dust collecting main pipe 241 and the first pre-delivery bin 20, a second dust collecting branch pipe 243 connected between the first dust collecting main pipe 241 and the discharge end of the first elevator 51, a third dust collecting branch pipe 244 connected between the first dust collecting main pipe 241 and the second pre-delivery bin 22, a fourth dust collecting branch pipe 245 connected between the first dust collecting main pipe 241 and the discharge end of the third elevator 131, and a fifth dust collecting branch pipe 246 connected between the first dust collecting main pipe 241 and the second transition bin 18. The first dust collecting branch pipe 242, the second dust collecting branch pipe 243, the third dust collecting branch pipe 244, the fourth dust collecting branch pipe 245, and the fifth dust collecting branch pipe 246 are respectively provided with a third manual butterfly valve 247 (only one of them is marked in the figure) at one end away from the first dust collecting main pipe 241. There are two cement tanks 1, which also include a second pulse dust collector 25, a second dust collecting main pipe 251 connected to the second pulse dust collector 25, a sixth dust collecting branch pipe 252 connected between the second dust collecting main pipe 251 and the top of one of the cement tanks 1, and a seventh dust collecting branch pipe 253 connected between the second dust collecting main pipe 251 and the top of another cement tank 1. The sixth dust collecting branch pipe 252 and the seventh dust collecting branch pipe 253 are respectively provided with a fourth manual butterfly valve 254 at one end away from the second dust collecting main pipe 251.

[0046] like Figure 1 and Figure 7 As shown, the first transition bin 9 and the second cumulative scale 14 are located above the mixing cylinder 19, and also include a third pulse dust collector 26, a third dust collecting main pipe 261 connected to the third pulse dust collector 26, an eighth dust collecting branch pipe 262 connected between the third dust collecting main pipe 261 and the first transition bin 9, and a ninth dust collecting branch pipe 263 connected between the third dust collecting main pipe 261 and the second cumulative scale 14. The eighth dust collecting branch pipe 262 and the ninth dust collecting branch pipe 263 are respectively provided with a fifth manual butterfly valve 264 at one end away from the third dust collecting main pipe 261, and the discharge end of the third pulse dust collector 26 is connected to the top of the mixing cylinder 19.

[0047] Implementation effect: (1) The centralized, continuous and intelligent production of UHPC premixes in factories has been realized to a high degree. At present, most of the UHPC premix (dry mix) fields adopt the open-air intermittent production method of "metering-lifting-production-metering-lifting-production", and have failed to realize the closed and continuous production method of "raw materials lifting into tanks + automatic batching and metering + temporary storage + continuous production". This production line realizes the above production method through the effective combination of targeted material analysis and mechanical principles, with better production capacity; at the same time, it realizes the advance premixing of UHPC dry mix, and in the later on-site construction, a number of mobile wet mixers are set up according to the construction progress requirements, thereby increasing the output of UHPC finished materials and construction efficiency, ensuring metering accuracy, and improving quality. (2) By analyzing the characteristics of UHPC raw materials, different transportation and storage methods are adopted for each raw material to ensure the basic physical properties of each raw material, effectively solve the mechanized storage and distribution of each raw material of UHPC, and reduce the intensity of manual work; for example, cement, fine quartz sand, and coarse quartz sand are transported by spiral conveying, and are cumulatively weighed by the first cumulative scale 6, so as to ensure the measurement accuracy of each raw material; silica ash and fly ash have fine particles and small bulk density. In order to reduce mass loss and ensure measurement accuracy, their storage and weighing work are arranged above the mixing tank 19, and they are directly put into the mixing tank 19 after measurement; steel fiber has the characteristics of large feeding amount and easy to agglomerate, so it is transported by belt conveyor 17 to increase the feeding amount. The steel fiber is broken up by the vibration of weight loss scale 16 to improve the dispersion degree, which is convenient for uniform mixing in the mixing tank 19, and the large-angle belt conveyor 17 (the inclination angle is 65-75 degrees) avoids the problem of high labor intensity caused by directly transporting steel fiber to a height for feeding, and is convenient for replenishing and measuring steel fiber. (3) Cement, coarse quartz sand, fine quartz sand, silica fume, and fly ash are stored and managed in a closed manner without contact with the outside, so as to maximize the original characteristics of the raw materials and thus ensure product quality. (4) The design theory of UHPC is the maximum packing density theory, and the particles of different particle sizes of its constituent materials form the most compact stacking in the best proportion, that is, the gaps between the stacking of millimeter-level particles (aggregates) are filled with micron-level particles (cement, fly ash, mineral powder), and the gaps between the stacking of micron-level particles are filled with submicron-level particles (silica fume). The volatilization and loss of micron-level and submicron-level particle materials during the production process can easily form small "holes" in the mixture, greatly reducing the strength of concrete. In order to solve the problem of volatilization and loss of fine particles during the feeding and mixing process, the dust generated during the feeding process of the first transition bin 9 and the second cumulative scale 14 is recovered by pulse dust removal (the third pulse dust collector 26), and the recovered dust is put into the mixing tank 19 to ensure that the core components of the core material are not lost. (5) The entire process of feeding production is closed and pulse dust removal is carried out. The entire production site is enclosed by a canopy and adopts workshop-style management, which is far higher than the emission standards and meets the requirements of a "green" environmentally friendly site.

[0048] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A UHPC premixing process, characterized in that: The steps include: Step S1: transporting cement into a cement tank, transporting fine quartz sand into a first quartz sand tank, transporting coarse quartz sand into a second quartz sand tank, transporting silica ash into a silica ash tank, and transporting fly ash into a fly ash tank; Step S2: First, by means of spiral conveying, the cement in the cement tank, the fine quartz sand in the first quartz sand tank, and the coarse quartz sand in the second quartz sand tank are respectively conveyed to the first cumulative scale for measurement, and then conveyed to the first transition bin; by means of spiral conveying, the silica ash in the silica ash tank and the fly ash in the fly ash tank are conveyed to the second cumulative scale for measurement; the steel fiber is conveyed to the weight loss scale for measurement, and then conveyed to the second transition bin; Step S3: transporting cement, fine quartz sand and coarse quartz sand in the first transition bin to the mixing tank, transporting silica ash and fly ash in the second cumulative scale to the mixing tank, and transporting steel fiber in the second transition bin to the mixing tank, and premixing them uniformly through the mixing tank; At the same time, in step S1 to step S3, the silica ash tank and the fly ash tank are located above the second cumulative scale, and the second cumulative scale is located above the mixing tank.

2. A UHPC premixing process according to claim 1, characterized in that: In step S2, the steel fibers in the weight loss scale are broken up, and the agglomerated steel fibers are screened out when being transported to the second transition bin.

3. A UHPC premixing process according to claim 1, characterized in that: In step S3, the dust generated during the unloading process of the first transition bin and the second accumulating scale is recovered by means of pulse dust removal, and the recovered dust is put into the mixing tank.

4. A UHPC premix production line for the UHPC premix process according to any one of claims 1 to 3, characterized in that: Includes the following parts: A cement, fine quartz sand and coarse quartz sand conveying and weighing system comprises a cement tank (1), a high-pressure air pump (2) for pumping cement into the cement tank (1), a fine quartz sand tank (3), a coarse quartz sand tank (4), a first lifting and conveying device for conveying coarse quartz sand and fine quartz sand into the fine quartz sand tank (3) and the coarse quartz sand tank (4), a first cumulative scale (6), a plurality of first screw conveyors (7), a plurality of first pneumatic butterfly valves (8), a first transition bin (9), and a feeding device for conveying raw materials in the first cumulative scale (6) to a first filtering bin; the plurality of first screw conveyors (7) respectively and sequentially convey the raw materials in the cement tank (1), the fine quartz sand tank (3) and the coarse quartz sand tank (4) into the first transition bin (9); the plurality of first pneumatic butterfly valves (8) are respectively arranged between the plurality of first screw conveyors (7) and the first cumulative scale (6); A silica ash and fly ash conveying and weighing system comprises a silica ash tank (11), a fly ash tank (12), a second lifting and conveying device for conveying silica ash and fly ash into the silica ash tank (11) and the fly ash tank (12), a second cumulative scale (14), and two second screw conveyors (15), wherein the silica ash tank (11) and the fly ash tank (12) are located above the second cumulative scale (14), and the two second screw conveyors (15) respectively convey the raw materials in the silica ash tank (11) and the fly ash tank (12) into the second cumulative scale (14); A steel fiber conveying and weighing system comprises a weight loss scale (16), a belt conveyor (17) for conveying the steel fibers to the weight loss scale (16), and a second transition bin (18) for receiving the steel fibers output from the weight loss scale (16); The mixing and premixing system comprises a mixing tank (19) for receiving raw materials from a first transition bin (9), a second cumulative scale (14) and a second transition bin (18) and mixing them.

5. The UHPC premix production line of the UHPC premix process according to claim 4, characterized in that: The coarse quartz sand tank (4) and the fine quartz sand tank (3) are both provided with two, the first lifting and conveying device comprises a first elevator (51) for conveying fine quartz sand or coarse quartz sand, a pneumatic four-way valve (52) for receiving materials from the first elevator (51), a third screw conveyor (53) connected to one of the discharge ends of the pneumatic four-way valve (52), and a first pneumatic material dividing valve (54) connected to the discharge end of the third screw conveyor (53), the other two discharge ends of the pneumatic four-way valve (52) are respectively connected to the two coarse quartz sand tanks (4), and the two discharge ends of the first pneumatic material dividing valve (54) are respectively connected to the two fine quartz sand tanks (3).

6. The UHPC premix production line of the UHPC premix process according to claim 5, characterized in that: The loading device comprises a fourth screw conveyor (101) connected to the discharge end of the first cumulative scale (6), and a second elevator (102) connected to the discharge end of the fourth screw conveyor (101) and conveying the raw materials to the first transition bin (9).

7. The UHPC premix production line of the UHPC premix process according to claim 6, characterized in that: The second lifting and conveying device comprises a third hoist (131) for conveying silica ash or fly ash, and a second pneumatic dividing valve (132) connected to the discharge end of the third hoist (131), wherein the two discharge ends of the second pneumatic dividing valve (132) are respectively connected to the silica ash tank (11) and the fly ash tank (12).

8. The UHPC premix production line of the UHPC premix process according to claim 4, characterized in that: The middle part of the belt conveyor (17) extends upwardly and obliquely toward the direction close to the weight loss scale (16), and the inclination angle of the obliquely upward extending part of the belt conveyor (17) is 65-75 degrees. The weight loss scale (16) includes a base (161), a vibration plate (162), a plurality of buffer rubber blocks (163) arranged between the base (161) and the vibration plate (162), a vibrator (164) arranged on the outside of the vibration plate (162), and a buffer rubber block (163) and a base. (161) and used to detect the gravity from the buffer rubber block (163); a discharge channel (166) which is connected to the discharge end of the vibration plate (162) at one end and extends downward at the other end; a screen (167) arranged at one end of the discharge channel (166) away from the vibration plate (162); and a return channel (168) connected between the discharge channel (166) and the vibration plate (162) and used to recover the clumped steel fibers left by the screen (167) during the vibration process.

9. The UHPC premix production line of the UHPC premix process according to claim 7, characterized in that: The first elevator (51) is provided with a first pre-delivery bin (20) at the feeding end, a first manual butterfly valve (21) is provided between the first pre-delivery bin (20) and the feeding end of the first elevator (51), the third elevator (131) is provided with a second pre-delivery bin (22) at the feeding end, a second manual butterfly valve (23) is provided between the second pre-delivery bin (22) and the feeding end of the third elevator (131), and further includes a first pulse dust collector (24) and a first pulse dust collector (24). a first dust removal main pipe (241) connected to the first dust removal main pipe (241) and the first pre-delivery bin (20); a first dust removal branch pipe (242) connected between the first dust removal main pipe (241) and the first pre-delivery bin (20); a second dust removal branch pipe (243) connected between the first dust removal main pipe (241) and the discharge end of the first elevator (51); a third dust removal branch pipe (244) connected between the first dust removal main pipe (241) and the second pre-delivery bin (22); a third dust removal branch pipe (245) connected between the first dust removal main pipe (241) and the discharge end of the third elevator (131); The cement tank (1) is provided with two dust removal branches (245), and a fifth dust removal branch (246) connected between the first dust removal main pipe (241) and the second transition chamber (18); the first dust removal branch (242), the second dust removal branch (243), the third dust removal branch (244), the fourth dust removal branch (245), and the fifth dust removal branch (246) are respectively provided with a third manual butterfly valve (247) at one end away from the first dust removal main pipe (241); the cement tank (1) is provided with two second pulse dust collectors (25 ), a second dust removal main pipe (251) connected to the second pulse dust collector (25), a sixth dust removal branch pipe (252) connected between the second dust removal main pipe (251) and the top of one of the cement tanks (1), and a seventh dust removal branch pipe (253) connected between the second dust removal main pipe (251) and the top of another cement tank (1), wherein the sixth dust removal branch pipe (252) and the seventh dust removal branch pipe (253) are respectively provided with fourth manual butterfly valves (254) at their ends away from the second dust removal main pipe (251).

10. The UHPC premix production line of the UHPC premix process according to claim 4, characterized in that: The first transition bin (9) and the second cumulative scale (14) are located above the mixing cylinder (19), and further include a third pulse dust collector (26), a third dust collection main pipe (261) connected to the third pulse dust collector (26), an eighth dust collection branch pipe (262) connected between the third dust collection main pipe (261) and the first transition bin (9), and a ninth dust collection branch pipe (263) connected between the third dust collection main pipe (261) and the second cumulative scale (14). The ends of the eighth dust collection branch pipe (262) and the ninth dust collection branch pipe (263) away from the third dust collection main pipe (261) are respectively provided with fifth manual butterfly valves (264). The discharge end of the third pulse dust collector (26) is connected to the top of the mixing cylinder (19).

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