CN108500819A - A kind of concrete or asphalt aggregate particle shape decorating device - Google Patents

Abstract

The invention discloses a concrete or asphalt mixture aggregate particle shape modification device, which comprises a feed bin and a stirrer. The feed bin is divided into a granular modification bin and a collection bin by a material partition, and the agitator is a spiral agitator, which is placed vertically in the granular modification bin. A number of metal grinding balls are arranged in the grain shape modification bin, and a feed inlet is arranged on the upper side of the grain shape modification bin. The feed holes are evenly arranged on the surface of the material partition board; the bottom of the collection bin is provided with a discharge port. The device of the invention has simple structure, convenient installation and use, low energy consumption, and can effectively improve the particle shape of aggregate and eliminate edges and corners. During use, the aggregate modification time can be controlled to avoid damage to the aggregate. Cooperating with screening machines, continuous production operations can be realized.

Description

A concrete or asphalt mixture aggregate particle shape modification device

technical field

The invention relates to a concrete or asphalt mixture aggregate processing device, in particular to a concrete or asphalt mixture aggregate particle shape modification device.

Background technique

Aggregate is the main material used in the preparation of asphalt mixture and cement concrete. Aggregate accounts for more than 3/4 of the volume and mass of concrete. Its characteristics are important for the rheological properties of fresh concrete, the mechanical properties and durability of hardened concrete. influences. The particle shape characteristics have a great influence on the characteristics of the aggregate. It is generally believed that the particle shape of the coarse aggregate is the best sphere or cube. With the increase of the needle-shaped coarse aggregate content, the porosity and ratio In this way, it is easy to increase the water absorption on the surface of the aggregate, which in turn affects the fluidity of the fresh concrete, resulting in poor workability of the concrete, which is not conducive to pumping and construction. At the same time, the needle flake aggregate is easy to be oriented in the process of mixing and vibrating the concrete, which will lead to a decrease in the strength of the concrete. Therefore, the content of needle and flake particles in coarse aggregate should be controlled within a certain range. For fine aggregates, the shape of the particles has an important influence on the close packing. In practical applications, it is more desirable to obtain round particles, which are not only conducive to close packing, but also conducive to the performance of concrete work performance. Therefore, the edges and sharp corners of fine aggregate particles should be minimized.

With the acceleration of urbanization, pebbles have been exhausted. In this case, crushed stone is the first choice for concrete as coarse aggregate. The main sources of fine aggregate are artificial sand and river sand and sea sand. Although the modulus and gradation of river sand and sea sand are relatively ideal, since natural sand is a non-renewable natural resource, the massive exploitation of natural sand has caused damage to the environment and ecology in many places. Resources are already running out. Excavation of sand from rivers has been expressly prohibited by the state, which has also caused tension in sand sources. Artificial sand emerged as a substitute for natural sand and developed rapidly.

However, the use of crushed stone and artificial sand presents a significant problem when preparing concrete. Pebbles and natural sand have a roughly spherical shape and a relatively smooth surface. Crushed stone and artificial sand are often crushed by mechanical equipment, resulting in angular or needle-like shapes with sharp corners. The smooth profile of crushed stone and artificial sand compared to natural aggregates is very disadvantageous in terms of controlling rheology in concrete, in terms of water requirements and finishability.

Based on the above reality, how to efficiently reduce the content of needles and flaky particles in crushed stones and remove the angular shape of artificial sand has become a realistic demand for the preparation of concrete or asphalt mixtures.

Contents of the invention

The technical problem to be solved by the present invention is to provide a concrete or asphalt mixture aggregate particle shape modification device to overcome the defects of the prior art. The device of the present invention can effectively weaken the protruding edges and corners of the aggregate, reduce the content of needle flake particles in the aggregate, maintain the original particle size of the aggregate to the greatest extent, and make its performance close to that of natural aggregate, thereby improving the quality of freshly mixed concrete. Workability, Strength, Durability.

In order to realize the purpose of the above invention, the present invention proposes a technical solution as follows: a device for modifying the aggregate shape of concrete or asphalt mixture, including a silo and a mixer. It is characterized in that: the silo is designed as a double silo, which is divided into a grain-shaped modification bin and a collection bin by a material partition, and the collection bin is located under the grain-shape modification bin. The agitator is a helical agitator, which is placed vertically in the particle shape modification bin. A number of metal grinding balls are arranged in the grain shape modification bin, and a feed inlet is arranged on the upper side of the grain shape modification bin. The blanking holes (grit holes) are evenly arranged on the surface of the material partition board. A discharge port is provided at the bottom of the collection bin.

The top of the grain modification bin is provided with a bearing seat, and a motor-driven transmission is arranged above the bearing seat. The spiral agitator is installed on the bearing seat through a bearing and connected to the power output shaft of the transmission.

Another improvement scheme is: the grain shape modification bin is in the shape of a horizontal barrel, the upper part of the grain shape modification bin is provided with a feed inlet, the lower part of the grain shape modification bin is open and docked with the collection bin, and the opening is provided with the partition sheet. The agitator (non-helical agitator or helical agitator can be selected) is arranged laterally on the axis of the particle shape modification bin.

The bottom of the collection bin is funnel-shaped.

The surface of the metal grinding ball is evenly distributed with several protrusions. These raised metal grinding balls increase the effective friction with the aggregate, and facilitate the use of extrusion, kneading, grinding, shearing, etc. to weaken the protruding edges and corners of the aggregate and reduce the needle-like particles of the aggregate. content, to obtain concrete aggregate with better particle shape.

The metal grinding balls are steel grinding balls.

The diameter of the metal grinding ball is larger than the diameter of the cutting hole of the partition plate. So that the modified aggregate can enter the collection bin, while the steel balls are kept in the granular modification bin. The aggregate silo can control the grain shape modification time and temporarily store the grain shape modified aggregate.

The aggregate particle shape modification device for concrete or asphalt mixture of the present invention, after the aggregate to be processed enters the particle shape modification bin from the feed port, it is driven by the stirring of the agitator in the particle shape modification bin, thereby driving the steel ball to move and stir Aggregate, so that the aggregate particles are squeezed and rubbed against each other, so that the needle-like particles are broken into small regular particle shapes, the sharp edges and corners of the material particles are worn, and the material particles become full, smooth and round. The optimal modification time T of the concrete aggregate is determined by the crush resistance of the concrete aggregate to be treated and the content of needle-like particles, so as to reduce the damage and fragmentation of the aggregate due to excessive mechanical collision. While improving the particle shape of needle flakes, the original particle size of the concrete aggregate is maintained to the greatest extent, thereby improving the workability, strength and durability of fresh concrete. The aggregate silo can temporarily store the modified aggregate, and the outlet at the lower part of the aggregate silo can be connected to a screening machine. While releasing the modified aggregate (the amount of discharge is V ₂ ), add granular materials according to production requirements through the feed port. Concrete aggregate to be modified. At every t time point, the amount of material fed and discharged is V ₂ , and they are synchronized. While the sieving machine is sieving the aggregate, the concrete aggregate particle shape modification device continues to modify the aggregate particle shape to achieve continuous reciprocating operation.

In the use of the device of the present invention, in order to optimize the particle shape modification effect, the specific treatment process is as follows:

1) Determine the performance parameters: the optimal modification time T of the aggregate is determined by the anti-crushing performance of the aggregate to be processed and the content of the needle-like particles. Volume V ₂ and screening time t (i.e. discharge time interval), the total volume of the material in the particle shape modification bin is V ₁ , .

2) Feed material: According to the production requirements, add the aggregate volume V ₁ of the concrete aggregate to be processed through the feed port.

3) Grain shape modification: Start the agitator to stir the aggregate, the stirring time is T, and the stirred aggregate passes through the grate hole and enters the aggregate bin.

4) Discharging: at every time point of t, the aggregate of volume _V2 in the aggregate bin is added to the screening machine for screening;

5) Feeding: While discharging, add the aggregate to be processed through the feed port according to the production requirements. The amount of material for feeding and discharging is V ₂ , and they are kept in sync. While the sieving machine is sieving, the aggregate particle shape modification device continues to stir the aggregate to achieve continuous reciprocating operation.

The device of the invention has simple structure, convenient installation and use, low energy consumption, and can effectively improve the particle shape of aggregate and eliminate edges and corners. The traditional grinding ball with a smooth surface is transformed into a grinding ball with several protrusions on the surface to increase the effective friction and facilitate the use of extrusion, kneading, grinding, shearing, etc. to break the needle-like particles into small pieces. Regular particle shape, the sharp edges and corners of the material particles are worn away, and the material particles become full, smooth and round. Realize the modification of aggregate particle shape, make it tend to be spherical, and meet the performance requirements of concrete aggregate.

During the use of the device of the invention, the time for modifying the aggregate can be controlled to avoid damaging and breaking the aggregate. The optimal modification time T of the concrete aggregate is determined by the anti-crush performance of the concrete aggregate to be treated and the content of needle-like particles. According to the performance parameters of the screening machine, determine the volume V ₂ of the single screening aggregate of the screening machine and the screening time t (that is, the time interval for discharging), and the total volume of the feed at the feed port is V ₁ , , by controlling the total volume V ₁ of the feed inlet, and controlling the aggregate particle shape modification time T, thereby reducing the damage and breakage of the aggregate due to excessive mechanical collisions. While improving the particle shape of the needle flakes, the original particle size of the concrete aggregate is maintained to the greatest extent, so that the particle size of the aggregate will not become smaller and smaller, and the best modification effect is achieved.

The device of the present invention can cooperate with a screening machine for continuous production operation. The discharge port at the bottom of the collection bin is connected with a screening machine. Add a certain quality of concrete aggregate after particle shape modification to the screening machine, and at the same time add the same volume of concrete aggregate through the feed port. While the screening machine is screening the concrete aggregate, the concrete aggregate particle shape modification device continues to stir the aggregate to achieve continuous production with the screening machine. The sieving machine sieves the processed aggregate, which can screen out the materials that do not meet the specifications, which is convenient for subsequent use.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the device for modifying the aggregate shape of concrete or asphalt mixture according to the present invention.

Fig. 2 is a plan view of the bulkhead in Fig. 1 .

Fig. 3 is a structural schematic diagram of the metal grinding ball.

Fig. 4 is a schematic structural view of the concrete or asphalt mixture aggregate particle shape modification device (second technical solution) of the present invention.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

Example 1

Figure 1 shows the concrete or asphalt mixture aggregate particle shape modification device according to the technical solution 1 proposed by the present invention, including a silo and an agitator 6 . The silo is a vertically arranged drum-shaped silo, designed as a double silo, and is divided into a particle shape modification silo 5 and a collection silo 8 by a material partition plate 7 . The collection bin 8 is located under the granular modification bin 5 . The agitator 7 is a helical agitator, which is placed vertically in the particle shape modification bin, on the center line of the vertical axis. A plurality of metal grinding balls are arranged in the grain shape modification bin, and a feed inlet 4 is arranged on the side upper part of the grain shape modification bin. The blanking holes (grit holes) are evenly arranged on the surface of the material separating plate 7 . The bottom of the collection bin 8 is in the shape of a funnel, and the bottom of the funnel is a discharge port 9 . The whole feed bin is fixed on the concrete base 10 through the frame structure.

The top cover of the granular modification bin 5 is provided with a bearing seat 3, the top of the granular modification bin 5 is provided with a speed changer 2 and a motor 1, a pulley (driving pulley) is established on the motor shaft, and a pulley is established on the power input shaft of the speed changer (from drive wheel), the motor powers the transmission through the belt. The spiral agitator 6 is installed on the bearing seat 3 through a bearing, and is connected to the power output shaft of the transmission 3 . The present invention also can select motor to transmit power to speed changer through chain sprocket or gear mode.

The metal grinding ball is a steel grinding ball, and several protrusions are evenly distributed on its surface. These raised metal grinding balls increase the effective friction with the aggregate, and facilitate the use of extrusion, kneading, grinding, shearing, etc. to weaken the protruding edges and corners of the aggregate and reduce the needle-like particles of the aggregate. content, to obtain concrete aggregate with better particle shape. The diameter of the metal grinding ball is larger than the diameter of the feed hole of the partition plate. So that the modified aggregate can enter the collection bin, while the steel balls are kept in the granular modification bin. The aggregate silo can control the grain shape modification time and temporarily store the grain shape modified aggregate.

(1) Raw materials for testing

Divide the aggregate into two parts, denoted as S1 and S2 respectively. Use the concrete or asphalt mixture aggregate particle shape modification device of this embodiment to modify the particle shape of S2. The sieve analysis, apparent density, water absorption, bulk density, crushing value and needle and flake particle content of S1 and S2 were measured respectively.

(2) Test methods for aggregate properties

The sieve analysis, apparent density, water absorption, bulk density, crushing value and content of needles and flakes of aggregates are all measured in accordance with JGJ52-2006 "Standards for Quality and Inspection Methods of Sand and Stone for Ordinary Concrete". The measured data See Table 1.

(3) Physical and mechanical properties of aggregates S1 and S2

Table 1 Physical and mechanical properties of S1 and S2

sample number Sieve analysis (%) Apparent density( ) Water absorption (%) Bulk density( ) Crushing value (%) Needle and flaky particle content (%) S1 17.2 2380 8.34 2380 17.2 19.5 S2 7.1 2820 2.53 2820 7.1 8.7

Example 2

Basically the same as the embodiment, the difference is: as shown in Figure 4, the granular modification bin is in the shape of a horizontal barrel, the upper part of the granular modification bin is provided with a feeding port, the lower part of the granular modification bin is open and connected to the The collecting bin is docked, and the material partition board is arranged at the opening. The agitator is arranged transversely on the axis of the grain modification bin. The agitator can be a helical agitator (as shown in Figure 4), or a non-helical agitator.

Claims (7)

1. a kind of concrete or asphalt aggregate particle shape decorating device, including feed bin and blender；It is characterized in that：The material Storehouse is divided into particle shape modification storehouse and collecting bin by material baffle, and the collecting bin is located under particle shape modification storehouse；The blender is Spiral agitator is vertically placed in particle shape modification storehouse；Particle shape is modified and is equipped with several metal grinding balls in storehouse, and particle shape is modified on the side in storehouse Portion sets feed inlet；Uniformly distributed blanking hole in the material baffle plate face；The collecting bin bottom sets out material mouth.

2. concrete or asphalt aggregate particle shape decorating device according to claim 1, it is characterized in that：The particle shape is repaiied It is provided with bearing block at the top of decorations storehouse, sets motor-driven speed changer above bearing block, the spiral agitator is pacified by bearing It is taken mounted in bearing, and connects transmission power output shaft.

3. concrete or asphalt aggregate particle shape decorating device according to claim 1, it is characterized in that：The particle shape is repaiied Decorations storehouse be the barrel shape being laterally arranged, and the top in particle shape modification storehouse sets feed inlet, particle shape modify storehouse lower openings and with gather materials Storehouse is docked, and opening sets the material baffle；The blender is horizontally set on particle shape modification storehouse axis.

4. according to the concrete of claim 1,2 or 3 or asphalt aggregate particle shape decorating device, it is characterized in that：It is described The bottom of collecting bin is funnel shaped.

5. according to the concrete of claim 1,2 or 3 or asphalt aggregate particle shape decorating device, it is characterized in that：It is described The surface of metal grinding ball uniformly spreads all over several protrusions.

6. concrete or asphalt aggregate particle shape decorating device according to claim 5, it is characterized in that：The metal mill Ball is steel abrading-ball.

7. according to the concrete of claim 1,2 or 3 or asphalt aggregate particle shape decorating device, it is characterized in that：It is described The diameter of metal grinding ball is more than the diameter of the material baffle blanking hole.