JPH10180133A - High voltage pulse crushing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high voltage pulse crushing device for avoiding the state in which high voltage pulses flow through a conductive material and crushing is not in progress in the case of crushing a material to be crushed including the conductive material inside such as reinforced concrete. SOLUTION: A material 10 to be crushed is disposed between a pair of electrodes 3, and high voltage pulses are applied between the paired electrodes 3 to crush gradually the material 10 to be crushed. At that time, resistance between a pair of electrodes 3 is sensed by a resistance sensing means, and the resistance sensing positions are changed over in compliance with the resistance values. Namely as far as the sensed resistance value is smaller compared with the specified value, a pair of electrodes 3 are connected together by the conductive material and the state in which crushing is not in progress is judged, and the resistance sensing positions, namely the positions of a pair of electrodes 3, are moved, and the application of high voltage pulse is resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage pulse crusher for crushing an object to be crushed by using a high-voltage pulse,
Specifically, the apparatus includes an electrode pair and a high-voltage pulse applying means for applying a high-voltage pulse between the pair of electrodes, disposing the object to be crushed between the pair of electrodes, and applying a high-voltage pulse between the pair of electrodes. The present invention relates to a high-voltage pulse crushing apparatus for crushing the above-mentioned crushed object by performing the above-described steps.

[0002]

2. Description of the Related Art In the disposal of waste concrete, waste reinforced concrete, telephone poles, sleepers, etc. generated by demolishing civil engineering and building structures, etc., these are crushed into small particles and discarded, and the internal coarse aggregate is disposed of. And steel bars are collected and reused. As one of the crushing methods, the Soviet Inventor's Certificate No. A method using a high-voltage pulse is proposed in 1392717. Hereinafter, FIG.
This will be described with reference to FIG. High voltage pulse crusher A shown in FIG.
Reference numeral 0 denotes a device to which the crushing method using the high voltage pulse can be applied, and the boosting rectifier 35, the high voltage pulse generator 34, and the electrodes 32 and 33 are main components. The electrodes 33 are arranged in a mesh at a predetermined distance from the bottom of the water tank 31, and are connected to the ground. Concrete material 37 to be crushed is placed in a water tank 3 filled with water.
It is arranged on one of the electrodes 33. At the time of crushing, first, the electrode 32 is pressed against the concrete material 37. The DC current boosted by the step-up rectifier 35 is converted into a high-voltage pulse by the high-voltage pulse generator 34, and the high-voltage pulse is applied between the electrodes 32 and 33. As a result, a shock wave is generated in the concrete material 37 between the electrodes 32 and 33, and the concrete material 37 is crushed by the shock wave. The high voltage pulse is applied intermittently at predetermined intervals, and the concrete material 37 is gradually crushed by the movement of the electrode 32. Concrete grains and coarse aggregate formed by the crushing pass through the mesh of the electrodes 33 and accumulate on the bottom surface of the water tank 31.

[0003]

In the crushing apparatus A0, even when crushing an object to be crushed such as reinforced concrete containing a conductor therein, a shock wave is generated in the concrete when the electrodes 32 and 33 are in contact with the concrete portion. Occurs and crushing proceeds. However, when the crushing progresses and the reinforcing steel inside the concrete is exposed, there is a possibility that the reinforcing steel contacts both the electrodes 32 and 33. At this time, since the high voltage pulse guided to the electrode 32 flows through the reinforcing bar to the electrode 33 and the ground, no shock wave is generated in the concrete, and the crushing is stopped at this point. Further, since the crushing device A0 does not have means for interrupting the generation of the high-voltage pulse even in such a case, the applied energy is not used for crushing,
It will be wasted. The present invention has been made in view of the above circumstances, and an object thereof is that even when crushing an object to be crushed such as reinforced concrete that includes a conductor therein, a high-voltage pulse flows through the conductor and the crush is performed. An object of the present invention is to provide a high-voltage pulse crusher capable of efficiently crushing an object to be crushed without wasting energy and avoiding waste.

[0004]

In order to achieve the above object, the present invention comprises an electrode pair and a high voltage pulse applying means for applying a high voltage pulse between the electrode pair. A high-voltage pulse crusher that is disposed between the electrode pairs and crushes the crushed object by applying a high-voltage pulse between the electrode pairs; A high voltage pulse crushing device is provided, comprising: a detection position switching means for switching a detection position of the resistance according to the resistance value detected by the resistance detection means. The detection position switching means may be configured to switch the detection position of the resistor by moving the electrode pair. Further, the resistance detecting means may detect the resistance value of a plurality of electrode pairs, and the detection position switching means may select the one having a large resistance from the plurality of electrode pairs. The switching of the resistance detection position can be performed quickly.

Further, if the resistance detecting means detects a resistance between the electrode pairs by applying a voltage lower than the voltage of the high voltage pulse between the electrode pairs,
The capacity of the resistance detecting means can be reduced as compared with the case where the resistance is detected by a high voltage pulse. At this time, a circuit including the resistance detecting means is configured to be connected to the electrode pair in parallel with the high-voltage pulse applying means, and further, the high-voltage pulse current from the high-voltage pulse applying means is connected to the electrode pair. It is also possible to provide an inflow prevention means for preventing inflow. The inflow prevention means can be constituted by an inductance and a resistance or a rectifying element. When the above-described inductance and resistance are used, a filter means for cutting a small amount of the pulse current flowing in is required. However, when the rectifying element is used, the flow of the pulse current can be completely prevented. No filter means is required. Further, as the inflow prevention means, means for interrupting conduction may be used. In this case, since the detection of the resistance by the direct current and the application of the high voltage pulse are performed alternately, the application of the high voltage pulse in the low resistance state between the electrode pairs can be completely prevented. The crushed material may be, for example, a reinforced concrete material.

[0006]

According to the present invention, the object to be crushed is disposed between the electrode pairs, and the object to be crushed is gradually crushed by applying a high-voltage pulse between the electrode pairs. At this time, the resistance between the electrode pairs is detected by the resistance detecting means. As the resistance detecting means, a means for detecting by the high voltage pulse or a means for detecting a resistance between the electrode pairs by applying a voltage lower than the voltage of the high voltage pulse between the electrode pairs can be considered. However, the latter can have a smaller capacity than the former. As an example of the latter,
A circuit including the resistance detecting means is connected to the electrode pair in parallel with the high voltage pulse applying means, and the high voltage is applied from the high voltage pulse applying means to the resistance detecting means by the inflow prevention means. It is conceivable to prevent the inflow of the pulse current. The inflow prevention means is constituted by inductance and resistance, a rectifying element, or means for interrupting conduction. When the above-described inductance and resistance are used, a filter means for cutting a small amount of the pulse current flowing in is required. However, when the rectifying element is used, the flow of the pulse current can be completely prevented. No filter means is required. If the means for interrupting the conduction is used, resistance detection by DC current and application of high-voltage pulse are performed alternately.
It is possible to completely prevent the application of the high voltage pulse in the low resistance state between the electrode pairs. When the resistance value is detected by the resistance detection means as described above, the detection position of the resistance is switched by the detection position switching means in accordance with the resistance value detected by the resistance detection means. That is, if the detected resistance value is smaller than a predetermined value, it is determined that the electrode pair is connected by a conductor and crushing does not proceed, and the resistance detection position, that is, the high voltage pulse is detected. Switch the application position. As a method for switching the resistance detection position, the resistance detection position can be switched by moving the electrode pair. Further, by installing a plurality of electrode pairs in advance and selecting one having a large resistance from among the plurality of electrode pairs, quicker switching is possible. As described above, the state in which the crushing does not progress due to the high-voltage pulse flowing through the conductor and the crushing can be quickly avoided, and the crushing process can be continued.
It is possible to efficiently crush the object to be crushed without wasting energy.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to facilitate understanding of the present invention. The following embodiments and examples are mere examples embodying the present invention, and do not limit the technical scope of the present invention. Here, FIG. 1 is a schematic diagram showing a schematic configuration of a high-voltage pulse crushing apparatus A1 according to an embodiment of the present invention, and FIG. FIG. 3 is a schematic diagram showing a schematic configuration of a high-voltage pulse crushing apparatus A2 according to the first embodiment of the present invention, and FIG. 4 is a schematic view showing a high-voltage pulse crushing apparatus A3 according to the second embodiment of the present invention. FIG. 5 is a schematic diagram showing a schematic configuration, FIG. 5 is a schematic diagram showing a schematic configuration of a high-voltage pulse crushing device A4 according to Embodiment 3 of the present invention, and FIG. 6 is a schematic diagram of a high-voltage pulse crushing device A4 according to Embodiment 3 of the present invention. FIG. 7 is a flowchart showing a processing procedure, and FIG. 7 is a schematic diagram showing a schematic configuration of a high-voltage pulse crusher A5 according to Embodiment 4 of the present invention. The high-voltage pulse crusher A1 according to the present embodiment is configured as shown in FIG. The high voltage pulse generator 1 (corresponding to a high voltage pulse applying means) for generating a high voltage pulse includes:
It is connected to the electrode 3 via an electrode moving section 2 (corresponding to a detection position switching means). The water tank 4 in which the objects to be crushed are placed is made of a conductive metal, and is connected to the grounding section 7.
Together form an electrode pair. The high-voltage pulse generating section 1 is connected to a ground section 8, and a current detecting section 5 (which constitutes a resistance detecting means together with a control section 6 described later) is provided on the connection line L1. The current detecting unit 5 is connected to a control unit 6, and the control unit 6 is connected to the electrode moving unit 2 and the high-voltage pulse generating unit 1.

Hereinafter, the crushing operation of the high-voltage pulse crusher A1 will be described in detail by using the reinforced concrete 10 as the crushed object. The reinforced concrete 10 (consisting of the concrete portion 10a and the reinforcing bar 10b), which is the object to be crushed, is placed in the water tank 4 filled with water. The electrode 3 is pressed against the upper surface of the reinforced concrete 10 by the electrode moving unit 2. As a result, the reinforced concrete 10
It will be located between the electrode pair consisting of the electrode 3 and the water tank 4. Subsequently, a high voltage pulse is applied between the electrode 3 and the water tank 4 at a predetermined interval by the high voltage pulse generator 1. As a result, a shock wave is generated between the electrode 3 and the water tank 4, that is, in the reinforced concrete 10, and the reinforced concrete 10 is gradually crushed by the shock wave. However, as the crushing of the reinforced concrete 10 progresses, the reinforcing bars 10b hidden inside the concrete portion 10a gradually appear on the surface, and eventually the electrodes 3 and the water tank 4 as shown in FIG.
May come into contact with the reinforcing bar 10b. In such a state, the high voltage pulse is applied from the electrode 3 to the reinforcing bar 10.
b to the water tank 4 and reinforced concrete 1
No shock wave is generated within 0, and the progress of crushing is stopped. Prolonging such a state not only reduces the efficiency of the crushing process, but also wastes energy to be used for crushing.

Therefore, in the high-voltage pulse crusher A1,
In order to detect the connection state between the pair of electrodes by a conductor such as the reinforcing bar 10b, the current detection unit 5 is provided on the connection line L1 between the ground unit 8 and the high-voltage pulse generation unit 1. The current detector 5 measures the current flowing through the connection line L1 due to the generation of the high-voltage pulse, and sends the measured current value to the controller 6. In the control unit 6, the current detection unit 5
From the current value measured in step (a), the connection state between the electrode pairs by the reinforcing bar 10b is detected. That is, when the state where the electrode 3 and the water tank 4 are not connected to each other is changed to the state where the electrode 3 and the water tank 4 are connected by the reinforcing bar 10b, the resistance value between the electrodes decreases, and thus the state shown in FIG.
(A) → As shown in FIG. 2 (b), the rise of the current due to the high voltage pulse becomes faster, and the change in the rise of the current detects the connection state between the electrode pairs by the reinforcing bar 10b. The control unit 6 controls the reinforcing bar 10b between the electrode pairs.
When the connection state is detected, the generation of the high-voltage pulse by the high-voltage pulse generation unit 1 is temporarily interrupted, and at the same time, the electrode moving unit 2 is instructed to move the electrode 3. When the electrode 3 is moved to the position 3 'in the figure by the electrode moving unit 2 and the contact state between the electrode 3 and the reinforcing bar 10b is released, the control unit 6 controls the high voltage pulse generation unit 1 to generate a high voltage pulse. Restarts the occurrence of As described above, in the high-voltage pulse crusher A1 according to the present embodiment, the current flowing due to the generation of the high-voltage pulse is measured by the current detection unit 5, and the control unit 6 performs the operation based on the measured current value. The connection state by the reinforcing bar 10b between the electrode pairs is detected. When the connection state is detected, the control unit 6 temporarily suspends the generation of the high-voltage pulse, and at the same time, moves the electrode 3 by the electrode moving unit 2, and resumes the generation of the high-voltage pulse when the contact state is resolved. Let it. Therefore, the state in which the crushing does not proceed due to the high voltage pulse flowing through the reinforcing bar 10b can be quickly avoided to continue the crushing process, so that the crushed object can be efficiently crushed without waste of energy.

[0010]

【Example】

(Example 1) In the high-voltage pulse crushing apparatus A1 according to the above-described embodiment, a current by a high-voltage pulse is measured, and a change in the measured value detects a connection state between the electrode 3 and the water tank 4 by the reinforcing bar 10b. However, the contact state can be detected by flowing a DC current having a lower voltage than the high voltage pulse between the electrode 3 and the water tank 4 and measuring the DC current. Hereinafter, this will be described in detail with reference to FIG. As shown in FIG. 2, in the high-voltage pulse crusher A2, a current detection unit 5 'is provided on a connection line L3 connecting the connection line L2 and the ground unit 9. That is, the current detector 5 ′ is connected in parallel with the high-voltage pulse generator 1 to an electrode pair including the electrode 3 and the water tank 4. Further, on the connection line L3, an inductance coil 11, a resistor 12,
And a DC power supply 13 are connected. The above current detection unit 5 '
Is connected to the control unit 6 similar to the high-voltage pulse crushing apparatus A1, but a filter unit 14 for cutting a pulse current is provided on the connection line. The crushing process is similar to the above-described high-voltage pulse crushing apparatus A1.
This is performed by applying a voltage between them. At the same time, the DC power supply 13 is continuously operated. However, the DC power supply 1
3 is a very low voltage compared to the high voltage pulse, so that the DC current does not flow unless the electrode 3 and the water tank 4 are connected by the reinforcing bar 10b. Therefore, if the current is measured by the current detector 5 ', the controller 6 determines that the electrode 3 and the water tank 4 have been connected by the reinforcing bar 10b, and performs the same processing as that of the high-voltage pulse crusher A1.

However, if the connection line L3 has a low resistance, the current caused by the high-voltage pulse flows in the direction of the arrow X from the connection line L2. is there. This inflow prevention means is formed by the inductance coil 11 and the resistor 12. The inductance coil 11 exhibits a high impedance with respect to an instantaneous voltage load (the time constant at that time varies depending on the resistance value of the resistor 12).
Therefore, the current flowing into the connection line L3 due to the high voltage pulse is very small. On the other hand, since the impedance of the inductance coil 11 with respect to the DC current is very small, the resistance with respect to the DC current is only the resistor 12.
Therefore, by cutting the pulse current slightly flowing in the direction of the connection line L3 by the filter unit 14, the connection state by the reinforcing bar 10b between the electrode 3 and the water tank 4 can be detected by measuring the DC current as described above. Becomes possible.
As described above, the high-voltage pulse crushing device A2 according to the first embodiment measures a low-voltage DC current instead of a high-voltage pulse, and thus is compared with the high-voltage pulse crushing device A1 according to the above embodiment. It is possible to reduce the capacity of the current detection unit. (Embodiment 2) As in the high-voltage pulse crusher A3 shown in FIG. 4, a rectifying element such as a diode 15 can be used instead of the inductance coil 11 used as the inflow prevention means in the first embodiment. In this case, the connection line L
Since the inflow of the pulse current in the direction of arrow X from 2 can be completely prevented, the filter section 14 used in the first embodiment is not required.

(Embodiment 3) As in a high-voltage pulse crusher A4 shown in FIG. 5, a switch 16 and the like are used instead of the inductance coil 11 and the diode 15 used as the inflow prevention means in the first and second embodiments. Can be used. Both the inductance coil 11 and the diode 15 in the first and second embodiments allow the DC power supply 13 to allow the DC current to flow out in the direction of the connection line L2, while the current connection line L by the high-voltage pulse.
Although the inflow in three directions was prevented, the third embodiment
The switch 16 in FIG. 1 is for simultaneously blocking or passing both the DC current and the current by the high voltage pulse. Therefore, unlike the first and second embodiments, the direct current and the current by the high voltage pulse cannot be simultaneously applied. Hereinafter, the procedure of the crushing process using the high-voltage pulse crusher A4 will be described with reference to the flowchart shown in FIG. The control unit 6 'includes a high-voltage pulse generation unit 1
Before the high-voltage pulse is generated, the switch 16 is first connected so that a DC current from the DC power supply 13 can flow (S1). As a result, the current detector 5 '
If the current is not measured in step 2, the control unit 6 'determines that the electrode 3 and the water tank 4 are not connected by the reinforcing bar 10b (S2). Then, the switch 16 is turned off to prevent the current from flowing into the connection line L3 due to the high voltage pulse (S3), and the high voltage pulse generator 1 generates the high voltage pulse once (S4). Subsequently, the control unit 6 'connects the switch 16 again (S1), and judges connection or non-connection by the reinforcing bar 10b between the electrode 3 and the water tank 4 based on the current measurement result by the current detection unit 5' (S1).
2) While the connection state continues, the processing of S1 to S4 is repeated. As the crushing of the reinforced concrete 10 progresses and the current is measured by the current detector 5 ', the electrode 3
If it is determined that the tank and the water tank 4 are connected by the reinforcing bar 10b (S2), the control unit 6 'instructs the electrode moving unit 2 to move the electrode 3 before generating the high voltage pulse (S2).
5). The movement of the electrode 3 avoids the connection state between the electrodes by the reinforcing bar 10b, and when it is confirmed that the current is not measured by the current detection unit 5 '(S1 to S2), the control unit 6' cuts off the switch 16. At the same time, the high-voltage pulse generator 1 generates a high-voltage pulse once (S3
~ S4). The crushing process is performed by repeating the above processes.

As described above, in the high-voltage pulse crushing apparatus A4 according to the third embodiment, the check of the connection state between the electrodes using the DC current by the reinforcing bar 10b and the generation of the high-voltage pulse are alternately performed. Therefore, generation of a high-voltage pulse in a state where the electrodes are connected by the reinforcing bar 10b can be completely prevented, and the object to be crushed can be crushed without wasting energy. (Embodiment 4) In the above embodiment and Embodiments 1 to 3, the electrode moving section 2 is used as the detection position switching means, but as shown in FIG. 7, a plurality of electrodes 3a, 3b, 3c,. It is also possible to use an electrode switching unit 17 that is installed and selects one of the electrodes 3a, 3b, 3c,... And connects to the high-voltage pulse generator 1. When the electrode switching unit 17 is used, the position where the high voltage pulse is applied can be quickly moved by switching the electrodes, which leads to an increase in efficiency of the crushing process.

[0014]

The high voltage pulse crusher according to the present invention is
An electrode pair; and a high-voltage pulse applying means for applying a high-voltage pulse between the pair of electrodes. An object to be crushed is arranged between the pair of electrodes, and a high-voltage pulse is applied between the pair of electrodes. In a high-voltage pulse crusher for crushing an object to be crushed, a resistance detecting means for detecting a resistance between the pair of electrodes, and a detecting position for switching a detecting position of the resistance according to a resistance value detected by the resistance detecting means. It is configured as a high voltage pulse crushing device characterized by comprising a switching means, so that it is possible to quickly avoid a state in which high voltage pulses flow through a conductor or the like and crushing does not proceed, and continue the crushing process. Thus, it is possible to efficiently crush the object to be crushed without wasting energy. The detection position switching means may be configured to switch the detection position of the resistor by moving the electrode pair. However, the detection position switching means may detect the resistance value of a plurality of electrode pairs. Since the detection position switching means is configured to select one having a large resistance from the plurality of electrode pairs, the resistance detection position can be switched more quickly. Further, if the resistance detecting means detects the resistance between the electrode pairs by applying a voltage lower than the voltage of the high voltage pulse between the electrode pairs, the resistance is detected by the high voltage pulse. As compared with the case, the capacity of the resistance detecting means can be reduced. At that time,
A circuit including the resistance detecting means is configured to be connected to the electrode pair in parallel with the high-voltage pulse applying means, and further to detect the inflow of the high-voltage pulse current from the high-voltage pulse applying means. If an inductance and a resistance are used as the inflow prevention means, a filter means for cutting a small amount of inflowing pulse current is required. Is used, since the inflow of the pulse current can be completely prevented, the filter means is not required.
As the inflow prevention means, a means for interrupting conduction can be used. In this case, resistance detection by DC current and application of a high voltage pulse are performed alternately, so that a low voltage between the electrode pair is low. The application of the high voltage pulse in the resistance state can be completely prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a high-voltage pulse crusher A1 according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a time history of a current caused by a high-voltage pulse in a connection or non-connection state between a pair of electrodes by a reinforcing bar or the like.

FIG. 3 is a schematic diagram showing a schematic configuration of a high-voltage pulse crushing device A2 according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing a schematic configuration of a high-voltage pulse crushing device A3 according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram showing a schematic configuration of a high-voltage pulse crusher A4 according to a third embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure of a high-voltage pulse crusher A4 according to a third embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a schematic configuration of a high-voltage pulse crusher A5 according to a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram showing a schematic configuration of a conventional high-voltage pulse crusher A0.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... High voltage pulse generation part 2 ... Electrode moving part 3 ... Electrode 4 ... Water tank 5, 5 '... Current detection part 6, 6' ... Control part 7, 8, 9 ... Earth part 10 ... Reinforced concrete 10a ... Concrete part 10b ... Reinforcing bar 11 ... Inductance coil 12 ... Resistance 13 ... DC power supply 14 ... Filter unit 15 ... Rectifier element 16 ... Switch 17 ... Electrode switching unit

Claims (10)

[Claims] An electrode pair; and a high-voltage pulse applying means for applying a high-voltage pulse between the pair of electrodes. An object to be crushed is arranged between the pair of electrodes. In a high-voltage pulse crusher for crushing the object to be crushed by applying a voltage, resistance detecting means for detecting a resistance between the electrode pairs, and detection of the resistance in accordance with a resistance value detected by the resistance detecting means. A high-voltage pulse crushing device comprising: a detection position switching means for switching a position. 2. The high-voltage pulse crushing apparatus according to claim 1, wherein the detection position switching means switches the detection position of the resistor by moving the electrode pair. 3. The resistance detecting means detects a resistance value of a plurality of electrode pairs, and the detection position switching means selects a resistance value of the plurality of electrode pairs from among the plurality of electrode pairs. 2. The high voltage pulse crushing device according to claim 1, wherein 4. The device according to claim 1, wherein said resistance detecting means detects a resistance between said pair of electrodes by applying a voltage lower than a voltage of said high voltage pulse between said pair of electrodes. High voltage pulse crushing equipment. 5. The high voltage pulse crushing apparatus according to claim 4, wherein a circuit including said resistance detecting means is connected to said electrode pair in parallel with said high voltage pulse applying means. 6. The high-voltage pulse crushing apparatus according to claim 5, wherein said resistance detecting means includes an inflow preventing means for preventing the high-voltage pulse current from flowing from said high-voltage pulse applying means. 7. The high-voltage pulse crushing device according to claim 6, wherein said inflow prevention means comprises an inductance and a resistance. 8. The high-voltage pulse crusher according to claim 6, wherein said inflow prevention means is constituted by a rectifying element. 9. The high-voltage pulse crushing device according to claim 6, wherein said inflow prevention means is means for interrupting conduction. 10. The high-voltage pulse crushing apparatus according to claim 1, wherein the object to be crushed is a reinforced concrete material.