KR100701589B1 - Device for measuring compressive strength of constructing member used in compression - Google Patents

Abstract

The present invention is to compress the structural members for compression use that can easily estimate the early strength of concrete and the compressive strength of concrete structures, etc. A main body part comprising a measuring shelf part configured to fix a compressive material sample, and a transfer frame part configured to move vertically along a moving axis of the measuring shelf. The transfer frame unit and the motor unit having a reducer for maintaining a constant speed; Compression member strength measurement tip part mounted on the fixed part of the motor shaft, the moving distance measurement including an encoder with a resolution of 5000 pulses (separated resolution) for measuring the excavation depth of the sample mounted on the transfer frame part fixed to the measuring shelf By constructing the part, it is characterized by more accurate strength can be measured by applying to the compressed material, such as rock samples and concrete collected on the soil survey.

Basic survey, rock sample, concrete, encoder, 5000 pulse

Description

Device for measuring compressive strength of constructing member used in compression

1 is a perspective view showing an apparatus for estimating compressive strength for structural members for compressive use in a preferred embodiment of the present invention.

Figure 2 is an internal partial cross-sectional view showing a compressive strength estimation device for the structural member of the compression application of the present invention.

Figure 3 is a side sectional view showing a compressive strength estimation device for a structural member for compression use of the present invention.

4 is an exemplary photograph showing measurement data of the current meter and the unit cutting depth meter of the present invention.

* Description of Symbols for Major Symbols in Drawings *

10: reduction unit 20: motor unit

30: wire 40: moving shaft

50: pulley shaft 60: motor unit

70: belt 90: bundle of measuring lines

100: winding unit 120,160: first and second tension roller unit

170: measuring line 180: fixing part

190: strength measurement tip 200: compressed material sample

210: fixed vise 220: fixed lever

230: fixing ring 240: measuring shelf

250: moving distance measuring unit 280: current measuring instrument

290: unit cutting depth measuring instrument 300: main body

310: record and storage device

The present invention relates to an apparatus for measuring compressive strength of structural members for compression purposes, and more particularly, to an apparatus capable of easily estimating rock samples, concrete structures, and early strength of concrete.

In general, in various field measurement applications in the field of civil engineering and geotechnical field, the soft ground field measurement data are compared with the predicted data such as the physical and mechanical characteristics of the ground or ground obtained from the ground survey, and are not considered in design. It is widely used for predicting and analyzing the behavior at the next construction stage after correcting the errors of the construction, and quickly analyzing the measurement results such as the changes generated during construction. In addition, by predicting the strength and quality of concrete early in the construction site and reflecting it in process management, it prevents bad construction with reliable construction quality, secures structural stability of the building, and concerns about demolition and reconstruction after completion of hardening. Various judgment techniques are used to solve the problem and to allow construction to proceed smoothly, resulting in air shortening, labor reduction, and cost reduction.

Existing foundation pile laying method uses a pile of H beams or steel pipes in the construction of large high-rise buildings in consideration of the ground characteristics of the foundation construction, and then drills the foundation pile after drilling using an excavator. It uses the method of directly injecting the foundation pile by using the helm.

Among the existing methods, the method of directly injecting the foundation pile by using a driving method is whether the rock state is in a state of receiving a real force or when the foundation pile during the indentation encounters a rock, or a structure similar to the rock. It is necessary to determine in what circumstances the indentation has stopped.

In the above case, the base pile of the stagnant state is inserted and fixed when the stability of the rock state is determined according to the degree of indentation of the foundation pile by using the Tomari check method. After attaching the paper on the surface of the foundation pile so as to face the surface of the foundation pile (RAM) to drive the basic pile to make a fine descent operation was determined based on the data drawn by marking the amount of movement every time on the paper to move the pen.

Since the determination method as described above is checked in a small amount, it is very difficult to check the check amount precisely using a pen and paper, and thus there is a problem that the reliability of the check such as difficulty in reading is inferior.

Accordingly, an object of the present invention to solve the conventional problems is to provide a compressive strength estimation device for a structural member for compression applications that can measure the strength of the optimal base for embedding the foundation pile.

Another object of the present invention is to provide a compressive strength estimating apparatus for structural members for compression applications that can increase the reliability by early prediction of the strength or quality of concrete to be reflected in the process control.

The present invention for achieving this object can be measured by comparing the strength of the existing data rock to measure the current and the measurement of the depth of current generated per second / minute when drilling using a rotating body to estimate the strength of the ground The present invention provides an apparatus for estimating compressive strength for structural members for compression purposes.

In another aspect, the present invention comprises a main body portion including a measuring shelf configured to hold a compressive sample and a transfer frame configured to move vertically along a moving axis vertically coupled to the measuring shelf; The transfer frame part includes a main motor part having a reducer for maintaining a constant speed, and a compressive material strength measuring tip part mounted on a fixed part of the motor shaft; The transfer frame unit is equipped with a moving distance measuring unit having an encoder for measuring the cutting depth of the sample of the compressed material fixed to the measuring shelf; A current measuring device for measuring and displaying the current supplied to the main motor unit, and a unit cutting depth measuring device connected to the encoder to measure the cutting depth of the compressive material strength measuring tip unit, and transmit data in real time to compare data. It characterized in that it comprises a recording and storage unit for outputting.

In addition, the moving distance measuring unit: is configured to be mounted to the transfer frame, the motor unit is equipped with a reducer, and set by setting a constant load value, if the load is applied to the load value or more during rotation, the motor unit while sliding The pulley shaft connected to the rotating unit is wound around the measuring line bundle to which the measuring line is wound so that a rotation device is provided with a clutch, and the measuring line drawn out from the winding unit is connected to have a first tension. A tension roller unit, an encoder for measuring the distance traveled by the measuring line while the measuring line supported by the first tension roller unit is wound, and a second tension roller such that the measuring line wound on the encoder has a constant tension. And a first tension roller part, the encoder, and the second tension roller part so that the measuring line is wound around the encoder at the longest point. Geujae consists therefore arranged, wherein the measuring line is characterized in that it is sequentially wound around the first tension roller unit, the encoder, and the second tension roller, arranged in a zigzag pattern.
In addition, the main unit is the current measuring unit for measuring the change in the current supplied to the main motor unit, and the unit cutting depth measuring instrument for measuring the moving distance of the encoder to display the result of the constant RPM of the main motor unit in 0.01mm units And a recording and storage device for centrally controlling the measurement data of the current measuring instrument and the unit cutting depth measuring instrument to transmit, compare, store and output the data in real time (1 second interval).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an apparatus for estimating compressive strength of a structural member for compressive use in a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Compressive strength estimation device for the structural member of the compression use of the present invention is determined the strength reference value of the support rock according to the height and load of the building during the foundation pile construction requiring pile crushing work, the strength in a wide range must be measured from time to time Therefore, the point is that it takes a lot of time and manpower, can measure the strength of concrete structures, and can estimate the strength when predicting the strength or quality of concrete early.

Compressive strength estimation apparatus for the structural member of the compression use of the present invention shown in Figures 1 to 3 is a measuring shelf 240 configured to fix the compressed material sample 200, and the moving shaft 40 of the measuring shelf The main body 300 is configured to include a transfer frame 250 configured to move vertically along the side.

In addition, the main body 300 is a current measuring instrument 280 for measuring the change result of the current supplied to the main motor unit 20, and measuring the moving distance of the encoder 140 in accordance with a constant RPM of the main motor unit 20 It is provided with a unit cutting depth measuring instrument 290 to display a cutting depth of 0.001mm unit, and compares, stores, and outputs the data of the measured values of the current measuring instrument and the unit cutting depth measuring instrument in real time (in seconds). And a recording and storage device 310 for central control.

The measuring shelf 240 is configured so that the compressed material sample does not move by configuring a fixed lever 220 to be adjusted with the fixed vise 210 to fix the compressed material sample 200.

Since the compressed material sample is different in size and shape, it is possible to manufacture a variety of shapes of the fixed vise to fix the sample.

A pillar is formed on one side of the measurement shelf part 240, and the pillar is a moving shaft 40 configured to move the transfer frame part 250 in the vertical direction.

The transfer frame unit 260 coupled to the movable shaft 40 to move up and down has a main motor unit 20 so as to puncture the compressed sample, and the main motor unit 20 has a constant rotational speed (RPM). The speed reducer 10 is incorporated in the speed reducer 10 so as to hold.

At the end of the main motor unit 20, the fixing unit 180 is configured to fix the strength measuring tip unit 190 so that the strength measuring tip unit 190 according to the compressive strength can be combined and exchanged.

In order to measure the moving distance of the next transfer frame unit 260, that is, to measure the cutting depth of the sample, the motor unit 60 is provided with a reducer so that the rotational speed RPM is constantly rotated. The pulley shaft 50 of the unit 60 transmits the rotational force to the pulley shaft 80 of the winding device unit 100 through the belt 70.

The winding device unit 100 is connected to the measuring line bundle unit 90, and if a load of a predetermined level or more is applied to the measuring line wound on the measuring line bundle unit 90, the measuring line bundle unit (for the pulley shaft 80) As the 90 is slid, the pulley shaft 80 is rotated, and the measurement string bundle unit 90 is not rotated. That is, the measuring line 170 is pulled by the rotational force of the motor unit 60 to maintain the tension while preventing excessive rotational force, a known friction between the measuring line bundle 90 and the pulley shaft 80 Or it is preferable that a high strength spring clutch (not shown) is provided. When the pulley shaft 50 is rotated due to the rotation of the motor unit 60, the pulley shaft 80 of the winding device unit 100 is rotated by the belt 70. As the pulley shaft 80 rotates, the measuring line 170 wound around the measuring line bundle unit 90 is pulled in the winding direction to maintain the tension. If a certain load or more is applied to the pulley shaft 80, the measurement string bundle unit 90 slides with respect to the pulley shaft 80, and the gap between the pulley shaft 80 and the measurement string bundle unit 90 may be lost. Accordingly, when the main motor unit 20 rotates and the strength measurement tip unit 190 digs the compressive material sample 200, the transfer frame unit 250 connected thereto is lowered, and the measurement line 170 transfers the transfer frame unit 250. ) Is lowered so that the gap between the measuring line bundle 90 and the fixing ring 230 is pulled by the motor unit 60 to maintain tension, and at the same time, excessive force is applied to the measuring line 170. There is no case of losing or stretching.

In addition, the first and second tension roller parts 120 and 160 are configured to maintain the tension of the measuring line 170, and are arranged in a zigzag form (see FIG. 3) at the front and rear of the encoder 140 to determine the measuring line 170. It is configured to minimize the error. That is, the first tension roller unit 120, the encoder 140, and the second tension roller unit 160 are sequentially arranged in a zigzag manner, and the measurement string 170 is wound in a zigzag manner and supported therebetween. In this case, the first tension roller unit 120 and the second tension roller unit 160 serve to pull the measurement string 170 to the maximum in many areas of the encoder 140.

The encoder 140 is configured to measure the moving distance of the measuring line 170 in real time (1 second interval) as a numerical value, and usually, when the power (Vcc) is first applied and the light emitting device emits light, the emission is performed. The light passes through the slit of the rotating disk with the encoder shaft and then through the slit of the mask to reach the light receiving element. Thereafter, the light receiving element detects the light emitted from the light emitting element, converts the light into an analog signal, and then outputs the analog signal to a comparator, and the comparator compares the input analog signal with a reference voltage Vref. The signal is converted into a signal and then output to an amplifier. The amplifier amplifies the input digital signal, is displayed on a unit cutting depth measuring instrument 290, and is transmitted to a recording and storage device 310 which is a central controller.

As described above, the measuring line 170 is connected to the hook portion 230 of the measuring shelf 240 to measure the distance that the strength measuring tip 190 is moved by the encoder 140 and is displayed on the unit cutting depth gauge. The data to be measured is configured to be recorded in the recording and storage device together with the data of the current meter.

The current meter 280 measures and displays the current supplied to the main motor unit 20 in real time, and the data is stored in the recording and storage device 310 to compare and analyze the two data and output the data. have.

By configuring as described above, the samples of the ground were measured and made into a database to compare and analyze with the newly collected samples to estimate the limit range within the measurement range.

The device configured as described above is a sample of the main body of the present invention with respect to the support ground samples, such as weathered rock soft rock or hard rock obtained as a result of the excavation of the ground, such as concrete, boring, etc. in the ground investigation process before construction of concrete and structural materials of construction or civil engineering After being fixed to the stationary vise 210, the material to be cut for the unit rotation [1/2 rotation] of the cutting edge in the cutting process concrete is mainly used as a structural material for the use of compressed materials. The unit cutting depth of the rock and the like was compared and stored in the recording and storage device 310 in real time using the unit cutting depth measuring instrument 290 and the current measuring instrument 280 that can be measured in units of 0.01 mm.

The electric motor [unit: W] increases or decreases while the voltage [unit: V, 220V] is constant by measuring the current [unit: A] that changes during the compression material cutting process using a main motor with a capacity of 800 to 1,000 watts. Analyze the electrical energy [unit: W] to record and store the measurement results with the unit cutting depth at the same time as the unit cutting depth and the same measuring device. By comparing the depth of cut and applying the following theoretical and experimental data, the compressive strength of compressive material, ie, concrete, can be estimated.

 First of all, the prerequisite for estimating compressive strength is to cut the compressive strength of the workpiece by theoretical formula in processing long holes such as rifle barrel, long axis of rotation, connecting rod, oil field drilling machine, etc. The main reason why the stress is difficult to estimate is that most of the above steels are tensile materials, and thus, there is a difficulty in theoretical analysis of the cutting stress due to the fine tension of the workpiece, which is one of the characteristics of the tensile materials during the cutting of the steel. Chips generated during cutting of workpieces are not separated into pieces, but are connected in a helical length, while samples such as concrete, which are structural materials for construction and civil engineering, and rocks generated during the soil investigation, Most of them are compressed materials, and when the compressed materials are cut by a drilling machine, the cutting part is instantaneously cut during the cutting of the workpiece. At this time, if the cutting stress is calculated using the following equation with the electric energy [unit: W] value at the same time as the unit cutting depth [cutting edge 1/2 turn] of the cutting edge, the compressive strength of the compressive material can also be estimated.

When cutting the compressed material with a drilling machine with a capacity of 800 ~ 1,000W of electric energy or a hand drill for concrete drilling, the vertical compressive force acting on the drilling machine, that is, the transfer force of the drilling machine, is the cutting stress due to the cutting edge rotation of the drilling machine. Compared with, it is about 1/100 as shown in the following formula, so it can be judged as a negligible value in the estimation of compressive strength of compressive material.

Compressive strength estimation device for the structural member of the compression use of the present invention, the main motor unit 20 is used as a weight rotating body of the electric energy capacity 800 ~ 1,000W, the drilling depth of the sample, such as the compression material is in the range of 10 ~ 20mm, The size of the strength measuring tip 190 of the present invention uses a 10mmØ and the main motor portion of the rpm 120 is always maintained at a constant speed, that is, a constant rpm during the cutting process of the sample and the cutting edge at the rpm 120 above two revolutions per second Therefore, the unit feed distance of the cutting edge can be calculated in the unit rotation [1/2 rotation] of the cutting edge.

In the measurement of unit cutting depth, in case of concrete with compressive strength of 210kg / cm2 among samples related to compressive strength estimation, the unit cutting depth for unit rotation [1/2 rotation] of cutting edge is about 0.3 ~ 0.5mm and strength measurement tip part The unit cutting depth measuring instrument uses a rotary encoder with resolution [P / R] 3,600 pulses that can measure up to 0.02mm of linear travel distance, and records and saves with the change of current with respect to the change of cutting depth in 1 second. Stored on the device.

As shown in FIG. 4, the vertical movement distance of the 10 mm cutting drill is indicated numerically in the current measuring instrument and the unit cutting depth measuring instrument. Since the setting is set at 0.02 mm per pulse, the distance traveled while cutting the sample in the current vertical direction is 1979 ×. Since 0.02 = 39.58mm and the current cutting point current value is 3.552A on tachometer, the value of electric energy E can be expressed as follows.

E = VA thus E = 220 × 3.552 = 781.44 W

The measurement of current is in the range of 1 ~ 5A and the output is displayed digitally or numerically as the unit cutting depth measurement, and it can be displayed up to the third digit after the decimal point for the precise measurement of the electric energy [unit: W]. The formula for energy calculation is as follows.

Pin [W] = E [V] × I [A]

Pout [W] = 1.027 × N [RPM] × T [gf cm] × 10 ⁵

η [%] = Pout / Pin × 100

Where η is the output efficiency of the drilling machine (main motor section).

The recording and storage device 310 of the present invention is a device capable of recording and storing the cutting depth and the degree of increase or decrease of the current value every moment [1 second unit] to convert the electrical signal into a digital signal to record and store .

Based on the above data, the application formula related to the estimation of compressive strength of compressive materials such as concrete, rock, etc.

Ad = t × Sd = D / 2 × Sd

Cutting capacity in the center of the cutting edge

Fd = Ad × k = Sd × k

here

D: diameter of drill, mm

S: Feed every revolution of the drill, mm / rev

Sd: Feed per drill cutting edge, mm / rev

: S / 2 [in drill with 2 cutting edges]

Ks: Specific cutting force in turning, kg / mm2

k: 2ks = specific cutting force in drilling, kg / mm2

Torque [Torque]

Md = Fd × D / 2 = D ² × Sd × K = (D ² × S × KS) / 4

Md = (D ² × s × k) / (8 × 1,000) kg.m

Driving power of drilling machine N: unit, kw

N = (Md × n × 2π) / (102 × 60 × η) = (Md × n) / (975 × η) = D ² × S × k × N (kw)

When power is supplied to the main motor, rotational characteristics are generated accordingly, and mechanical energy is generated in the main motor.

Therefore, shear failure stress k:

k = (7.8 × 10 ⁶ × N × η) / (D ² × S × n) = (7.8 × 10 ⁶ × V × η) / (D ² × n) × (A / s)

k ∞ A / s

The shear failure stress (k) of the compressive material is equal to the voltage (V), the efficiency (η), the diameter of the cutting edge (D), and the rotation speed (n). Rotation] is determined by the cutting depth (s).

Knowing the relationship between shear fracture stress (k) of compressive material and compressive strength of compressive material, compressive strength of compressive material can be estimated through shear fracture stress (k) of compressive material.

 Feed force Nf of drilling machine

Nf = (Ff × s × n) / (6.12 × 10 ⁶ × η) KW

Ff: Feed thrust of the drilling machine, kg

The value Nf is determined to be negligible because it is about 1/100 of the driving power [unit: KW] required for cutting the compressed material of the main motor unit.

The relationship between the cutting force, that is, shear stress and compressive stress, can be judged that the cutting edge of the main motor part, that is, the strength measurement tip, cuts the compressive material to match the shear stress acting on the inclined surface of the member. The relationship between the shear stress and the vertical compressive stress calculated theoretically in the field of rods subjected to axial load of material mechanics was investigated.

Σθ and τθ can be obtained by creating an equilibrium equation for the triangular free body diagram of the member cut out from the element.

σθAθ-(σAθcosθ) cosθ = 0

Finding the vertical stress on the P plane

σθ = σcos ² θ

(Reference plane face P through rod at an angle to axis 1)

(Reference figure 2. Free body diagram to find stress on P plane)

(Reference figure 3. (a) Area of each side (b) Force on free object diagram)

summing the forces in the τθ direction

τθAθ + (σAθcosθ) sinθ = 0

Finding the shear stress on the P plane

τθ =-σsinθcosθ

The above relation represents the vertical and shear stresses acting on the inclined plane at an angle to the axis of the uniform cross-section member.

The following figure shows the ratio of σθ / σ and τθ / σ from θ = 0 to θ = 180˚.

It also shows the elements corresponding to specific values of θ and the values of σθ and τθ.

In the figure above, the magnitude of shear stress on the plane inclined at 45 ° to the cross section of a particular member is half the maximum vertical stress.

lτθl = lσ / 2l

The maximum magnitude of shear stress can be expressed by

The derivative of τθ with respect to θ gives θ = 45 ° and 135 ° if the above equation is set to '0' in order to find the angle at which τθ has the maximum or minimum.

τθ = − σ / 2 at θ = 45 °, and τθ = σ / 2 at θ = 135 degrees.

The maximum compressive normal stress acting on any surface of the compression member such as the pile under axial load is σ = P / A and the magnitude of the maximum shear stress is σ / 2.

(Reference figure 4. Vertical and shear stress as a function of θ)

More precise compressive strength than conventional compressive strength measuring equipment by applying simple principle to concrete and supporting ground that supports the basic structure of facilities that are used as compressive material among structural members in large-scale facility construction of existing construction or civil engineering Develop a device for estimating

Non-destructive testing on concrete with compressive strength of 500 ~ 700kg / ㎠ or more, which is expected to be used as structural member for compressive materials, is expected in the construction work of high-rise apartments with 30 ~ 40 floors or more expected in the future. It is possible to measure with compressive strength measuring equipment that can be effectively applied to the development of building industry.

As described above, the present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely exemplary, and it should be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. will be. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, if the present invention can be widely used in civil engineering, construction, etc., the strength of the ground can be easily measured, and thus, the samples of various rocks can be measured quickly and precisely.

In addition, there is an excellent effect that can be measured without taking a sample directly at the time of supervision of the construction structure.

It is a very useful invention in the civil engineering industry as a new technique that can measure the new ground measurement and the strength of compressed materials such as concrete more precisely and shorten the time.

Claims (3)

A main body portion including a measurement shelf portion configured to fix a compressive material sample, and a transfer frame portion configured to move vertically along a moving axis vertically coupled to the measurement shelf portion; The transfer frame part includes a main motor part having a reducer for maintaining a constant speed, and a compressive material strength measuring tip part mounted on a fixed part of the motor shaft; The transfer frame unit is equipped with a moving distance measuring unit having an encoder for measuring the cutting depth of the sample of the compressed material fixed to the measuring shelf; A current measuring device for measuring and displaying the current supplied to the main motor unit, and a unit cutting depth measuring device connected to the encoder to measure the cutting depth of the compressive material strength measuring tip unit, and transmit data in real time to compare data. Compression strength estimation device for a structural member for compression purposes, characterized in that it comprises a recording and storage unit for outputting. The method of claim 1, wherein the moving distance measuring unit: Is configured to be mounted on the transfer frame, A motor unit equipped with a reducer, The load is set by setting a constant load value, and when a load equal to or greater than the load value is applied at the time of rotation, the pulley shaft connected to the motor unit is rotated while the clutch is rotated, and the clutch is provided so that the rotation force is not applied to the measuring line bundle unit to which the measuring line is wound. Winding unit, A first tension roller unit for connecting the measuring line drawn out from the winding unit to have a constant tension; An encoder for measuring a distance traveled by the measuring line while the measuring line supported by the first tension roller unit is wound; It is provided with a second tension roller unit for the measurement line wound around the encoder to have a constant tension, The first tension roller part, the encoder, and the second tension roller part are arranged in a zigzag manner so that the measuring line is wound around the encoder at the longest point, and the measuring line is the first tension roller part arranged in a zigzag pattern. Compression strength estimation device for the structural member for compression, characterized in that the winding sequentially to the encoder, the second tension roller. The method of claim 1, wherein the body portion: The current measuring unit for measuring the current supplied to the main motor unit changes, and the unit cutting depth measuring instrument for measuring the moving distance of the encoder to be displayed in 0.01mm units of the result of the constant RPM of the main motor unit, And a recording and storage device for centrally controlling the current measuring device and the measurement data of the unit cutting depth meter in real time (1 second interval) to compare, store and output the measured data. Compressive strength estimation device.

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