Measuring method of 3.6 m 4.5 m pavement deflection meter
Measuring method of 3.6 m 4.5 m pavement deflection meter
Hangzhou Sansi Instrument Co., Ltd. 3.6 m, 4.5 m Beckman beam pavement deflection device is suitable for measuring the elastic deflection value of the road surface during static loading or very slow speed loading, and can reflect the overall strength of the road surface.
Main technical parameters of pavement deflection instrument
1. Total length: 3.6m, 4.5m
2, leverage ratio 2:1
3, the fulcrum to the front measurement point length: 2.4m / 3.6m
4. Stiffness: With the center of the shaft hole as the fulcrum, 200g is loaded at a third of the total length of the fulcrum, and the deflection is not more than 0.05mm.
5, the table accuracy is 0.01mm, the range is 1cm
6, the equipment is made of cast aluminum
7, bending test sink measurement range: 0-10mm,
8, measurement accuracy: ± 0.01mm
9, the main parts and materials requirements
A. The aluminum detection beam and the probe are made of cast aluminum, which conforms to ZL401 and GB1173-74 "Mechanical properties of cast aluminum alloy";
B. The middle bushing adopts 45# steel GB699-65 "Quality carbon structural steel"
10. Assembly requirements: the front and rear lever connections are flat and firm, and there must be no looseness. In the whole length range, the unevenness should be less than 2mm in all aspects.
11. Appearance requirements: The color of the instrument is silver-gray, to reflect light, avoid temperature influence, the surface of the paint should be smooth, the color is uniform, the paint layer should not be leak-coated, wrinkled, scratched and peeled off, and the dial gauge should be plated. There should be no marks on the plating of the electroplated parts, and the bubbles should be exposed and scratched.
Pavement deflection instrument structure:
The pavement deflection device is composed of a front lever, a rear lever, a base, a dial gauge, and a bracket.
Use the front lever and rear lever to connect with 4 M12 bolts. When not in use, remove the bolts and insert the front and rear levers into the box separately. The rear lever is connected with the bracket seat, and the centripetal ball bearing is connected between the lever and the base, which overcomes the disadvantages of unstable structure and poor flexibility of the ball bearing bearing, and is provided with a dust cover to prevent dust and rain from entering. , with enough grease, the base is equipped with leveling screws and horizontal device, easy to adjust. There is a watch clip on the dial indicator, which can be adjusted according to the height of the measurement. Each instrument is equipped with a 0~10mm primary accuracy dial indicator.
The principle of the pavement deflection instrument:
The pavement deflection value refers to the vertical deformation generated by the road surface under the load of the wheel. It is an indicator reflecting the strength of the pavement. The thicker the pavement structure, the higher the strength of the pavement material or subgrade, the smaller the deflection value. Therefore, the greater the deflection value, the road design, construction, maintenance, reinforcement and other work to develop an economic and reasonable plan. Pavement deflection is an indispensable means and has been widely used in the highway sector in recent years.
The pavement deflection instrument is made by the principle of leverage and is used to determine the deflection of the road between the two wheels of the rear axle of the car. The road surface forms a local subsidence under the action of load (ie, vertical deformation), and the shape reflected by the road surface is a basin shape centered on the load point, which is called a deflection basin. When the load is removed, the elasticity returns the road surface to its original shape, and the deflection basin disappears. The difference between the load and the front is called the deflection value. The test proves that the total deflection and the elastic deflection are not equal, that is, after the load is removed, the road deflection basin does not completely disappear, and there are trace residual deformations on the road surface. The road deflection value is closely related to the vehicle speed and temperature.
The pavement deflection instrument has the characteristics of simple structure, convenient use, high sensitivity, and fast and light structure. It is not affected by objective conditions such as weather, wind, and sunshine.
Pavement deflection test method:
1. Preparation for measurement:
A. Connect the instrument levers back and forth in one piece and check them as required.
B. One truck, the single axle of the rear axle shall be calibrated according to the regulations, used for road loading, and the pneumatic tire pressure is also adjusted according to regulations.
C, 1 thermistor thermometer, accuracy 1 ° C, used to determine the road surface temperature (due to the deflection value with temperature).
D. Three sides of the red flag for traffic control, three small iron bars 700~300mm, diameter 20mm, each test except the driver usually requires 3 staff members, one person directs the car, one person records the data, and the other one handles the deflection. instrument.
2. Determination steps:
A, wipe the instrument
B. After the measurement is selected, the center distance of the two-wheel gap of the rear axle of the car to be measured shall not exceed 10 cm.
C. Put the dial indicator on the frame of the dial indicator, then move the deflection meter to the road surface so that the measuring end is just at the center of the double tire gap (perpendicular to the center point of the axle), and adjust the level with the table clamp. And the leveling screw of the dial indicator bracket adjusts the dial gauge reading to about 5mm, so that the pointer points to zero, the contact of the watch against the center of the measuring point screw, and record its reading B1.
D. The car starts forward, so that the rear wheel is outside the influence radius, generally about 5m away. At this time, the dial indicator moves. After the dial gauge reading is stable (less than 0.01mm per minute), the reading C1 is recorded.
E. Measure and record the temperature t of the road surface with a thermal thermometer.
F. The measurement results are recorded in the following formula.
G. Calculate the elastic deflection value of the road surface based on the recorded readings.
Rt=(B1-C1)×2
Where: Rt—subgrade temperature, the elastic deflection value of the road surface, unit: mm.
B1—Percentage reading with load, unit: mm
C1—Percentage reading when removing load Unit: mm
Verification method
1. Measurement accuracy: Place the deflection meter on a stable platform, place the probe on the lower platform of the press, place the dial indicator, and dispose of a dial indicator on the probe. (To measure the displacement of the lower bearing platform), start the press, so that the pressure platform is slightly raised (or lowered) while reading the dial gauge readings of the deflection meter and the probe, and calculate the displacement value, the magnitude range is 0.2. -4.0 mm, the measurement was repeated 5 times each time, and the accuracy was within ±0.02 mm.
2, the length of the instrument, the length of the probe, the width and thickness of the probe, using the measured steel ruler or caliper measurement, the accuracy should meet the requirements
3. The transverse stiffness of the beam: measured by a dial gauge or a dial gauge, the swing should meet the requirements.
4, instrument quality: weighing with small scales, quality should meet the requirements
5, the main parts and materials: visual inspection, experience or simple method to check
6. Assembly and appearance requirements: visual inspection or simple method.
Hangzhou Sansi Instrument Co., Ltd. 3.6 m, 4.5 m Beckman beam pavement deflection device is suitable for measuring the elastic deflection value of the road surface during static loading or very slow speed loading, and can reflect the overall strength of the road surface.
Main technical parameters of pavement deflection instrument
1. Total length: 3.6m, 4.5m
2, leverage ratio 2:1
3, the fulcrum to the front measurement point length: 2.4m / 3.6m
4. Stiffness: With the center of the shaft hole as the fulcrum, 200g is loaded at a third of the total length of the fulcrum, and the deflection is not more than 0.05mm.
5, the table accuracy is 0.01mm, the range is 1cm
6, the equipment is made of cast aluminum
7, bending test sink measurement range: 0-10mm,
8, measurement accuracy: ± 0.01mm
9, the main parts and materials requirements
A. The aluminum detection beam and the probe are made of cast aluminum, which conforms to ZL401 and GB1173-74 "Mechanical properties of cast aluminum alloy";
B. The middle bushing adopts 45# steel GB699-65 "Quality carbon structural steel"
10. Assembly requirements: the front and rear lever connections are flat and firm, and there must be no looseness. In the whole length range, the unevenness should be less than 2mm in all aspects.
11. Appearance requirements: The color of the instrument is silver-gray, to reflect light, avoid temperature influence, the surface of the paint should be smooth, the color is uniform, the paint layer should not be leak-coated, wrinkled, scratched and peeled off, and the dial gauge should be plated. There should be no marks on the plating of the electroplated parts, and the bubbles should be exposed and scratched.
Pavement deflection instrument structure:
The pavement deflection device is composed of a front lever, a rear lever, a base, a dial gauge, and a bracket.
Use the front lever and rear lever to connect with 4 M12 bolts. When not in use, remove the bolts and insert the front and rear levers into the box separately. The rear lever is connected with the bracket seat, and the centripetal ball bearing is connected between the lever and the base, which overcomes the disadvantages of unstable structure and poor flexibility of the ball bearing bearing, and is provided with a dust cover to prevent dust and rain from entering. , with enough grease, the base is equipped with leveling screws and horizontal device, easy to adjust. There is a watch clip on the dial indicator, which can be adjusted according to the height of the measurement. Each instrument is equipped with a 0~10mm primary accuracy dial indicator.
The principle of the pavement deflection instrument:
The pavement deflection value refers to the vertical deformation generated by the road surface under the load of the wheel. It is an indicator reflecting the strength of the pavement. The thicker the pavement structure, the higher the strength of the pavement material or subgrade, the smaller the deflection value. Therefore, the greater the deflection value, the road design, construction, maintenance, reinforcement and other work to develop an economic and reasonable plan. Pavement deflection is an indispensable means and has been widely used in the highway sector in recent years.
The pavement deflection instrument is made by the principle of leverage and is used to determine the deflection of the road between the two wheels of the rear axle of the car. The road surface forms a local subsidence under the action of load (ie, vertical deformation), and the shape reflected by the road surface is a basin shape centered on the load point, which is called a deflection basin. When the load is removed, the elasticity returns the road surface to its original shape, and the deflection basin disappears. The difference between the load and the front is called the deflection value. The test proves that the total deflection and the elastic deflection are not equal, that is, after the load is removed, the road deflection basin does not completely disappear, and there are trace residual deformations on the road surface. The road deflection value is closely related to the vehicle speed and temperature.
The pavement deflection instrument has the characteristics of simple structure, convenient use, high sensitivity, and fast and light structure. It is not affected by objective conditions such as weather, wind, and sunshine.
Pavement deflection test method:
1. Preparation for measurement:
A. Connect the instrument levers back and forth in one piece and check them as required.
B. One truck, the single axle of the rear axle shall be calibrated according to the regulations, used for road loading, and the pneumatic tire pressure is also adjusted according to regulations.
C, 1 thermistor thermometer, accuracy 1 ° C, used to determine the road surface temperature (due to the deflection value with temperature).
D. Three sides of the red flag for traffic control, three small iron bars 700~300mm, diameter 20mm, each test except the driver usually requires 3 staff members, one person directs the car, one person records the data, and the other one handles the deflection. instrument.
2. Determination steps:
A, wipe the instrument
B. After the measurement is selected, the center distance of the two-wheel gap of the rear axle of the car to be measured shall not exceed 10 cm.
C. Put the dial indicator on the frame of the dial indicator, then move the deflection meter to the road surface so that the measuring end is just at the center of the double tire gap (perpendicular to the center point of the axle), and adjust the level with the table clamp. And the leveling screw of the dial indicator bracket adjusts the dial gauge reading to about 5mm, so that the pointer points to zero, the contact of the watch against the center of the measuring point screw, and record its reading B1.
D. The car starts forward, so that the rear wheel is outside the influence radius, generally about 5m away. At this time, the dial indicator moves. After the dial gauge reading is stable (less than 0.01mm per minute), the reading C1 is recorded.
E. Measure and record the temperature t of the road surface with a thermal thermometer.
F. The measurement results are recorded in the following formula.
G. Calculate the elastic deflection value of the road surface based on the recorded readings.
Rt=(B1-C1)×2
Where: Rt—subgrade temperature, the elastic deflection value of the road surface, unit: mm.
B1—Percentage reading with load, unit: mm
C1—Percentage reading when removing load Unit: mm
Verification method
1. Measurement accuracy: Place the deflection meter on a stable platform, place the probe on the lower platform of the press, place the dial indicator, and dispose of a dial indicator on the probe. (To measure the displacement of the lower bearing platform), start the press, so that the pressure platform is slightly raised (or lowered) while reading the dial gauge readings of the deflection meter and the probe, and calculate the displacement value, the magnitude range is 0.2. -4.0 mm, the measurement was repeated 5 times each time, and the accuracy was within ±0.02 mm.
2, the length of the instrument, the length of the probe, the width and thickness of the probe, using the measured steel ruler or caliper measurement, the accuracy should meet the requirements
3. The transverse stiffness of the beam: measured by a dial gauge or a dial gauge, the swing should meet the requirements.
4, instrument quality: weighing with small scales, quality should meet the requirements
5, the main parts and materials: visual inspection, experience or simple method to check
6. Assembly and appearance requirements: visual inspection or simple method.
Tel ：0571-86688649
Fax : 0571-86688346
Tel：13567560820 Manager Chen
13216192676 Manager Wang Lili
Rul：www.hzssyq.com
Mail： hzssyq@126.com
Add:No. 601, Jiangling Road, Binjiang District, Hangzhou
新闻中心
NEWS CENTER
Article classification
