Cangzhou Xinglong Engineering Instrument Co

Wholesale price of type in-situ press press testing machine
Product description
The in-situ press is a special equipment that uses a hydraulic system to conduct on-site testing of the compressive strength of masonry. It is better than testing bricks Compared with the indirect calculation of masonry compressive strength from mortar strength, it is more intuitive and provides reliable data for the reliability appraisal, reinforcement, reconstruction, adding layers and analysis of engineering accidents of houses. This product adopts a low-power high-precision digital pressure gauge produced by Aerospace Science and Technology. It is the smallest and most integrated new generation product in China, ensuring the accuracy of detection data. It implements the national standard "Technical Standard for On-site Inspection of Masonry Engineering" ( B).
Technical parameters:
, rated load
, resolution.
, relative error of indication value
, maximum stroke
, limit stroke
, Maximum unit weight
, Test range wall,
Structure and working principle:
The system is composed of a manual pump and a jack connected with a high-pressure oil pipe. When the oil return valve is closed, the manual pump begins to The oil is delivered by a thousand pounds, pushing the piston upward, and the digital display changes as the pressure continues to increase until the object being measured is destroyed. After the work is completed, the oil return valve can be opened, and the oil will flow back into the manual pump. Record the maximum peak value of the pressure gauge and calculate the masonry strength according to the formula.
Structural composition
, manual oil pump, digital pressure gauge, high-pressure oil pipe, jack, tie rod (four), reaction plate, nuts, masonry, sand cushion layer
Installation and debugging:< br/> After unpacking, check and count the number of parts according to the packing list to see if they are complete, and wipe all parts clean for installation.
. Connect the tee directly to the outlet of the manual pump, and then use a high-pressure hose to connect the hand pump to the hydraulic cylinder through the tee.
, close the oil pump valve, open the oil pump filling cap, and inject clean #hydraulic oil into the manual pump tank.
. Add a certain load such as a counterweight to the hydraulic cylinder, open the exhaust screw, pressurize the hand pump to deflate until oil flows out, it is deemed that the air has been exhausted, and then tighten the screw. If it cannot be exhausted at one time, you can Repeat several times. After the air is drained, close the oil pump valve and wait for use. The above steps need to be repeated each time the instrument is disassembled and assembled.
Test steps:
When digging a horizontal groove at the test point, the following regulations should be followed: the measuring point should be located in the middle of the wall about one meter above the ground, and the restraining walls on both sides should be at least . As mentioned above, the same wall measuring points should not be more than one. Open two holes up and down on the selected wall. The size of the upper hole is ㎜ and the size of the lower hole is ㎜. The upper and lower holes must be aligned. The vertical distance between the two holes is the height of the skin brick. The distance between the wall and the wall is the height of the skin brick. . When opening holes, care should be taken not to loosen the masonry between and around the two holes. The lower surface of the upper hole and the surface of the lower hole should be flat brick surfaces.
When placing the in-situ press between the slots, the following regulations should be met: Place the reaction plate in the upper slot, place the jack in the lower slot, and place the reaction plate in the upper slot and the top surface of the jack. , lay wet fine sand evenly, with a thickness no greater than . Before formal testing, a trial loading test should be conducted, and the trial loading value can be % of the estimated failure load. Check the flexibility and reliability of the test system, and whether the contact between the upper and lower pressure plates and the masonry pressure surface is uniform and dense. After the test load was applied, the test system was normal and then the load was unloaded and the formal test began.
During formal testing, loading should be carried out in stages. The load at each level can be % of the estimated failure load, and should be added evenly within ., and then dead loaded. After loading to % of the estimated failure load, the load should be continuously applied at the original loading speed until the masonry between the slots is damaged. When the cracks in the masonry between the slots expand and increase rapidly and the number of the pressure gauge no longer increases, the masonry between the slots reaches the ultimate state.
During the test, if it is found that the upper and lower pressure plates and the masonry pressure-bearing surface are in a local or eccentric pressure state due to poor contact between the upper and lower pressure plates and the masonry pressure-bearing surface, the test should be stopped. At this time, the test device should be adjusted and the test again. If the adjustment cannot be made, the measuring point should be replaced.
During the test, the initial cracks and crack development of the masonry between the slots should be carefully observed, and the oil pressure gauge readings, measuring point locations, and simplified diagrams of the crack changes with load under progressive loads should be recorded.
Data analysis:
Based on the digital pressure gauge readings at the time of initial cracking and failure of the masonry between the slots, calculate the initial cracking load and failure load of the masonry between the slots.
The compressive strength of the masonry between slots should be calculated according to the following formula.

In the formula, the compressive strength of the masonry between the slots at the th measuring point in the formula ()
The compressive failure load value of the masonry between the slots at the th measuring point in the th measuring area ()
The compressive area of the masonry between the slots at the th measuring point in the th measuring area ()
The compressive strength of the masonry between the slots should be converted into the compressive strength of the standard masonry according to the following formula Calculation:
.+.
In the formula, the standard masonry compressive strength conversion value of the th measuring point in the th measuring area
The dimensionless strength conversion coefficient of the in-situ axial compression method
The working compressive stress () of the upper wall of the measuring point can be calculated according to the actual load standard value of the wall
. The average compressive strength of the masonry in the measuring area should be calculated according to the following formula:
In the formula, the average compressive strength of masonry in the measuring area ()
The number of measuring points in the measuring area.
Precautions during the test process:
When assembling the instrument, the two pressure-bearing plates should be aligned up and down, and their parallelism should be adjusted when tightening the nuts. Wet can be evenly laid between the contact surfaces with the masonry. The thickness of the fine sand cushion or gypsum should be no greater than 1, and the clearance error between the upper and lower nuts of the four tie rods should be no greater than 1.
During the inspection process, due to poor contact between the upper and lower pressure plates and the masonry, eccentric compression occurs. When the distance error between the upper and lower plates is greater than , causing damage to the cylinder.
During the test, the piston should be extended in translation. If the piston is not extended smoothly and jumps, it means that the air in the cylinder has not been completely exhausted. The test should be suspended and the exhaust should be repeated. After the air is completely exhausted, the test can be restarted. .
During the test process, the hydraulic system should not be disassembled. If it is to be disassembled, the oil return valve should be opened first, and then disassembled when there is no pressure in the system.
Since the hydraulic cylinder does not have an automatic retraction function, after the test is completed, please open the oil return valve, tighten the nuts on the self-balancing tension screw evenly and diagonally at the same time, and restore the piston position.