Testing system for measuring static cracking agent swelling pressure and testing method thereof

Abstract

The invention provides a testing system for measuring static cracking agent swelling pressure and a testing method thereof, belonging to the technical field of geotechnical engineering. According to the system, a pressure testing machine rigid frame is provided with a pressure sensor, a barrel, a first piston and a second piston are arranged between a pressing head and the pressure sensor, the second piston is in contact with the pressing head, and the first piston is in contact with the pressure sensor. The testing method comprises the steps of placing the first piston into the bottom of the barrel and placing the barrel on the pressure sensor, loading a static cracking agent into the barrel and leveling the agent and then covering the barrel with a plastic film, placing the second piston into the barrel, starting a pressure testing machine and driving the pressing head to move downward through an oil cylinder such that the pressing head is in contact with the second piston, with the volume swelling of the static cracking agent, axially pushing the first piston and the second piston with the agent and recording a numerical value of swelling pressure with the pressure sensor, and dividing the numerical value of the swelling pressure with the cross section area of the first piston or the second piston to obtain the value of the static cracking agent swelling pressure.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, in particular to a test system and a test method for measuring the expansion pressure of a static breaking agent. Background technique [0002] Since the appearance of the static breaking agent, it has been widely used in the fields of stone mining, rock crushing and slope repair engineering, among which the expansion pressure is the most important performance index used to measure the static breaking agent, and the size of the expansion pressure also directly affects the static breaking. The key to the crushing effect of the agent. [0003] At present, the commonly used methods for testing the expansion pressure of the static breaker are the outer tube method, the inner tube method and the pressure sensor method, and these three test methods all use resistance strain gauges to measure (electrical measurement) the static breaker within the limit. The strain value generated in th...

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Problems solved by technology

[0007] 2. The testing process is complicated:

[0008] The high temperature generated by the hydration reaction of the static breaking agent can reach 120°C, and the nozzle hole phenomenon is prone to occur during the test. In addition, the high temperature can lead to the failure of the glue pasting the resistance strain gauge and cause the resistance strain gauge to fall off. Therefore, the steel pipe should be placed in the water tank during the test. To cool down, the resistance strain gauge should be waterproofed before putting it into the water tank. The whole test process is complicated and the success rate is low;

[0009] 3. High cost of testing:

[0012] Hydraulic balance manometer test method: Although this method avoids the influence of mechanical hysteresis and temperature effects on the measurement results in the electrical measurement method, it still has the disadvantage of low accuracy of test results;

[0013] Hydraulic pressure transmission test method: This method is to put the solid expansion material and the medium to expand it into a closed container connected with a measuring instrument and filled with liquid, and the pressure generated by the compression of the liquid in the closed container through the expansion of the solid expansion material , to reflect the expansion pressure, but this method has high requirements for the sealing of the airtight container, and does not consider the effect of the heat of reaction on the temperature of the liquid in the container, resulting in distortion of the expansion pressure test results;

[0014] Measuring ring pressure test method: This method is based on the displacement-pressure theory, laterally constraining the static breaking agent through the steel mold, and testing its axial expansion displacement, and calculating its expansion pressure, but the measured value is different from that of the outer tube Compared with the method, the trend is the same, the measured value is much smaller than that of the outer tube method, and the proportional coefficient between the two can reach 2.5-4.0, and the coefficient variation range is large, resulting in large dispersion of test results and low accuracy. In the force ring test, the expansion of the static breaking agent in the steel mold will produce a certain amount of axial displacement, which has a great impact on the test results

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