A testing device and method for the anti-leaching ability of heavy metal ions in permeable concrete

Abstract

The present invention discloses a testing device and method for the anti-leaching ability of heavy metal ions in permeable concrete, comprising a testing device and a concrete test block to be tested, wherein the testing device is composed of an upper water tank and a lower water tank, wherein the upper water tank is located above the lower water tank, and the bottom of the upper water tank is opened, and a placement groove matching the shape of the test block is provided at the opening, and the upper water tank is provided with a water inlet pipe and a water outlet pipe connected to the inside of the lower water tank, and the water inlet pipe is provided with a water pump. Compared with the prior art, the present invention innovates on the basis of the circulating flow dissolution test method and the osmotic dissolution method, better simulates the actual on-site situation, makes the experimental method and experimental data more reliable, and fills the gap in the testing method for the anti-leaching ability of heavy metal ions in permeable concrete.

Description

Technical Field

[0001] The invention relates to a test for the anti-leaching ability of heavy metal ions in permeable concrete, and in particular to a test device and method for the anti-leaching ability of heavy metal ions in permeable concrete. Background Art

[0002] The test methods for testing the anti-leaching ability of heavy metal ions in ordinary concrete include: 1. Immersion dissolution method; 2. Vibration extraction test method; 3. Tumbling and rolling extraction test method; 4. Penetration dissolution method; 5. Circulation flow dissolution test method, etc. Permeable concrete test blocks with different mix ratios or the same mix ratio often have different or slightly different permeability coefficients during the production process due to the lack of standard and unified processes. Since the above methods cannot simulate the actual on-site conditions, the reliability of the experimental methods and experimental data is poor. There is currently a blank in the test method for the anti-leaching ability of heavy metal ions in permeable concrete. Summary of the invention

[0003] The purpose of the present invention is to provide a device and method for testing the anti-leaching ability of heavy metal ions in water concrete which solves the above-mentioned problem.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a testing device for the anti-leaching ability of heavy metal ions in permeable concrete, including a testing device and a concrete test block to be tested, the testing device is composed of an upper water tank and a lower water tank, the upper water tank is located above the lower water tank, the bottom of the upper water tank is opened, and a placement groove matching the shape of the test block is provided at the opening, the upper water tank is provided with a water inlet pipe and a water outlet pipe connected to the inside of the lower water tank, and the water inlet pipe is provided with a water pump.

[0005] Preferably, the water pump is provided with a timing switch controller.

[0006] Preferably, the water inlet position of the water inlet pipe in the upper water tank is higher than the water outlet position of the water outlet pipe in the upper water tank.

[0007] Preferably, the height of the placement groove is smaller than the thickness of the test block, and the test block and the placement groove are fixed and sealed by wrapping with adhesive tape around them.

[0008] Preferably, a funnel for receiving the permeate is provided below the placement tank, and the bottom of the funnel is connected to the interior of the lower water tank.

[0009] Preferably, the upper water tank and the funnel are fixed to the lower water tank or the ground via a bracket.

[0010] A method for testing the anti-leaching ability of heavy metal ions in permeable concrete is conducted using the above-mentioned testing device. The testing method is as follows:

[0011] Step 1: Use the test device to sample the seepage of permeable concrete under constant water head.

[0012] Step 2: Fill the water tank with 20kg of deionized water, then start the water pump and set the time T. f Seepage test, T f The value of is calculated using formula C-1:

[0013]

[0014] Among them, T f is the operating time of the permeable concrete seepage sampling device, hours; H y is the annual precipitation in the area where permeable concrete is used, mm / year; T l is the service life of permeable concrete, years; H s is the height of the permeable concrete specimen, mm; H r is the thickness of the permeable concrete road slab, mm; P f is the permeability coefficient of permeable concrete, mm / s.

[0015] Step 3: After the deionized water has completed the infiltration of the permeable concrete, extract 200 ml of the exudate from the water tank and use spectrophotometry to test the heavy metal ion content. The types of heavy metal ions that need to be tested are: arsenic ions, hexavalent chromium ions, and lead ions.

[0016] Step 4: For the heavy metal ion content (mg / L) obtained by the test, the correction factor C is calculated using formula C-2: c To make a correction:

[0017]

[0018] Among them, C c is the correction factor of heavy metal ion content in the leaching solution; S s is the cross-sectional area of ​​the permeable concrete specimen, mm*mm.

[0019] Preferably, the testing device needs to be rinsed with deionized water before testing.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] 1. This experimental method is innovative on the basis of the circulating flow dissolution test method and the osmotic dissolution method to better simulate the actual on-site conditions and make the experimental method and experimental data more reliable.

[0022] 2. Permeable concrete test blocks with different mix ratios or the same mix ratio often have different or slightly different permeability coefficients due to the lack of standard and unified processes during the production process. This experimental method can achieve the same total water volume passing through test blocks with different permeability coefficients by adjusting the test time under the condition that the permeability coefficient and other conditions remain constant.

[0023] 3. This method is more reasonable, convenient and simple, and the experimental data is more reliable.

[0024] 4. Under the condition of constant water head, the permeable concrete test block is sampled for the exudate and the heavy metal ion content is tested by spectrophotometry. The types of heavy metal ions that need to be tested are: arsenic ions, hexavalent chromium ions, and lead ions. This method fills the gap in the test method for the anti-leaching ability of heavy metal ions in permeable concrete test blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the testing device of the present invention.

[0026] In the figure: 1. lower water tank; 2. upper water tank; 3. water inlet pipe; 4. water outlet pipe; 5. placement tank; 6. test block; 7. funnel; 8. water pump. DETAILED DESCRIPTION

[0027] The present invention will be further described below.

[0028] Example: See Figure 1 A testing device for the anti-leaching ability of heavy metal ions in permeable concrete includes a testing device and a concrete test block 6 to be tested. The testing device consists of an upper water tank 2 and a lower water tank 1. The upper water tank 2 is located above the lower water tank 1. The bottom of the upper water tank 2 is opened, and a placement groove 5 matching the shape of the test block 6 is provided at the opening. The upper water tank 2 is provided with an inlet pipe 3 and an outlet pipe 4 connected to the inside of the lower water tank 1, and a water pump 8 is provided on the inlet pipe 3.

[0029] The testing device for the anti-leaching ability of heavy metal ions in permeable concrete of the present invention fills the gap in testing the anti-leaching ability of heavy metal ions in permeable concrete. Compared with simple test block immersion, this device is more efficient and utilizes the structural characteristics of permeable concrete to allow deionized water to circulate sustainably and pass through the entire permeable concrete test block 6. The experimental test time is relatively short, making the principle more reasonable, convenient and simple, and the experimental data more reliable. However, simple test block immersion cannot better simulate the actual situation on site, the experimental cycle is relatively long, and the experimental data is unreliable. The testing device for the anti-leaching ability of heavy metal ions in permeable concrete better simulates the actual situation on site, making the experimental method and experimental data more reliable.

[0030] The water pump 8 is provided with a timer switch controller. The time is set before the experiment, and then the water pump 8 is started. When the time is up, the water pump 8 stops and the experiment ends.

[0031] The water inlet position of the water inlet pipe 3 in the upper water tank 2 is higher than the water outlet position of the water outlet pipe 4 in the upper water tank 2, forming a certain water head difference, and maintaining a constant water head difference while entering and discharging. Under the condition of constant water pressure, it is guaranteed that there is enough water volume and water passes through the test block 6 at a uniform speed.

[0032] The height of the placement groove 5 is less than the thickness of the test block 6, and the test block 6 and the placement groove 5 are fixed and sealed by wrapping tape around them. The test block 6 is fixed to prevent water from flowing out from the gap or around the sample. Simulating a real permeable concrete road section, rainwater flows in from the top and flows out from the bottom. After the deionized water seeps into the permeable concrete, 200 ml of the exudate is extracted from the water tank, and the heavy metal ion content is tested by spectrophotometry. The types of heavy metal ions that need to be tested are: arsenic ions, hexavalent chromium ions, and lead ions.

[0033] A funnel 7 for receiving the permeate is provided below the placement tank 5, and the bottom of the funnel 7 is communicated with the interior of the lower water tank 1. The funnel 7 serves to collect the permeate passing through the permeable concrete above to prevent the permeate from splashing and causing loss.

[0034] The upper water tank 2 and the funnel 7 are fixed to the lower water tank 1 or the ground through a bracket, and the fixing method is a conventional fixing method to achieve fixed limit.

[0035] A method for testing the anti-leaching ability of heavy metal ions in permeable concrete is conducted using the above-mentioned testing device. The testing method is as follows:

[0036] Step 1: Adoption Figure 1 The test device shown is used to sample the seepage of permeable concrete under constant water head.

[0037] Step 2: Fill the water tank with 20kg of deionized water, then start the water pump and set the time T. f Seepage test, T f The value of is calculated using formula C-1:

[0038]

[0039] Among them, T f is the operating time of the permeable concrete seepage sampling device, hours; H y is the annual precipitation in the area where permeable concrete is used, mm / year; T l is the service life of permeable concrete, years; H s is the height of the permeable concrete specimen, mm; H ris the thickness of the permeable concrete road slab, mm; P f is the permeability coefficient of permeable concrete, mm / s.

[0040] Step 3: After the deionized water has completed the infiltration of the permeable concrete, extract 200 ml of the exudate from the water tank and use spectrophotometry to test the heavy metal ion content. The types of heavy metal ions that need to be tested are: arsenic ions, hexavalent chromium ions, and lead ions.

[0041] Step 4: For the heavy metal ion content (mg / L) obtained by the test, the correction factor C is calculated using formula C-2: c To make a correction:

[0042]

[0043] Among them, C c is the correction factor of heavy metal ion content in the leaching solution; S s is the cross-sectional area of ​​the permeable concrete specimen, mm*mm.

[0044] Note: In order to avoid external influences and influences from the previous experiment, the test device needs to be rinsed with deionized water before testing.

[0045] The specific method is: before each test, rinse the equipment with deionized water and circulate it for 5 minutes.

[0046] The above is a detailed introduction to the testing device and method for the anti-leaching ability of heavy metal ions in permeable concrete provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope, and changes and improvements to the present invention will be possible without exceeding the concept and scope specified in the attached claims. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A test method for the anti-leaching ability of heavy metal ions in permeable concrete, which is tested by a test device for the anti-leaching ability of heavy metal ions in permeable concrete. The test device includes a test device and a concrete test block to be detected. The test device consists of an upper water tank and a lower water tank. The upper water tank is located above the lower water tank. The bottom of the upper water tank is provided with an opening, and a placement groove matching the shape of the test block is arranged at the opening. An inlet pipe and an outlet pipe communicating with the inside of the lower water tank are provided on the upper water tank. A water pump is provided on the inlet pipe; a timing switch controller is provided on the water pump; the water inlet position of the inlet pipe in the upper water tank is higher than the water outlet position of the outlet pipe in the upper water tank; the height of the placement groove is less than the thickness of the test block, and the test block and the surrounding of the placement groove are fixed and sealed by winding with tape; a funnel for receiving the permeate is arranged below the placement groove, and the funnel communicates with the inside of the lower water tank below; the upper water tank and the funnel are fixed to the lower water tank or the ground by brackets. It is characterized in that: The test method is as follows, Step 1: Use the test device to sample the permeable concrete seepage under constant water head. Step 2: Fill the water tank with 20kg of deionized water, then start the water pump and set the time T. f Seepage test, T f The value of is calculated using formula C-1: Among them, T f is the operating time of the permeable concrete seepage sampling device, hours; H y is the annual precipitation in the area where permeable concrete is used, mm / year; T1 is the service life of permeable concrete, years; H s is the height of the permeable concrete specimen, mm; H r is the thickness of the permeable concrete road slab, mm; P f is the permeability coefficient of permeable concrete, mm / s; Step 3: After the deionized water has infiltrated the permeable concrete, 200 ml of the exudate is extracted from the water tank and the heavy metal ion content is tested by spectrophotometry. The types of heavy metal ions that need to be tested are: arsenic ions, hexavalent chromium ions, and lead ions. Step 4: Correct the heavy metal ion content (mg / L) obtained by the test using the correction factor Cc calculated using formula C-2: Wherein, Cc is the correction coefficient of heavy metal ion content in the leachate; Ss is the cross-sectional area of ​​the permeable concrete specimen (mm*mm).

2. The test method for the anti-leaching ability of heavy metal ions in permeable concrete according to claim 1, characterized in that: The test device needs to be rinsed with deionized water before testing.

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