Asphalt concrete permeation meter is a testing instrument that meets the requirements of the Ministry of Electric Power's hydraulic asphalt concrete test regulations DL / T5326-2006, and is used to determine the permeability coefficient of asphalt concrete. The asphalt concrete permeation meter conforms to DL / T5362-2006 hydraulic asphalt concrete test procedures to determine the permeability coefficient of asphalt concrete. The common water head test is suitable for test pieces with large permeability coefficients, and the variable water head test is suitable for test pieces with smaller test pieces.
Technical parameters of asphalt concrete infiltration meter:
■ Test specification: ￠ 101.6mm, thickness 63.5mm
■ Power supply voltage: 220v 50HZ
■ Dimensions: 600 × 750 × 1900mm
■ Machine weight: 150Kg
■打开阀门 ③、⑥ ，开动抽气机进行抽气，至抽气瓶内无气泡排除。关闭阀门 ⑥ ，打开阀门④，使试件从上下两端充水饱和，关闭阀门④，打开阀门⑥，进行抽气，至抽气瓶内无气泡排出时，关闭阀门⑥，打开阀门④，使试件充水饱和。如此反复进行，至气泡完全排除。饱和排水结束后，将全部阀门关闭。
■先打开阀门①、④，使进水口测压管水位达到一定水平后关闭阀门④，分别记录进水口和出水口测压管的水位，同时开动秒表计时，经时间t后，在记录两测压管相应的水位 。如此反复试验三次～四次后，在打开阀门 ④ ，使进水测压管水位重新上升后，再重复进行测试。记录试验开始和结束时的水温。每次试验的水头应不小于50mm,并应在3h～4h内完成。如两次试验结果出现较大偏差时，应在试验前重新抽气饱水，在进行试验。
Third, the asphalt concrete infiltration instrument operating procedures:
■ Asphalt mixture is prepared according to regulations, and Marshall test pieces are formed according to regulations. If the core sample is used for the test, the upper and lower ends of the core sample are cut flat with a cutting machine, and the average height and diameter of the test piece are measured.
■ Remove the upper cover of the penetration test mold, put the test piece in the middle of the test mold, clean the surface of the test piece, remove oil stains, dust, etc., to prevent the surrounding of the test piece from being badly bonded to the asphalt and leak water, and fill the hot asphalt to seal the test mold With the gap around the test piece. When filling joints, avoid hot asphalt contaminating the surface of the test piece and leaving the asphalt outside. After the asphalt has cooled to room temperature, install the cover and tighten the bolts. After the penetration test piece is installed, it should be inspected to confirm that the test mold is well sealed and the pipeline is unobstructed.
■ The test should use distilled water or filtered water, and use the exhaust method or the boiling method to evacuate before the test. The water temperature during the test should be 3 ℃ ～ 4 ℃ higher than the room temperature. Before the test, sufficient water for one test should be prepared.
■ Install the penetration test mold on the penetration test device. During installation, close all valves to prevent water from flowing into the penetration test mold.
■ Open the valve ③, ⑥ and start the air extractor to evacuate until there are no bubbles in the air extractor. Close the valve ⑥ and open the valve ④ to saturate the test piece with water from the upper and lower ends. Close the valve ④ and open the valve ⑥ to perform air extraction. When no air bubbles are discharged from the pump cylinder, close the valve ⑥ and open the valve ④. The test piece was saturated with water. This was repeated until the bubbles were completely eliminated. After the saturated drainage is completed, all valves are closed.
■ Open the valves ① and ④ first, and then close the valve ④ after the water level of the pressure measuring pipe at the water inlet reaches a certain level. Record the water levels of the pressure measuring pipe at the water inlet and the water outlet separately, and start the stopwatch at the same time. The corresponding water level of the pressure pipe. After repeating the test three to four times in this way, the test is repeated after the valve ④ is opened and the water level of the inlet pressure measuring pipe is raised again. Record the water temperature at the beginning and end of the test. The head of each test shall not be less than 50mm, and shall be completed within 3h to 4h. If there is a large deviation in the results of the two tests, the air should be pumped and saturated before the test, and the test should be carried out.
■ Kt=（QL/At）x IN x(△h1/△h2) （9.8 4-1）
Kt=QL/AHt （9.8 4-2）
K20=Kt X(nr/n20) （ 9.8 4-3）
4. Test results of asphalt concrete infiltration meter:
■ Kt = (QL / At) x IN x (△ h1 / △ h2) (9.8 4-1)
In the formula:
_A_____ Cross-sectional area of pressure measuring tube, cm2;
h1____ The water level difference between the inlet pressure measuring tube and the outlet pressure measuring tube at the beginning of the period t, ㎝
At the end of h2____ period t, the water level difference between the inlet pressure measuring tube and the outlet pressure measuring tube, ㎝.
■ Perform the test according to the penetration test device shown in the figure, and the permeability coefficient of the normal head test is calculated according to the formula:
Kt = QL / AHt (9.8 4-2)
In the formula:
H_____ Water head, eh.
■ The permeability coefficient calculated from several tests of a single specimen, and the average value is taken as the permeability coefficient of the specimen. Three to five test pieces shall be measured in parallel. The range of permeability coefficient is given when the permeability coefficient is less than 1.0x10㎝ / S; when the permeability coefficient is 1.0x1.0㎝ / S or more, the average value is taken.
Kt can be converted to K20 according to the formula:
K20 = Kt X (nr / n20) (9.8 4-3)
In the formula:
K20______ Permeability coefficient at 20 ℃, ㎝ / s;
nr_______ Dynamic viscosity coefficient of water at temperature T ℃, Pa .s;
n20_______ Dynamic viscosity coefficient of water at 20 ℃, Pa .s;
nr / N20 ______ can be found by formula 9.8.3.
1、储水瓶 5、接水管 9、指示灯
2、进水测压管 6、抽气瓶 10、进水管
3、出水测压管 7、放水阀 11、出水管