Sand-based water permeability rate testing device\Sand-based permeable bricks\Sand-based water permeability rate

Sand-based permeable brick water permeability test device 1. Scope of application
This test device tests the water permeability of sand-based permeable bricks through program control to simulate water flow from light rain to heavy rain. It is suitable for testing the water permeability rate of sand-based permeable bricks or Simulation tests with the same test requirements.
2. Structural description
, spray system
, metering pump
, waterproof cover
, liquid level acquisition system
, program control system
> 3. Sample preparation
Permeable brick sample with minimum side length greater than. Sample gauge block. Drying oven, distilled water.
4. Test steps
Put the sample into a drying oven and dry it until the mass change does not exceed .%
. Soak the dried sample in distilled water for several minutes and then take it out.
Place the sample face up on the support frame, adjust it to the level, turn on the instrument program control system, and adjust the waterproof cover and liquid level collection device according to the position of the nozzle and the detection and collection area.
, record the waterproof cover area and the height of the liquid level collection device from the sample surface, and set the metering pump flow acceleration
, click start, the metering pump flow rate continues to increase, and the top spray realizes simulated light rain increasing to During the process of heavy rain, until the alarm sounds, the final water permeability rate is measured
5. Calculation results
The water permeability rate per unit area should be calculated according to the formula (.)
/

Equation Medium
Maximum water permeability rate, unit is milliliter per minute per square centimeter【/(】
Metering pump flow rate when liquid level collection alarm, unit is milliliter per minute【/】
Flow acceleration, The unit is milliliters per square minute
The area of the waterproof cover, the unit is square centimeters
The height of the liquid level collection device from the sample, the unit is centimeters
6. Testing principle
With a constant The flow acceleration adds water to a certain permeable area on the surface of the sample (the area in the waterproof cover). It is assumed that all the water added passes through the sample in time before the flow rate reaches the maximum water permeability rate of the sample, that is, the water permeability flow rate of the sample is equal to the water addition flow rate. Starting from reaching the maximum water permeability rate of the sample, the water permeability flow rate of the sample remains constant, and the water level on the surface of the sample begins to rise. The water flow continues to increase continuously within a certain period of time and the increased water volume is recorded. The above process is carried out under the condition of constant flow acceleration. Therefore, the relevant data calculation formula can be used to calculate the result.