Highway compaction degree sand filling method test tool

The sand filling method is the use of uniformly sized sand to replace the volume of the test hole. It is currently a commonly used method, and many engineering projects have listed the sand filling method as the main method for on-site density measurement. This method can be used to test the density of various soil or pavement materials, but its disadvantage is that it carries a large amount of sand and has more weighing times, so its testing speed is slow. When using this method,Highway compaction degree sand filling method test toolIt should comply with the following regulations:
(1) When the large particle size of the aggregate is less than 15mm and the thickness of the measuring layer does not exceed 150mm, a small sand filling cylinder with a diameter of ￠ 100mm should be used for testing.
(2) When the particle size of the aggregate is equal to or greater than 15mm but not greater than 40mm, and the thickness of the measuring layer exceeds 150mm but not more than 200mm, a large sand filling cylinder with a diameter of ￠ 150mm should be used for testing
1. Instruments and materials
(1) Sand filling cylinder: There are two sizes available, depending on the needs Type and size There is a circular hole at the center of the bottom of the sand storage cylinder, and an inverted conical funnel is installed at the bottom. The upper end of the funnel is open, and the diameter is the same as the circular hole of the sand storage cylinder. The funnel is welded onto an iron plate, and there is a circular bar L in the center of the iron plate that connects to the opening on the funnel. There is a switch between the bottom of the sand storage cylinder and the funnel. There is also a circular hole of the same diameter on the switch iron plate.
(2) Metal calibration tank: A metal tank made of thin iron plate, with a rim around the upper end, used in conjunction with a sand filling cylinder.
(3) Substrate: A metal square plate made of thin iron plate, with a circular hole in the center of the plate.
(4) Glass panel: a square panel with a side length of approximately 500600mm.
(5) Sample tray: Samples excavated from small tubes can be stored in aluminum boxes, while samples excavated from large tubes can be stored in enamel trays measuring 300mm x 500mm x 40mm.
(6) Balance or platform scale: Weigh 10-15kg with a sensitivity not exceeding 1g. The accuracy of the balance used for moisture content determination should be 0.0lg, 0.1g, and 1.0g for fine-grained soil, medium grained soil, and coarse-grained soil, respectively.
(7) Moisture content measuring instruments: such as aluminum boxes, ovens, etc.
(8) Sand measurement: Clean and dry sand with particle sizes of 0.30-0.60mm and 0.25-0.50g, approximately 2040g. Before use, it must be washed, dried, and left for a sufficient amount of time to reach equilibrium with the humidity of the air. (Purchased from the testing manufacturer for measuring sand)
(9) Containers for sand: plastic buckets, etc.
(10) Other: chisel, hammer, long spoon, small dustpan, brush, etc. (The chisel is made of ф 22 threaded steel and processed into flat and pointed shapes, with a length of about 40-50cm)
2. Experimental methods and steps
(1) Calibrate the quality of sand in the lower cone of the calibration cylinder
① Fill the sand filling cylinder with sand until it is about 15mm away from the top of the cylinder. Weigh the total mass m1 of the loaded cylinder and sand, accurate to 1g. The sand loading height and mass should be maintained unchanged for each subsequent calibration and test.
② Without shaking the sand in the sand storage cylinder, gently move the sand filling cylinder onto the glass plate, turn on the switch to allow the sand to flow out until the sand inside the cylinder no longer flows down, then turn off the switch and carefully remove the sand filling cylinder.
③ Collect and weigh the sand left on the plate or in the weighing cylinder, accurate to 1g. The sand on the glass plate is the mass m2 of the sand in the cone.
④ Repeat the above measurement three times and take the average.

Soil moisture content test (drying, alcohol combustion method) drying method

1、 Definition

The moisture content of soil is the ratio of the mass of water lost when dried to a constant amount at 105-110 ℃ to the mass of dry soil after reaching a constant amount, expressed as a percentage. This method is the standard method for determining moisture content.

2、 Scope of application

Clay soil, silt soil, sandy soil, and organic soil.

3、 Main instruments and equipment

Oven: It can be an electric oven or other energy oven that can maintain a temperature of 105-110 ℃, or an infrared oven can be used

Balance: Sensitivity of 0.01g.

Weighing box (regularly adjusted to constant mass)

4、 Calculation formula

Moisture content=(wet soil mass - dry soil mass)/dry soil mass × 100%

Note: Calculate to 0.1%.

5、 Allowable difference

This experiment requires secondary parallel measurements, and the arithmetic mean of the average should be taken. The allowed parallel difference should comply with the following regulations

Moisture content (%) allows for parallel difference (%)

Below 5, 0.3

Below 40 ≤ 1

Above 40 ≤ 2

Permafrost with layered and networked structures<3

Alcohol combustion method

1、 Scope of application

This method is suitable for rapid and easy determination of the moisture content of fine-grained soil (excluding organic matter).

2、 Main instruments and equipment

Weighing box (regularly adjusted to constant mass).

Balance: Sensitivity of 0.01g.