Chapter 1: Product introduction

TD528 series of concrete mix Bleeding rate tester was developed by Hebei Tianqixingzi Testing Equipment Co., Ltd. according to the test requirements of T0528-2005 "Test Method for Cement and Concrete Mix Bleeding" and GB/ T50080-2002 "Standard for Performance Test Method of Ordinary Concrete Mix".

This product is suitable for the determination of bleeding of cement concrete mix with aggregate nominal maximum particle size not greater than 31.5mm.

Reference standard:

GB/ T50080-2002 "Standard of test method for Performance of ordinary concrete Mixtures"

JG3021 -- 1994 "Cement concrete slump meter"

T0521 -- 2005 "The Method of on-site Sampling of Cement and Concrete Mix and the fourth Method"

ASTM F2029

Chapter 2 Model parameters

1. TD528-1 concrete bleeding rate tester

Technical Parameters:

1) Volume of sample barrel: 5L

2) Sample cylinder specifications: inner diameter and inner height are 186mm±2mm, wall thickness is 3mm, and equipped with a cover

3) Measuring cylinder: measuring cylinder and straw with capacity of 10mL, 50mL and 100mL, and the indexing value of the measuring cylinder is 1mL.

4) Pound rod: in line with the provisions of JG3021-1994.

5) Stopwatch: the indexing value is 1s.

6) Platform scale: measuring range is 50kg, sensing capacity is 50g.

2. TD528-2 concrete pressure bleeding tester

1) Maximum range of pressure gauge: 6MPa

2) Minimum separation value: not more than 0.1MPa

3) Cylinder body diameter: 125±0.02mm

4) Inside the cylinder height: 200±0.2mm

5) Working piston diameter: 125mm

6) Working piston pressure: 1.2MPa

7) Screen mesh aperture: 0.315mm

8) Net weight: ≈20kg

Chapter three: Test steps

1. TD528-1 concrete bleeding rate tester is a natural bleeding rate tester with the following operating procedures:

The room temperature should be kept at 20℃±2℃ during the test.

After wetting the inner wall of the sample tube with a wet cloth, it was weighed immediately to record the quality of the sample tube. The concrete sample is then loaded into the sample barrel. The concrete loading and compaction methods are as follows:

The slump is not greater than 70mm. Use a shaking table to vibrate. Load the sample into the sample barrel at one time, and open the shaking table. The vibration shall continue until the surface is out of the pulp, and over-vibration shall be avoided; And make the concrete mix 30mm±3mm below the surface of the sample barrel, and smooth with a spatula. After smoothing, immediately weigh and record the total mass of the sample barrel and sample, and start the timing.

If the slump is greater than 70mm, tamper with a tamper. The concrete mixture should be divided into two layers, each layer of tamping times of 25 times; The tamping rod is evenly inserted from the edge to the center. When the bottom layer is inserted, the tamping rod should run through the whole depth. When the second layer is inserted, the tamping rod should be inserted through this layer to the surface of the next layer; After each layer is ramped, use a rubber hammer to gently knock the outer wall of the container 5 ~ 10 times, until the mixing surface inserted and ramped holes disappear and do not see large bubbles; And make the surface of the concrete mix 30mm±3mm lower than the surface of the sample barrel, and smooth with a spatula. After smoothing, immediately weigh and record the total mass of the sample barrel and sample, and start the timing.

Keep the sample barrel level and do not vibrate. In addition to water absorption operation during the test, the lid should always be covered.

Mixing the mixture with water began to time, from the start of the time within 60 minutes, absorb once every 10 minutes of the sample surface seepage water. After 60 minutes, absorb the water from the surface of the sample every 30 minutes until it is considered no longer bleeding. In order to facilitate water absorption, 2min before each water absorption, put a 35mm thick pad on one side of the bottom of the cylinder to make it tilt; After absorbing water, restore level. The sucked water is put into the measuring cylinder, record the amount of water absorbed each time and calculate the total amount of water absorbed, accurate to 1mL. When the calculation is accurate to 0.01mL/mm2. The average water yield of the three samples was taken. If the difference between one of them and the median is more than 15% of the median value, the median value is used as the test result. If the difference between the maximum and minimum values and the median value is more than 15% of the median value, the test is invalid.

2. TD528-2 Concrete pressure bleeding tester is a special instrument mainly used to measure the amount of water in pumped concrete under a certain pressure, and then calculate the ratio of bleeding rate and pressure bleeding rate. The operation steps are as follows:

Open the top cover, load the concrete mix to be tested into the test cylinder, insert the ramming rod from the periphery to the center for 25 times, add the piston, and unscrew the air vent screw of the piston, press down the piston to the surface just in contact with the concrete, tighten the air vent screw, cover the top cover and tighten the nut, and connect the quick joint of the manual pump and jack (see the schematic diagram of the structure).

Then tighten the manual rebound oil valve clockwise, turn the handle of the manual pump, and increase the oil pressure to 30mpa(the value indicated by the pressure gauge). At this time, the pressure of the piston against the concrete mix is 3.0mpa.

When the oil pressure reaches 30Mpa, the bleeding valve is opened immediately, and the bleeding water is inserted into the 1000ml cylinder. At the same time, the timing starts, and the bleeding water V1 and V140 are read at 10 seconds and 140 seconds, respectively, as the basic data for the calculation of bleeding rate.

After the data is obtained, loosen the oil return valve in the counterclockwise direction to make the system relieve pressure, remove the top cover and the test cylinder, put the test cylinder on the release device (attached with the device), cover the top cover, and tighten the two nuts. Tighten the oil return valve in the clockwise direction, pressurize the jack until the concrete and piston automatically fall off, remove the top cover and test cylinder, loosen the oil return valve, and manually press back the jack piston, the end of a test.