Improvement of VC method roller compacted concrete digital Weber viscosity meter

1、 VBR-II typeImprovement of VC method roller compacted concrete digital Weber viscosity meterProduct Introduction

This instrument is designed and manufactured according to the national standard GB/T50080-2016 of the People's Republic of China. It is mainly used to test the Weibull consistency of concrete mixtures. It determines the consistency value of concrete mixtures by the length of the vibration time (seconds) of the mixture, and is suitable for measuring the consistency of concrete mixtures with a maximum aggregate size of no more than 40mm and a Weibull consistency between 5-30s.

2、 Main technical parameters

Slump cone: Inner diameter of upper opening 100 ± 2mm

Bottom inner diameter: 200 ± 2mm

Tube height: 300 ± 2mm

Capacity cylinder: Inner diameter: 240 ± 3mm

Internal height: 200 ± 2mm

Disk: transparent and flat

Diameter: 230mm ± 2mm

Thickness 10mm ± 2mm

Total mass of sliding part: 2750g ± 50g (when measuring VC value, add two 7500g ± 50g counterweight weights, and when measuring improvement value, add two 8700g ± 50g counterweight weights)

Vibration frequency: 50Hz ± 3.3Hz

Vibration table amplitude (with empty container): 0.5 ± 0.10mm

Table size: length 380mm, width 260mm

Timing range: 0.1-99.9 seconds

Dimensions: 380 × 520 × 87

3、 VBR-II typeImprovement of VC method roller compacted concrete digital Weber viscosity metertesting procedure

1. Place this instrument on a solid and level platform, and use a damp cloth to moisten the container, slump cone, inner wall of the feeding port, and other utensils.

2. Lift the feeding port above the slump cone and tighten it, adjust the position of the container so that its axis coincides with the axis of the feeding port, and then tighten the circular nut.

3. Use a small shovel to divide the concrete sample obtained according to the requirements into three layers and load them into a slump cone. After each layer is compacted, the material is about one-third of the height. Use a tamping rod to evenly tamp the cross-section of each layer 25 times. When tamping the second and top layers, the tamping rod should be inserted through this layer and just enter the top layer of the next layer. After tamping, scrape the flat surface.

4. Rotate the transparent disc to the top of the slump cone, tighten the positioning screw, and adjust it to zero.

5. Turn the feeding port and disc away, lift the slump cone vertically, and be careful not to cause lateral twisting of the concrete sample.

6. Turn the transparent disc onto the top surface of the concrete circular table, loosen the positioning screw, lower the disc so that it can gently touch the surface of the concrete, and read the value to obtain the slump value.

7. Press the 'Start/Stop' button on the controller and simultaneously press the stopwatch to start timing. When the bottom of the transparent disc comes into contact with the cement slurry (a small amount of closed bubbles are allowed), immediately stop the stopwatch and close the vibration table

8. Record the time on the stopwatch, accurate to 0.5s

4、 The time s read by the stopwatch is the Weber viscosity value of the concrete mixture

5、 Maintenance and inspection

1. Every time it is used, the container, feeding port, slump cone, and transparent disc must be cleaned and wiped clean with a cloth, especially the mud on the transparent disc must be wiped clean for the next observation. (After cleaning the instrument, wipe it dry, especially the electrical parts, be sure to pay attention to moisture prevention).

2. Before each vibration, it is necessary to check whether all components and parts are positioned, and whether all screws are tightened.

3. Long term use, if the transparent disc is worn, it should be polished in a timely manner. If the thickness is less than 8mm, it should be replaced in a timely manner. In use, if the weight is less than 2700 grams, the transparent disc should be replaced or a counterweight should be added. The method of adding a counterweight is to fix a washer equivalent to 50 grams under the top screw.