Apparatus of CBR Test

 

41. APPARATUS

1.1. Molds­- The molds shall be cylindrical in shape, made of metal, with an internal diameter of 152.40±0.66mm (6.0±0.026 in) and a height of 177.80±0.46mm (7.0±0.018 in), and provided with an extension collar approximately 50 mm (2.0 in) in height and a perforated base plate that can be fitted to either end of the mold. (See Figure 1.) It is desirable to have at least three molds each soil to be tested.

1.2. Spacer Disk- A circular spacer disk made of metal 150.8±0.8mm (5^15/16±^1/32 in.) in diameter and 61.37±0.25mm (2.416±0.01 in.) in height.  (See Figure1.)

Note 1 –When using molds having a height of 177.80 mm (7.0 in.) (Figure 1.), a spacer disk height of 61.37 mm (2.416 in.) is needed a thickness of compacted specimen that conforms to the thickness: 116.43 mm (4.584 in.) of specimens in T 99 and T 180.

1.3. Rammer-A rammer as specified in either T 99 or T 180.

1.4. Apparatus for Measuring Expansion-This consists of a swell plate with adjustable stem (Figure 1), and a tripod support for a dial indicator (Figure 1. ). The swell plate is made of metal, 149.2 ±1.6mm (5^7/8±^1/16 in.) in diameter and is perforated with 1.6-mm (1/16-in) diameter holes. The tripod used to support the dial indicator is arranged to fit the mold extension collar.

1.5. Indicators- Two dial indicators: each indicator shall have a 25-mm (1-in.) throw and read to 0.02 mm (0.001 in.)

1.6. Surcharge Weights-One annular metal weight with a center hole approximately 54.0 mm(21/8in.) in diameter and several slotted or spilt metal weights, all 149.2 ± 1.6mm(5^7/8±^1/16 in.) in diameter and each having a mass of 2.27± 0.04 kg (5 ± 0.10lb) (Figure 1.) (Note 2.)

Note 2- When using spilt weights, the mass of the pair shall be 2.27± 0.04 kg (5 ± 0.10lb).

1.7. Penetration Piston- A metal piston of circular cross-section having a diameter of 49.63± 0.13mm (1.954 ± 0.005 in).area= 1935mm² (3 in²) and not less than 102mm (4 in) long (See Figure 1.)

1.8. Loading Device-A compression-type apparatus capable of applying a uniformly increasing load up to a capacity sufficient for the material being tested at a rate of 1.3mm/min. (0.05 in. /min), used to force the penetration piston into the specimen.

1.9. Soaking Thank-A soaking tank suitable for maintaining the water level 25 mm (1 in.) above the top of specimens.

1.10. Drying Oven- A thermostatically controlled drying oven capable of maintaining a temperature of 110± 5°C (230± 9°F) for drying moisture samples

1.11. Moisture Content Container-As specified in T 265.

1.12. Miscellaneous- Miscellaneous tools such as mixing pans, spoons, straightedge, filter paper, balance, etc.

For Further Detail ...........See (Figure 1.)