LIQUID LIMIT DEVICE:

AS PER IS: 2720 (Part V), 9259, BS: 1377, AS: 89.

Introduction:

• Casagrande method in mechanical form is known as Liquid Limit Method and has been in use for soil mechanics for a number of years.
• The Liquid Limit data of soils is useful to correlate mechanical properties of soil, such as compressibility and lower shear strength.
• Liquid limit is the water content at which soil passes from zero strength to an infinitesimal strength, hence the true value of liquid limit cannot be determined.
• For determination purpose liquid limit is that water content at which a part of soil, cut by a groove of standard dimensions, will flow together for a distance of 1.25 cm under an impact of 25 blows in a standard liquid limit apparatus.
• The soil at the water content has some strength which is about 0.17 N/cm. sq. (17gms/sq.cm.)
• At this water content soil just passes from liquid state to plastic state.

General Description and Specifications:

1) LIQUID LIMIT DEVICE (HAND OPERATED):

It consists of a brass cup held on an adjustable bracket. The cup can be adjusted for a fall of 1 cm and can be raised and dropped on a rubber base of standard hardness by cam action. Complete with one Casagrande grooving tool, one ASTM Grooving tool and a high gauge block (Type A of IS 9259).

2) LIQUID LIMIT DEVICE (WITH COUNTER):

It consists of a brass cup held on an adjustable bracket. The cup can be adjusted for a fall of 1 cm and can be raised and dropped on a rubber base of standard hardness by cam action. Complete with one Casagrande grooving tool, one ASTM Grooving tool and a high gauge block (Type A of IS 9259) Fitted with a counter to register the number of blows.

3) LIQUID LIMIT DEVICE (MOTORISED):

It consists of a brass cup held on an adjustable bracket. The cup can be adjusted for a fall of 1 cm and can be raised and dropped on a rubber base of standard hardness by cam action. Complete with one Casagrande grooving tool, one ASTM Grooving tool and a high gauge block (Type A of IS 9259) with a counter & fitted with a motor geared down to give approximately 120 r.p.m. Suitable for operation on 230 Volts, single phase, 50 cycles, A.C. supply.

Spares: Casagrande grooving tool. ASTM Grooving tool, Height block, 1 cm high.