IS. 4031 – 1968, IS: 1344- 1959,
Concrete moulds are cast by using a tamping bar or a vibrating table. However air trapped in cement mortar paste can not be thus removed while casting cement mortar moulds. Easy method is to impart greater vibration of lesser amplitude to the mould while casting. This is achieved in a Vibrating Machine. Vibrating Machine is used for the preparation of mortar cubes for the determination of compression strength of ordinary and rapid hardening Portland cement, low heat portland cement, portland blast furnace cement and high alumina cements.
The machine consists of a vibrating frame assembly and an electric motor mounted on a sturdy base. The complete frame assembly consists of a vice to hold a 7.06cm cube mould and two studs threaded at top and a hopper to feed the sample in the mould. This assembly is supported on four springs and has an in built rotating shaft which rotates eccentrically and thus imparts vibrations to the entire frame. A balance weight is an integral bottom part of the frame. The centre of gravity of the assembly is brought to the centre of the eccentric shaft or within a distance of 25mm below it. The electric motor drives the shaft of the frame and thus imparts required vibrations to the mould. The frequency of vibration is 12000 ±400 vibration per minute. Supplied complete with on 7.06cm cube mould with loose base plate, a time switch 0-5mins x 1 min and certificate of vibration from a standard laboratory.
Poking rod wooden
Poking rod rubber