Concrete mixers For small jobs conc. mixers are used to mix the ingredients of the concrete

Following type of concrete mixers are used in the construction

Hand felt tilting drum mixers

These are smaller capacity mixers ,aggregate cement and water fed in to the drum by hand Loader fed tilting drum mixers

These are larger capacity as compared to hand fed mixers These are fixed with the loading hopper operating by the wired rope for loading

Reversing drum mixers

This type of mixer is used on comparatively larger works

The mixer drum is horizontal and it is non tilting type

 It has blades which work alternatively

Roller pan mixers

These mixers are primarily used for mortars ,the rollers and mixer blades rotate in a pan and not only mixing material but also kneading and crushing it

Tunneling equipment

Selection of equipment

Selection of equipment for tunneling depends upon quantum of work involved

So that the tunneling work is carried out economically,speedly and safely

Muck loading

Mucking is the operation of loading the broken rock or earth for removal from tunnel Mucking process can be done by the following equipment’s

·         Power shovels Tractor

·         loader Mucking machines

·         Tunnel boring machines

·         Tunnelling is mostly done by conventional and drilling and blasting methods

 Working principle of tunnelling these machines perform the bring operation through the rotation of the front head against the rock face

The mole has circular cutter head in the front provided with fixed cutters of desired shapes The cutter head while rotating is pressed against the rock to cut or pulverize it

The tunnel boring machines are two types

Single stage machine

These are recommended for small dia tunnels of 3 to 6 m

These machine are allowed to access change in bore hole diameter and this can be done without any change of machines