Blade mixing

Blade mixing is the least precise of the mixed-in-place methods since everything is dependent on the experience of the motor grader operator. In an attempt to achieve uniform and adequate coating, it is possible that bitumen coating is stripped from the aggregate. 

For the above reasons, blade mixing is only used when short lengths or small areas are to be laid with cold asphalts or when stabilisation with bitumen emulsion is to be carried out. 

Rotary/reclaimer mixing requires the use of mobile rotary mixers or reclaimers (more powerful machines equipped with strong tines for pulverisation of old bituminous layers or other road materials). 

This type of in-place mixing is quite common in cold in-place recycling. 

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Z-blade mixers Shearing and kneading by the specially shaped blades Mixing heavy pastes, creams and doughs Bakery industry, mbber doughs, plastic dispersions... 

Place about three drops of clean water in the dish containing the salvaged primer compound. Employing only a wooden stick or stainless knife blade, mix the material into a thick paste. Add a few more drops of water as necessary. 

A more recent study of the course of the polymerization used 50 gm of inhibitor-free styrene, 0.5 gm of potassium persulfate dispersed in 400 ml of deionized water heated in a 500 ml four-necked flask and using a Teflon-coated steel shaft with a dual-bladed mixing paddle at 70° 0.5°C under nitrogen with a rate of stirring of 200 20 rpm. It was found that there was a limited conversion phenomenon to the process. After conversion between 89 and 95%, the process came to a stop. After prolonged heating conversion barely reached 100%. (In this particular preparation, the particle diameter was 0.54 /im [79]. 

Cold bituminous mixtures produced in-place (in situ) are mixed in a variety of mixing procedures. They can be mixed in a travel plant (travel plant mixing), by a motor grader (blade mixing) or by rotary/reclaimer mixers (rotary/reclaimer mixing). 

Travel plant mixing and blade mixing are used when the cold bituminous mixture is to be produced from virgin aggregate material. Rotary/reclaimer mixing is normally used when the cold bituminous mixture consists of reclaimed material. 

Glass impregnation Instantaneous controlled no kneading area Poor control long kneading areas Poor blade mixing causes fiber degradation... 

Velocity vectors of concentric single pitched flat blade mixing tank at Re = 130. 

For highly viscous blends, the mixer needs to have a higher shear efficiency or to be heated at higher temperatures. In this case, the energy consumption is close to 100 kJ kg . Mixing or pulverization of pigments needs machines equipped with a friction blade mixing powders with liquids is done in turbomixers (Fig. 14.6). 

Very small batches (100-500 g) can be made, for example, to evaluate experimental new additives, in sigma blade mixing heads for torque rheometers, either by dry or wet blending methods. Alternatively, such equipment can be used to prepare concentrates of experimental additives for incorporation using larger-scale equipment. 

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