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Production Benefits

WMA production benefits

My WMA publications

            http://www.springer.com/energy/renewable+and+green+energy/book/978-3-662-44718-5

Zaumanis. Warm Mix Asphalt., K. Gopalakrishnan et al. (eds.), Climate Change, Energy, Sustainability and Pavements, Green Energy and Technology, Springer-Verlag, (2014), DOI: 10.1007/978-3-662-44719-2_10

Zaumanis, Martins, and Juris Smirnovs. 
Analysis of Possibilities for Use of Warm Mix Asphalt in Latvia.” 
In Civil Engineering. International Scientific Conference. Proceedings. Vol. 3. Jelgava, Latvia, 2011.
 
Laboratory Evaluation of Organic and Chemical Warm Mix Asphalt Technologies for SMA Asphalt.” 
The Baltic Journal of Road and Bridge Engineering 7, no. 3 (2012): 191–197. doi:10.3846/bjrbe.2012.26.
 
“Laboratory Evaluation of Warm Mix Asphalt Properties.”
 In 
5th International Conference “Bituminous Mixtures and Pavements.” Thessaloniki, Greece, 2011.
  
Development of Calculation Tool for Assessing the Energy Demand of Warm Mix Asphalt.”
Procedia - Social and Behavioral Sciences 48 (January 2012): 163–172. doi:10.1016/j.sbspro.2012.06.997.
 
“Laboratory Testing of Organic and Chemical Warm Mix Asphalt Technologies.” 
St. Louis, MO, USA: National Asphalt Pavement Association, 2011


My book:                                          My Masters thesis:  
http://www.amazon.com/Asphalt-Going-Green-Overview-technologies/dp/384430018X
                 

·  WMA can be produced with existing asphalt plants by retrofitting the required equipment for a particular technology. 

·  Reduced binder aging, decreased mixture viscosity and less superheating of virgin aggregates required for WMA processes allows increased stiff Reclaimed Asphalt Pavement (RAP) and Reclaimed Asphalt Shingles (RAS) content in mixtures.

·  Easier permitting for a plant site in urban areas, because of the reduced emissions.


Concerns:

·  Residual moisture left from foaming technologies or incomplete drying of aggregates due to reduced temperature can increase moisture susceptibility.

·  When RAS and RAP is used in production, the temperature must be sufficient to activate the hard, aged binder. In some cases (especially when using RAS) the temperature may need to be increased above the normal WMA temperature.

·  Because of the lower production temperature, the aggregate exposure to the flame in the heating drum can be reduced. This can potentially increase production rate and therefore provide higher production efficiency. However, this should be done with caution, because insufficient time of exposure to heat may leave residual moisture in the aggregates and result in insufficient coating of the aggregates with binder.

·  Plant burners may need tuning to account for lower output due to reduced temperature. This will allow an increase in burner efficiency, reduced fuel consumption, reduced stack emissions and avoiding mixture contamination with liquid fuel.

·  The lowered temperatures during production of WMA can lead to condensation in the baghouse which can result in mudding of baghouse fines and corrosion. The proposed methods to keep the baghouse temperatures high enough are described in details by Prowell et al. (2012) and include:

– Preheating the baghouse. 
– Insulating the baghouse and ductwork. 
– Removing veiling flights. 
– Increasing air flow by opening the exhaust damper. 
– Adding a duct heater. 
– Installing a variable frequency drive on drum drive or slinger. 
– Ensuring complete aggregate drying. 
– Insulating the dryer shell.
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