The use of cold mix and cold recycling with emulsions is growing in many countries. In developed countries recycling is becoming more and more popular as there are restrictions on mining new aggregates and also there is savings if one uses recycled materials. Cold recycling with emulsions have a much higher impact on sustainability due to significant reduction in energy, reduction in emission and the use of recycled materials. The use of emulsions is also attractive as the oxidized and aged pavement does not undergo further oxidation by being subjected to higher temperatures as in hot-recycling. In certain countries the use of virgin cold mix is growing such as in India for secondary roads in remote regions where hot-mix plants are not accessible. Countries such as Sweden are promoting cold mix to reduce emissions and energy consumption associated with paving.

Cold in-place Recycling (CIR) as a pavement rehabilitation technique has several advantages. The use of existing or in-place materials instead of transporting mixes from a different site generates additional cost saving and provides environmental benefits. The use of emulsions as a binding or stabilizing agent reduces in energy costs and emissions as the production and placement of mixes are done at ambient temperatures compared to a hot or warm mix application.

In cold-in-place recycling (CIR) there is a need for an emulsifier or emulsion systems that builds faster cohesion but still gives enough workability. Often a certain amount of cement is used in such mixes and the emulsifier system that is used needs to give enough workability in the presence of cement. The existing emulsifier systems are too slow and do not build strength quickly after placement and compaction (see RoadMat Note 4 to know more about how to choose an emulsifier). The systems that build quick cohesion quickly breaks in presence of cement and does not give enough workability. Nouryon introduced the Redicote® E-7100 emulsifier that can be used to produce emulsions for CIR applications that builds faster cohesion development and reduce curing time compared to common Cationic Slow Set emulsions (CSS) emulsifiers. It is also compatible with cement and so will give enough workability in mixes with or without cement. In addition, Redicote® E-7100 emulsions exhibit less settlement and better storage stability compared to other CSS emulsifiers.