Bitumen emulsion SS1, cationic and anionic, slow setting
The properties of bitumen emulsions contribute to the construction, rehabilitation and maintenance of roads (from low to high traffic roads). Our experience and technological know-how enable us to offer our customers solutions tailored to the specific requirements of their individual projects or market needs.
Primer Coat
A primer is usually the application of low viscosity bitumen to a granular substrate to prepare it for the application of an asphalt mixture. A primer performs several important functions.
Coats and binds loose particles of material on the surface of the substrate.
Hardens or toughens the surface of the substrate.
Waterproofs the surface of the substrate by closing capillary or interconnected voids. Provides adhesion or bonding between the substrate and the asphalt mixture.
Bitumen emulsions used for priming are Cationic Slow Setting Emulsion 1 (CSS1) and Cationic Slow Setting Emulsion 1h (CSS1h) according to the latest MoRTH specifications.
Tack coat
A tack coat is a thin bituminous liquid bitumen emulsion applied between HMA pavement layers to improve adhesion. Adequate adhesion between construction layers, and particularly between the existing road surface and a top layer, is critical for the finished road structure to behave as a unit and provide sufficient strength. If adjacent layers do not adhere to each other, they essentially behave as several independent thin layers – none of which is designed to withstand the expected traffic-induced bending stresses. Inadequate adhesion between layers can lead to delamination (delamination), followed by longitudinal wheel track cracking, fatigue cracking, potholes and other damage such as rutting, which significantly reduce the life of the pavement.
Tack coats should be applied evenly across the entire road surface, giving approximately 90 percent surface coverage. In order to achieve this uniformity consistently, all aspects of the application must be considered and carefully controlled. Specific aspects include:
- The condition of the road surface receiving the tack coat
- The application rate
- Dilution of the tack coat
The road surface receiving the tack coat should be clean and dry to ensure maximum adhesion. Emulsified tack coat materials can be applied to cool and/or damp roads, however, curing time may be increased. Since existing and milled roads can be very dirty and dusty, their surfaces should be cleaned by sweeping or washing before applying a tack coat, otherwise the tack coat material may bind to dirt and dust rather than to the adjacent road layers. This may result in excessive tack coat material tracking. Construction vehicles and equipment pick up the tack-dirt mixture with their tires, leaving little or no tack coat in the wheel tracks on the existing road surface. Slip cracks and delamination are problems that typically occur when there is a lack of cleanliness.
Anionic Bitumen Emulsion SS-1 & SS-1h
Bitumen Emulsion SS1 / SS1h are slow setting, anionic asphalt emulsions manufactured to the specifications of ASTM D977 – “Standard Specifications for Anionic Emulsified Asphalt”.
It is a dispersion of small droplets of asphalt cement in water with the aid of an emulsifier. The size of the droplets is usually in the order of 1-20 microns, with some particles as large as 100 microns. Since these droplets are negatively charged, breakup (coalescence) occurs solely by evaporation of water.
Use
Tack coat – a very thin layer of diluted asphalt emulsion. It is used to ensure a bond between a surface to be paved and the new layer. Tack coat is one of the main uses of Spramul SS-1h. It is used to ensure adhesion of hot or cold mix asphalt surface layers to existing asphalt roads.
Primer – RAHA Bitumen Emulsion SS1 is used for primer and performs several important functions such as coating and binding loose mineral particles on the surface of the base, hardening and toughening the surface of the base, sealing the surface of the base by closing capillary or interconnected voids and providing adhesion or bonding between the base and the asphalt mix. This type of emulsion penetrates quite deeply into the WMM/WBM surface and provides effective priming.
Fog Seal - a thin layer of asphalt emulsion diluted with water, similar to a tack coat. It is used to renew old asphalt road surfaces that have become dry and brittle over time, to fill small cracks and surface voids and to prevent fraying. No further surface treatment is carried out after Fog Sealing.
