This grade of emulsion penetrates quite deep in WMM / WBM surface providing an effective Prime Coat. It is used to guarantee adhesion of hot mix or cold mix asphalt overlay to existing asphalt paved roads.Ģ.2 Prime Coat- RAHA Bitumen Emulsion SS 1 is used for Prime Coat application and perform several important functions such as coating and bonding loose mineral particles on the surface of the base, hardening and toughening the surface of the base, waterproofing the surface of the base by plugging capillary or interconnected voids, and providing adhesion or bond between the base and the asphalt mixture. Tack coating is one of the major uses of Spramul SS- 1h. It is used to ensure a bond between a surface being paved and the new course. UsesĢ.1 Tack Coat – a very light application of diluted asphalt emulsion. Since these droplets are negatively charged, breaking (coalescence) is purely by evaporation of water. The size of the droplets is normally in the order of 1-20 microns, with some particles as big as 100 microns. It is a dispersion of small droplets of penetration grade asphalt cement in water with the aid of an emulsifier. Anionic Bitumen Emulsion SS-1 & SS-1hīitumen Emulsion SS 1 / SS 1h are slow-setting, anionic type of asphalt emulsions manufactured according to specifications of ASTM D 977 – “Standard Specifications for Anionic Emulsified Asphalt.” Slippage cracking and delamination are distresses typically seen when cleanliness is lacking. Construction vehicles and equipment pick up the tack-dirt mixture on their tires and leave the existing roadway with little or no tack coat in the wheel paths. This can result in excessive tracking of the tack coat material. Since existing and milled pavements can be quite dirty and dusty, their surfaces should be cleaned off by sweeping or washing before any tack coat is placed, otherwise, the tack coat material may bond to the dirt and dust rather than the adjacent pavement layers. Emulsified tack coat materials may be applied to cool and/or damp pavement, however, the length of time needed for the set to occur may increase. The pavement surface receiving the tack coat should be clean and dry to promote maximum bonding. The condition of the pavement surface receiving the tack coat T.
In order for this uniformity to be consistently achieved, all aspects of the application must be considered and carefully controlled. Tack coats should be applied uniformly across the entire pavement surface and result in about 90 percent surface coverage. Inadequate bonding between layers can result in delamination (debonding) followed by longitudinal wheel path cracking, fatigue cracking, potholes, and other distresses such as rutting that greatly reduces pavement life. If adjacent layers do not bond to one another they essentially behave as multiple independent thin layers – none of which are designed to accommodate the anticipated traffic-imposed bending stresses. Adequate bonding between construction lifts and especially between the existing road surface and an overlay is critical in order for the completed pavement structure to behave as a single unit and provide adequate strength. Tack CoatĪ tack coat is a thin bituminous liquid bitumen emulsion applied between HMA pavement lifts to promote bonding. Waterproofs the surface of the base by plugging capillary or interconnected voids Provides adhesion or bond between the base and the asphalt mixture.īitumen emulsions used for Prime Coat are Cationic Slow Setting Emulsion 1 ( CSS 1) and Cationic Slow Setting Emulsion 1 h (CSS 1h) as per latest MoRTH specifications. Hardens or toughens the surface of the base. A prime coat performs several important functions.Ĭoats and bonds loose material particles on the surface of the base. Prime coat typically is the application of low viscosity Bitumen over a granular base, preparing it for laying an asphalt mixture on it. Our experience and technological expertise enable us to offer our customers solutions designed for the specific requirements of their individual projects or market needs. The properties range of bitumen emulsions help to contribute towards the construction, rehabilitation and maintenance of roads (from low to high traffic volume roads). Bitumen Emulsion SS1 Cationic and Anionic Slow Setting
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