Rejuvenator Liquid for Reclaimed Asphalt (RAP)
“Wetbond-REX” is a performance grade liquid rejuvenating additive for RAP based hot mix pavements. This is a versatile product which combine properties of Rejuvenation of old oxidized asphalt (present in RAP), Anti-stripping (Water damage protection) and Warm mix asphalt (better compaction on below normal compaction temperatures).
Due to continuous exposure to environmental factors like UV radiation from sunlight, frictional heat generated from moving traffic tyres, freeze thaw, regular change in day and night road temperatures, deposition of clay, sand and other mineral substances on road surface and natural aging process of Bitumen, the bitumen used in construction of asphalt pavements becomes oxidized and brittle over a period of time. This results in loss of flexibility of asphalt layers, formation of cracks, potholes and finally complete failure.
An important factor contributing to brittleness is loss of maltene part of bitumen which chiefly consists of resins, oils, oleifins, naphthenes, and natural polymers. During recycling of asphaltic pavements, a substantial quantity of Reclaimed asphalt (RAP) is produced which is generally wasted in the form of landfills. However by using a liquid rejuvenating additive capable of replenishing the lost maltene part and by adding a little quantity of fresh bitumen to this RAP, the same can be reused for fresh paving and provide a lot of savings in terms of materials, time and money.
Physical Properties :
“WETBOND-REX” liquid is a dark brownish oily liquid at room temperature. This product has a characteristic smell.
This product is internal rejuvenating liquid where it can be added in required dose with fresh bitumen to be used in RAP based hot-mix asphalt constructions. When added to the hot bitumen, it readily disperses with minimal stirring and lowers the surface tension of bitumen for easier wetting of RAP and the fresh aggregates. This product has special resins and polymers to replenish the lost maltene part of the oxidised bitumen present in RAP. "WETBOND-REX" has been thoroughly evaluated by the "Anulab, Agra".
This product also have inherent anti-stripping and warm mix properties, it provides easy mixing even with cold RAP added in hot-mix plant pug mill, takes care of minor water present in RAP due to open storage and provides maintenance of temperature during transportation of mix to laying site and easy compaction even on lower than normal temperatures, so it provide un-comparable economy in its class.
Mode of Action :
“WETBOND-REX” is based on a balanced mixture of various natural ingredients which are very identical to maltene part of bitumen in addition to amine compounds and anti-oxidants. This product assist in replenishing the lost bitumen fractions & restore its flexibility. The additional components ensure better protection from re-oxidation, better resistance to water damage and easier compaction of RAP containing Hot-mix even at below normal compaction temperatures. This product also assist in formation of a stable covalent bond (bridge) between bitumen and surface of road aggregates.
When “WETBOND-REX” treated hot bitumen is mixed with add-on aggregates and RAP, it provides dose dependent balanced diffusion into oxidized bitumen, thus ensure achievement of balanced Marshall Stability and flow values for the hot mix.
Chemical Properties :
Dose: 0.1 to 0.2% by weight of RAP ( 1 to 2 Kg per MT of RAP)
Specific Gravity : 0.94 - 0.96
Flash Point: > 150 Degree Centigrade
Pour Point : > 5 Degree Centigrade
Water Content : < 1.0%
Active content : 100%
Shelf Life : 3 Years from the date of production in sealed containers.
Colour : Dark Brownish thick liquid.
Compatibility : All grades of Road and Industrial Bitumen / RAP.
Advantages of WETBOND-REX :
“WETBOND-REX” is oily liquid product for mixing with fresh hot bitumen.
This product has several advantages over competitors:
Optimum dose product.
Provides additional advantage of anti-oxidant for hot mix surfaces.
Assist in active bridge formation between Bitumen and aggregates.
Gives excellent performance even with RAP having high degree of hardening.
Additional water damage protection and warm mix asphalt properties.
Provides exceptional economy as compared to competitor products.
Procedure for dose calculation of WETBOND-REX :
"WETBOND-REX” dose can be conveniently calculated and used in RAP based hot-mix pavement by following method:
(1) The percentage dose (by weight of RAP) of “WETBOND-REX”, sufficient to achieve the target Marshall stability and mix flow values is determined using Marshall Mix design method. The dose per cubic meter of hot mix is calculated in Kgs.
(2) From final mix design, the quantity of fresh bitumen required for total fresh aggregate + RAP in Kgs per cubic meter is calculated. The percentage of “WETBOND-REX” by weight of fresh bitumen is calculated by:
(Quantity of “WETBOND-REX” in Kg per cubic meter / Quantity of fresh Bitumen in Kg per cubic meter) X 100
(3) Based on above dose, required quantity of “WETBOND-REX” is added in bulk bitumen storage tank and stirred for 10 minutes. After that, the treated bitumen can be used as normal.
WETBOND-REX Liquid Rejuvenator for RAP in 200 Kg. MS Drums.