Warm Mix Asphalt Additive for low temperature asphalt paving
Warm-mix is a form of Hot-mix Asphalt produced and laid at lower than recommended HMA temperatures to decrease fuel consumption, reduce green house gases and to achieve same degree of mix compaction even at lower temperatures. The additives used for this purpose are called Warm-mix additive and they include a range of chemical and wax based products.
During initial evolution of warm-mix concept, most of the additives contained water to achieve “foaming” of bitumen resulting in warm mix properties. These additive carried a number of problems like uncertain results, induced stripping, tedious process, increased oxidation and premature failure of pavement, human health hazard etc.
With advancement of technology, fat, chemical and wax based meltable solid type additives were introduced by many reputed organizations with varied levels and advantages in terms of dose, emission, field performance, stripping and oxidation control etc.
In latest of Warm-mix technology, very high performance liquid additives were introduced with advantages of low dose, easy mixing, safe handling, maintain temperature during haulage, outstanding control of stripping, minimized oxidation, cost effective etc. “WETBOND-WMA” liquid is the shining star of this category of low dose, high performance additives with unique feature of being non-hazardous.
Physical Properties :
“WETBOND-WMA” liquid is a brownish dark oily liquid at room temperature. This product has a characteristic fatty smell. When added to the hot bitumen, it readily disperses with minimal stirring and lowers the surface tension of bitumen for easier wetting of aggregates. The achieved lower surface tension remains active until the temperature of asphalt mix is dropped below 80 degree centigrade, after which the asphalt mix properties return back to normal.
“WETBOND-WMA” in its normal dose, does not have any significant effect on physical properties of bitumen. It however enhances the “flow” properties of asphalt mixes for easy compaction even at lower temperatures. This product also provides excellent water protection (Anti-stripping) and anti-oxident properties to bitumen for longer pavement life.
Mode of Action :
“WETBOND-WMA” liquid is based on chemically modified fatty materials fortified with rheology modifiers for maintaining the temperature of the mix during transportation to application site and low temperature flow properties of asphalt mixes. The chemical inclusion of certain organic and inorganic molecules activate this product and assist in formation of a stable covalent bond (bridge) between bitumen and surface of aggregates. The flow properties of the asphalt mix are maintained by the special molecules to achieve best compaction even in lower paving and compaction temperatures.
WETBOND-WMA has special feature of enhancing bond between bitumen and aggregates of asphalt mix, which ensures complete protection from stripping and water damage.
Chemical Properties :
Dose: 0.3 to 0.5% by weight of Bitumen ( 3 to 5 Kg per MT of Bitumen)
Specific Gravity : 0.95 - 0.98
Flash Point: > 150 Degree Centigrade
Pour Point : > -5 Degree Centigrade
Water Content : < 1.0%
Active content : 100%
Shelf Life : 2 Years from the date of production in sealed containers.
Colour : Brownish thick liquid.
Compatibility : All grades of Road and Industrial Bitumen.
Advantages of WETBOND-WMA :
“WETBOND-WMA” liquid is easy to use product for premixing in hot bitumen. This product has several advantages over competitors:
Provides fuel saving and reduction in carbon footprints by providing lower hot-mix production and laying temperatures.
No water ensures no spattering or foaming of bitumen and best warm mix properties even in cold climate pavement constructions.
Not covered under hazardous products so easy to use and safe storage.
Liquid product, easy to mix and convenient for direct dosing in HMP.
Provides additional advantage of Anti-stripping Agent and anti-oxidant for hot mix surfaces. This ensures defect free bituminous pavements for years.
Special ingredients for high thermal stability.
Space age technology for best in class performance.
Performance grade yet economical as compared to costly imported products.
Low dose product.
Procedure for mixing of WETBOND-WMA :
"WETBOND-WMA” can be conveniently mixed with hot bitumen by following method:
(1) Post addition in hot bitumen stored in bulk bitumen tank. In this method, the required quantity of WETBOND-WMA is slowly added to stored hot bitumen through the open manhole of the tank or using a suitable pump. After addition of complete dose, the bitumen will be circulated for 15 minutes and then it can be used as normal.
.(2) Direct dosing in Hot Mix Plant by precise dosing device. This method helps in eliminating human contact and ensures better regulatory compliance. However this system must be selected with care to ensure proper dosing and the Hot mix plant manufacturer must be consulted for proper installation.
WETBOND-WMA Liquid Additive for Warm Mix Asphalt in 200 Kg. HDPE Drums / 50 Kg. Cans / 20 Kg. Cans.