DERBO & WETBOND Conventional Anti-stripping Agents

The problem of stripping can be effectively minimized using "DERBO" and "WETBOND" range of anti-stripping agents. Since they are made from Polymeric amines, the amine group of "DERBO" and "WETBOND" anti-stripping agents reacts with acidic aggregates and makes the aggregate surface hydrophobic (repulsive to water). Further lipophilic (oil loving) Fatty chain remains well suspended in bitumen to form a bridge between bitumen and aggregates. This prevents stripping even in presence of water.

Amine based "DERBO" and "WETBOND" Anti-stripping agents also act by changing the interfacial tension between Bitumen and aggregates and strengthening the bonding for long term durability.

In construction of bituminous pavements, the aggregates are used in two ways e.g. in coated form (Hot Mix etc.) and uncoated form (spraying work etc.). When used in proper dose, "DERBO" and "WETBOND" are equally effective in both the applications. In coated form they prevents stripping even when coated aggregates are submerged in water and in uncoated form they provides active adhesion of bitumen even with wet aggregates.

Dose of DERBO and WETBOND :

• Dosing of DERBO and WETBOND can be done at different stages of mixing and application. An automatic dosing system can be installed in hot mix plant, however an easier way is to add pre-determined quantity in bitumen storage tank before unloading the bitumen from bulk tanker. Alternatively it can be mixed in stored bitumen by gentle stirring for 15 minutes by a mechanical or manual process.
• The required dose of each grade will be different depending on type of bitumen used, type of aggregates and type of surfacing. (The dose can be estimated by some simple tests covered under testing page)