Liquid Anti-Strip Agents
Moisture causes many common pavement distresses such as potholes, raveling, and rutting. Moisture related damage in asphalt concrete occurs when water removes, or “strips”, the asphalt binder from aggregate surfaces. Scientists and engineers developed anti-strip technologies in response to this serious and expensive problem that greatly decreases pavement ride quality and the expected life span of our roadways.
Liquid Anti-strip agents are liquid chemical additives added to asphalt mix to increase the occurrence and strength of asphalt to aggregate adhesion, which mitigates stripping and the deterioration of the asphalt. Common liquid anti-strip additives based on amine chemistry include:
- Ethylene amines
- Polyamines
- Fatty (tallow) amines
- Amidoamines
Dytek® BHMT is among the best amine liquid anti-strip additives in prolonging the service life of asphalt
| Additives Description | |
|---|---|
| Control | No LAS Additive |
| PEG | Polyethylene Glycol |
| HMD | Hexamtheylenediamine |
| TETA-OA | TETA - Oleyl Amide |
| HMD-EO | HMD - Ethylene Oxide adduct |
| TEA | Triethanolamine |
| TETA | Triethylenetetramine |
| TETA-DA | TETA - Dioleyl Amide |
| Dytek® BHMT | Bis(hexymethylene)triamine |
| TETA-EO | TETA - Ethylene Oxide adduct |
Measurements used to quantitatively describe the moisture damage on changes to adhesion and cohesion in an asphalt mix
| TSR | Tensile Strength Ratio | Decrease in TSR => loss of cohesion │ softening by water |
| MR | Resilient modulus | High MR => increase in stiffness; may lead to poor fatigue life |
| Nw/ND | Ratio of wet life to dry life | a measure of the effectiveness of chemical in improving the service life of asphalt │ higher the value, better the performance |
| (TSR)2/MRR | Toughness ratio | Alternative to NW/ND │ larger value preferred |