Asphalt Additives: Understanding The Key
Components That Improve Asphalt Performance

What
are Asphalt Additives?

Bitumen additives are materials added in small amounts to asphalt binders or
mixes to improve their properties. Some key additive categories include
modifiers, anti-strip agents, lubricity enhancers, and recycled asphalt
pavement (RAP) boosters. Modifiers are usually polymers that enhance the
physical hardening characteristics and high temperature performance of the
asphalt. Anti-strip agents help maximize the adhesion between aggregate and
binder. Lubricity enhancers address issues with low-friction binders containing
high percentages of recyclate. RAP boosters assist recycled materials by
restoring lost properties from aged binders.



Modifier Additives

Polymer modifiers are one of the most common additive types used to enhance the
properties of asphalt cement. They function by forming a
"three-dimensional network structure" within the asphalt binder after
being blended in. This network structure strengthens the binder and improves
its elastic response to traffic loads and temperature variations. Some popular
polymer additives include styrene-butadiene-styrene (SBS), styrene-butadiene
rubber (SBR), ethylene-vinyl acetate (EVA), and polyphosphoric acid (PPA). SBS
is widely used for its ability to significantly boost rutting resistance and
temperature susceptibility of the binder.



Anti-Strip Additives

Another important category is Asphalt
Additives which are designed to maximize adhesion between the asphalt
binder and aggregate surface. This bond is critical for keeping pavement layers
intact under stresses from traffic and climate. Common anti-strip options work
by maintaining a waterproof bond line or by creating a physical barrier against
moisture damage. Typical functional anti-strip agents include amines, portland
cement, hydrated lime, and polysulfide polymers. These promote stronger
binder-aggregate bonding through chemical and mechanical means. Proper
anti-strip selection and dosage can help prevent premature pavement failures
from moisture infiltration.

Get More
Insights On, Asphalt
Additives