Hydrated lime has been used in asphalt for decades to improve pavement performance and extend service life. While it is widely recognised as an anti-strip additive, research and industry experience have shown that hydrated lime can provide a range of additional benefits that contribute to long-term pavement durability.
Today, hydrated lime is commonly incorporated into asphalt mixes used in road construction, transport infrastructure and other demanding pavement applications where long-term performance is important.
Why is Lime Added to Asphalt?
Asphalt pavements are exposed to a range of environmental and operational stresses throughout their service life, including moisture, traffic loading, temperature fluctuations and ageing. Hydrated lime can help address many of these challenges by improving the interaction between the asphalt binder and aggregate.
The use of hydrated lime in asphalt has become a recognised method of enhancing pavement durability and supporting long-term performance.
Key Benefits of Lime in Asphalt
Improved Moisture Resistance
One of the best-known benefits of hydrated lime in asphalt is its ability to improve resistance to moisture damage. By helping maintain the bond between the asphalt binder and aggregate, hydrated lime can reduce stripping and support pavement durability over time.
Increased Resistance to Rutting
Hydrated lime helps stiffen both the asphalt binder and hot mix asphalt, improving resistance to rutting under traffic loads and high temperatures. This can contribute to improved pavement performance in demanding operating conditions.
Enhanced Durability
By improving moisture stability and reducing some ageing effects within the asphalt binder, hydrated lime can contribute to longer-lasting pavements and improved lifecycle performance.
Improved Resistance to Cracking
Studies referenced within the lime industry have found that hydrated lime can improve asphalt toughness and resistance to fracture growth at lower temperatures, supporting pavement durability across varying environmental conditions.
How Lime Supports Asphalt Performance
Hydrated lime influences several aspects of asphalt performance simultaneously. In addition to helping reduce moisture-related damage, it can alter the chemistry of the asphalt binder and improve the interaction between binder and aggregate. These changes can help support improved durability, stability and long-term pavement performance.
Hydrated lime may also be used alongside polymer-modified binders and other pavement technologies to support the development of high-performance asphalt systems.
Lime in Road Construction
Road networks are expected to perform under increasing traffic volumes and challenging operating conditions. Hydrated lime is commonly incorporated into asphalt mixes to help improve pavement resilience and support long-term infrastructure performance.
The use of hydrated lime in asphalt complements its broader role in road construction, where lime products are also used for soil stabilisation and subgrade improvement.
Which Lime Product is Used in Asphalt?
Both Hydrated Lime and Premium Hydrated Lime may be suitable for asphalt applications depending on project requirements and specifications. Hydrated lime products are commonly used as additives within asphalt mixtures to support durability, moisture resistance and pavement performance.
For project-specific advice, consult technical specifications and speak with the Boral team to determine the most suitable solution for your application.