low-temperature-asphalt

Low-Temperature Asphalt – Background, Production and Benefits

Regulatory pressure, occupational health and climate goals

The production and installation of conventional asphalt mixtures require high temperatures, typically between 160 °C and 180 °C. These conditions place a significant physical strain on construction workers and are associated with potential health risks. Asphalt fumes and aerosols can irritate the respiratory system and are increasingly subject to occupational safety regulations. Studies by the Asphalt Association show that lower temperatures significantly reduce environmental burden.

At the same time, the road construction industry faces growing regulatory and societal pressure to reduce energy consumption and greenhouse gas emissions. The efficient use of resources and the mitigation of global warming have become central objectives in modern infrastructure projects.

In response to these challenges, asphalt technologies that allow for reduced production and installation temperatures are gaining importance. Low-temperature asphalt represents one such approach, with technical additives - like TOPCEL^® add FT60 - offering potential solutions.

Conventional asphalt production

Traditional asphalt consists of mineral aggregates, bitumen and, in some cases, additional additives. The aggregates are heated to remove moisture and ensure proper coating with bitumen. Bitumen itself is heated to reduce viscosity and allow effective mixing and compaction.

These high temperatures result in:

• increased energy consumption,

• significant heat exposure for workers,

• emissions of fumes and gases during production and paving.

What is low-temperature asphalt?

Low-temperature asphalt refers to asphalt mixtures that can be produced, transported and installed at significantly lower temperatures compared to conventional hot-mix asphalt. Temperature reductions of 20 °C to 40 °C are common.

This is achieved through:

• specialised additives,

• physical or chemical modification of bitumen,

• improved coating and workability at lower viscosities.

The fundamental composition and performance requirements of the asphalt remain unchanged.

What makes low-temperature asphalt different?

The key difference lies in improved workability at reduced temperatures. Bitumen can coat aggregates more efficiently and remains sufficiently workable during transport and paving.

This leads to:

• reduced heat exposure on construction sites,

• lower emissions of asphalt fumes,

• decreased energy demand during production.

From an operational perspective, low-temperature asphalt can be integrated into existing paving processes with minimal adjustment.

Benefits of low-temperature asphalt

Worker safety

• Reduced thermal stress

• Lower exposure to fumes and aerosols

• Improved working conditions on site

Energy efficiency and environment

• Lower energy consumption during production

• Reduced CO₂ emissions

• Contribution to sustainable asphalt production

Technical and economic aspects

• Extended workability and paving windows

• Reduced thermal ageing of bitumen

• Potential for more efficient construction processes

Technical solutions and further information

The implementation of low-temperature asphalt requires suitable technical solutions. Additives such as TOPCEL^® add FT60can support reduced mixing and paving temperatures by influencing bitumen viscosity while maintaining asphalt performance.

Further technical details on TOPCEL^® add FT60 and its application can be found here:
Low-Temperature Asphalt with TOPCEL^® add FT60