Low-temperature asphalt

Groups: 
  • Design-Build Contracts
Category: 
  • Materials

Basic

Requirements and Criteria Type: 
  • Contract Terms

Main Objective: 

Asphalt production is energy-intensive and some asphalt plants are also gas-fired. Less energy is required when producing asphalt at lower temperatures and emissions from production are also reduced.

Asphalt workers are exposed to asphalt fumes that are harmful to health when spreading asphalt. The use of low-temperature asphalt (LTA) reduces harmful emission of fumes.

With LTA, CO2 emissions during production can be reduced by 30 to 40 per cent, while also providing a reduction of up to 50 per cent in asphalt fumes during spreading.

Requirement Specification: 

Emissions from the production and spreading of asphalt must be reduced.

The maximum production temperature when spreading low-temperature asphalt must not exceed 140°C.

When using polymer-modified binders, which increase service life, production temperatures up to 155°C are permitted.

Contractors may deviate from the temperature limits if the total solution results in lower emissions than selecting products based on the requirements.

Documentation of the Requirement Specification: 

The contractor must submit a technical report and project planning showing the asphalt composition and spreading techniques, as well as the maximum temperatures required for these techniques. Technical datasheets from producers, including specification of binders and asphalt composition, must be available in a digitally structured format adapted for open BIM. 

As documentation of the asphalt having been produced using low-temperature techniques, a printout of the temperature log from the automatic temperature records in the asphalt production must be submitted at the same time as the asphalt is supplied and no later than two weeks afterwards.

Information about the Requirement Specification: 

This requirement may be used both for the specification of requirements or as a contractual condition, depending on the outcome of dialogues with the market. If you know that the market is able to supply low-temperature asphalt, this could be used for specification of requirements, otherwise the recommendation is to use the requirement as a contractual condition, so that contractors can obtain this type of asphalt.

Normal production temperatures for asphalt fall within a range from 150 to 180 degrees. Each time the production temperature is reduced by 15 degrees, bitumen fume emissions are reduced by half. Investigations conducted by the Norwegian Institute for Road Technology, Veiteknisk Institutt, show that the quality and service life of LTA surfacing is the same as for hot asphalt.

Emissions reductions in low-temperature asphalt:

  • Between 30 and 40 per cent reduction in CO2 emissions from production as a result of lower fuel (diesel/gas) consumption.
  • Up to 35 per cent reduction in SO2 emissions from production.
  • Between 10 and 30 per cent reduction in CO2 emissions from production.
  • Up to 60 to 70 per cent reduction in NOx emissions from production.
  • Between 25 and 55 per cent reduction in dust emissions from production.

Polymer-modified binders (PMB) are used in asphalt surfacing for high-traffic roads. PMB has higher CO2 emissions than ordinary bitumen, but the asphalt surfacing has a longer service life, which results in less overall impact on the environment.

Advanced

Requirements and Criteria Type: 
  • Contract Terms

Main Objective: 

Asphalt production is energy-intensive and some asphalt plants are also gas-fired. Less energy is required when producing asphalt at lower temperatures and emissions from production are also reduced.

Asphalt workers are exposed to asphalt fumes that are harmful to health when spreading asphalt. The use of low-temperature asphalt (LTA) reduces harmful emission of fumes.

With low-temperature asphalt (LTA), CO2 emissions during production can be reduced by 30 to 40 per cent, while also providing a reduction of up to 50 per cent in asphalt fumes during spreading.

Requirement Specification: 

Emissions from the production and spreading of asphalt must be reduced.

The maximum production temperature when spreading low-temperature asphalt must not exceed 120°C.

When using polymer-modified binders, which increase service life, production temperatures up to 155°C are permitted.

Contractors may deviate from the temperature limits if they are able to document that the overall solution would result in lower emissions than selecting products based on the requirements.

Documentation of the Requirement Specification: 

The contractor must submit a technical report and project planning showing the asphalt composition and spreading techniques, as well as the maximum temperatures required for these techniques. Technical datasheets from producers, including specification of binders and asphalt composition, must be available in a digitally structured format adapted for open BIM. 

As documentation of the asphalt having been produced using low-temperature techniques, a printout of the temperature log from the automatic temperature records in the asphalt production must be submitted at the same time as the asphalt is supplied and no later than two weeks afterwards.

Information about the Requirement Specification: 

This requirement may be used both for the specification of requirements or as a contractual condition, depending on the outcome of dialogues with the market. If you know that the market is able to supply low-temperature asphalt, this could be used for specification of requirements, otherwise the recommendation is to use the requirement as a contractual condition, so that contractors can obtain this type of asphalt.

Normal production temperatures for asphalt fall within a range from 150 to 180 degrees. Each time the production temperature is reduced by 15 degrees, bitumen fume emissions are reduced by half. Investigations conducted by the Norwegian Institute for Road Technology, Veiteknisk Institutt, show that the quality and service life of LTA surfacing is the same as for hot asphalt.

Emissions reductions in low-temperature asphalt:

  • Between 30 and 40 per cent reduction in CO2 emissions from production as a result of lower fuel (diesel/gas) consumption.
  • Up to 35 per cent reduction in SO2 emissions from production.
  • Between 10 and 30 per cent reduction in CO2 emissions from production.
  • Up to 60 to 70 per cent reduction in NOx emissions from production.
  • Between 25 and 55 per cent reduction in dust emissions from production.

Polymer-modified binders (PMB) are used in asphalt surfacing for high-traffic roads. PMB has higher CO2 emissions than ordinary bitumen, but the asphalt surfacing has a longer service life, which results in less overall impact on the environment.

Criteria Relations and Conflicts: 

Recycled asphalt

Relatert kriterium

This contractual condition may be used in conjunction with the requirements concerning recycled asphalt.

Related links: 

Published: 24. Nov 2020, Last modified: 28. Dec 2020