warm sulfur-modified asphalt mixtures

Mario Roberto Jair
Shell CAPSA
CABA (Argentina)

Gary L. Fitts
Shell Oil Products (USA) 

ABSTRACT

For many years there has been particular interest in the use of alternative binders to replace part of the bituminous binder in asphalt mixtures. With the oil embargo in the years 70, the use of sulfur as a substitute product in North America with various projects built in the US and Canada was investigated. Despite the proven success, there was no further development of extended asphalt mixtures with sulfur after years 80 because economic factors changed in favor of the use of traditional asphalt mixes. Now there is renewed interest in alternative binders for economic, environmental reasons and to improve performance (a) thereof.

"Shell Specialties" has focused, especially in the last decade, large-scale innovative projects that maximize the potential value of sulfur, being "Shell Thiopave" an example of the above.

The development of technology "Shell Thiopave" using a solid product to be introduced into the asphaltic mixture similar to a warm mix temperature allows the use of sulfur to replace between 20 and 25% of the volume of bitumen in the asphaltic concrete (b) minimizing the risk of potential problems in the environment and health of workers. Sulfur also modifies the mechanical properties of asphalt mixtures, reducing its sensitivity to temperature changes, improving resistance to permanent deformation, increasing its rigidity at high temperatures under heavy / sluggish charges and increasing its resistance to fuel spill.

The purpose of this paper is to show the evolution of sulfur-modified asphalt mixtures from the 70 until today as well as today in terms of design, production and construction, including some recent research as an example.

KEYWORDS

asphalt, bituminous Chipboard, sulfur, sulfur-extended asphalt mix, asphalt tibia, modified asphalt, asphalt mixtures Recycling, Environment, Temperature.