Field trials, sulfur-asphalt pavement

Early field trials were conducted in Saudi Arabia using this technology (22, 23). Considerable interest in sulfur asphalt pavements has been generated, but not projects of significance have been completed. Considerable research and development as well as demonstrations are continuing under the guidance of the Sulphur Development Institute of Canada. 

Various types of sulfur-asphalt pavement field test sections have been placed in the U.S., Canada, and Europe. Shell Canada Ltd. has conducted field trials in Canada (1,18,19,20). Gulf Oil Canada has also placed test sections of sulfur-asphalt pavement in which the sulfur and asphalt cement were incorporated into the mixture as an emulsion (4). Societe Nationale des Petroles D Aquitaine (SNPA) placed field test sections in France using the emulsion process (5). 

The U.S. Bureau of Mines participated in a field trial of sulfur-asphalt concrete pavement on U.S. Highway 93 near Boulder City, Nev. in January 1977. This test section is 2100 ft long. The aggregate-asphalt-sulfur (AAS) system was used to mix the ingredients. The sulfur and AC 40 asphalt cement were introduced into the pugmill as individual components. The sulfur comprised 27 w/o of the total binder. The aggregate used in the mixture was a crushed volcanic rock which conformed to the Asphalt Institute type IVb gradation. This test section is now in post-construction evaluation. 

Paving Trials. A number of sand-asphalt-sulfur test pavements were constructed in Canada without rolling the mixes. The pavements were designed so that mix durability and field performance variables could be evaluated under actual in-service conditions. 

The performance of the above pavements is being evaluated, and although the results are promising, a longer test period is necessary before conclusive results are obtained. A further field trial will be conducted at McLean, Saskatchwan during 1974. This trial will compare the performance of various sulfur-asphalt compositions and structures with conventional asphalt structures under low temperature conditions. The test road will include appropriate instrumentation. 

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