Asphalt with sulfur, extension

For the 6 wt % asphalt - 12 wt % sulfur Thermopave formulation under consideration, assuming 20% extension of the asphalt with sulfur, the effective binder content is ... 

Extension And Replacement Of Asphalt Cement With Asphalt Cement with Sulfur", FHWA Report No. FHWA-RD-78-95, March, 1978. 

Pickett, D, E. Saylak, D. Lytton, R L. Conger, W E. Newcomb, De Schapery, R k. "Extension and Replacement of Asphalt Cement with Sulfur " Report FHWA-RD-78-96,... 

Elemental sulfur is an inexpensive material available in high purity and large quantities, and has repeatedly been suggested for new uses in the civil engineering field. It is used as an extension to asphalt in road pavements and as an insulating material, but use as a construction material requires modification with additives designed to stop the embrittlement that occurs with pure elemental sulfur. If pure liquid sulfur is cooled to ambient temperature, monoclinic octasulfur (/S-Sg) is instantaneously formed, which then slowly converts to orthorhombic a-Sg. Because of the difference in densities between a- and )3-Sg, a brittle material results. Many additives have been proposed to modify elemental sulfur, nearly... 

A sharp increase in price and decrease in availability of sulfur reduced the experimental effort temporarily, but laboratory work based on the above findings continued. Pourable paving mixes were developed containing one-sized sands which could be cast in place without rolling, much as portland cement concrete is handled. Based on satisfactory laboratory findings, a test road was constructed in Richmond, British Columbia in 1970, where a sand—asphalt—sulfur mix was cast between forms (5). The success of this trial, coupled with a decrease in the price of sulfur and the forecast for a long-term world sulfur surplus, led us to initiate an extensive research and development program to exploit sand-asphalt-sulfur mixes as road base and surface materials. 

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