Beneficial Use of Sulphur in Highway Pavements: Characterization and Analysis of Plasticized Sulfur Concrete

This program was carried out in three phases and was directed towards (a) establishing a familiarity with basic mix and sample preparation techniques, (b) material characterization, and (c) structural analysis of sulfur concrete mixtures using binders plasticized at 5, 10, 20, 30, and 40 percent. Materials were furnished by the Bureau of Mines Boulder City Engineering Laboratory. Phase I involved the preparation of suitable concrete specimens using the five binders listed above. For mix design operations the Marshall or Hveem procedures for asphaltic mixtures were found to be acceptable. For tests requiring larger size specimens such as unconfined compression and repeated-load creep, the California DOT Test Method 304 is preferred. In Phase II, sulfur concrete mixtures were subjected to a characterization testing program designed to provide input to a linear viscoelastic pavement design system called VESYS IIM. A comparison of pavement performance characteristics such as rutting, roughness, cracking, and serviceability of sulfur concrete materials and asphaltic concretes indicated the former could be expected to behave as well as, or superior to, conventional pavement systems. Phase III investigated the potential of an in-situ characterization device called the Duomorph for monitoring property changes in the five modified-sulfur binders given above. An apparatus and testing procedure is described for measuring moduli of these binders over a range of test temperatures and loading rates.