A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M. Eng.) - Asian Institute of Technology, 1981

The primary objective of this study was to examine by review of past work and laboratory study the direct substitution of Sulphur for asphalt in binders f or highway paving materials. This comparatively new paving mixture, which has received both laboratory a nd field trials for a number of years, ma inly in temperate or colder climates, was tested in the laboratory using the Marshall test method with two types of graded aggregate used currently in road construction in Thailand. Result obtained on the physical properties of the S-A mixture were compared to those of the convention al asphalt concrete. The data indicated that the Sulphur could be substituted for a significant part of the asphalt binder while maintaining satisfactory properties such as Marshall stability, flow, density, voids filled with binder, voids in mineral aggregate percent of air voids. No problem was found in connection with segregation of Sulphur in the materials . In fact, Sulphur additions can offer a considerable increase in Marshall stability without having a detrimental effect on the other properties . In the cost analysis it was shown that the price of these Sulphur pavement mixes decreased as the amount of Sulphur substituted increased. Therefore , a potential saving of energy and cost is indicated by replacing part of the asphalt binder with Sulphur. In summary , the results of this study and development work have demonstrated that adding Sulphur to asphalt to produce Sulphur-asphalt (SA) binders with consequent lower asphalt contents, can improve the properties and lower the costs of asphalt paving mixtures.