Sulphur concrete is a strong but brittle material. Concrete with a higher sulphur binder content is weaker but more flexible than concrete with a smaller content of binder. Sulphur concrete has unique properties, such as rapid strength development, high ultimate strength, low permeability and superior resistance to strong acids and saline solutions. It has a wide range of potential engineering applications, particularly in situations where problems are encountered in the use of portland cement concrete. Sometimes, sulphur concrete shows poor durability, which may result from expansion and cracking on exposure to water, a behaviour that has been found to result from the use of certain types of aggregates. Admixtures have been found which lead to significant improvements in the strength and durability characteristics of sulphur concretes.
Sulphur concrete was made with seven types of rock as aggregate: granite, syenite, diorite, basalt, greywacke, quartzite and marble. Mixes were made with 20% and 230f sulphur binder and with and without admixtures. Admixtures used were crude oil, glycerine and two types of silane surface active agents. When crude oil was included in the mix, strength decreased significantly but ductility increased. When the aggregate was pre-treated with glycerine the strength of the concrete was affected only slightly but flexibility increased. With silane type A treatment to the aggregate the sulphur concrete had good strength and greater strain capacity than the control mixes made with no admixture. When the aggregate was treated with silane type Z the concrete was very strong but brittle. Treatment of the aggregates with glycerine and the two varieties of silane improved the moisture durability of the sulphur concrete. A comparison of the static and dynamic moduli showed that the three types of sulphur concrete which were more ductile behave similarly to portland cement concrete in that the dynamic modulus was larger than the static modulus. In the stiff and brittle sulphur concretes, that relationship was reversed.