Sulphur impregnated cement materials

The technology of concrete impregnation with organic polymers is the most commonly known [173]. The sulphur impregnated concrete was also studied, however, the durability of this material was poor, because of the instability of sulphur in the highly basic cement matrix. 

One method of overcoming some of the instability and loss in strength of oxychloride cements when exposed to water has been to modify them by impregnation with sulphur (Beaudoin, Ramachandran Feldman, 1977). The resulting material appears to be a composite in which the respective components complement each other. The magnesium oxychloride part has relatively poor resistance to water as initially formed, whereas the sulphur is difficult to wet and is completely insoluble in water. 

Overall, these studies showed that sulphur could be used to impregnate magnesium oxychloride cements thereby yielding materials of superior... 

Pastes inpregnated with PMMA or sulphur are still sufficiently permeable to water that expansion occurs on long exposure (F46). In polymer-impregnated (S108) and MDF (R64) cement pastes, there is evidence of interaction between Ca ions and carboxylate and possibly other groups of the polymer. In MDF pastes made with calcium aluminate cement, the polymer (PVA) was found to inhibit the normal hydration reactions of the cement, but to react with Ca and AH to give an ionically cross-linked polymer and calcium acetate. TEM showed the material to be essentially a dispersion of grains of clinker or hydration products in a continuous polymer matrix. 

Acid-resisting Cement. The principal types are as follows 1. Silicate an inert filler bonded with silica gel that has been precipitated in situ from Na- or K- silicate in the presence of Na2SiFg, or from silicon ester. 2. Rubber Latex essentially cement sand mixes impregnated with rubber. 3. Synthetic Resin with an inert filler. 4. Sulphur Cements usually with sand as filler. 5. Bituminous Cements. ASTM specifications for these materials are listed in Vol 4-05 of the Annual Book of ASTM Standards, and number some 25, including specifications for mortars and grouts. 

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