Self-cementing

Major categories of industrial waste solidiflcation/stabilization systems are cement-based processes, pozzolanic processes (not including cement), thermoplastic techniques, organic polymer techniques, surface encapsulation techniques, and self-cementing techniques (for high calcium sulfate sludges). Vitrification (discussed previously) can also be considered a solidification process. 

Applicability Self-cementing processes require large amounts of calcium sulfate and calcium sulfite and are appropriate for immobilizing heavy metals. 

Although many Ca-rich fly ashes are self-cementing, strength gain is usually too slow for most practical applications. Moreover, aluminosilicate rich ashes are essentially unreactive with water. The most important application of fly ash is as a partial replacement for Portland cement. In this application, Portland cement furnishes much of the early strength, up to 1 month, while the high alkalinity of cement chemically activates the ash such that its slow reaction with cement components and water contribute increasingly to... 

Methods of solidification by self-cementation are applicable to wastes that contain large amounts of calcium sulfate or calcium sulfite. A small quantity of the waste is dried, calcined, and added to the rest of the waste with other additives to form a hardened mass [30]. 

Many fixation processes have been developed, including cement-based, lime-based, thermoplastic, organic polymer, encapsulation, glassification and self-cementing techniques [ 2 ]. These processes vary widely in their applicability to certain waste types. This research deals only with the cement-based technique. 

Stabilized base Aggregate Cementitious materials - Pozzolan - Pozzolan activator Self-cementing material... 

Either pozzolanic or self-cementing fly ash can be used in flowable fill... 

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