Development of Pond Ash (PA)–High Carbon Ferrochrome (HCFC) Slag‐Based Geopolymer Cementitious Materials

Abstract

Pond ash (PA) is a reject of thermal power stations which contains silica (62.8%) and alumina (28.3%). However, these materials possess low-calcium. High-carbon ferrochrome (HCFC) slag has comparatively low silica (28%) as compared to the silica content of pond ash. Judicial mixing of these two materials is thought to be an important proposition for balancing alkali materials which help geopolymer (GP) formation have with good strength. In this century, researchers have put their efforts into geopolymer concrete. In this investigation, pond ash, high-carbon ferrochrome (HCFC) slag, sodium silicate and other ingredients, such as sodium hydroxide (NaOH) and water-soluble plasticizer (Sika), have been used to prepare novel GP products for use in heavy construction application(s). The mechanism involved in such polymer is that the silicon and the aluminum in the mixture of PA and HCFC slag react with an alkaline solution of sodium silicate, sand and aggregates with water-soluble plasticizer to form the geopolymer concrete that binds the non-reactive materials. Scanning electron microscope (SEM) analyses indicate that the mixture of crystalline and non-crystalline phases in HCFC slag may have beneficial effects when added with PA. In fact, enhanced mechanical properties, such as compressive strength, have been observed with the addition of slag to PA. DSC isotherm studies have indicated the formation of geopolymer; and TGA analysis has indicated the stability of prepared GP products. The structural investigation and stoichiometric calculation were made by analytical testing like XRD and EDX. These observations suggest new-generation materials for construction engineers in the near future.