The Assessment of the mechanical functioning and robustness of geopolymer cement incorporating chloro-brine sludge waste

Chloro-brine sludge (BS) is a solid waste that results at a high rate from the coagulation-flocculation process in the chlorine industry. Accumulating this waste without recycling or beneficial usage represents an environmental problem and economic loss. This study used BS with blast-furnace slag (B) to fabricate geopolymer cement (GP) as a source of silica, alumina, and calcium oxide. After 28 days, the GP was hydrated and cured under two conditions: either at ambient temperature or in a humidity chamber at 60°C. The GP pastes were evaluated for their mechanical performance after firing at 800°C and exposure to H2SO4 acid or acetic acid. Replacing BFS with 20% of BS in GP mixes normally soaked at 25°C causes a decrease in compressive strength by 8% while 30 % replacement causes a 45% decrease in strength by 45%. GP mixes hydrated at 60°C exhibit a higher rate of strength development during the first seven days compared to those hydrated at room temperature. Furthermore, 10% replacement of BS showed a comparable compressive strength to the reference mix for GP cured hydrothermally. GP mixes containing 10 % BS acquired higher resistivity against corrosion by acetic or H2SO4 acids than the reference mix in the two curing conditions. Additionally, GP mixes cured normally at room temperature exhibit comparable behavior against the firing action to the reference mix, while those cured at 60 °C exhibit a lower thermal resistivity. According to this finding, the manufacture of geopolymer incorporating BS by 5 to 20 % BS can reduce the preparation cost, and reduce the waste accumulations. Besides, the prepared GP has an effective robustness against the acid attack and can be introduced as an eco-friendly binder that can replace the traditional cement in some of its applications.