Chemical Durability And Mechanical Properties Of Geopolymer Pastes Prepared With Brine Sludge, Metakaolin, And Dealuminated Kaolin solid Wastes

As the demand for Portland cement (PC) is anticipated to rise significantly in the coming years, it is essential to explore environmentally friendly alternatives. Geopolymer cement (GP) may be considered a greener and viable substitute for Portland cement (PC). Brine Sludge (BS) is from the promising material because it is newly used in that field, dealuminated kaolin (DAK), and meta kaolin (MK) are solid waste materials and metastable phases produced from the chlorine and caustic soda plant during the chemical treatment of the brine solution to produce the ultra-pure brine solution before electrolysis process, and the different alum production steps in the alum production industries, respectively. These three solid wastes are considered a heavy burden on the environment nearby. In the current investigation, Brine Sludge (BS), dealuminated kaolin (DAK), and metakaolin (MK) were mixed with the control mixture blast furnace slag (BFS) to produce a geopolymer cement composite. The fabricated geopolymer mixes were cured for up to 28 days under two different hydration conditions to investigate their mechanical performance: at 25°C and in an oven under hydrothermal conditions (60°C, 0.02 MPa). The robustness of different hardened geopolymers mixes was investigated in terms of tough durability in two distinct environments: against acid attacks (10 % acetic and10 % sulfuric), the loss in compressive strength (CS) ranged approximately from 20 to 83 % for all mixtures, and their thermal stability was tested at temperatures ranging from 300°C to 800°C. Geopolymer mixes containing up to 10% brine sludge exhibited higher resistance to acid attacks and greater thermal stability than the other Geopolymer mixes. Moreover, mixes cured at room temperature conditions showed higher resistance when compared to those cured under hydrothermal conditions. All instrumental analysis was conducted to demonstrate the effect on their microstructure after acid and thermal curing.