Multiple optimization of physical and mechanical properties of alkali activated mortars

Today, due to intense energy consumption and negative environmental effects, the use of different materials has gained importance in order to consume as little cement as possible. For this purpose, the use of alkali activated materials (AAM) is becoming widespread. In the study; the physical and mechanical properties of the mortars produced by hybridizing alkali activated blast furnace slag and fly ash with Portland cement were investigated. In the study; fly ash (FA), blast furnace slag (BFS), Portland cement (PC), sodium hydroxide (NaOH), sodium metasilicate (Na2SiO3), standard sand, distilled water and chemical additives were used. It consists of two stages: a preliminary trial study and an experimental study. In the preliminary trial study, the effect levels of the main, interaction and second order terms of the effect variables (ratio of activator, A; total alkaline solution/binder ratio, B; NaOH molarity value, C; Na2SiO3 solution water/Na2SiO3 solution ratio, D) on the response variables (ultrasonic pulse velocity, UPV; flextural strength, ff; compressive strength, fc) were determined and the trial point that provided the optimum physical and mechanical properties in the selected variation intervals was determined (A: 1,88; B: 0,4; C: 11,5; D: 60; UPV: 4,18; ff: 6,6; fc: 45,3). The experimental study was carried out by using the values of the effect variables at the optimum trial point determined within the scope of the preliminary trial study. In experimental study, the effect levels of the main, interaction and second order terms of the effect variables (A-PÇ, B-(YFC+UK), C-Age) on the response variables (ultrasonic pulse velocity, UPV; flextural strength, ff; compressive strength, fc; unit volume weight, BHA; water absorption ratio, ASE; void ratio, BO) were determined and the trial point that provided the optimum physical and mechanical properties in the selected variation intervals was determined. Optimization performed separately for mechanical, physical and both mechanical and physical response variables. The desirability values obtained are 1; 0,97 and 0,67 respectively.