Experimental and numerical investigation of the mechanical and durability properties of 3D printed reinforced geopolymer beams optimized using the taguchi method

Increasing costs due to high energy consumption and harmful carbon dioxide emissions in cement production have necessitated research into alternative binders. This study aims to experimentally and numerically investigate the mechanical and durability properties of beams produced using geopolymer mortars obtained by using industrial wastes at different ratios and 3D-printed reinforcements produced with different filaments. High furnace slag and fly ash were used as the main binding materials. Marble powder, mining waste, and titanium dioxide were used as additives. The optimization of the mixture ratios was performed using the Taguchi L27 orthogonal matrix, and three different levels and six different parameters were evaluated. Sodium hydroxide solution and sodium silicate were used as alkali activators. The samples were subjected to unit mass, flexural strength, compressive strength, and ultrasonic wave velocity tests at curing periods. The highest compressive strength was obtained as 65.75 MPa in 90-day specimens. As a result of the analysis of variance, curing temperature was determined to be the most influential parameter on mechanical performance. The optimal ratios obtained as a result of statistical analyses were determined, and samples were produced by 3D printing to improve the performance of geopolymer beams. Thus, 3D reinforcement types were produced, and their effect on mechanical properties was investigated. Three-dimensional finite element models of the produced beam specimens were created and numerical analyses were performed. The high agreement between the experimental 1.8 mm and numerical 1.82 mm deformation values in the PPS CF15 braced beam demonstrates the accuracy of the model.