GEOMETRICAL ACCURACY OF CONCRETE WALLS MANUFACTURED BY 3D PRINTING

The presented results were obtained during a theoretical and experimental study of the geometric accuracy and surface quality parameters of concrete walls manufactured using additive technologies. Theoretical aspects of the classification of defects and deviations of surfaces obtained by layered concrete construction have been developed. The study examines the influence of layer thickness on printing precision and defect formation in 3D concrete printing (3DCP) processes. Two experimental samples were fabricated with different layer thicknesses: 20 mm and 15 mm. Systematic measurements were conducted to evaluate crack depth on vertical surfaces, pore depth on horizontal surfaces, track width variations, and deviations from straight-line geometry. The experimental methodology involved comprehensive measurement protocols using precision instruments to assess geometrical parameters and surface quality characteristics. Statistical analysis was performed to quantify the relationships between layer thickness and printing accuracy, including calculations of mean values, standard deviations, and coefficients of variation for all measured parameters. Results demonstrate significant improvements in geometrical accuracy when reducing layer thickness from 20 mm to 15 mm. Crack depth on vertical surfaces decreased by 56%, while deviations from straight-line geometry improved by 32%. Most notably, track width stability showed a remarkable enhancement, with the coefficient of variation improving by 91%, indicating substantially improved process repeatability. The 15 mm layer thickness configuration exhibited superior performance across all measured parameters, demonstrating enhanced layer adhesion, reduced surface defects, and improved dimensional consistency. The coefficient of variation for crack depth decreased from 43% to 24%, while deviation variability reduced from 32% to 12%, confirming improved process control and predictability. These findings provide valuable insights for optimizing 3D concrete printing parameters and establishing quality control protocols for additive construction applications. The research contributes to the development of standardized practices for concrete 3D printing technology and demonstrates the critical importance of layer thickness optimization for achieving high-quality printed concrete structures. The results confirm the effectiveness of implementing thinner layers, given the increased requirements for geometric accuracy and surface quality in automated concrete construction processes. This research was conducted at "Geopolimer" LTD to implement innovative technologies in the construction industry.