Modified Ash-Containing Construction Mixtures for 3D Printing (2026-02)¶

This study investigates the technological properties of cement-ash mortar mixtures modified with polyfunctional additives (PFM) for advanced construction applications, including 3D printing. Key parameters such as water demand, water-retaining capacity, workability, adhesion, strength, deformation, and durability were systematically examined using algorithmized experimental designs with regression modeling. The influence of individual and combined modifiers—superplasticizer SP-3, air-entraining agents, and cellulose ether—was analyzed in relation to ash-cement (Ash/C) and water-cement (W/C) ratios. Results indicate that SP-3 significantly reduces water consumption due to electrostatic repulsion mechanisms, with optimum dosages around 0.7% of cement mass, while air-entraining additives enhance plasticity and stabilize workability by increasing entrained air. Synergistic effects of combined modifiers improve consistency and extend the viability of mixtures under varying temperatures. Cellulose ether, although increasing viscosity, enhances water retention and contributes to long-term stability. Adhesion strength was shown to depend critically on Ash/C and W/C ratios, with maximum performance achieved at Ash/C=0.35–0.40. Grinding fly ash further improved adhesive bonding by increasing surface energy. Strength tests revealed that SP-3 enhanced compressive and flexural strength by 20–35%, while excessive air-entraining or water-retaining additives reduced these values. Modified mortars demonstrated improved crack resistance, reduced shrinkage deformations, enhanced frost resistance (up to F250), and high sulfate resistance. Optimization models suggest optimal ash content of 35–40% for structural mortars and tailored PFM dosages for maximum efficiency. Overall, cement-ash mortars modified with PFM exhibit superior technological performance, making them suitable for durable, cost-effective, and sustainable construction, particularly in 3D printing applications.