3D printability and mechanical properties of steel fiber-reinforced high-volume fly ash-slag-based alkali-activated mixes
7th fib Congress on Structural Concrete 2050: Towards Carbon Neutrality, AI Design, and Robotic Construction, 2026, Lisbon, Portekiz, 15 - 19 Haziran 2026, ss.5218-5227, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Basıldığı Şehir: Lisbon
- Basıldığı Ülke: Portekiz
- Sayfa Sayıları: ss.5218-5227
- Anahtar Kelimeler: 3D printing, fly ash, One-part alkali activated materials, rheology, steel fiber
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
Interest in 3D concrete printing with greener alternative binders is growing as an alternative to carbon- intensive ordinary Portland cement. Although alkali-activated materials (AAMs) significantly reduce emissions by utilizing industrial by-products, conventional two-part systems are often hindered by high- viscosity activators and substantial energy requirements. In this context, one-part AAMs emerge as a more feasible and user-friendly solution. This study aims to produce high-volume fly ash-slag-based one-part sodium silicate-activated mixes with suitable rheological properties and 3D printability for digital construction applications. Several mixes were prepared by replacing slag with fly ash at high levels, such as 20% and 40% by weight. Sodium silicate was used as an alkali activator. Short steel fibers were also incorporated into the mixes, and their effects on printability and mechanical properties of 3D-printed samples were determined. Fresh-state properties, including slump, flow diameter, and rheological parameters such as dynamic and static yield stress and viscosity, were measured. The 3D printability and buildability were evaluated by producing mortar beams consisting of 4 layers, each 10 mm thick, and observing whether the samples collapsed or buckled. Moreover, compressive and flexural strength tests were performed on 3D-printed mortar samples at 28 days to determine their mechanical properties. This study highlights the producibility, via 3D printing, plain and steel fiber-reinforced high- volume fly ash-slag-based one-part sodium silicate-activated mixes.