Potential Use of Sugarcane-Bagasse-Ash in Cementitious Mortars for 3D Printing (2023-10)¶

Mortars, in particular 3D printing (3DP) ones, rely heavily on Portland cement (PC), a material that entails high carbon emissions and energy consumption related to its manufacture. As its use must become more moderate to comply with the growing environmental regulations and concerns, alternatives to PC or additives to reduce its percentage are being sought. Due to providing adequate pozzolanic activity and filler effect, many supplementary cementitious materials (SCM) have been used, such as agricultural waste. Sugarcane bagasse ash (SCBA) emerges as a strong contender, since sugarcane is available in rich quantities in Brazil and India, with almost no land left to dispose the raw bagasse. The aim of this research is to present a mixture for 3DP with a suitable SCBA content that conforms with the properties in the fresh (flow table and slump) and hardened states (compressive and flexural strength). SCBA with a particle size up to 250 µm was used to replace PC with different dosages (5, 10, 15, 20, 25%), by volume of binder. The fine aggregates used (two types of sand) were kept constant, according to the reference mixture, and no plasticizers or superplasticizers were incorporated. Experimental results showed that an increase in SCBA caused an increase in the water content and the mixture with 5% of SCBA showed similar results of mechanical strength at 28 days when compared to the reference mixture.