Preparation of architectural 3D printing material with a solid waste-derived sulfoaluminate matrix: A high-value conversion of solid waste

The preparation and development of eco-friendly building materials have emerged as feasible options for large-scale solid waste management. This research prepared a high-performance three-dimensional (3D) printing material and printed building components using the two-stage conversion of solid waste. In the first transition process, a sulphoaluminate cementitious material was produced by calcination at 1270℃ using industrial solid waste, including municipal solid waste incineration fly ash, flue-gas desulfurization gypsum, and aluminum ash. Then, four admixtures, namely, water-reducing agent, sodium gluconate, dispersible latex powder, and hydroxypropyl methylcellulose, were selected to improve its performance and achieve a further transition of solid waste. The effect of admixtures, standard sand, and fiber on the properties of cementitious materials was studied. It was found that the addition of appropriate proportion admixtures increased the fluidity, extended the initial setting time, and controlled the decrease of compressive strength of the materials. A 1:1 ratio of cementitious material to standard sand with a fiber length of 12 mm, generated a high-performance sulfoaluminate-based cementitious material suitable for the preparation of 3D building components. The material has a fluidity of 188 mm, an initial setting time of 53 min, one-day compressive strength of 37.8 MPa, and one-day flexural strength of 7.6 MPa. Therefore, utilizing solid waste through this two-stage transition to prepare 3D printing materials has significant economic benefits, providing valuable ideas for large-scale solid waste treatment.