Upgrading the Syrian refugee shelter design serves humanitarian needs, especially since the currently used T-shelters have a life span of 2–4 years, and there are no clear signs of an imminent return of Syrian refugees to their country, even after the end of the civil war. The use of 3D concrete printing can provide a promising method to construct new durable shelters with a long life span and provide better protection against extreme change in the desert climate, privacy, and cultural constraints. This research aims to use multi-criteria decision methods—in particular, the Analytical Hierarchal Process (AHP) method—to select the best 3D concrete printing to construct these shelters. The proposed model takes the following into consideration: the machine’s technical characteristics, building structure characteristics, and economic and environmental aspects. The three basic developed technologies—contour crafting, D-shape, and concrete printing—were used as alternatives in the model. The results show that contour crafting is the best technology for this application, and the inconsistency test and sensitivity analysis indicate an effective and reasonable technology ranking.

This experimental study produced recycled sand–silica fume–hair fiber concrete to enhance concrete sustainability. Recycled sand and silica fume can be used to address the environmental issues caused by excessive river sand mining and the carbon footprint of the concrete industry. In addition, waste hair fibers (0.5–2%) were introduced to enhance the properties of newly developed concrete mixes. The absolute volume method was employed for four newly developed sustainable concrete mixes. A 100 mm slump was set as a structural concrete requirement, which was maintained by adding 0.5%, 1%, 1.4%, 1.9%, and 2.6% of the admixture by weight of the cement to the proposed mixes. The compressive strength, splitting tensile strength, and density of the hardened concrete mixtures were estimated. The study results show that combining optimized 10% silica fume with 0.5–2% hair fibers enhanced the properties of the newly developed sustainable mixes. The slump threshold was met when 1.5% of hair fibers were mixed with 10% silica fume, 50% manufactured sand, and 50% recycled sand. However, the splitting tensile strengths of the mixes with 1.5% and 2.0% hair fibers were found to be almost the same at 5.62 MPa and 5.65 MPa, respectively. The bulk density of the mixes increased with increasing percentages of hair fibers. Furthermore, in the mixes with 1.5% and 2.0% hair fibers, the bulk density was very similar at 2.708 g/cm³ and 2.792 g/cm³, respectively. Thus, it can be concluded from the study results that concrete containing recycled sand, silica fume, and hair fibers in optimal percentages is acceptable as structural concrete.